Well crap....

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MeGrunt
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Well crap....

Post by MeGrunt » Sun May 31, 2020 11:06 am

I had really high hopes that my 300 Blk pistol would be a perfect cast bullet platform.

I was wrong....really really wrong.

I have yet to find a cast bullet that will give groups vs patterns. I've tried several different bullets, several powders.

I'm an experienced bullet caster with success in other cartridges. The 300 Blackout is giving me fits.

Maybe I should have gotten a 300 Hamm'r instead.

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rebel
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Re: Well crap....

Post by rebel » Sun May 31, 2020 10:48 pm

I doubt a Hamr would solve your problem. Many successful casting stories and experiences in this forum. Maybe it's your build, or barrel, seeing as as most folks choose bargain basement crap these days. I would hardly blame the cartridge because you cant get it to shoot. Experienced caster is great but the 300 BLK is an animal that must be tamed with knowledge,patience and experience. Gotta problem with you trashing it because YOU have an issue. How about giving some details of load data and maybe someone here will help you out.
You can't beat the mountain, pilgrim. Mountains got its own way.

MeGrunt
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Re: Well crap....

Post by MeGrunt » Mon Jun 01, 2020 6:47 pm

I'm not rich. I didn't know it was a prerequisite to being on this forum.

I'm a 100% P&T Veteran. I live on a fixed income. I have a certain amount of "play" money I can spend every month.

I'm sure there are people here that have spent more on a BCG than I have in my build.

It's an Anderson lower, with a Anderson LPK. The upper is a 7.5" BCA with a 1/8" twist.

The first cast bullet I've tried is the MP 311410 hollow point. I did ladder loads, every .3 grs with H110, MP 300, 11FS, CFE Black and Heavy Pistol.

I did the same for the same bullet in a solid.

Next bullet is a NOE 311-158 FN, here I did ladder loads, every .3 gr with Reloader 7, CFE Black, Accurate 1680, Socom, Blackout, IMR 4227, and Lil Gun.

Next bullet is a NOE 311-198 SP. Loads every .3 gr with IMR 4198, RL7, CFE Black, 1680, IMR 4227, Socom, and Blackout.

Next bullet is a MP 311-235 Loads every .3 gr with same powders as NOE 311-198.

Load data was taken from closest weight jacketed bullet I could find. I started .3 gr under jacketed starting load and went to the closest load to max, but no over max.

Alloy used was half lino half pure. All bullets were plain base, all were either powder coated or Hi-Tek. Bullets were sized to .310.

In the past two months I've tested close to 200 different loads.

None of them will group. Not a single one. I'm lucky if I can keep five rounds on a 12" target at 25 yards.

Speer 125 TNT and Hornady 147 FMJ both shoot quite well.

I'm not getting any leading in the barrel but the muzzle device shows lead deposits as does the tail of the bolt. The gas rings were welded closed with lead.

I know that the 300 Blackout isn't the most accurate cartridge, nor is a 7.5" barrel the most accurate. But when jacketed bullets are shooting into one ragged hole and cast are in a wide pattern there's something wrong.

20X11
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Re: Well crap....

Post by 20X11 » Mon Jun 01, 2020 7:27 pm

Take the muzzle device off and see if the groups improve.

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dellet
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Re: Well crap....

Post by dellet » Mon Jun 01, 2020 7:50 pm

MeGrunt wrote:
Mon Jun 01, 2020 6:47 pm
I'm not rich. I didn't know it was a prerequisite to being on this forum.

I'm a 100% P&T Veteran. I live on a fixed income. I have a certain amount of "play" money I can spend every month.

I'm sure there are people here that have spent more on a BCG than I have in my build.

It's an Anderson lower, with a Anderson LPK. The upper is a 7.5" BCA with a 1/8" twist.

The first cast bullet I've tried is the MP 311410 hollow point. I did ladder loads, every .3 grs with H110, MP 300, 11FS, CFE Black and Heavy Pistol.

I did the same for the same bullet in a solid.

Next bullet is a NOE 311-158 FN, here I did ladder loads, every .3 gr with Reloader 7, CFE Black, Accurate 1680, Socom, Blackout, IMR 4227, and Lil Gun.

Next bullet is a NOE 311-198 SP. Loads every .3 gr with IMR 4198, RL7, CFE Black, 1680, IMR 4227, Socom, and Blackout.

Next bullet is a MP 311-235 Loads every .3 gr with same powders as NOE 311-198.

Load data was taken from closest weight jacketed bullet I could find. I started .3 gr under jacketed starting load and went to the closest load to max, but no over max.

Alloy used was half lino half pure. All bullets were plain base, all were either powder coated or Hi-Tek. Bullets were sized to .310.

In the past two months I've tested close to 200 different loads.

None of them will group. Not a single one. I'm lucky if I can keep five rounds on a 12" target at 25 yards.

Speer 125 TNT and Hornady 147 FMJ both shoot quite well.

I'm not getting any leading in the barrel but the muzzle device shows lead deposits as does the tail of the bolt. The gas rings were welded closed with lead.

I know that the 300 Blackout isn't the most accurate cartridge, nor is a 7.5" barrel the most accurate. But when jacketed bullets are shooting into one ragged hole and cast are in a wide pattern there's something wrong.
The bullets are too soft or not properly sized for the bore.

The lead on the muzzle device is a clue, the lead welded gas rings are a no brainer. you are vaporizing lead in the barrel.

There is an outside chance that it is just the bore or gas port is so rough cut that it is shaving lead.

But a properly sized cast bullet, matched even reasonably close hardness to pressure, properly coated should leave no lead behind.
300 Blackout, not just for sub-sonics.

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Re: Well crap....

Post by Hogbuster » Mon Jun 01, 2020 11:10 pm

Try a bullet that uses gas checks as the powder is vaporizing the base of your bullets.
Most semi auto weapons do not like lead bullets. They are not designed to shoot lead bullets especially soft lead bullets.

excess650
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Re: Well crap....

Post by excess650 » Tue Jun 02, 2020 9:15 am

I would suggest trying cast bullets as large in diameter as will chamber. My one and only try with plainbase bullets was with a GC design, powder coated, but no gas check grouped about 2" at 50 yards. The same bullet with GC will print most holes touching, so I use GCs.

IMR 4227 is a very flexible powder and should work with every bullet weight you mentioned.
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MeGrunt
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Re: Well crap....

Post by MeGrunt » Tue Jun 02, 2020 9:22 am

Half lino half pure isn't soft.

My HK 91 eats the same bullets all day long.

Powder can't vaporize the base of the bullet. That's simple physics.

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dellet
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Re: Well crap....

Post by dellet » Tue Jun 02, 2020 9:53 am

50/50 lead Linotype isn’t exactly hard either. Somewhere between wheel weights and #2. Some of the loads you were shooting were in excess of 30,000 psi, some probably approaching 40,000 with the heavy pistol. And yes, gas cutting will essentially blow lead into small enough chunks that I would consider it vaporizing. Call it what you want.

Bottom line, either bullet size and hardness does not match the pressure and bore size for the load, or your barrel is crap and shredding the bullets. Also don’t rule out poor bullet coating.

Since you stated that there is no leading in the barrel, what is showing up on the bolt rings is airborne. One more reason to consider gas cutting.
300 Blackout, not just for sub-sonics.

MeGrunt
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Re: Well crap....

Post by MeGrunt » Tue Jun 02, 2020 2:48 pm

Let's put it this way.

Has anyone successfully used cast bullets in the 125 gr to 150 gr range in an AR with a 1/8" twist.

If so how.

Cast bullet RPM is limited to around 140,000 rpm. Above that you start to have problems.

With a 1/8" twist that would limit you to a velocity of around 1550 fps.

At this point if I want to use these lighter bullets I think my only option is a custom barrel with a 1/12" twist.

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