My quest for speed and accuracy with powder-coated cast bullets

Ian

Well-Known Member
The checks are a perfect snap-fit on these bullets. First I use a Lee push-through .225" die to install the checks and pre-size, then powder coat, then nose-first size in a bump die I made, CBA-style. I also made an ejector that fits the nose profile and acts as a positive stop, and made a flat-face top punch that rides down in the die to bump the base square at the same time it's re-forming the nose. Should be square, but I it's hard to check that unless I sand off the pc, which I do before nose-forming. If I work up a load with buffer it should eliminate base imperfections as a cause of my flyers.
 
My GC are 0.0002-3 larger than the bands after sizing(Cu springback and these are annealed). Just makes a difference in neck tension - you don't have much in the neck - a problem? I just pick the 30 cal out of the bucket with hemos and wipe the base on a flat paper towel - removes the PC powder. Unfortunately I don't have a rig like you and Bama, just the Lee and flat top punches. 223 GC as thick as 30 cal?.
 

Ian

Well-Known Member
More shooting, this time from the new machine rest. I shot a group yesterday with the same 24.0/H335 load and it did the usual except for a few wild shots from a loose strap. After resetting the straps the last few shots went back in the group.

Today I switched to Reloder 7 and cleaned the carbon out of the barrel. First group was ok with two pretty wild flyers. Bases were rough so I sanded ten more by hand and tried again, toatally wild group with no rhyme to the pattern, and one really wild flyer I accidentally cropped out of the photo, 3:00 at the edge of the paper.

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I cleaned the bore again, with a brush and Ed's Red, then sanded the bullet bases with the bullets chucked in a drill motor, then gave them a light coat of BLL and loaded again with the RX7.

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I dunno what's going on. It ain't the shooter, I know that much. Rechecked the action torque and the rear screw was at 15 inch pounds, had set it at 30 but the plastic trigger guard makes it very squishy. I think it's bore condition throwing off the shots when using RX7. After the BLL group, a dry patch felt very jerky going through the bore, unlike the even carbon fouling I get with H335.

Maybe I should try H335 again, and some lube in the grooves?
 
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fiver

Well-Known Member
reminds me of the 61.1 lube.
the first 5-6 shots were beautiful then you couldn't even guess at anything after that until the barrel was completely cooled off and hazed over again.
you might have to do 5 shots and a patch then 5 more?
 

Ian

Well-Known Member
Yeah, in my case I had to chase the 61.1 lube with 61.0 (or maybe it was .3 with .1, I don't remember now) and get another five in under half an inch.

I might try patching every few, or every shot, but sometimes the flyer sequence doesn't make sense. I'm still trying to figure out if I have a bad launch half the time, or erratic bore condition, or just a rifle that won't shoot. I ordered some jacketed lapping bullets and some bore paste, so as a last ditch effort I'm going to put a few of those through it and go back to the H335 load. I might also change primers and this brass is on 11 firings so I'll change that out too.

One thing that is pretty good here is the first, cold-bore shots all go in the same place, and pretty much in the center of the groups, no matter what I do. The second shots go a little high, pretty much always. The third shot may be high and left, or way wild.
 
Try .020 w/ same load as before.

Reason I was going that way before and again now, oal was absolutely critical in my 223/hf pc adventures to find the length then adjust charge in tiny increments. Might suck worse, but it might not. My velocity was only 1800 or so, but the tiny variance your fighting makes it worth a try. Seems like .015-.020 off always did best for me.

Backing it up worked the first time.......wonder;)
 

fiver

Well-Known Member
yeah worth a go.
it did seem to help the first go-round.

the neck tension could be contributing too, you could burn them back to dead soft and do a 5 shot 5 times thing and see if you see a pattern develop.
all we are really looking for right now is a direction.

without the flyers I think that, that top left target would be about the best you've done yet.
 
From book value, your 335 load is about max. Do you H.T. after PC? IMHO, I don't have the equip or ability nor have ever even shot a 223 - find a slick side mould to try. Grooves are weak spot both torsional and compressive. Consider lowly 22lr HV. No grooves, high pressure, weak alloy. Had a caldwell AR lead sled, SIL & I 'competed' with factory FTX ammo, my 30/30 vs his 308MX. He did a one hole with 3 lobes but took 10-15 min to set up each shot. Thumb behind the trigger guard and index on the trigger the trigger. Hornady/Marlin tuned that MX for good accuracy.
 

Ian

Well-Known Member
I could easily make a slick-sided mould, but I still don't believe in them. HV and slicks means bad PC fouling accumulation from what others have seen. These are heat treated during the coating, water quenched, 21 bhn stabilized. I was shooting ACWW up to 2750 with about the same results, I only hardened them as an experiment.

Last night I did some nose-sizing experimentation to see if I could get by with less sizing, and it appears I can. The throat entrance is .2263", so I'm also going to try sizing the bullets down to .226" and see if I can get them to not lead. I was able to nose bump just enough to get the bullet to engrave the lands lightly on the first two bands, not touch the third, and just scuff halfway up the fourth band. Seated like that, the gas check is flush with the bottom of the neck. My lapping bullets came in today, so I'll be playing with that a little. One thing I've noticed with this barrel is it is tight for about 2-3" in front of the chamber and then opens up slightly for the rest of the length. I bet it was profiled after broaching and the thick part in front of the chamber kept its tighter form. Mainly I'm trying to smooth it up so it fouls less and hopefully that will make the PC shoot better. After lapping, I'll re-evaluate how much nose-sizing I'll need to do because I'm sure it will push the lands out a little and probably open up the bore dimension a bit. Fortunately, there's plenty of front band diameter on this bullet to work with. Once all that's done I'll get a new jam length and nose-sizing depth established and work on the jam-minus numbers some.

I'm almost out of bullets again, so I'll cast some more out of 6/4 alloy and give that a go, and probably experiment with lube again. If all else fails, I'll just have to live with it being a ~2 moa rifle with a very predictable first shot, until I wear out the barrel.
 
I still don't believe in them. HV and slicks means bad PC fouling accumulation from what others have seen. I haven't seen that in 308W or BO pushed hard. Even using HF red. Bama says he has a bacon grease PC from Smoke that shows less fouling. Increased surface area for land contact.
I'm perplexed! Off the shelf dies, stock DPMS (BO has a McGowan barrel), no special tratetment of cases or cast and decent results. Never even chamber cast or slugged. I am not that lucky or skilled. I am getting 'tested' trying soft alloy and jacketed fps in the BO pistol. May have to put a scope on it to verify actual performance accuracy wise. I've HiTekd some loads to try but with 3-4' of rain a week (and the range is next to an overflwing creek) don't know when I'll get some testing done.
I know there can be problematic or worn out rifles, hope your bore lap solves the problem.
 

Ian

Well-Known Member
I got bored and did a little webcrawling. Found this article, MVP Patrol (short barrel) averaging 2" groups with a variety of ammo, wild flyers abound and no real pattern consistency going on. https://rifleshooter.com/2016/06/re...o-223-remington-and-7-62-nato-308-winchester/.

Here's another review where the writer brags on the accuracy...of three-shot groups. When he did try for five, guess what, un-called wild flyer: https://www.thetruthaboutguns.com/2013/01/joe-grine/gun-review-mossberg-mvp-predator/

Another one who couldn't hit a barn from the inside, though he blames it on himself not being a good shooter. My exact model here. https://www.thefirearmblog.com/blog/2012/05/22/mossberg-mvp-review/

Here's one who got sub-moa, 3-shot groups from some ammo but 1.5" for three with the Federal AE 50-grain varmint bullets....that I can shoot ten of into a slightly smaller group with mine (see post #104 for proof). https://blog.cheaperthandirt.com/range-report-mossberg-mvp-great-rifle/

2900 fps with 68.4-grain wheelweight bullets, getting 2" or less for ten-shot groups fired fast enough to make the barrel too hot to hold, not so bad? Sometimes I feel like the man of La Mancha. Anyway, if this doesn't sort out pretty quickly I'm going to switch gears and continue this HVPC testing with a different rifle, likely my Savage Hog Hunter since it's threaded for a can and already shoots sub-moa groups with sub-sonic, PC cast bullets.
 
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Will

Well-Known Member
I feel that the lube grooves in the bullet allow the place for lead to flow evenly during the initial launch into the throat.

A slick sided PC bullet really doesn’t have a choice but to elongate and deform at the base when it gets squeezed into the rifling.

When I would recover my MP 308 hunting bullets fired at 2400 FPS usually all I found was about half of the bullet. But you were able to see where the crimp groove and lube groove had allowed the bullet to flow into these areas.
 
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Please excuse my ignorance regarding PC bullets with my question. I somehow missed the PC cast bullet innovation during my break from casting. I am familiar with powder coating desks, frames, roll bars etc. but not its use in cast bullets. Its an oven cured coating.

Isn't it too hard to obdurate? Do the same lube parameters apply as to alloyed bullets? Do you need to change sizing parameters? Does it act like a jacketed bullet? If y'all find this question too tedious, can anyone point me in a direction to understand it better?

Thanks in advance, Danny
 
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Will, I a gre e. , my moulds ha be very shallow and thin, junk collected groove, close to the base. They have a large land gripping area. My Marlin is tight at both ends that does cause problems. Chandler, it works very well. The other site has big section about it.
 

Ian

Well-Known Member
It's been a thing for a few years now. Way too much to cover here. Originally it was conceived as a lube coating to replace traditional grease or film lubes, but it does more than that. Only a few people have really pushed the coating in rifles, but I believe it is actually quite revolutionary in that it adds a tiny bit of much-needed surface strength and abrasion resistance to rifle bullets being pushed hard and fast in normal-twist, factory rifles.

My principle interest in PC is it reduces or eliminates suppressor leading, and most of my shooting is done with suppressors

I'm trying to learn more about polyester TGIC-coated bullets and blaze a trail for others by answering some questions about how things like alloy/pressure balance, sizing, and bullet design need to be optimized to make the most from the coating. Also, I'd like to prove that powder coating rifle bullets solves some classic issues involving temperature and lube problems, bore seasoning/cleaning issues, and alloy failure in fast twists. Finally, I'd like to settle the question of whether PC bullets can ever shoot as well as traditionally-lubed bullets.....or copper-jacketed bullets.

So far, all I've proved is that sub-2 moa groups are possible at full jaxketed velocities using ww-type alloy....air cooled. Even got real close to max fps with 10.4 bhn 50/50 ww/pure alloy in .308 with better than jax accuracy using coating plus lube. Still learning about alloy, launch, fit, bore condition, and a bunch of other things.
 

fiver

Well-Known Member
the PC is supposed to remove the need for lube.
BUT it has shown that it CAN shoot better with some lube applied.

you do need to follow the same basic rules as you do for cast.
the coating allows for some latitude, such as sizing closer to bore/groove diameter,, however too small is too small and you can still get leading.

you can get away with a bit softer alloy than with a naked bullet if your trying to duplicate the same results.
your also going to need to up the load some to retain accuracy and velocity. [5-7% seems about right]

as far as a jacketed bullet?
well yes and no, think about it more like a windbreaker than a jacket.
 

fiver

Well-Known Member
So far, all I've proved is that sub-2 moa groups are possible at full jaxketed velocities using ww-type alloy....air cooled. Even got real close to max fps with 10.4 bhn 50/50 ww/pure alloy in .308 with better than jax accuracy using coating plus lube. Still learning about alloy, launch, fit, bore condition, and a bunch of other things.
we proved pretty much the same thing with naked lead bullets in the XCB project and with a couple of 10 twist 308 rifles too.
it's still chasing the tail with either method, and the rifle needs to be up to the task.
if the rifle isn't accurate enough to be interesting with GOOD jacketed bullets of a known quality, then it isn't really going to perform with ANY OTHER TYPE EITHER.
you get what you get...
 
Thanks. No one has mentioned any negatives regarding the PC and the bore or any special cleaning tips. Sounds like a thing to explore. I do enjoy reading these threads. I always considered PC as a hard coating but lead is too soft for bondo to stick to so someone is always making new rules and that makes it more interesting. Lead is a hard thing to attach to.
 

Ian

Well-Known Member
This has been frustrating because one of the rifles I chose wasn't up to the fundamental accuracy task. It was a new rifle and scope, and initial jacketed groups were 1.5 to 2.5" until I worked on the rifle a bunch, so at this point my cast loads may be nearly as good as it can shoot.

PC has no trouble adhering to clean lead alloy. It sticks so well that a bulket can be smashed flat as a coin with a hammer and the coating doesnt flake or chip. We were just discussing fouling issues with the coating a couple of posts before you joined the thread. So far my fouling issues have been very mild to nonexistent.
 
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