311365 bearing Surface

[rays308]

I've been playing with my new NOE 311365 boolits in 308win. I have found a couple loads that work well at 1900fps ish. Heat treated WW, seated with the 305 nose .010 off the rifling.

I also reduced the nose to 300 on 1 mold and got it to shoot within an inch at 100yds with the boolit seated out farther. Nose rider bearing surface? It still wanted to stay around 1800fps.

I would like to ring all I can out of this boolit for the longer ranges.
I've been looking through the posts on bearing surface and center of gravity. I have a 314365 mold that should have a nose of 308. I'm thinking that if I size the bands to 310 and seat .010 off the rifling I MIGHT be able to push the boolit to 2200 ish fps in a 10" twist.

Before I invest time and resources in the effort I would like to know if my theory sounds right.

Would I be moving the CofG in the right direction?

Could this gain me some velocity?

Thanks
Ray

[Doc Highwall]

What does your gun slug at both bore and groove diameters? I am shooting a 30:1 alloy with a SAECO #315 bullet at close to that velocity with great accuracy.

[MT Chambers]

My results are better with both the bullets mentioned when I seat the bullets right into the rifling as far as possible.

[Bass Ackward]

Before you worry about CofB, see if you can launch well first.

Your ability to shoot high velocity is contingent upon the bullet holding the rifling so that it can rotate around it's center, thus exiting the muzzle without damage or wobble. (launching well)

No matter what the hardness, when lead accuracy fails, it is because the slug is no longer increasing in RPMs enough to compensate for the resulting damaged slug "OR" an unstable (wobbly) launch. And RPMs will actually begin to drop as rotation is no longer imparted even though velocity continues to increase.

This makes a damaged slug more susceptible to deviation or deflection in air / game with even slight velocity loses. (under stabilized)

So no one can actually answer your question as to your results only to say that it has been done before. The less you damage the slug and the better the launch, the less RPMs you will need for stabilization regardless of weight / length. So the faster you can go with reasonable accuracy.

[rays308]

barrel slugs at .308 and .3005

I may add some shot to the WW to get hardness up a little.

I've been a little leary of seating into the rifling. I was afraid it would create a constriction. I will give it a try though.

The boolit shoots very good with slow powders:
40gr H4831sc
35gr H4350
I've had decent results with about 30gr of H4895, IMR-4064 and Varget.

All these loads get me to a little under 1900.

With slower powders showing the better results, I'm thinking that the slower start is causing less damage to the boolit, and stabilizing better.

I was thinking that more lead to grip on might mean better stablization with the faster powders, then I could add some more velocity.

If I seat the boolit about .060 beyond where the rifling starts without crimping and let the bolt closure finish the seating, would that be too much or possibly be step toward better performance?
Seems I've heard of this being done in the days of black powder but, that was soft lead.

I know I may not be able to get where I'm trying to go however, its alot of fun trying.



Thanks for the advise.

[Doc Highwall]

With a groove diameter of .308" and a bullet sized to .310" sounds good. Are you using a Lyman M-die to expand the case mouth and what size is it? An expander diameter of .309" or slightly larger by a few tenths will help the bullets to be seated straight in the case for less run-out. An expander that is too small means you have to use more pressure to seat the bullet causing more run-out and can size the bullet down some. I would also seat the bullets to touch the rifling to aid in entering the rifling straighter and give an more even start pressure and anneal your gas checks. I use Forster bench-rest seating dies to seat my bullets.

[selmerfan]

Doc Highwall - are you using factory stock Forster BR seaters or have you bored them out to your cast boolit diameter? I've been thinking about using mine, but I don't think I can run a .311" boolit in my .308 Win Forster seater.

[rays308]

I don't have the M die yet. I use a Lee flair die.

I run the cases through an RCBS die that has a small expander then i run them up a lee 308 sizer die just enough to hit the expander with the neck because the lee expander is about 309.

I've checked runout in a V block. Except for MIL cases I usually see under 001. I tend to leave my dies somewhat loose using lee o-ring nuts and just snug them slightly.

I have the gas checks in place when heat treating. They change color so I figured that might be anealing them.

My rifle boolit prep is to alox, size 311 and install gas check then heat treat if desired then alox again then run through my lyman sizer with a 310 die and add Javaline to the grooves.
310 on the bands just touches the throat. If I color a 310 band with a marker then insert into the throat, the die rubs off(mostly).

I will give the kissing the rifling a try.

Thanks

[Doc Highwall]

selmerfan, I do ream the Forster die to .312" to allow cast bullet diameters. I have also modified a Forster bench rest die to use as a case neck expander. This is the thread I started on it. http://castboolits.gunloads.com/showthread.php?t=90241

rays308, your gas checks are not being annealed at the temperature you use for heat treating your bullets. I use a propane torch and heat them until they glow which turns them black which does not hurt them but the last batch I did I dropped them in the Lemi Shine which turns them a nice pink-rose color the same stuff for cleaning my cartridge cases.

[rays308]

Thats easy enough to do.

Any thoughts on the 314365 and the extra bearing surface idea?

[Doc Highwall]

You have to watch out for extra bearing surface by going to a larger bullet diameter. The reason some barrels have five grooves is so it does not distort the bullet too much when it engraves into the rifling. The metal has to go somewhere. think of a banana in your hand and squeezing it, it comes out both ends. The relationship between our bore-groove size and the width of the lands and grooves and the size of the bullet how much it will distort. Some distortion to conform to the rifling in order to spin the bullet is good but you can have too much of a good thing. This is one of the reasons Marlin came out with Microgroove rifling less distortion. Bearing surface is best accomplished by bullet design like a round-nose bullet but you get a gain in one thing but give it up in another area like B.C.. This is why when a new shooter asks what is the best bullet and we ask for what purpose and what kind of gun and they will get different answers for different situations. I am assuming you are just punching holes in paper and want extreme accuracy. I am after the same with my 308 Winchester and right now I am shooting the SAECO #315 bullet and I am going to try .310" , .3105" and .311" diameter bullets and have already honed and polished my sizing dies to these dimensions. The next test will be with my floating case neck expander's in .309" , .3095" and .310" to see what the gun is telling me what it wants. Check out this thread I started about doing this.
http://castboolits.gunloads.com/showthread.php?t=90241

[rays308]

I hadn't thought of the squish facter.
Thats why I come here.

Am now the proud owner of 1000 carboned 3cent peices. I will be adding these to the next batch. If it ever stops raining long enough.

I'm finding alot of boolits I need to scrape the base flat on to. Just a enough extra lead to make the check wobble. I can spin the boolit before sizing and see the mis-alignmet.

I hope to try the rifling kissing on thursday, the weather is supposed to clear for a day.

Yes I want to punch single holes in paper as far away as possible. The gun does it with SMKs so, I want to do it with my cast. Its a fun challenge and I get to shoot alot.
I don't expect to get 1K yards but 600 and a little beyond would be WAY kool. I figure if any boolit will do it a pointy would have to be the one.

Thanks much for your advise. I'll report back results, hopefully, with good target pics.

[rays308]

Thanks for the link to your writeup.

You are where I want to be and beyond.

I see some re-tooling in my future.

[madsenshooter]

Just when I thought I'd come up with an original idea! I have one of the 316365 molds, it has a .311 nose. My favorite Krag has a .310 groove diameter, guess what's going to happen. Got some cast, but busy trying to get the bothersome little Eagan boolit to shoot in my 6x45 right now. Squish factor is an interesting thought, but a banana in hand doesn't seem to be a good analogy, there's 30,000psi or so on the base of one end, so the squish, I'd think, would be more toward the front end.

[rays308]

madeshooter,

I took Docs post to be about the effect of the rifling on large nose. If the rifing takes up half the space of the bore. The lead must be displaced to somewhere. Forward and back are the only 2 directiions it can go. Any lead going forward is gonna mess up that pretty nose. Theres no way to control how the long, unsupported nose will push out. It isn't likely to push straight and that would set the point off at an angle. When that happens you've got an unguided missle.

I will likely still try a few for the curious factor but, I'd be surprised if my 100yd and beyond will stay together reliably.

[CWME]

In my 308 testing with the NOE boolit I ran up to 45gr of 4831SC. My first groups were with ACWW and they were nothing special around 1 1/4". I started water dropping the boolits to prevent nose distortion when sizing. Shot the 45gr loads again and had 10 shot groups that rivaled the 40gr loads.
I also found that this boolit liked to be driven pretty hard with the slower powders.
Running a 10 twist 30" tube on my 308.

I am not really doing anything special for load technique. I have the forster BR set but never got around to using it for my testing. The standard RCBS 308 dies were working. I also didn't get around to anealing the GC. Planning on getting back to this project soon for my 300 and 600 yard testing. I will pull out the Forster set for these loads and give them a go.

I guess what I am saying is that before you go to extremes with your loads (sizing down 314's etc) play with the simple stuff. I found that really working on my casting technique played a big role in my accuracy. I did my best to keep my pot at 700 degrees by turning it up or down, dropping in a few spues etc to maintain the temp. Got into a good cadence with the casting before I kept boolits etc. I was unforgiving in the sort, weight and visual inspections etc.

Rambling done.

[rays308]

CWME,

It was the pics you posted that got me fired up and promted this thread. It can be done what am I missing?

I noticed that your boolits were seated way out in the 308 cases. i took that to be a customized rifle. Still I want to get the best I can from this boolit.

I can get 38gr of H4350 into the case behind the boolit. It causes my groups to begin opening t about 4 inches at 50yds.

I'm gonna try some more loads tomarrow afternoon with the nose against the rifling. I've started being more criticle of the boolits during inspection, only the premiums are being used for this project now.

[Doc Highwall]

Two other things to take into consideration are the time pressure curve of the powder you are using and the rate of acceleration/G force in the barrel. A slower powder with a longer barrel along with a rate of twist that is not too fast will help a lot in achieving higher velocities.

rays308, when I cut the sprue I only use a gloved hand and squeeze the sprue plate down on the top of the mould while twisting the sprue plate at the same time and this gives nice flat bases. This is a good reason to have a mould warmer so the mould is up to temperature when casting the first bullet. When a bullet sticks in one side of the mould try pushing on one mould half with a wooden stick when opening the mould and this will help out greatly with out beating on the mould. I also close the mould slowly then turn the sprue plate back to prevent mould damage.

[rays308]

Doc,

Thats My meathod with my double cavity molds also. I've been using a 5 holer, It's a little tuff to cut all 5 by hand. I'm sure you're right, its likely using the mallot to cut the sprues.
I'll do some 3 or 4 at a time next batch. I can always us the extra cavity for brass jackets.

Not negating what you are saying about G force and pressure curve(I know its an important factor) but, CWME had some pretty good groups with 20gr of 5744 also. Thats pretty fast stuff for rifle.
That being said, I think I'm searching for that happy curve with something slower than H4895 and faster than H4831sc. If I can get the accuracy from a case full of H4350 by tweaking the bullet placment and quality then I will move down the scale to say Varget or IMR-4064 until they start to fail. Somewhere in there I hope to find the best I can do with this boolit.

Its cerainly possible that I've already hit that point, I gotta find out though.

[Doc Highwall]

What are you using for a bullet lube? I am using BullShops NASA lube in my AA5744 loads with great results. I have fired hundreds of shots with out cleaning not even a patch on a jag and the rifle continues to shoot small groups.

[rays308]

I tumble lube with white lable then size in my lyman and add Javalina.

My thinking is that the alox will help the rifling engrave the nose like cutting oil helps reduce friction on a mill or lathe.

I was happier with the RCBS green stick lube in warm weather, if Javalina melts in hot weather I may take some of the alox add bees wax and make a batch of my own so I can get the consistency I want for summer.

I haven't seen any leading since I loaded 30rnds with 33gr Varget. These were WDWW that were sized 309 and seated at 2.750. Too small & too short for the bolt gun.
Lately I have sized them 310 seated to 2.780.
Now I have some seated at 2.795 to slightly engauge the rifling. I should be able to shoot tomarrow afternoon.
I gotta pour some more before I can try 311 and annealed gas checks. Crossing my fingers the rain holds off tonight so I can get some pour time.

[Dutch4122]

Don't overlook IMR-4007ssc in your .308 with boolits over 200 grains. My 16.5 inch barreled Spanish FR-8 Mauser loves the NOE 316299 sized to .314" over this powder. Ran it all the way up to 2,180 fps and the gun shot "minute of rock" way out past my meager shooting skills. The alloy is 50% wheelweight and 50% pure lead, water dropped. Lube was Lar45's BAC. You can find the load data for this powder on the Hodgdon website. Look under .308 Winchester and 200 grain bullets. They will have a load range listed for IMR-4007ssc.

Hope this helps, :D

[rays308]

IMR-4007 is between H4350 and IMR-4064. Could be a good next step if I can get H4350 to shoot good with a full case.

[Doc Highwall]

I am sizing my SAECO #315 with the NASA lube and I just wipe some of it on the nose with my finger when I am sizing them and placing them in a box before I load them. I would just try the Javalina by itself and get the best accuracy you can by working with powder charge and seating depth before mixing lubes. Set a standard by which to judge accuracy then make only one change at a time and write down every thing you did so you do not forget how you got where you are for accuracy.

[CWME]

Might jump to the .311 sizing before you go to far with anything else. Find your best load to date and duplicate it with the .311. I am also only lubing 2 of the lube grooves.

As Doc said, change 1 thing at a time and take lots of notes. I have my targets labeled and 3 hole punched for my load book. If the load looks good I have a master log as the first page for each caliber/rifle combo that the load gets logged for future reference. I always have the targets but saves me the time looking at them.

[CWME]

What kinda of groups are you getting now? You made mention of 1 group going 4". What are your best loads doing? Think you said that your 40 gr 4831sc load is shooting pretty good. Just curious how much of an improvement you are looking for.

Not sure if some extra speed beyond your 1900fps would be absolutely nessesary for 600 yards. Haven't crunched the BC tables yet to see. Do you know if they would still be supersonic at 600? If yes find an accurate load, dial in your elevation, shoot, and forget about a few 100 FPS.

[rays308]

40gr H4831sc, old win cases and seated about .010 off the rifling will give me half inch groups at 50yds, 10 shots with a couple of flyers. I figured that the flyers were just me. Now I'm hoping it was more the bullet and I can correct the problem.

I got 60 loaded last night that are just inton the rifling, I hope to shoot this afternoon.

The H4831sc is for now my goto load. If the weather allows, I will be trying them at the longer ranges this weekend.

I also stoned the sprue plate on the mold last night and poured about 300. I didn't see any high spots on the bases while culling. I did throw out 18 for wrinckles. They are water dropped so, I may not HT them. I really want to use them this weekend with increments IMR-4064 or H4895.

Using the link below, i need to be at or above 2200fps. 1800fps would go subsonic at about 400yds.

http://www.biggameinfo.com/index.aspx?page=%2fbalcalc.ascx

I'll try to get some pics of targets this weekend.

[rays308]

Well the kids took the camera. Something about pics of the little ones hunting eggs. Sometimes I don't think they have their priorties straight. LOL.

After the egg hunters left I was allowed to go shooting, as long as I didn't shoot the easter bunny. Purple dinasours are always in season though.[smilie=l:

All the suggestions about setting the bullets out to the rifling, sizing 311 and annealing the gas checks paid off, with dividends.

All targets have been shot at 50yds this weekend.

Though their groups were good, the H4831sc and H4350 just weren't going to get me the speed I wanted for long range work.

38gr H4895 still wouldn't do better than basket ball sized patterns.

I filled some cases with 39gr of IMR-4064. OH MY GOODNESS! THEY GROUPED!
Golfball size to baseball size, but THEY GROUPED! I can work with this.
Not just the 311365 but so did the Lee 200gr and the 311332. I was grinning from ear to ear.

Heat treated might have had a slight edge over WDWW but that might just be consistency of hardness.

The 311365 seems to be yawing at 50yds, I've had that with all the loads I've tried. Extending the range to 100 rounds out the oblong holes.

I ran the 314365 with 36gr 4064 side by side with 311365 36 gr 4064 HT and WDWW. Both 10 shot strings had a good center collection of hits the size of a golf ball with 3 or 4 hits about an inch out out of the group. I my try some more at 100yds just to be stubbern.

Now I can start varying primers, tweeking seating depth more and maybe some alloy changes.

I'll start a different thread with pics when I get my camera back.

Thanks for all the suggestions. I'm certain they got me the good groups.

[Doc Highwall]

When you start with powder charge weight for your tests work in 1% increments and keep your case weight variance to 2 grains max and 1 grain is even better. Bullet size diameter and expander size diameter make a difference also, just do one change at a time.

[rays308]

Thanks Doc.

Ordered the M Die expander this evening along with a couple of other items.

I actually did do the 1 to 1/2 gr increments, just not all at the same time. The loads came from the little all inclusive 308 load book that compiles listed loads from different sources.

When I went back through my targets for the Lee 200gr, it appears that there may be more than one sweet spot.

I had used 4064 on the Lee before, my normal load is 30gr 4064 for this boolit. At 33gr it opened up and had stayed large through 35gr.

Normal load for the 311332 is around 30gr also. It opens up at 32gr. I hadn't tried for higher on this one.

The 36gr loads and above were worked up with the Lee 180 gr. I was figuring it was spin and length of boolit.

I'm left wondering if there is such a thing as more than 1 sweet spot?