Stuck Cartridge - Suggestions?

[Pr589]

So hoping for some thoughts from you folks.

I am reloading for a new 223 Wylde chambered AR and have experienced 2 incidents of unfired rounds being stuck in the chamber. This occurs on feeding where the bolt isn't closed and the charging handle can't extract the round.

I won't go into the PITA my gunsmith went through to extract the rounds but the real question is why is this happening?

The rounds are full sized and trimmed and have been loaded with no crimp. I've loaded thousands of 223 for other rifles and haven't had any issues like this. On measuring the case diameter of the sized brass, just below the shoulder, several of the cases were over 4 thousandths larger than SAAMI spec.

My only thought is that this older brass has work hardened sufficiently that it is springing back after sizing and in the tight chamber of the AR, it is getting stuck. Any other ideas for me?

 

[Spawn-Inc]

Were the 2 rounds that got stuck then removed damaged badly from the removal?

I don't think a bullet seated to long would cause it to jam that badly, but that's a possible cause. Do your other rounds freely drop in and out of the chamber?

 

[jethunter]

Does it happen with different kinds of brass or just one? You need to determine if it is the cartridge or the rifle chamber that's creating the problem. Are your bullets seated a bit too far out for this chamber? Check that first. If it's just oversize brass then that's easy to fix - get new brass. If it's the rifle then you need to determine if the chamber is dirty/sticky, or if the chamber needs polishing, or if the chamber is undersize and needs to be re-cut. If you're lucky it's just the brass or bullet seating issue.

 

[Pr589]

Thanks for the input guys. The rounds are loaded for mag length so seating depth should not be an issue. The rounds that I have tried drop in freely and the ones that don't fit with a light press, then all fall out with a bump to the back of the upper. None of the brass show stretch marks or have loose primer pockets. I'm just stumped as to why full-length resizing would result in some cases being out-of-spec. I'd hate to have to mike each sized case to ensure that they are in spec.

This barrel has a few hundred rounds through it at this point...80 rounds to the first jam and about 120-ish to this jam. When it is working, it does so flawlessly. My smith has taken a close look at the barrel and chamber and he says other than a rough chamber cut (Rainier Arms Ultra Match barrel) it looks fine. He polished the chamber a bit after he removed the last jam, and we test fired some factory ammo.

 

[herpinator45]

Try case gauging your ammo, see how it comes up. When I was learning to reload I didn't set up my dies with a case gauge and had a couple of rounds lock up the gun because they would chamber just barely, but then if I wanted to extract a live round from chamber I had to mortar the rifle. As just above the rim was not fully resized.

 

[Pr589]

Try case gauging your ammo, see how it comes up. When I was learning to reload I didn't set up my dies with a case gauge and had a couple of rounds lock up the gun because they would chamber just barely, but then if I wanted to extract a live round from chamber I had to mortar the rifle. As just above the rim was not fully resized.

Every round gets case gauged, if for no other reason just to check for neck length in case it needs trimming. In my case, the bolt is very open - probably 5 mm from being closed. Good thought though.

 

[TedNugent]

Every round gets case gauged, if for no other reason just to check for neck length in case it needs trimming. In my case, the bolt is very open - probably 5 mm from being closed. Good thought though.

Hmm that's pretty strange. I would have expected any variation in neck size/dimension to show up in a case gauge.

 

[Spawn-Inc]

Is it the same brand of brass getting stuck? I wonder if your chamber is tighter then the case guage .

 

[Pr589]

I'm using a Wilson case gauge. These are good for case and neck length but they do not gauge case diameter or profile. So even if the cases fit into the gauge, they may be too large for the chamber.

It is going to be a pain miking my brass as part of the normal processing.

 

[636andy636]

Have you tried using a small base die? I had some 308 that would not chamber unless it was sized with a small base die

 

[Pr589]

Have you tried using a small base die? I had some 308 that would not chamber unless it was sized with a small base die

I have thought of these but kinda hate the thought of having 2 dies sets for the same caliber. This may be in my future though. I suspect that the tight Wylde chamber of the barrel is causing the AR to be picky.

One thing I still don't understand is why some cases are up to 4 thou. larger in diameter just under the shoulder than the majority of the full sized cases. One thought is that these might have have had inadequate neck lube, and the expander ball pushes the shoulder and the case wall outward. This might be possible since 223 is a tapered case, so as the case is lowered through the die the die walls are wider lower in the die than the SAAMI spec near the shoulder. If this is the problem, then I just need to be more careful lubing my case necks.

 

[bigedp51]

Question, were these cases causing the problem fired before in a 5.56 chamber?

A case when fired tries to spring back to its original shape and becomes smaller than the chamber. This same spring back action applies to a resized case and after full length resizing the brass can become larger after sizing.

There are two things you can do to reduce the brass spring back when sizing.

1. If your using a standard full length die then pause at the top of the ram stroke four or five seconds. This lets the brass know who is the boss and spring back is greatly reduced.
2. Use a small base die, and remember all a small base die does is return the brass to factory dimensions. My small base .223/5.56 die only makes the case .0005 smaller in diameter "BUT" it sizes further down the case.
Other fixes
3. Use new brass only fired in your Wylde chamber.
4. The Wylde chamber has a modified throat diameter, angle and length and your bullets "may" be jamming into the throat.
5. My primary guess is brass springback caused by the cases being fired in a larger military 5.56 chamber.

I have two AR15 rifles and a .223 bolt action rifle and I also load for my sons AR15 rifles and the only way to insure reliable chambering in all four AR15 rifles is to use a small base die.

And you can never have too many dies when you reload for different rifles of the same caliber.

Bottom line, get a small base die and a Hornady cartridge case headspace gauge. I'm reloading four different AR15 rifles and the cases have to be sized to fit the smallest chamber.

 

[Pr589]

Bigedp51 - Thanks for the detailed post. I'm not sure what the brass was previously fired in. It could have been a 5.56 chamber.

Its interesting seeing the range of variation in the reamer dimensions. Have not seen this before. Well small base die it is....sigh.