Cast Bullets in AR Grendel

[Mad Charlie]

Jeepster:
Did you mean to say vaporized lead from getting into the gas system?
Some of the folks doing PC cast use gas checks so they don't get an uneven buildup of PC on the base.
Size and alloy are very important with cast, whether PC or GG. I don't use PC, but I think that if I was going to run cast in my gas guns I would go with a PC/GC. Most likely won't though. I do run cast in all of my pistols and lever guns. I have found that running a cast bullet that is designed for a gas check without one has been very inaccurate in my firearms.

[Gusmeister]

Sorry if this is slightly off topic but...

If hard cast lead bullets are shot out of an AR, is there a chance the lead will eventually clog or restrict the gas system?

[LR1955]

Sorry if this is slightly off topic but...

If hard cast lead bullets are shot out of an AR, is there a chance the lead will eventually clog or restrict the gas system?

GM:

A very high probability.

LR55

[Jeepster18_88]

Yes, that's what I was referring to. I have been working too many 16-20 hr days straight and my brain is mush at times. I think I typed that at a record long red light on the way to work. I haven't had an issue with uneven PC on the base since I bought a PC gun and place them nose down. It doesn't burn off and almost doesn't wear off after being fired into sand. I tried many different recommendations on lube in one particular gun and had leading in as little as 6 shots. Some worked better than others but PC corrected the issue so I started using it with all my cast loads.

[louielouie]

I've been having some luck with this mold and Accurate 2495 - the 25.7 gr load grouped about 1.5". These are powder-coated & gas-checked then weight-sorted about 126.3 +/- 0.3 gr:
126gr_Grendel.jpg
Gonna try the 25.8gr load next. This is with HDY brass and Winchester SRP

[louielouie]

While the next batch of test bullets were about 127.5 +/- .3 grains and still sized to .265, using 10-shot groups the 25.8 gr charge of A2495 was definitely tighter - not quite as tight as VonGruffs - but worth some quality trigger (mil-spec with some lighter springs) time.
Once again, the the action on my AR was exceptionally clean along with the barrel and nothing but powder residue anywhere on the patches - no red powder coat seen, the bore was nice n shiny before I started cleaning.
I may have mentioned elsewhere that I have an H3 buffer plus an AGB on an 18" BCA barrel and the brass consistently comes out about 4:30 with these cast loads. All velocity measurements were with a Magnetospeed.

[Jeepster18_88]

That's been my experience with powder coated bullets as well. One particular pistol is a lead magnet no matter what you use and will have some even with one shot. PC has completely stopped that and the last time out I fired off 50 rounds and only had a little powder residue. I don't think I'll be casting lead for my Grendel anytime soon but thanks for sharing your experiences with us. I love having options.

[papapaul]

I've been trying the 170 gr cast bullet from Lee via Mid South Shooters. I've been using Unique, down to 1.5 grs. In an AR15 with side charging handle. It is really hard to extract the low powered loads. The AR platform doesn't seem to have enough initial extraction using the side handle. Anybody got any ideas besides going to a bolt gun?

[Gusmeister]

I've been trying the 170 gr cast bullet from Lee via Mid South Shooters. I've been using Unique, down to 1.5 grs. In an AR15 with side charging handle. It is really hard to extract the low powered loads. The AR platform doesn't seem to have enough initial extraction using the side handle. Anybody got any ideas besides going to a bolt gun?

Any chance you have a lead buildup in the chamber?

[papapaul]

Maybe, but full loads extract and eject just fine.

[JSH]

Low power loads will cause a lot of rearward thrust. Maybe not a lot but more than normal. Low pressure does not let the brass do its job and grab the walls of the chamber.
Contrary to most thoughts, low pressure are not as safe as some would believe.
Jeff

[coachallen]

[LR1955]

I've been trying the 170 gr cast bullet from Lee via Mid South Shooters. I've been using Unique, down to 1.5 grs. In an AR15 with side charging handle. It is really hard to extract the low powered loads. The AR platform doesn't seem to have enough initial extraction using the side handle. Anybody got any ideas besides going to a bolt gun?

PPP:

You are using only 1 1/2 grains of powder? I would think a better charge would be around ten to fifteen grains of Unique with that cast bullet.

What are you looking for in terms of cast bullets out of your AR-15? Not exactly a efficient combination since you probably won't find a load that will function the rifle. Big risk of leading the barrel while trying to find that load.

LR55

[papapaul]

I found the problem. Bolt lugs were a little rough and headspace was a little tight. It started to act up all the time, it wouldn't easily open on unfired factory ammo. I took a light facing cut on the bolt lugs and polished them. It works ok now. If it starts doing it again that means a soft bolt maybe. This was a new build. I had a catastrophic failure with full loads first time out. Never happened in 50 years experience with ARs. Case head ruptured and blew the guts out of the magazine. I don't know why. Looked like excessive headspace and an unsupported case. Maybe Grendel I bolt with Grendel II barrel? Other way around? They were supposed to be both Grendel II from BCA. The barrel extension was ruined but the bolt looked ok so I replaced the barrel extension and set the headspace as tight as I could. I used a Swedish Mauser barrel to build my other Grendel and it shoots sweet. [/I]