300-221 problems with ejection

[grey2112]

300-221 problems with ejection

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Wondered if some of you might be able to help. I have a 16" .300-221 upper, pistol length gas tube, 3-way gas block (High, Low, and Off). My handload 125 grain supersonic ammo, which works fine in my 8" .300-221 (same specs other than barrel length) is doing the following:

1 - It loads fine into battery, and I can hand-clear it - so the chamber/barrel isn't too tight

2 - It fires just fine.

3 - 90% of the time, though, it will not eject the spent case. It is stuck and I have to tap it out with a rod. The rim is slightly mangled from where the extractor tried to grab it and obviously yanked off some brass when it wouldn't budge.

4 - It doesn't try to strip and load a new cartridge, though.


So, I assume this is a gas problem? Perhaps over-gassed - i.e. too much gas is getting into the system and before the bolt has a chance to work and pull out the spent case it causes the brass to expand and gets stuck in the chamber?

I've tried it with all three settings - the High setting (which slightly restricts gas) does what is described above, the Low setting (which opens it up totally) really tears off a bit of rim, and of course doesn't eject, and the Off setting doesn't work the bolt at all, doesn't hurt the brass, but is very tough to tap out the brass.

I'm thinking that maybe a JP adjustable (screw) gas block might do the trick since I can adjust it a lot more than the 3 settings I have right now. Could it be the pistol length gas tube is too short? Could it be gas block alignment, though that wouldn't make much sense if I'm overgassed.

Or could it be something else? Buffer, buffer spring, etc.?

[N310toN170]

Please post the load details that you're currently using.

[robrob]

It doesn't sound like a gas problem to me. The fact that when completely shut off you still have a tough time tapping out the spent shell means you probably have a brass/chamber size problem or you're pushing chamber pressure over the limit. Are there any other marks on the brass? Any primer flattening or other signs of overpressure?

[grey2112]

Originally Posted by N310toN170

Please post the load details that you're currently using.

125 gr Nosler Ballistic Tip

18.5 grains H110 powder

CCI primer

Brass is new/reformed bought from member here who advertises all the time for brass - made from .223, I believe.

2.04 OAL

.333 at neck

.360 at shoulder

.373 at end


The subsonics are the same except:

220 SMK BTHP

9.6 gr. H110

2.20 OAL

[grey2112]

No marks on the brass, but here's something new I just noticed.

I decided to try and dry chamber and eject both the subsonic and supersonic rounds in the 16".

While the chambered fine, they would NOT eject manually - I had to use a mallet on the charging handle to unstick the rounds from the chamber.

So, I gave the dimensions of the cartridges I've loaded. If those are not out of spec, it appears my chamber is not right in the 16".

What can be done about this? Any gunsmiths out there that can fix this problem?

[N310toN170]

Are you shooting the subs in newly loaded brass or were they shot first as supers?

I would recommend first fire forming by super then loading sub.

I also had a hard time with H110 and eventually moved to AA1680.

From your most recent post it's looking like an issue with thick necks.

[grey2112]

Originally Posted by N310toN170

Are you shooting the subs in newly loaded brass or were they shot first as supers?

I would recommend first fire forming by super then loading sub.

I also had a hard time with H110 and eventually moved to AA1680.

I'm using the newly loaded brass for both subs and supers.

I'm not having ANY problems with the subs in my 8". It is the supers I'm having problems with in my 16".

What I need to do is try supers in my 8" and subs in my 16"

But as noted above, tonight when I tried loading and ejecting by hand the subs and supers in the 16", I couldn't extract them and had to use a mallet to pop the charging handle back.

No such problems on my 8".

[N310toN170]

Looks like the chamber specs on the 16" are a bit snug.

You can either get someone to touch them up with a reamer, or get a neck trimmer and work them down a few .001's at a time until the issue is resolved.

[grey2112]

BTW - I just looked at the spent cases - the primers are very flattened. What does this mean?

[N310toN170]

It would lead me to believe that your loads are running at higher than recommended pressures. However, after you having tested a loaded round and without firing it having problems extracting it... leads me to believe that the neck tension may be causing the excessive pressure.

I would consider getting something like:

http://www.midwayusa.com/viewproduct...tnumber=462291