300-221 / 300 BLK problem I'm having

[greywolf2112]

I have a 16" .300-221 that has never run right.

It is a 1:8 twist with gas block in the pistol position, and has a High, Low, and Off setting on the block. My 8" gun with the same thing and made by the same manufacturer runs perfect.

The 16" for the longest time would fire, but the cases wouldn't eject. They'd get stuck, bad, and the rim would get ripped off partially (about 20% where the extractor claw tried to pull it out of the chamber). I'd have to use a cleaning rod to tap it out. If I just tried to hand load/eject I'd end up having to really pound the hell out of it to get it out.

I triple-checked all my dimensions on my reloads, and I was still having issues so I sent it back to the maker. He reamed it out to .300 AAC BLK, saying that this should fix the problem.

Well, took it out to the range today to test it. Some strange things are happening.

Before I sent the barrel off, it never had a problem chambering or firing. The problem was occurring when it came to ejecting (either by hand before firing just to see if it would eject, and it wouldn't, since the chamber was too tight) or after firing the case would get stuck and the rim would get ripped off.

Well, when I got the barrel back and put it back together I was hand chambering the cases and they wouldn't eject due to the bolt/extractor apparently not gripping it, but I thought that the gases and recoil would help this. The cases weren't getting stuck at all (they wold fall right out when I tilted the rifle back), and things seemed pretty slick there.

At the range I chambered a round and pulled the trigger - nothing happened. I ejected the round and saw not even a slight dimple in the primer. This is the same bolt/upper I used before that never had a problem getting a round to fire. I then swapped lowers (different triggers in each) - no dice. I then swapped bolts - again hardly a mark on the primer.

Is it possible that somehow now the chamber is too long and the bolt isn't engaging the back of the shell enough to allow not only extraction by hand (as previously written about) and also the firing pin even when fully extended isn't reaching the primer due to a chamber/size problem?


Here are my loads and dimensions:

Load 1: Nosler 125 grn Ballistic Tip, 18.5 grn H110, OAL 2.046", Case Length 1.360" - 1.363"

Load 2: 115 grn. FMJ, 16.5 grn H110, OAL 2.041", Case Length 1.360-1.363"

Is it possible that I cannot use this .300-221 ammo in my newly chambered .300 BLK, but that if I get BLK dies and load those up per spec I can then use the new ammo (as well as factory ammo) in the 16" upper? Would I be able to use my current .300-221 brass and just resize in the new dies?

[Todd.K]

It's not the ammo being 300-221 unless there is something wrong with your dies. Headspace is the same as 300 BLK.

If the extractor is not going over the rim it could be excess headspace. Can you use the BCG in another upper to check for problems?

[greywolf2112]

Originally Posted by Todd.K

It's not the ammo being 300-221 unless there is something wrong with your dies. Headspace is the same as 300 BLK.

If the extractor is not going over the rim it could be excess headspace. Can you use the BCG in another upper to check for problems?

Did that - took my bolt from my 5.56 and same issue.

Could it be that I didn't torque down the barrel nut enough? I swear I had it quite tight.

The maker is pretty well known on the 300 Whisper boards and no one else ever complains about his work, but I've had lots of problems with the 16" - but no issues at all with the 8" he made for me.

[hozer]

If you are tearing up/off rims it is because you are getting too much gas.

Try a heavier buffer.

Be sure you are completely full length resizing. Take a sized case and see if it will chamber.

[greywolf2112]

Well, color me embarassed. I think I figured it out and I feel like an idiot. It seems that my shoulder is set a little too far back. For some reason when I reloaded these rounds the dies (must have been the way I set them up) pushed the shoulder back too much.

So, a question - should I get a .300 AAC go and no-go gauge and perhaps also send my 8" barrel in for rechambering, so that way I'll be up to spec on both barrels? It is working fine, but I wonder if perhaps since all of the new factory ammo is going to be for the .300 AAC perhaps I should go that route with a rechamber on the 8". I assume I'll still be able to use my current ammo that is working fine in the 8" even after the rechamber, correct?

Also wondering if I should get the new .300 BLK dies, or if I can continue to use my current .300-221 Forster dies.

One final question - can I salvage my current loaded ammo? Since the shoulder is pushed back too far, after I pull the bullets can I somehow bring the shoulder forward? Or is that brass all pretty much unusable now?

[Clod Stomper]

I've had similar problems with a different cartridge. I believe that the first problem you were having (the cases getting stuck and the rim being torn off) was being caused by, as hozer said, excess gas pressure. More precisely, premature opening of the bolt caused by excess gas. A pistol length gas system on a 16" barrel leaves a lot of barrel in front of the gas port. So probably the bolt was trying to unlock before the bullet was out of the barrel and the pressure had dropped. Did you try firing it with the gas on "low" or "off".

Now it sounds like there is an excess headspace problem in the 16" barrel. But since your rounds fired fine in the 8" and the 16" before it was reamed, I suspect that the headspace problem may be with the barrel and not your handloads. I would definitely try a no-go gauge in the 16" barrel before I did anything to the 8" barrel. Especially since you haven't had any problems with it up to this point.

I just realized that this is my first post on this forum. Hello Everybody!

Will

[Stickman]

Welcome to the board.