Unable to retract bolt with round in chamber.

[andy52]

I've had that happen a few times and some of my friends have also. Ammo is the first culprit the second is a relatively new AR. Sometimes with a new AR there are small burs on the bolt lugs and or chamber lugs. These can cause a slight lock up until the rifle is fired enough times to wear them off. I wouldn't do this on the range but you can generally dislodge the cartridge with the "Mortar Maneuver"

[ame]https://www.youtube.com/watch?v=APD5pP2DpUY[/ame]

 

[WR Moore]

The gent in the above post forgot to mention the need to collapse the stock before performing this maneuver. Otherwise you run the risk of shearing the stock pin.

About needing to trim once fired brass, that depends upon the specs of the chamber the rounds were fired in. I used to get brass from my employers range. I learned real quick the brass fired in (our) Colts required quite a bit of effort to resize and definitely needed trimmed after first firing. The length of the brass used in the ammo can also makes a difference, as can how malleable the brass is. If the brass was fired in am M249 SAW, you'll also note extra effort needed to resize and a need to trim.

A "generous" chamber is seen as a good thing in a full auto military firearm. It helps ensure reliable operation even at elevated temperatures.

 

[Moe Mentum]

Use a case gauge, and inspect the round after it is resized. I have had many LC cases that failed the case gauge test after resizing... They would have certainly have gotten stuck in the chamber...

 

[Steve912]

I note you mention it happens with factory ammo, I'd suggest calling S&W about a return for inspection.

Probably had chamber dimensioned right before tooling was due for replacement.

 

[Rastoff]

I suspect it's not the ammo.

 

[ChattanoogaPhil]

Since you've determined it not a cleaning issue... and if it's occurring with standard factory 55/62 Federal ammo then I'd suggest getting a return label to send your rifle back to S&W.

Your reloads may be a problem but that would be a separate issue since factory ammo is also getting stuck, right?

 

[cyphertext]

Since you've determined it not a cleaning issue... and if it's occurring with standard factory 55/62 Federal ammo then I'd suggest getting a return label to send your rifle back to S&W.

Your reloads may be a problem but that would be a separate issue since factory ammo is also getting stuck, right?

Agree... get it working with factory ammo as a baseline.

 

[Okie21]

I bought my 15 Sport 2 almost a month ago and just fired it today for the 1st time. I had 2 rounds that were extremely difficult to eject. They were Aguila 55gr .223. I fired Federal 55gr with no problems.


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[otisrush]

I bought my 15 Sport 2 almost a month ago and just fired it today for the 1st time. I had 2 rounds that were extremely difficult to eject. They were Aguila 55gr .223. I fired Federal 55gr with no problems.

[Thread drift risk......]

Can you explain more precisely what you mean? Were they extremely hard to eject when they were fired? (Meaning you fired them...but then had to work like the dickens to get them to eject?). Or did you do as the original post did: You chambered a round and then, for whatever reason, you tried to pull back the charging handle and the unfired round was essentially stuck in the chamber?

If it's the latter.....this seems to be heading into "Ruh Roh!" territory for S&W.

Thx.

 

[Okie21]

Yes, it was the same as OP said, I was clearing the weapon. It did not happen while firing.

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[WR Moore]

With the billions of rounds produced by each of various factories, not every round comes out of the factory in pristine condition. Dies wear, adjustments slip and stuff happens.

I've seen factory ammo from major manufacturers with bullets backward or seated over length, primers backwards or sideways or missing, powder missing and in a couple of events, flash holes missing from the cases. Also seen bullets jammed into the cases during the feed cycle.

Unless the ammo has been gauged acceptable before loading, and has no visible flaws caused by the feed cycle upon ejection, don't assume the firearm is at fault. It may be, it may not be.

 

[WR Moore]

I may have inadvertently stumbled over a possible cause of the OPs problem. I grabbed several rounds of my own reloads and after not finding any suicidal Bambis pulled the mag and went to eject the chambered round. I'd ridden the bolt when closing and used the forward assist to finish the chambering without the "CLANG" letting the bolt run would cause.

I had some minor difficulty extracting the chambered round. When I checked my records, I discovered this ammo had been run through a small base body die because of a chambering issue in a tight chamber/minimum headspace in the rifle it was intended for. The important part here is when this didn't completely solve the problem, I discovered that the sizing die had become slightly out of adjustment and the case shoulder was a couple of thousandths too far forward. Note: ball duplication ammo loaded with the same dies worked like a charm in the AR. Yes, readjustment of the sizing die solved the problem. No, I don't want to sell the body die.

This suggests the issue with the OPs rifle (assuming the factory ammo gauges acceptable) MAY be headspace less than minimum. There might be an other issue, but this seems logical. Those who believe that barrels & bolts are completely interchangeable, no need for gauges , please take note. FWIW, the AR in question has ~1K+ rounds through it and still won't accept a NO-GO guage. Does pass a GO gauge.

 

[MichiganScott]

I may have inadvertently stumbled over a possible cause of the OPs problem. I grabbed several rounds of my own reloads and after not finding any suicidal Bambis pulled the mag and went to eject the chambered round. I'd ridden the bolt when closing and used the forward assist to finish the chambering without the "CLANG" letting the bolt run would cause.

I had some minor difficulty extracting the chambered round. When I checked my records, I discovered this ammo had been run through a small base body die because of a chambering issue in a tight chamber/minimum headspace in the rifle it was intended for. The important part here is when this didn't completely solve the problem, I discovered that the sizing die had become slightly out of adjustment and the case shoulder was a couple of thousandths too far forward. Note: ball duplication ammo loaded with the same dies worked like a charm in the AR. Yes, readjustment of the sizing die solved the problem. No, I don't want to sell the body die.

This suggests the issue with the OPs rifle (assuming the factory ammo gauges acceptable) MAY be headspace less than minimum. There might be an other issue, but this seems logical. Those who believe that barrels & bolts are completely interchangeable, no need for gauges , please take note. FWIW, the AR in question has ~1K+ rounds through it and still won't accept a NO-GO guage. Does pass a GO gauge.

I suggested the shoulder may need to be set back more in post #14.

 

[WR Moore]

Yeah, but he has the issue with factory ammo also. Without a gauge, we can't tell if the ammo is within spec, but it's a pretty decent bet. This suggests it may be an issue with the rifle itself.