That's what I was hoping for!

[berksglh]

(Update Nov 23 2015) Jump to post 74 for my most recent results to date.
>>>>>>>>>>>

Got out today to test some 223 groups with some of my BBDT powder coated and gas checked 72grain NOE boolits in my AR. I am happy to say i got some good results.

I found with my AR if you chrono a string of increasing charge weights of powder, there is a point where increasing charge weights, speed stays constant, then next charge or two, speed gets back in line and increases. If you plotted it on a graph, there is a pause or dip in the plot.

I have found that if i load somewhere just above that dip, I get what seems to be an OCW load. Maybe its just how my gas gun works, maybe its a quicker way to get to OCW? I have no idea, but it works for me.

So the test pointed to 17.5 or 18g of Ramshot TAC. So i loaded up 5 each of 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5, 21g and went to the range. As predicted, groups went to hell @ 17g then shot this 1.10" group at 100 yds with 17.5g TAC at 2110 fps.

http://images.tapatalk-cdn.com/15/06/05/9170cb60ab60e39a43fe5764ce5fe640.jpg

Will do some more testing, but based on point of impact of the other charges and this group, i have high hopes for this venture.

DPMS 3G2 AR15. 1 in 9 twist. Throat measured .229"

NOE .228" 72g x4 mold @ 430°F
Lead derived from 50lbs COWW & 1lb 95/5 solder.

Gaschecked with a lee 225 sizer reamed out to 228. Then powder coated with Smoke's carolina blue and loaded to COL of 2.255"

Brass was LC range pickup, sized full length with a modified die to give neck I.D. of 0.2235"

http://images.tapatalk-cdn.com/15/06/05/164c3c344daf0faa5d4618f0c63ddbf8.jpg

http://images.tapatalk-cdn.com/15/06/05/5e2df3b46daca2f2621921bb92189c0c.jpg

[mongoose33]

Very nice! I haven't done casting of rifle boolits yet, but that gives me reason to think on it.

[DR Owl Creek]

What was the distance to your target? Also, is the grid pattern 1/4"?

Thanks,

Dave

[berksglh]

Shot at 100 yds. Pattern was 1/4" drawn in autoCAD, but it printed smaller. 4 lines is 0.96"

[DR Owl Creek]

Shot at 100 yds. Pattern was 1/4" drawn in autoCAD, but it printed smaller. 4 lines is 0.96"

berksglh,

Thank you sir. Sorry I didn't get back on-line sooner!

That's a very impressive group! In fact, I would say that's the best 100 yard target I've ever seen from someone using powder coating so far. Matter of fact, it's good enough to change my feelings about using powder coatings.

Not to take anything away from what you've done, but I'd also say that with a little tweaking of that load you could easily get a sub MOA group. It seems like you have some vertical stringing there for some reason, but if that top shot was down with the other four shots, you would have a group well under MOA. I would say that load would then be OUTSTANDING!

I may have to consider giving coatings a try too now.

Dave

[berksglh]

I wasn't being overly critical on aim and squeeze. Was just trying to assess where there was hope if any. I seem to recall jerking the trigger on a few, not sure if it was in that group?

The 55g bators with my lube were grouping 12" at best at 100 yds and 2-3" with Powdercoating. But, that is most likely due to my AR's large throat. The PC is probably adding .002- .004" to nose diamater, centering the nose sooner/more causing better groups. But I think Id just prefer not to pan lube, so went with PC on the NOE's

Haven't had a chance to load some more and do more testing yet. But hoping to get to it before Monday. Would love to get it dialed in sub MOA and shoot them at the Hi power match father's day.

Later I may try the Bators in my Savage bolt gun. That has a small throat and barrel adjusted close to action so factory 223 ammo was close to lands.

[berksglh]

Another note, (while I'm loading some more ammo) I do have 1# of RL7 and 4#'s of benchmark, but haven't tried either with the NOE's yet. I just had a **** load of TAC and its served me well and about $4.00 a Lb less then benchmark.

RL17 and IMR 4064 were way to slow. Had unburned powder left behind as hollow short little orange straws.

[berksglh]

just a single coat. Admittedly, the powder is a bit thin, but any thicker and they wouldn't chamber.

My .228 mold bullets noses just kiss into the rifling, so i do my PC fairly light as well.

[DR Owl Creek]

If you don't mind, I have a few more questions:

With your cast bullets, how closely did you inspect your bullets for defects before coating? Did you sort them by weight?

It seems to me that an alloy of WW + tin wouldn't be hard/tough enough for the pressures generated by your loads. Have you tried water dropping your bullets, or heat treating them to increase the hardness/toughness?

When doing your coating, what was your baking temperature and how long did you bake them?

You said your brass was LC range pick-ups. Did you separate them by dates, or do anything else like weight sorting or measuring case water capacity? Were they trimmed to length? Did you check for concentricity of the loaded rounds?

How uniform were your powder charges?

Thanks,

Dave

[Doc Highwall]

berksglh (http://castboolits.gunloads.com/member.php?33789-berksglh), when I find the flat spot after graphing the load I make up a load that is in the middle of the flat spot and play with seating depth to find the best load.

[berksglh]

All great questions.

I sort all my brass by headstamp. The LC I separate into one of 3 piles: 14/13/all other combined.

I have checked weight of watter from one brand to the next, and I'm not convinced there's much of a difference to worry about. Have also turned necks, but these were not fired with turned necks.

I did a lot of reading here and the big things I found were "fit is king". If you get the bullet fit to the throat and chambered properly, that seemed to be the most important part to me. And to be sure fit was still good, after loading a dummy, carefully pull the bullet out and remeasure to see that it didnt get swaged down from a tight case neck defeating the good fit. So I modified a lee collet die with a larger rod and no decaaping pin to expand and straighten already full length sized necks up to .2235" ID. My RCBS would leave the ID at .218" and that swaged the rnds down a bit.

Next was use gas checks for all cast rifle boolits, and if using PC and gaschecks together, It sounds like lead hardness wasn't as critical.

Last case prep action is to use a lyman VLD chamfer tool on the necks, helps seat the PC'd rnds with no scraping.

I keep my pot about 700° and mold at about 450°, cast fairly fast and drop into gallon pail of water. I visual inspect for defects, the segregate to 73 or 72 grain piles. The bulk of it being 73.5g

I install gas checks with a lee push through reamed out for my throat to .228" then bb dry tumble powder coat with light coat. Stood on end and baked at 400 per my ovens digital reading for 20 mins then dumped into cold water. Then run through my .228" sizer again.

Not sure if baking anneals any hardening from the first drop? And not sure if dropping with a coat of baked on powder insulates from re hardening.?

I have visually checked runout by just turning the finished rounds in my fingers carefully. It did identify a bad Lee bullet seater that was out of round. These long cast rnds are easy to see when they were crooked. Since I replaced that die, I check every 20th rnds or so and they seem true.

Powder charges on these test loads were all measured to + or - 0.1g from desired charge.

My AR throat is large. These wont come close to starting to chamber into my Savage Bolt action 223.

[OuchHot!]

You sure got my attention! This looks very useful. In the past, I have annealed and 400F at 20min would just start to draw the hardness down. I don't think that your powder coating affected the hardness much. It would be nice to verify that, however. Now if the GC could be dropped from the combination this would be a very cost effective projectile.

[berksglh]

berksglh (http://castboolits.gunloads.com/member.php?33789-berksglh), when I find the flat spot after graphing the load I make up a load that is in the middle of the flat spot and play with seating depth to find the best load.
I'd like to know if its repeatable and if so, how this flat spot relates to the accuracy nodes. Does it point to one, or come prior to/after one? Or is it just a fluke..

[berksglh]

Now if the GC could be dropped from the combination this would be a very cost effective projectile.

Lead $0.30/lbs. or $3.15/1000 rnds
Primers $25/1000
2#'s of powder $50
1000 gas checks $13.75
Free brass, and my time...

$91.90/1000 rnds. [emoji41]

That's what 2 bricks of 22LR cost me if I can even find them locally. And I'd rather shoot my AR with ammo I cast and loaded, then pop my little toy 10/22.

I enjoy smelting the lead, casting, and reloading as much as I enjoy shooting, so its well worth it to me. [emoji4]

However.... When I'm all caught up, I do want to retest without the checks and see what we get.?

[DR Owl Creek]

berksglh,

Thanks for all the info on your loads. That was very interesting and most helpful. You do a great job on documenting your procedure. I like that!

If you don't mind, I have a few more questions:

Could you go into a little more detail about how you do your BBDT coating? You also mentioned that you do a "light coat". Have you compared the accuracy results between doing a light coat and multiple or heavier coats?

As far as your shooting procedure, do you shoot from a solid bench? Do you use range bags or a rest? Do you shoot any fouling shots before shooting for group? Do you clean your rifle between strings, or at all? Do your first shots go to group?

Thanks again for your help.

Dave

[DR Owl Creek]

I just finished loading the PC'd rounds with 17.1-19.6gr Benchmark. These were PC'd by the "shake & bake" method, and just a single coat. Admittedly, the powder is a bit thin, but any thicker and they wouldn't chamber.


excess650,

I know from seeing some of your posts on other threads that you have a very respectable load worked up using the NOE 70gr bullet and conventional lube. I would be most interested in seeing your results using that same bullet with coatings. I don't want to highjack the OP's thread by including your data here, unless he doesn't mind of course, but it would be very nice to see those results either here or in another thread.

Would it also be possible that once you work up a load, hopefully at 100 yards, could you also try that load at 200 yards to see how that load holds up at distance?

Thanks,

Dave

[borg]

Lead $0.30/lbs. or $3.15/1000 rnds
Primers $25/1000
2#'s of powder $50
1000 gas checks $13.75
Free brass, and my time...

$91.90/1000 rnds. [emoji41]

That's what 2 bricks of 22LR cost me if I can even find them locally. And I'd rather shoot my AR with ammo I cast and loaded, then pop my little toy 10/22.

I enjoy smelting the lead, casting, and reloading as much as I enjoy shooting, so its well worth it to me. [emoji4]

However.... When I'm all caught up, I do want to retest without the checks and see what we get.?


Where do you get gas checks for $13.75?

[berksglh]

Could you go into a little more detail about how you do your BBDT coating?

As far as your shooting procedure, do you.....

Dave

I did a light coat cause the bullet nose seats into the lands bare, didn't want a thick coat to cause jams or pressure issues. The drive bands get seized back down, but not the nose.

Basically I added one layer of BBs to my small bowl, then 30 bullets and a 1/4 tsp powder and swirl and flip as usual. Adjust powder and swirl time to get desired amount. Just same tricks I've read on here. As long as the drive bands look good, i don't get to worried about the noses.

I shot those off front and rear sand bags, good scope mount with a Ziess conquest @ 14 power.

I did a quick clean with just patches after 200 rnds from previous day, then shot 3 foulers and proceeded to test. That group i posted was about my 5th group, so shots 28-33 after the few patches.

I also use frog lube on that bore. Only thin I've ever use on it. The rest if the gun gets fireclean.

[Doc Highwall]

berksglh, I like to think of the flat spot in velocity like a perfect air fuel mixture on a cars carburetor. This flat spot allows you to throw charges that are in the middle where a slight difference in charge weight does not affect the bullets velocity, and the different bullet seating depths are affected by barrel vibrations.

Years ago I had a Remington 40X chambered in 222 Rem. and plotting the velocities by powder charge showed the flat spot. I did the tests with IMR-4198 and a Sierra 55gr. FB bullet with the bullet touching the lands. I don't recall all the load data but the load I found that worked best was 19.7 grains that was .017" off the lands. The charges were worked up in .2 grain increments and there was less change in velocity between 19.4 grains and 19.6 grains, then there was between 19.8 to 20 grains, so I chose the 19.7 as the best choice.

I then loaded all the cases with 19.7 grains of IMR-4198 and varied the seating depth in .005" increments starting with the bullet just .005" off the lands and working to .025" off the lands. The best load came with the bullet being between .015" and .020" with the .010" being slightly smaller then the .025 so I erred towards .017" seating depth. All shooting was done off a bench at 200 yards.

This rife had a very worn throat and with the bullet seated .017" off the lands only about .050"-.060" of the flat base was in the case neck, but it would still hold 10 shots under one inch at 200 yards.

[berksglh]

I don't want to highjack the OP's thread by including your data here, unless he doesn't mind of course.
<snip>
could you also try that load at 200 yards.

Dave

I would be interested as well. Feel free to jump in.

Likewise, im hoping to test at longer ranges. We have a nice range in Shiocton Wi that goes out to 550yds?

[berksglh]

Where do you get gas checks for $13.75?
Trying some aluminum ones of e-bay. I used coper hornady on the last ones. Think they were $25/1000?

[borg]

What do those aluminum measure for thickness?

[berksglh]

Gas checks showed up today.
After messing around with my lee push through and trying to seat these and ruining rnds and checks, well to each their own, but I'll never buy aluminum checks again.

(Edit). The checks were sized wrong. They were made too small. I've resolved by resizing them and they seat fine now.

[DR Owl Creek]

berskglh,

Thanks again for your info. That's really interesting and helpful. I'm really interested in seeing how your loads hold up at 200 yards too. Please keep posting your results.

Thanks,

Dave


Lead $0.30/lbs. or $3.15/1000 rnds
Primers $25/1000
2#'s of powder $50
1000 gas checks $13.75
Free brass, and my time...

$91.90/1000 rnds. [emoji41]

That's what 2 bricks of 22LR cost me if I can even find them locally. And I'd rather shoot my AR with ammo I cast and loaded, then pop my little toy 10/22.
...




One of the larger gun stores in my area seems to have a pretty good stock of CCI 22 LR ammo now. Mini Mags are $12/100, and Green Tag is $20/100.

With a .223 load for an AR that shoots MOA, or better, at 2110 fps, why would anyone want to shoot a 22 LR any more?

Dave

[DR Owl Creek]

Gas checks showed up today.
After messing around with my lee push through and trying to seat these and ruining rnds and checks, well to each their own, but I'll never buy aluminum checks again.


FWIW. That might be a blessing in disguise. It's probably best when tweaking a load for best accuracy to only change one variable at a time, so you really know what each change does to your load.

Dave

[rr2241tx]

Where do you get gas checks for $13.75?

Not where, when: 1968

[DR Owl Creek]

...

I had my normal Reloader 7 loads, and 17.1-19.6gr Benchmark all powder coated, and 17.6gr Benchmark with conventionally L&S. I shot at turkey silhouettes at 385m only.
...

when all was done, 17.6gr Benchmark with and without PC appeared equal, and all other charges of BM with PC not as good. 18.6gr looked pretty good, but 19.1 and 19.6 were "minute of 55gal drum". I fully expected the bore to look terrible, but it appeared sparkling clean, so I didn't clean prior to shooting more conventionally L&S with their normal result....excellent accuracy.

This test was just a snapshot, and not to be assumed all inclusive. No advantage in velocity potential with equal accuracy was observed in THIS test. My 5.56 loads don't have any exposed lube, so no cleanliness advantage either.


excess650,

Thank you for posting your results! Great report again!

I think it's really interesting that you didn't see any significant differences in accuracy, velocity, or clean-up between using traditional lube and powder coating in your test. That's very helpful.

Just for clarification, I do have a few more questions for you though, if you don't mind:

What type of scope or optics were you using on your rifle?

How were you doing the shooting? From a bench, prone, kneeling, standing unsupported, etc?

Were you shooting at 385 meters or yards? If you were shooting at 385 meters, that would actually be at about 421 yards...

Were your "turkey" targets the standard 19" wide by 23" tall silhouette targets, or reduced scale?

Could you give us any indication about after you established your zero, of how many of your shoots in each string hit the target itself, such as 10 for 10, 9 for 10, 8 for 10, etc, with the various loads? I'm just curious about the possible number of fliers in any particular string.

With your various groups on the target, could you provide any indication about the overall group sizes for the various strings, such as 6", 9", 12", etc? The reason I'm asking this is because at 421 yards, 1 MOA would be about 4.4", 2 MOA would be about 8.8", 3 MOA would be about 13.2", 4 MOA would be about 17.6", and having some idea of overall group size would be most helpful in comparing your results with others shooting at different distances.

My reasons for asking are because I'm most interested in finding load info that would be most appropriate for groundhog and coyote hunting with cast bullets in an AR out to at least 200 yards. Coyotes are getting to be quite a problem in my area, and having a cast bullet load that would be accurate enough to use would be very useful.

I would also like to have a load that would have enough punch to work well. It appears that your load with a 70gr bullet at 2199 fps would produce about 750 ft lbs of energy at the muzzle. This would probably drop to about 1500 fps and 350 ft lbs at 200 yards, which would still be satisfactory for my purposes.

Thank you for all your help.

Dave

[DR Owl Creek]

Excess650,

Thank you for your report! You answered all my questions very well. I guess my basic question was would the PCing cause any detriment to accuracy, and it appears to not be a problem. I'd say that was also some pretty fine shooting considering you were using a 4.5x scope, and getting 2 to 2.5 MOA at over 400+ yards.

As I stated previously, my main desire was to try to come up with a cast load for my ARs that would work out to a maximum of 200 to 250 yards for ground hogs, or particularly coyotes. I would like an effective load to eliminate these critters, but I want to make a humane kill, with no wounded animals running off. Where I live, it's hilly and wooded, and most shots would probably be much closer. There are also a lot of rolling fields to the west of where I live, but I would most likely use some other rifles, like my 22-250 or 243 WSSM with jacketed bullets when the shots would be pushing 400 yards or more.

The rifles I'd be using for the .223/5.56 loads are a Bushmaster XM15 Varmint Special, chambered in 5.56 NATO, with a heavy, free floating 24" stainless 1:9 barrel, and a Leupold VX-III 4.5-14x40mm LR scope. The other is a Bushmaster XM15 A3 carbine, chambered in 5.56 NATO, with a 16" free floating 1:9 barrel, with a Leupold Mark 4 CQ/T 1-3x14mm scope, however, for load work-ups I'd switch that to an older Leupold Vari-X III 3.5-10x50mm scope. Both of these rifles are capable of shooting sub MOA with jacketed handloads.

I've had NOE 225 60gr RN-GC (SAECO #221), and NOE 225 70gr RN-GC mould for awhile now, but both of these moulds cast a little smaller than I would like using my WW + tin (pewter) alloy. I just recent bought a MP 227-65 (aka Mihec 22 NATO) mould, but haven't tried it yet.

I've been thinking about using another alloy to add a little more girth (as well as strength/toughness) to these bullets. Some other possibilities could be Lyman #2 alloy, or linotype, but my main interest has been with trying a copper enriched alloy. It appears, however, from both your results and berksglh's, that a single PC coat might work too.

There's a "sticky" in the Lead and Lead Alloys forum that discusses the copper enriched alloys. I originally thought about going with RotoMetals Bearing Grade #3 Babbitt (aka Super Tough), and a certified alloy, but for now I might just try using the #3 Babbitt with wheel weight alloy, since I have a good bit of that. RotoMetals charges about the same for their Super Tough Babbitt as they do for pure tin ingots. Here's a link to that sticky for more info on the copper enriched alloys. For an overview, start at Post #429 on Page 22, and continue on through Page 24. For the specifics of what I was thinking about, look at Posts #458 through #470 on Page 24. See: http://castboolits.gunloads.com/showthread.php?172475-High-Copper-Alloys-Lets-discuss-this-further/page22

It seems like either using a harder/tougher alloy could work, as well as a single coat of PC. What do you think?

Dave

[berksglh]

I did get out Sunday to further test and typed up a report, but some connection failure and lost the whole thing.

100 yd shooting that day basically pointed to 17.3 grains of TAC.

17.0 and 17.2 were virtually identical on the chrono, with 17.2 giving better group of the 2 at about 1.8"

Groups opened up a bit that day, but 17.4g was at 1.6" and about 50 fps for extreme spread.

17.6 went to hell at 4" then 17.8 dropped back down to 1.9" and extreme spread went upward of 200 fps.

And with no gas checks things opened up to almost 5". The 200 yd range was busy, so i just bugged out.

So I'm going to work on COL with 17.3 or 4.

Then will go to reloaded 17 and benchmark since i have both.

Will probably slow down a bit. I got pretty crazy the last few months with casting and my family isn't to crazy about it

[DR Owl Creek]

...

100 yd shooting that day basically pointed to 17.3 grains of TAC. And with no gas checks things opened up to almost 5".
...

Groups opened up a bit, but 17.4g was at 1.6" and about 50 fps for extreme spread.

...

So I'm going to work on COL with 17.3 or 4.

Then will go to reloaded 17 and benchmark since i have both.

...




berksglh,

That's still a mighty fine performance with a coated bullet! Thanks for keeping us updated. It will be really interesting to see how everything develops with the rest of your work.

Dave

[DR Owl Creek]

Cu enriched alloy is on my list of things to pursue. Its enhanced toughness without being brittle seems like a good place to be. My current mix was tested at ~96-2-2, and is simply water dropped. It seems to work in all of my rifles including the 300BO pushing 160s 1920fps+ through a 1-8" twist, so changing hasn't been a priority. I have about 50# of ingots that contain ~.5% Cu that would be good for enrichment purposes. The Michigan crew has a good handle on the Cu stuff. They no longer post much here, but I know where to find 'em.;-)


Those guys really had a handle on the cu enriched alloys. They helped me a lot. I wish they were still posting here too.


I try to get to the silhouette range several times a year to test loads. I really don't like a lot of magnification, and I think 6x an excellent balance between magnification, field of view, and light transmission without the need of a large objective. With good optics, lots of magnification isn't necessary. Lower powered variables seem to have accumulated here, 1-4x. 1.5-4.5x, 1.65-5x, 1.5-6x. I have fixed power 6x and 10x, and a couple of 4-12x, but use those on the bolt guns, and generally at 6-10x.


I usually prefer lower powered variables too. On my varmint rifles, however, I have 4.5-14x scopes but that's because I didn't want to have more than the 4.5x at the lower end of the magnification scale.



A lino boolit should cast larger, but will be a little lighter as well. If your NOEs cast smallish, lino + PC might solve your issue. What diameter are your NOE 225-70s and 225-60s dropping? I've considered trying that 225-60. Mine seem ideal for my barrel, and I S&L in a .227 die.


I don't know what the content is with my WW alloy because I've never had it tested. I bought a number of buckets back in the late 1990's, but I didn't get around to melting it down until a couple of years ago. With my alloy, both of my NOE 225 moulds cast in the .2260" to .2265" range. I think I actually need something about .001" larger to work best in both of my AR's. That's one of the reasons why I was thinking about going with the cu enriched alloy. It seems like one thin coating of either PC or Hi-Tek might serve that purpose too.




From some of the reading I've done on the Alternate Coatings section of the forum, it seems that the general opinion is that the coatings allow you to use a softer alloy. While this is probably true, I think it's still important to use an alloy suitable to the pressures and velocities for the load you're using. Generally, as the pressures and velocities increase, harder/tougher alloys are required. For most rifle cartridges, it seems that up to around 1900fps, air cooled wheel weights seem to work well enough. Above 1900fps to 200fps, something like Lyman #2, or a 50/50 pure lead/linotype alloy seems to work better. Up into 2500fps or so, something more like straight linotype may the best bet. IMO.

Some of the reasons for this seem to be that linotype produces less shrinkage. The less shrinkage, the more uniform the bullet will be, and the better balanced it will be too. All this seems to produce better and more consistent accuracy at higher velocities. There are a number of threads on this forum that have discussed this. There are also a number of threads on other forums, such as the CBA forum and their newsletter, "The Fouling Shot" that have discussed this. Even the competitors and champions in the CBA matches typically use linotype at the lower speeds they shoot at for these reasons.

I have plenty of WW alloy, so I don't want to buy some other alloys if I can make do with what I have. That's why I was thinking about trying the RotoMetals #3 Babbitt with my WW alloy to see if that would do what I need. I'm not opposed, however, to trying either a single PCing or Hi-Tek coating to see if that would work too.

Just for a little more background info, here are some links to some other threads that have some interesting info to consider:

This thread discusses shooting cast bullets at 3000+ fps with 2 MOA or better accuracy, and discusses how linotype produces a more accurate bullet, as well as why. See: http://noebulletmolds.com/smf/index.php/topic,541.0.html

This thread discusses shooting paper patched bullets at high velocity with 1 MOA or better accuracy. While paper patching allows the use of softer alloys, here too it seems that harder alloys are needed when you push the velocity up. See: http://castboolits.gunloads.com/showthread.php?241458-how-fast-can-I-go

Here's a link to a thread discussing shooting coated bullets at higher velocities, and it showed that using lubes on coated bullets actually enhanced the velocity and accuracy. See:
http://castboolits.gunloads.com/showthread.php?236746-Test-of-leadman-s-225438s-and-314299s-at-high-velocity

Here's a link to one more thread that shows the effects on velocity and accuracy by using different types of lubes. See: http://noebulletmolds.com/smf/index.php/topic,554.0.html

I think these are all things to consider. Comments?

Dave

[berksglh]

Just to follow up on my negative comment on aluminum gas checks and the lee push through.

Turns out the gas checks are undersized. My 72 NOE bullets have a 0.216" shank, and the aluminum gas checks i received had an ID of 0.208" at the lip.

Rigged a set if dies to flare them at a rate of about 25 per minute. And they seat flawlessly now.

I did test some Aluminum gaschecked PC'd bullets on Sunday as well. And noted no difference over the copper in accuracy. Which is good, cause I'm all out of copper checks.

[Dan Cash]

What is "OCW?" I really hate all the new age acronyms and texting short cuts.

[DR Owl Creek]

Just to follow up on my negative comment on aluminum gas checks and the lee push through.

Turns out the gas checks are undersized. My 72 NOE bullets have a 0.216" shank, and the aluminum gas checks i received had an ID of 0.208" at the lip.

Rigged a set if dies to flare them at a rate of about 25 per minute. And they seat flawlessly now.

I did test some Aluminum gaschecked PC'd bullets on Sunday as well. And noted no difference over the copper in accuracy. Which is good, cause I'm all out of copper checks.


If you don't mind, could you post photos of your die to flare the checks? I'd like to see that.

Dave

[DR Owl Creek]

I made up a batch of Cu enriched alloy yesterday. Air cooled it showed right at 15bhn, and the Sb content should be right at 3%. I cast up a batch in my 4 cavity NOE 225-70 and the sprues cut hard. It definitely behaves differently than a Pb-Sb-Sn mix. I have some 45-200-RF samples numbered and set aside to check over time and see how much they grow, and how hard they get.

Lubes are another variable. QUANTITY of lube is a variable in itself as I've found with my homebrew.


Please post your results using your Cu alloy. I'm really interested in seeing that. Also, could you post the size of your NOE 225 70 bullets as cast, as well any differences over time?

Thanks,

Dave

[DR Owl Creek]

I've always favored powders with a little slower burn rate for loads where I'm trying for more velocity and accuracy. I searched for a few threads where slower powders with cast bullets were discussed for use in AR's. Here are just a few. Does anyone have any current experience with these they could share? Inquiring minds want to know.


NOE 225 70Gr. RN:

Post #15: "... sub MOA at 100 with 22gr. of benchmark."

Post #20: "... powder was BL-C2 ... bullet is 60% WW and 40% lino ... powder charge was from 20 to 24 grains ... accuracy increased as charge went up ..."

http://castboolits.gunloads.com/showthread.php?102578-NOE-225-70-Gr-RN


Mihec 22 Nato Data:

Post #7: "We shoot 18gr of H4895 with the NOE 221 copy, cycles our 5.56 mid-length gas upper."

Post #8: "A good load range to try is 23.5gr to 24.2gr of Reloader 22 in front of CCI small rifle magnum primer ..."

http://castboolits.gunloads.com/showthread.php?156892-Mihec-22-Nato-Data


.223/5.56, how slow have you gone?:

Post #10: "... for your cast 223 loads I'd look at about 23gr of H414 in the AR ... and H380 next ..."

Post #16: "I've been shooting the Mihec 226 NATO mold boolits with 19gr of IMR-4895. functions the action fine ..."

http://castboolits.gunloads.com/showthread.php?190014-223-5-56-how-slow-have-you-gone


loading HM2 223 AR mold 225-62-1:

"20.7 grains of Varget has given me my best group ... The bullets are water quenched and have an approximate hardness of 28 BHN ...

"I wouldn't hesitate to start with 18grs of 3031 through 4064 powder speeds, and move forward from there. Any alloy harder than WW's but less than lino should be pretty decent too ..."

"I sorted my bullets by .1 gr. I tried 5 shots each of 17 - 21.5 gr of IMR-4895 in .5gr increments ... The action would not function reliably till 18.5gr, but at 18.5gr the bolt did not lock back on the last round. After that function was 100% but my groups started to spread out pretty bad after 19.5gr ... It looks to me that the 18.5 - 19gr groups were comparable in size to the factory jacketed loads with my rifle at that range."

"I started at 17.4 grains of AA-2230 and went up in .2gr increments to 18.2gr, with the best results around 17.8gr ..."

http://castboolits.gunloads.com/archive/index.php/t-205195.html


Any other info on loads with slower powders would be most appreciated too.

Thanks,

Dave

[berksglh]

If you don't mind, could you post photos of your die to flare the checks? I'd like to see that.

Dave
Posted my check expander per your request, in the gas check forum:

http://castboolits.gunloads.com/showthread.php?t=280949

[DR Owl Creek]

A freshly cast NOE 225-70 enriched with Cu was .227x.220. Lubed with GC it weighs 73gr.



THANK YOU VERY MUCH, SIR!!!

That's almost exactly the size I was hoping you would get with that alloy. For me, that would be almost ideal for my rifles. If it grew even a hair larger over time, that would probably be even better yet for me.

I've been using pewter to enhance my WW alloy, but I'm running very low on that now. I really need to order some of RotoMetals' Bearing Grade 3 Babbitt (aka Super Tough) to use for my rifle bullets. That way I can keep using my supply of pewter for less critical uses, like pistol bullets. For anyone not familiar with Super Tough, here's a link to it on RotoMetals' site: http://www.rotometals.com/product-p/alloy_super_tough_babbitt.htm . Super Tough has been running about $20/lb. Their price on 99.9% pure tin usually is about $19/lb, so it really wouldn't cost much more to use it than it would with pure tin from them.

I've had most of my WW alloy since somewhere in the late 1990's. I've never had the content tester, but I'd assume that the Sb content would be at least 2%, but no more than 4%. From discussions with our Michigan friends some time back, it was suggested to have the Sb and Sn content in balance (but also to not have the Sn content exceed the Sb content), and to keep the Cu content between 0.2% to 0.25% in the rifle alloy. I played around with the content amounts, and here's what I came up with using WW alloy for the base:

If the WW alloy had 2% Sb content, adding 1 lb of Super Tough to 20 lbs of WW alloy would yield:
93.3% Pb
2.3% Sb
4.0% Sn
0.4% Cu

If the WW alloy had 4% Sb content, adding 1 lb of Super Tough to 20 lbs of WW alloy would yield:
91.4% Pb
4.2% Sb
4.0% Sn
0.4% Cu

If the WW alloy had 2% Sb content, adding 1/2 lb Super Tough to 20 lbs WW alloy would yield:
95.6% Pb
2.0% Sb
2.1% Sn
0.2% Cu

If the WW alloy had 4% Sb content, adding 1/2 lb Super Tough to 20 lbs of WW alloy would yield:
93.7% Pb
4.1% Sb
2.0% Sn
0.2% Cu

To me it seems that if my WW alloy had somewhere around 3% Sb content to start, it would be almost ideal for what I want. The cost of using Super Tough would only add about 1/2 penney to the cost of the alloy for a 70gr cast bullet, over the cost of not using any tin at all in it. This would also give me the option to heat treat the bullets to achieve whatever degree of hardness I need for the pressures and velocities for my loads. In addition, I would still have the option to use any type of lube I want too.

Any comments or suggestions you have would be most welcome. Also, please keep posting your results.

Thanks,

Dave

[DR Owl Creek]

Posted my check expander per your request, in the gas check forum:

http://castboolits.gunloads.com/showthread.php?t=280949


That's pretty slick! I like that. Thanks for posting it,

Dave

[berksglh]

http://images.tapatalk-cdn.com/15/06/27/2a10fa39291694aebda2e5a21c2b4e19.jpg

Made some tooling to solve a few issues. On the left, built a tall gascheck punch from a design here on the forum. Modified dimensions to give me a taller check and properly sized for the 0.216" shank.

Center, I made my own gas check seater to push the checks on good and square prior to running through the push through sizer.

Last. Made a larger push through pin for the Lee .229" sizer. Probably going to make one contoured to the nose to push gascheck first, and my own version of a push through with a 0.232" lead in to properly align before hitting the sizing portion of the die.

Using left over roofing flashing, cut sheet large enough to fit in oven to anneal it, heat to 550°F, then let sit a minute or two and remove. The coating on the flashing browns slightly. Cut into strips and make checks with it.

Have 100 blue ones all ready to load and test.

[berksglh]

143155
Did some more test shots this weekend and recorded my results in a plot.

So far 17.3-17.4g has been where I've been shooting decent groups, but based on this plot, the speed is sporadic in that range, and 22.5g looks the most promising. I do have 3 charge weights noted in my notes for potential accuracy nodes, and 22.5 was one of them, but it's based only on the speed settling down around it, a 2 shot group that was hitting near the sweet spot on the target, and they were only 1.25" apart. So I'm going to retest that area and then work there if results are the same and groups are decent.

Now if you could get OCW accuracy nodes predicted and overlaid on here, you could pick the most stable node to use. Stable speed may not be a valid indication of OCW.? But the visual indication you get from the plot of 22.5g does have me curious to plot some more results like this.

[trixter]

Thank you for the cut away photo, that answers a lot of questions. "picture worth 1000 words"

[DR Owl Creek]

143155
Did some more test shots this weekend and recorded my results in a plot.

So far 17.3-17.4g has been where I've been shooting decent groups, but based on this plot, the speed is sporadic in that range, and 22.5g looks the most promising. I do have 3 charge weights noted in my notes for potential accuracy nodes, and 22.5 was one of them, but it's based only on the speed settling down around it, a 2 shot group that was hitting near the sweet spot on the target, and they were only 1.25" apart. So I'm going to retest that area and then work there if results are the same and groups are decent.

...



Very interesting. Please post you test results.

Dave

[berksglh]

Been trying to do further testing to zero in on a good load, but have been having inconsistent results and unable to repeat good groups consistently. By good I mean less then 1.5". @ 100 yds.

Decided to go back to my 17.3 g of TAC and work on a few ideas. I lubed then loaded some powder coated and non powder coated rnds all with 17.3g TAC, but at 3 different COL's. While wiping any excess lube off the bullets noses, I realized about 30% of the bullets could be turned in the shell while wiping the lube off. Some of the movable rnds required moderate grip to twist, and some were fairly easy.

Obviously being loose enough to twist, you could also change the seating depth by hand. Not good! Were they also moving in the shell while being cycled into the chamber? Causing inconsistent results?

My neck ID is about 0.222". And bullets are sized to 0.229"

So assuming that the small 22 caliber lead is too small and soft to be seated with no crimp, I adjusted and started crimping, which is against my religion. [emoji6]

Will see what kind of results I get.
143563

http://images.tapatalk-cdn.com/15/07/03/761ee4bb8f301a3f6c8e3a9f512391f0.jpg

[runfiverun]

the bigger gas check will do that to ya.
if you have some 748 kicking around that is always worth a try,so is varget.

[berksglh]

Ok, so shot the crimped test loads tonight on the new bench I made today. Found some direction again. I hope..
143689143690

All loads were 17.3g tack and crimped this time. I'm new to crimping, but all cartridges were trimmed to same lengths.

Loaded 3 different COL's, and each had lubed lead, and lubed powder coat as mentioned 2 posts up.

Two things seemed evident.

1. The lubed and powder coated loads grouped much better, and bare lubed lead grouped terrible. This could be a bad lube? Its home made from a recipe for rifle lube i found here.

2. the shorter loaded rnds grouped the best.

Top is lead, bottom is lubed powder coated.
143692

[BNE]

Nice write up and pictures. Thanks

[blackthorn]

Nice looking bench! What are you going to do when your left-handed buddies come over to shoot??LOL

[DR Owl Creek]

Ok, so shot the crimped test loads tonight on the new bench I made today. Found some direction again. I hope..
143689143690

All loads were 17.3g tack and crimped this time. I'm new to crimping, but all cartridges were trimmed to same lengths.

Loaded 3 different COL's, and each had lubed lead, and lubed powder coat as mentioned 2 posts up.

Two things seemed evident.

1. The lubed and powder coated loads grouped much better, and bare lubed lead grouped terrible. This could be a bad lube? Its home made from a recipe for rifle lube i found here.

2. the shorter loaded rnds grouped the best.

Top is lead, bottom is lubed powder coated.
143692


Great report! Very interesting! Great looking bench too!

A few more questions and comments, if you don't mind:

Were you using the gas checks you made, or were these the ones you bought?

With your coated and lubed bullets, that was a good group for the number of rounds you fired. That really shows any possible inconsistencies. Did you also try shooting your coated bullets in this test without the lube? That would be an interesting comparison too.

For your non-coated bullets with your alloy, what was the size of the bullets in relation to your rifle's throat? Too small of a size could really effect the accuracy. Also, with your WW plus <1.9% tin alloy, pushing the cast bullets at those pressures and velocities in your 1:9" twist rifle was probably beyond what those bullets could handle. That could also account for the overall group size. This might be a situation where you would have to work up to those velocities to see how much that particular alloy could handle.

As far as crimping cast bullets, I like to use the Redding taper crimp dies to prevent bullet set-back for my .223, .308, and 7.62x39mm gas operated guns. The taper crimp dies don't work the brass as much, or damage the bullet like the "factory crimp" dies do. Here's a link for the Redding .223 taper crimp die: http://www.midwayusa.com/product/726501/redding-taper-crimp-die-223-remington?cm_vc=ProductFinding

Overall, a great report! Thanks for posting it!

Dave

[popper]

Bullets cast yesterday were 15bhn air cooled(yesterday) and 24 bhn 18 hours later for the water dropped. Thanks for that info, about the same alloy I use but no BHN tester. Now I have data.

[berksglh]

Just for fun today, used my 72gNOEs tall gas checks, smoke's blue powder coat, and lubed with my lube as above.

Loaded up with Trailboss for a subsonic test. Shot in my DPMS 3G2 AR, 16". 1:9 twist.

None cycled, non stuck, no earplugs, no keyholes at 20 yds, but it was just a quick for fun night.

3.2g = 964 fps
3.3g = 965 fps
3.4g = 1006 fps
3.6g = 1020 fps
3.8g = 1070 fps
4.0g = 1092 fps
4.2g = 1115 fps
4.6g = 1167fps
4.8g = 1205 fps
4.2g = 1240 fps

[berksglh]

Tonight's project was making copper enriched alloy. Its new to me, but mixed up about 9 lbs of my alloy and added 10 grams of copper wire by TIG welding the wire into the ingot then remelting fluxing stirring and pouring into new ingots for about 0.24% copper if i figured correctly.

Something else to cast and play with soon.

[DR Owl Creek]

That's a really interesting way to come up with a Cu enriched alloy. I'd never thought of that. It sounds like it should work. You're right on with your calculations on Cu content too. I cauculated your alloy at .24% also. From everything I've read from what I believe are reliable sources, that should be the ideal amount. I'm really looking forward to seeing how that works for you.

While the CBA match competitors typically use linotype for their cast bullets, even at sub 2000fps velocities, I think the Cu enriched alloys have more of a practical application for our uses. If you haven't already seen it, there's an interesting article on Cu enriched alloys by Felix Robbins on the old Los Angeles Silhouette Club web-site. It's about using Cu based Babbitt as a source, but the information is still relevant to what we're discussing. Go to: http://www.lasc.us/FelixBabbitbulletAlloy.htm
(http://www.lasc.us/FelixBabbitbulletAlloy.htm)
On Page 4, Felix wrote:
"Some casters are serious seekers of high-speed applications. In my experiences, the top speed that can be achieved with linotype metal and wheel weight alloy is about 2400 feet per second in the .223 Remington. Faster boolits must be extra tough so they will not glide over the rifling. This is where the copper content of Babbitt comes into play. I recently alloyed some of my .223 boolits with lead based Babbitt containing copper and shot the same boolits at 2600 feet per second with good accuracy and no leading. The copper content in the mix is the "toughener" of choice, whereas the antimony is the "hardener" of choice".

On Pages 5 - 6, Felix also discussed alloying and casting with Cu enriched alloys, as well as saturation points. It's a good read.

There are some other good articles on heat treating bullet alloys on the old LASC site too, all of which are courtesy of Rick Kelter (cbrick on this forum): See: "Heat Treating Lead/Antimony/Arsenic Alloys", by Rick Kelter, at: http://www.lasc.us/HeatTreat.htm

This article has a discussion on determining minimum pressures for a given alloy, as well as using convection ovens in the process.

I hope this helps.

Dave

[DR Owl Creek]

...

I wonder if PCing over Cu enriched isn't a handicap in that the PC would be softer/less tough than Cu enriched fully into the rifling.

Too, I'm wondering if that long nose hanging out is limiting velocity with accuracy. The 225-70 looks like a scaled down 311290. Compare with the Saeco and you'll see the Saeco has wider driving bands, equal length full diameter for engagement, and a shorter nose.


Those are both valid questions. I believe the answer to both questions is Yes. The only way to prove it however, is by doing specific tests to find out, and I'm not in the position right now to do those tests.

It seems like it wouldn't be too difficult to answer the question about the strength needed for the alloys. The question about fit of the nose of the bullet could also be different for any particular gun. Not to mention the different twist rates used, there are a staggering number of different chamber/throat reamers being used out there by the manufacturers. Here are just a few of the different dimensions that are being used today: http://www.radomski.us/njhp/cart_tech.htm


Dave

[berksglh]

The posts this week brought up some great points, and some links with some great info. Thanks for posting.

I shot the last pictured groups with the tall gas checks from my DIY checkmaker. I am planning on doing some side by side comparisons with all else being consistent, will shoot groups with:
1. Short Alum GC's lubed.
2. Short Alum GC's PCed.
3. Short Alum GC's PCed & lubed.
4. Tall Alum GC's lubed.
5. Tall Alum GC's PCed.
6. Tall Alum GC's PCed & lubed.

I am sort of starting over and rechecking past testing due to the lack of a crimp and the COL changing.

I picked up the M die to flare before seating, and also decided on the Lee factory crimp die to crimp after seating. I will be using both moving forward.

You also have me curious on the whole PC or Cu toughness outer layer skidding the rifling thoughts. This is a great point to max velocity. I hadn't thought about that till now.

[DR Owl Creek]

That sounds like it will be some great tests. I'm really looking forward to seeing your results.

Dave

[berksglh]

Compared castings by squashing 2 different alloyed bullets together in a vise to compare toughness. 3 day old 0.2% Cu is definitely tougher then my base alloy. But fresh cast (1 hour old) 1.0% Cu is softer then my base alloy. The antimony age hardens the lead, so will have to compare again in 1-2 weeks.

[DR Owl Creek]

Very interesting. Please keep posting your test results as you can.

Dave

[berksglh]

144816
Finally got all loaded and ready for the next test as mentioned. I have 15+ rnds of each of the planned tests.

1. Short Alum GC's lubed.
2. Short Alum GC's PCed.
3. Short Alum GC's PCed & lubed.
4. Tall Alum GC's lubed.
5. Tall Alum GC's PCed.
6. Tall Alum GC's PCed & lubed.

All are cast and water dropped from my base rifle alloy of COWW + lead free solder and all used the M die to flare, and the Lee factory crimp die.

These were all cast 2 weeks back, and the powder coated rnds were all cured 2 days after casting. So they are somewhat aged.

Hoping to fire all tests in the morning Saturday.

[berksglh]

144931
144932

Had some issues with the backstop falling over and targets got wet. For what its worth, test listed above were shot in this order: 1,2,3,6,5,4. Made a scope adjustment middle of #1.

It appears that standard short gas checks shot slightly better then my DIY tall version, best average being short checks, powder coated and lubed.

Some other thoughts:
My tall checks were made with .013" and since then I've used .008" and had better results and fit installing them. So don't abandon the idea of tall checks yet.

These were all loaded with a charge I liked before using the M die and Lee crimp die, the COL was also shortened for better crimp location. Because COL may have been inconsistent before I started crimping, Retesting for optimal charge weight may point to a better weight of powder.

For now I'm going with standard short checks, powder coated and lubed.

[berksglh]

Been playing with my alloy contents and heat treating. Got some really hard tough rnds that are harder and tougher then anything I've made before, but second batch was heat treated slightly different and results weren't even close to my first batch.

So I'm unplugging to lock down the heat treating process for my alloy, and will regroup and start shooting again when I get this solved.

[DR Owl Creek]

FWIW. When you look at how well you did with the original load in your first post on this thread, one thing that stands out to me is that you used copper gas checks on those cast bullets. Since then, you have been using aluminum checks. This is another variable that could be effecting your groups.

Dave

[popper]

second batch was heat treated slightly different and results weren't even close to my first batch. Difference in alloy or H/T?
I use Cu enhanced without tin in 308W, works fine. You didn't say if it was 95/5 Cu or tin solder.

[berksglh]

FWIW. When you look at how well you did with the original load in your first post on this thread, one thing that stands out to me is that you used copper gas checks on those cast bullets. Since then, you have been using aluminum checks. This is another variable that could be effecting your groups.

Dave
Yup. And i have 50 or so of those that arent powder coated yet just sitting and waiting.

I haven't been shooting lately with my work schedule and the heat, But I wanted to try several things. I enjoy making and machining things and trying new ideas. Sometimes it sets me off on wild tangents that lead nowhere, sometimes you learn what not to do, and other times you learn great info.

I'm playing with my alloy and reading and learning a lot from the new group as well as adjusting my tall gas check maker for better fit.

Also tripped over something that made my alloy heat treat hard that I'm trying to determine how and repeat it.

I guess I see so much room for change to my final velocity, that I don't want to spend to much time down where that load was if I end up going faster.

[popper]

Curious as to the difference in your H/T method that caused the change. Any ideas? It is a function of the alloy content, time, temperature AND quench (temp) time. Your #67 post agrees with my experience, H/T is similar but takes about two days to get hard. My aged (week) 2% AC is harder than AC isocore but H/Td is about the same as superhard (70/30) after a week (I tested again today). AC, it doesn't appear to age harden much. Cu enhanced is strange; hard, malleable, shoots great but I've slumped several noses when loading into excessive neck tension cases, even the superhard ones. It does work soften, hammer test first whack barely made a dent, subsequent got it smashed thin with no breaking or shattering. Got tired hitting it.

[berksglh]

Difference in alloy or H/T?
I use Cu enhanced without tin in 308W, works fine. You didn't say if it was 95/5 Cu or tin solder.
Sort of both. I went with Edd's approach of balancing, but just added a bit of some solder I had on hand to balance out my remaining 30Lbs of low Cu enriched to work with moving forward. Basically adding to the tin %.

I was casting from that mix and working with adjustments to my check maker and changing my process for installing the checks and while powder coating some of them, i switched to a toaster oven and at the same time cranked the heat up and tried heat treating at presumably 450-460°F for an hour.

The timer only goes to 15 mins, and the temp was a best guess, I was suppose to be resetting the timer every 15 and after the first 40 minutes forgot and it cooled off for maybe 5-10 mins, then caught it and turned back on for 15 or more? Then directly into ice water for 10.

Those rnds are hard and tough unlike any i have done so far.

Next night I took some more of the same group of castings from the jar and simply installed gas checks and tried heat treating for an hour with a larger amount, but not powder coated, to try to get same results, but clamped the timer on for a solid hour.

Both batches were all cast in one session on the same night and placed in one large jar. Some of them were gas checked and powder coated and ran at that odd temp process the next night, the third night I tried the large batch that had the timer knob clamped an hour and no powder coat, it is no harder then my old batches, not even remotely close to these hard ones...

So what happened to make that one group so hard? Was the internal oven temp different? Did that partial cooling after about 40 mins then heating back up again do something? Was it the powder coating? Was it the evenly spacing of the rnds on the cooling rack and foil allowing them to evenly heat as opposed to the random scattering of a larger pile on the second attempt?

Id like to figure out how to repeat the results with the remaining bulk from that casting session, then try same process on basic CWW castings and 1.0% Cu just to compare and see what I get. (I assume the 1.0% will be softer, and or more malleable then the 0.2% from what I've seen so far. I also noticed the ingots have a large crystal looking texture on the surface of those..)

I also think its time for a good quality hardness tester and locating some way to analyze the alloy so I know about where I really am.

Today i picked up a small convection oven to use as well, so after i duplicate and determine how these got so hard, ill try it in there to hopefully get more consistent heating.

Dave

[berksglh]

Repeated the process as best as i could tonight. I also did one more test. I placed 5 rnds on same pan each with a binder clip on it to pinch a rnd in half when they hit to much temp. Got it up to 468°F (which is the hottest temp I recorded with my meter during my best efforts to duplicate the same events.). Then slowly bumped things up. One pinched off as meter peaked at 478, then 4 minutes later as It hit 480 the rest all pinched off one at a time.

Testing right out of the ice water, their not hardder them my CWW.

The super hard batch was obvious as heck 8 hours later. So ill retest the duplicated ones in the morning again.

Curious as to what temp standard CWW and the 1.0% rnds pinch off at.

This thread went off a bit, but I guess i started the whole mess.

Dave

[berksglh]

This morning after aging 9-10 hrs I got harder results with last nights heat treated batch.

My guess is its a simple function of the temperature during heat treating based on this chart from (LASC) Los Angeles Silhouette Clubs web sight.
http://images.tapatalk-cdn.com/15/07/29/eb34187519afad1ad04f894573529e4c.jpg

[DR Owl Creek]

Very interesting results! Please keep posting the results of your tests.

Dave


BTW. Good name!

[berksglh]

What I've found is, it is the temp they are baked at that determines age time and final hardness. Using a PID controlled convection oven, I tested straight CWW castings, and they also get super hard after Heat Treating like the Cu added ones. But the ones with Cu aren't as brittle.

So copper appears to not only make the castings more malleable, but increases the melt temp and seems to allow for a higher heat treat temp, resulting in harder and tougher bullets.

Moving forward, I'm going to keep post on alloy for this in the hi copper thread under bullet alloys section.

[DR Owl Creek]

What I've found is, it is the temp they are baked at that determines age time and final hardness. ... But the ones with Cu aren't as brittle.

So copper appears to not only make the castings more malleable, but increases the melt temp and seems to allow for a higher heat treat temp, resulting in harder and tougher bullets.

...



From the limited testing I've done, that's been my experience too.

Dave

[berksglh]

Finally got out to shoot and do some more testing. Had a few ok groups at higher speeds where i was testing, 2200-2800 FPS with the heat treated 0.2%cu loads. Was getting 1.5" - 3" groups till I got above 2700fps. Above that things went to hell.

Tried to load more afterwards and run further testing based on my good results, and nothing seemed to repeat.

So I loaded up some dummys and played around feeding rnds.

I believe whats messing me up is the bullet is such a tight fit to my throat, that there is no room for powder coat thickness on the nose of the bullet as it is being jammed into the rifling. And inconsistencies in thickness on the nose, afectiveness of the crimp and bullet getting pushed into the case affect initial burn rate and give inconsistent results.

Bare lead rnds seated in so the top drive band is just barely covered by the shell, feed and eject fine. But add PC and or longer COL and odd **** starts happening.

Have come to the conclusion that the .228" 72g NOE is just too long and fat to use PC in my AR's throat and be consistent.

Not wanting to shoot bare lubed lead, a different bullet choice is my next move.

[berksglh]

FWIW. When you look at how well you did with the original load in your first post on this thread, one thing that stands out to me is that you used copper gas checks on those cast bullets. Since then, you have been using aluminum checks. This is another variable that could be effecting your groups.

Dave

Been a while since I had time to shoot test groups. Saturday I ran a few hundred rounds with everything crimped with a Lee factor crimp die.

One thing i found was the regular aluminum gas checks shot worse groups then the copper checks i started out with. The tall Aluminum checks from my check maker now using the .008" stock shot as good as the copper checks. So ill be using my own checks moving forward.

The short aluminum checks are to small and had to be pressed open a bit to even fit the NOE shank, so it may just be a bad fit? Properly made standard check may give bette results?

With tall alu checks, shooting either MML lubed lead, or thin PC and lube gave about 1.5" with occasional flyer out to 2.5" at 100 yds running 18.6g of TAC. Im not set on that charge, just used it for the days testing.

All of the rnds were also loaded on my progressive lee Loadmaster press.

2 months back i had a short Alu gas check come off and take out the LCD on my chrono, so no velocity results for a while.

Happy shooting

[berksglh]

Been narrowing down a good accurate load for the 72g NOE in my AR again.
My tall gas checks
Powdercoated
Lubed with MML+soap
17.8g TAC
Comp = 2.065"
Cartridge length measured with comparator and best groups to date show 2.065".

This was the best of the 5 strings of 5 shots at different lengths between 2.080 and 2.060"

http://i1224.photobucket.com/albums/ee367/berksglh/Mobile%20Uploads/image_1.jpeg