Quesion on cast bullet accuracy

[stephen m weiss]

I went to the range yesterday and got some confusing results. I shot 4 loads of cast bare base bullets.

223, 50.5 gr at 1554fps sd=25 fps with cast bullets aged a week, Quenched with high Sb. Sized 225 Medium Lee Alox, 7.5 gr of Alliant 1200R and fill with grits.
Grade A bullets, no defects at all, 4 moa 5 round groups 50 yd
Grade B bullets, some small defects, maybe 60 cubic mils, 4moa 5 round groups 50 yd

308 117gr at 1500 fps sd=54 fps with cast bullets aged a week, quenched with high Sb. Sized 309 Medium Lee Alox, 17.5 gr of Accurate 2495
No defects at all, 4 moa 5 round groups, 50 yd

308 155gr at 1430 fps cast bullets aged 8 weeks, quenched with high Sb. Sized 309 Medium Lee Alox, 17.5 gr of Accurate 2495
Some small defects, maybe 100 cubic mills, 4 moa 5 round groups, 50 yd
These shot about 16 5 round 2 moa groups a week ago. Very consistent.

My question is why did my accuracy drop to 4 moa from 2 moa. It seem to be independent on aging time or flaw size. I shot another guys full power 308 in between my stuff and had .5moa. I my hold was wiggling the xhairs about .25" at the target during shooting. I find and calculate that equates to about .5 moa. It seems unlikely it was my hold doing the 4moa. I shot a 10 round off hand group at 10moa, about what I always shoot offhand, so I was shooting typical for me. (I was using hunting style, no strap, no shooting jacket, fast 1 second sighting)

A week ago it was about 40F, wet and 20 mph wind. Yesterday was 60F and still and foggy. I had thought I would get really tight groups. But that only happened with the factory ammo.

Suggestions as to cause?

[stephen m weiss]

Well, I did clean both guns with a nylon bore brush, then motor oil the brush and run it through 2 more times before shooting this week. I could expect a fouling shot, but that is not what seemed to be happening. I shot the B group first in case there was such an effect. It doesnt say that the motor oil was not affecting it, but less likely. As far as storage, I always store my bullets in random packed plastic sandwich bags in a backpack, all tossed together. This really limits available moisture. All the rounds were compacted with grits filler, no shifting is possible. The grits could have gotten stuck together, but the old rounds were 6 weeks older. The new rounds were only a few days older and had never left my basement.

[upnorthwis]

For starters, I would not be using grits in a .223 and would take longer than one second between shots.

[Wayne Smith]

What variables changed? All boolits from same alloy, from same casting session between the two shootings? Lube consistent or different? Same brand/lot of powder/primers?

[stephen m weiss]

Well, I did clean both guns with a nylon bore brush, then motor oil the brush and run it through 2 more times before shooting. I could expect a fouling shot, but that is not what seemed to be happening. I shot the B group first in case there was such an effect. It doesnt say that the motor oil was not affecting it, but less likely. As far as storage, I always store my bullets in random packed plastic sandwich bags in a backpack, all tossed together. This really limits available moisture. All the rounds were compacted with grits filler, no shifting is possible. The grits could have gotten stuck together, but the old rounds were 6 weeks older.

The fast shots were only the 10 moa off hand shots. It was 1 second from in my lap to trigger pull, not bang to bang. The other shots were typical double rest sandbag shots, slow and careful. With the 30% load, the barrel doesnt seem to get hot.

Only the old rounds, the 155 gr were from a different casting session. The alloy should be close since I ingoted my casting alloy. But note: flawed and unflawed rounds shot the same. It should not be alloy hardness since if the alloy were blowing out, the flawed rounds would shoot wilder.

Powder and primer different from 223 to 308 otherwise the same.

The change was one bag of bullets one week apart went from 2moa to 4 moa, lots of test, so unlikely to be luck. All the new bullets were also 4moa, that could be luck.

The lube was the same bottle of Lee Alox, got it 8 weeks ago. If somehow Lee Alox hates motor oil barrel lube in misty 60F weather that would explain it, but sounds sketchy to me.

If somehow the foggy conditions and the grits interacted that would match, but I cant see how a bullet pulled from a zipped bag and fired within minutes is gonna suck up much moisture past the primer seal or past the squished wax lube seal.

Other 2moa rounds with rice filler I shot from under a canopy during a freakin downpour and maintained 2moa on many groups, a month ago. Those bags of bullets were sitting out in a camper with fog on the inside windows for days and still shot fine.

[runfiverun]

velocity.

[williamwaco]

308 155gr at 1430 fps cast bullets aged 8 weeks, quenched with high Sb. Sized 309 Medium Lee Alox, 17.5 gr of Accurate 2495
Some small defects, maybe 100 cubic mills, 4 moa 5 round groups, 50 yd
These shot about 16 5 round 2 moa groups a week ago. Very consistent.

I shot another guys full power 308 in between my stuff and had .5moa.



This is a real no-no.

Many people claim shooting jacketed will prevent good accuracy. I don't know about that.

BUT

I absolutely know about this.

After changing the powder brand, it go wild and will take five to ten shots to settle back down.
This occurs almost 100% of the time in my testing.

In my experience, depending on the rifle and the shooter, you should get .5 to 1.5 " groups at 50 yards with that .308 load
Although I would size them .311.

[Larry Gibson]

velocity.

+1.....especially if the "bare base bullets" are designed for GCs.

Larry Gibson

[35 shooter]

Did you use motor oil the first time when you got good groups? I use atf to prep my bore but also run a dry patch through before shooting. I tried 2 stoke oil one time and it turned my normal 1 to 1 1/2 " @ 100 yds. into 3 to 5" groups with the same loads. It didn't get better till i cleaned it all out and went back to my usual atf.
Don't know if that had anything to do with your groups but it did with mine..so maybe?

[runfiverun]

bore condition is very important when shooting cast.
c.o.r.e condition will affect accuracy, cold barrel shots, and hot temp consistency.
ever notice that first shot flyer being high and maybe a little left?
or than one uncalled flyer in each, or every other group?
or groups suddenly getting bigger from one day to the next?
or them getting big for a group or two then shrinking again?

that's residuals, and barrel condition changes affecting things.

[glockky]

How do you control than r5r

[Cowboy_Dan]

...
I absolutely know about this.

After changing the powder brand, it go wild and will take five to ten shots to settle back down.
This occurs almost 100% of the time in my testing.

Not to hijack the thread, but I have a question.

Would cleanng between powder changes mitigate this effect? I ask because the next step in load devolopment with my Mosin is to try the best load from each of three different powders. I am using j-words if that matters.

-End hijack-

[303Guy]

I'd suggest the jacketed bullets upset the bore condition by adding copper fouling.

I've found that grits tends to cup the plain base boolit bases.

[jhalcott]

I had some strange results using Cream of Wheat filler a long time ago. It seemed the CoW was adhereing to the bare base of UN checked bullets. I found a few in the stack of wet pack that STILL had a bit of the filler stuck on them. The CoW groups were a good bit larger than those with DuPont polyester filler. These were 30 and 35 caliber rounds loaded for back yard pest control, and a few heavier loads for quiet deer culling.

[runfiverun]

there is a couple of way's to deal with it.
one is to pre repair the bore by swabbing it with a dampened patch coated with the oil used in the lube.
another is to control build up and residue left behind by the lube.
and a third is to tune your lube to the weather conditions [adjust the viscosity to temperature windows]
lubes with a carnuba content above 3% need to be repaired with either heat or by actually shooting a boolit down the barrel.
it giving the barrel that shine is a coat of wax, the wax glazes over and needs to be repaired.
other lube ingredients will do basically the same thing, or will build up by leaving something behind, and are purged.

dan:
cleaning between powder is an idea, you just have to build a little fouling back up consistent with the one you are going to test.
whether that's powder fouling, or pushing the lube seasoning back down the barrel, you are looking for that consistent stabilized bore condition.

[stephen m weiss]

Ah, the full power rounds were with the other guy's rifle. I do appreciate the advice on that because in my regular shooting I frequently switch back and forth between fmj and cast. That was what I was doing on the days where the same bag of bullets was producing 2moa. I would do like 20 rounds fmj, 20 rounds cast and back and forth, at different powders and loads collecting data for my internal ballistics model.

I tested the hardness on the old bullets, 2H pencil would not scratch. The new bullets could just be scratched by 2H. I dont think that velocity is the problem because I shot 80 bullets out of the bag at 2moa, and the velocity was unchanged and right around 1500 fps with hard lubed lead. It should have no problem at that velocity especially with a mild pressure powder like Accurate 2495.

I bet the 'sketchy' answer of lube and cleaning are the answer, especially in those weather conditions. I used to surf on carnuba/bees wax a great deal, and water and temperature definately affects the stuff. I can well believe that motor oil would freak it out as well. Motor oil worked great with fmj's....

I like the idea of brass brush cleaning with alcohol followed by a light oil wipe followed by a dry patch. Then a fouling shot that 'don't count'. The variable effects of temperature and depth of lube are bound to be minimized with almost no lube. In so many cases in machinery, lube light and wipe it off produces the best repeatability, if not the lowest friction.

[popper]

Change to dacron filler! What is your high Sb alloy %? You seem to be saying that barrel treatment, weather & time were the only change. How about aging of boolits? I usually don't shoot at least a week after casting/quenching for stability. Also some testing shows too hard at low fps gave larger groups (300BO 150 gr. PB). Pumped up the volume (1800+) on the harder & groups tightened. I changed to PC after finding Alox (& my try at Recluse) was too inconsistent in full power 308 loads. PC good from 30F to 100F, no POI change, no fliers or barrel prep. Not knocking other good lubes. I also don't claim to be a good shot.

[stephen m weiss]

Oh, to answer directly: I used wire brush with alcohol, patch wipe clean, then patch with light 3n1 oil when I had good groups. It was after I switched to motor oiled nylon brush no dry patch that I had bad results. I only shot less than 20 rounds per gun that day, so it may have never had time to settle down. I bet I have a bunch of now powder grimed motor oil in my barrel.

Cleaning now... !

[stephen m weiss]

Oh my! The answer was grits fill interacting with too much motor oil and Alox waxes. That was a dirty hole!! It reminded me of my experiments with oil and sawdust as a bullet stopper! There is no way I could have maintained nice groups with that much solid crud in the barrel.

I am not yet ready to give up on grits, but will try dacron at least at the range where I dont have to live with the fuzz for 20 years. With the toilet paper I was using, it was costing me 30 seconds a round for that one step. I watched one of you bullet master's using dacron, and it seemed about as slow to me. If I could put a station on my progressive press that would stuff a nice filler that was eco friendly and better than grits I would. Granny was throwing out some sugar substitute and I nearly grabbed it to try! I get 35% better powder efficiency using grits that doesnt appear by just keeping the powder back for a nice ignition. It needs the pressure. And the unburned powder in the barrel and action does not promote accuracy nor safety.

[Larry Gibson]

I've probably shot more Dacron than anyone else in over 40 years of use and have yet to have a problem with "fuzz" on any range, indoor or out door. If you have a "fuzz" problem you are either speeding or using to much Dacron.

I also have loaded quite a few rounds on my Dillon 550B using a Dacron filler.

I NS, deprime and reprime at station 1.

Throw the powder at station 2.

At station 3 is the M-die. After expanding and flaring the case neck/mouth the case is removed from the station (case retaining button left off) and is set in a case block to hold it. I then easily and quickly insert a precut tuft of Dacron and put the case back in at station 3 and set a bullet into the case mouth.

Station 4 seats the bullet.

It is quick and easy that way. However, with some loads where I like to clean primer pockets and inspect the cases I clean, NS/FL size clean primer pockets and inspect the cases on a single stage press (station 1 on the Dillon or other progressives can be used also). Then the M-die is at station 1, the powder dispensed at station 2, the Dacron filler is put in at station 3 and the bullet seated and crimping is done at station 4.

It is not difficult to use a Dacron filler at all.

Larry Gibson

[stephen m weiss]

Oh, whats PC bullet lube?

[stephen m weiss]

Oh, powder coat. That is on my do list. Is there a good thread with a starter set up for home use. My knowlege of industrial set-ups seems a little inappropriate to the task!

[williamwaco]

Not to hijack the thread, but I have a question.

Would cleanng between powder changes mitigate this effect? I ask because the next step in load devolopment with my Mosin is to try the best load from each of three different powders. I am using j-words if that matters.

-End hijack-

In my experience - cleaning has the same effect but to a much smaller degree. With most rifles, the first shot, or two, occasionally 3 will be flyers.
It corrects quicker I expect because all it has to do is condition the bore and does not have go wipe away the former conditioning. I am using the word conditioning here because I don't really know what is happening, just that it does.

As Runfiverun mentioned, in my experience, they are almost always high and left. As much as several inches at 100 yd.
When I start with a newly cleaned barrel, I expect the first five shot group to be bad. My confidence in this happening is high enough that I never take a newly cleaned bore on a hunting trip.

I didn't notice that part. I just assumed cast. I have noticed the same effect with jacketed but I shoot very few of them the past 30 years so I defer to those with more current experience.

[stephen m weiss]

Oh, the composition of my bullets was an attempt to duplicate WW. It is about 4%Sb and .17%Sn remainder Pb. I had to calc it. I made the recipe on the fly in my head, and wasn't exactly sure what the numbers came to. I wrote down what I did, just didnt calc it exactly.

Actual composition of the pot sorta varies as I go because I melt back in bullets from old shooting sessions which I count as 3% Sb. Actually, some of the early casting sessions were high in Lino, up to 30%% lino, so melting in those bullets raises the alloy a bit. But some of the bullets are from purchased fmj's, so who knows what was in them. The 308s are pertty hard but the 223s are dead soft. No clue whats in 7.62x39's.

As long as they age up to where H wont touch em and 2H will, I am happy. I do try to give them a week to harden, but it might be 5 days depending on when my wife lets me get to the range. My casting quality is climbing really fast, so shooting older bullets is of no value, I melt em down. For instance, I just installed continuous thermocouple temperature monitoring for the bottom of my pot and the mold side. That should increase yield and average quality even more. Using one thermocouple for pot, mold and oven was pretty hectic!

[popper]

I use the high temp (~$6)probe IN my melt - connected to PID, don't check mould temp anymore, just move the probe to the oven when needed. Thermocouple wire by itself doesn't have high temp insulation to use IN the pot. I generally use 3% Sb, HT,PC & GC in 308, same alloy PB in 300BO & 30/30. I am playing with Isocore now as it was less $$.

[1Shirt]

Lots of good advice here for lots of what I consider your problems. My first issue would be the grits filler: big mistake in my opinion. Don't shoot COW in any bottleneck case. Use Dacron and use minimal amount, just enough to do the job----no compression. Don't be shooting jacketed in between cast loads and expect anything but problems. At the end of shooting cast, know of some who will throw down one round of jacketed, and then clean. Never tried it, but some say it helps if there is any leading. Others say if there is leading, the jacketed will just iron it down into the grooves.
1Shirt!

[stephen m weiss]

I found some dacron .5" batting. Working on making up some test rounds. I will report accurately what I observe. My model predicts the dacron will drop the powder burn from 50% to 35% with my 2495. If the speed matches those findings, I am not gonna be impressed with the dacron till i get some faster powder or start shooting heavier loads. My model also shows it's a bad idea to use COW with over 75% load, and you really dont need it over 50%.

[Larry Gibson]

More like 5 - 20% increase in burn efficiency with 2495.

Larry Gibson

[stephen m weiss]

More like 5 - 20% increase in burn efficiency with 2495.

Larry Gibson

I really appreciate your help Larry. I would like it even more if I understood what you said. What increases burn efficiency 5-20%? What is that based on? I have read the forums enough to know you are well respected and know your stuff. I am not challenging that.. I just think that since you took the time to help, I should get the help you meant me to have!

Thanks again.. btw.. got Dacron test rounds made, they shoot tomorrow. I hope they do something I dont expect! haah more fun that way! I used roughly .5"x .5" squares of the half inch batting like your video. I didnt compact them, just pushed them to the bottom, tho.. might not have been perfect on that. I weighed the smallest and largest .4/.7 gr. That's right on the amount of toilet paper I was using. BTW. Toilet Paper does not burn when shot out of a gun. Going from 1000 atmospheres to 1 in a microsecond pretty much blows out any flame! After inspecting many rounds of TP blowout under 10x stereoscopic viewing, there is not even charring. (Gah.. sry just starting to dispell the myths that abound...)

[303Guy]

The Dacron needs to fill the whole free space, not pushed down onto the powder. That's to insure there won't be any chamber ringing. I don't think it has been proven that chamber ringing will occur if the batting is pushed down though.

[stephen m weiss]

Well, spent like 6 hrs at the range. Got distracted by bro-ing down with the guys and wasnt the perfect scientist... a few things I did learn:

* After a gun cleaning my 24 BHN 155 gr bare base Lee Alox at 1430fps shot either 4 moa or 1moa.. randomly.
* My 223 at 1500 fps shot about 4 moa, well 1 moa in horizontal and 4 vertical. Somehow speed control is suspect.
* The dang sun was hiding and my crony starved and gave about 2 readings in 80 shots.
* I shot the dacron stuff, accuracy was no better and not a single speed read.. gah
* There is a cool AR style pump 223 out by Troy for $1100, legal is commy states like NY an CA, with folding stock, flash hider. They seem to have ported the chamber oddly. It makes longitudinal bumps most of the way back the brass from pressure. I think they are trying to get the brass unstuck without the usual 20lb tug-fest. I would prefer perfect brass and a tugfest. but whatever. They guy gave me some brass and I am gonna form them and see if it irons out. I gave him some of my 30% powder loads with grits and they still showed the pressure marks but not as bad. I think he was shooting offhand because his holes were in like a 12" dia pattern at 50 yds... Hehe So often I cant figure out what people are doing at the range and how they get the results they get.. Or how they claim an 8"dia pattern at 50 yards is 1moa lol

I notice a pattern on these threads, every load that uses jo=blow average powder but not much of it and burns well has some weird impossible to prove claim that it will blow up guns and kill the shooter...or just ruin the guns or whatever. Ringing....without enough powder to create much pressure, with jack crud for case fill %.. So much good info, and so much that defies science and just plain looks like disinformation intending to sell more powder and parts.

/rant ended/ I will continue to connect the dots and learn. Someone noted that with cheaper better ammo, we didnt spend less, just became better shots. I know that by making my own ammo, I dont spend less, just shoot more.

Er.. .5" cube comes no where close to filling the freespace with a 30% powder charge. It was about 6 seconds per 308 round after pre-cutting the cubes. If I have to triple pack.. gah.