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6mm ARC sticking in chamber

Judgeh

Private
Minuteman
Nov 19, 2023
6
0
Oklahoma
I have had this happen 2 consecutive nights now. I go late at night with my 6 arc and thermal to coyote hunt. Hunt goes well, and when I get home I will go to clear the chamber to put my gun away. My bolt gets stuck and I have to pull the charging handle with 2 hands. The live round in the chamber will separate the case and projectile leaving the projectile in the chamber. It comes out with some taps from a brass rod but still shouldn’t be happening right? I’m shooting a proof research 18 inch on an AR platform running a dead air nomad L with it as well as Hornady black BTHP 105 gr ammo. I have yet to extract the other projectile but will soon and show photos. It is worth noting the humidity has been very very high both nights and the temperature is about 48 degrees. No issues with shooting and accuracy. Does this sound like an ammo issue or a barrel issue?
 

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That’s always fun with the powder that goes all over the internals when that happens.

Take some better close up photos of around the circumference of the bullet. Also how many rounds on the barrel and what’s your cleaning like? It’s possible it has a short chamber and the bullets are jamming into the lands and getting stuck. It’s also possible that there’s a hell of a carbon ring due to lack of maintenance and the bullet it getting stuck on that but less likely.
 
I’d be looking at that barrel for sure having a shirt chamber and your loading the bullets far into the rifling.
 
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Some of the early batches of Black 105 BTHP were loaded long.

 
That’s always fun with the powder that goes all over the internals when that happens.

Take some better close up photos of around the circumference of the bullet. Also how many rounds on the barrel and what’s your cleaning like? It’s possible it has a short chamber and the bullets are jamming into the lands and getting stuck. It’s also possible that there’s a hell of a carbon ring due to lack of maintenance and the bullet it getting stuck on that but less likely

About 100 rounds on the barrel cleaning hasn’t been too thorough but all shots have been suppressed. Is there any type of solution to the short chamber. I’m pretty inexperienced in it
 

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Some of the early batches of Black 105 BTHP were loaded long.

These could well be older. I’ll check the lot number
 
About 100 rounds on the barrel cleaning hasn’t been too thorough but all shots have been suppressed. Is there any type of solution to the short chamber. I’m pretty inexperienced in it

Bullet on the right you can pretty clearly see two different rifling marks with the right spacing to be consistent with the 4 groove rifling of a Proof.

Given what was posted about the ammo I’d say there’s a lot better chance that it’s the bad lot of ammo than the chamber. I just wouldn’t think that they could possibly be loaded out that long and still fit in the mag but I’m far from a 6ARC expert.

Given those pictures and round count I think it’s safe to rule out carbon.

If you have a Hornady bullet comparator and a modified case it would be pretty easy to figure out if it’s the ammo or barrel.
 
I have 2 Proof 18" barreled AR barrels shooting hand loads with Hornady 108 ELDM, at COAL 2.288" with no problem.
I've never shot a factory load in either Proof barrel, and never shoot with a suppressor, so brass comes out much cleaner.
Clean the chamber at closer intervals, when shooting suppressed, may help.
Could just seat a few .010 deeper and shoot them, and the check remaining loaded cartridges for some variation in COAL. This has been well documented to be a problem with early lots of Hornady factory 6mm ARC ammo.
 
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Bullet on the right you can pretty clearly see two different rifling marks with the right spacing to be consistent with the 4 groove rifling of a Proof.

Given what was posted about the ammo I’d say there’s a lot better chance that it’s the bad lot of ammo than the chamber. I just wouldn’t think that they could possibly be loaded out that long and still fit in the mag but I’m far from a 6ARC expert.

Given those pictures and round count I think it’s safe to rule out carbon.

If you have a Hornady bullet comparator and a modified case it would be pretty easy to figure out if it’s the ammo or barrel.
I have some comparable rounds at home, I’ll check. I appreciate the input
 
I’d put money on it being a short throat and possibly ammo loaded long. I hand loaded some 87 grain VMAX for my Proof barrel, eye balled the OAL to fit in an ASC mag never thinking I’d be near the rifling. Turns out they were into the rifling and causing increased pressure. I had to mortar the rounds out and was getting another 100 fps. Oh and it thrashed my bolt lugs to the point of needing replaced.

Try seating one deeper and see what it does.
 
I’d put money on it being a short throat and possibly ammo loaded long. I hand loaded some 87 grain VMAX for my Proof barrel, eye balled the OAL to fit in an ASC mag never thinking I’d be near the rifling. Turns out they were into the rifling and causing increased pressure. I had to mortar the rounds out and was getting another 100 fps. Oh and it thrashed my bolt lugs to the point of needing replaced.

Try seating one deeper and see what it does.
I don’t have equipment for hand loading I only buy factory ammo. Is there a resolution to my barrel having a “short throat”. I’m relatively new to all of this
 
I don’t have equipment for hand loading I only buy factory ammo. Is there a resolution to my barrel having a “short throat”. I’m relatively new to all of this
EDIT: what I mean to say below is you need more information. There’s a number things you could try such as different factory loadings, measuring the OAL of one of the rounds your having issues with and comparing to Hornady’s load information or customer service, or what I described below.

A Hornady bullet comparator, modified case, a set of calipers, and Hornady 105 gr BTHP from a pulled round or new box of projectiles would allow you to measure your chamber in relation to that projectile ogive. Then you’d compare your measured “jam” base to ogive length to the factory ammo and see if it’s longer than your measurement. This or take it to someone who already has the tools to help you out.

For what it’s worth, a short throat isn’t necessarily a bad thing especially in an AR that’s normally limited in COAL by the magazine. I wouldn’t even say it’s an issue and was probably a deliberate design by Proof in their chambering and I assume other Proof barrels are similar in chamber dimension.

Get your measurements and go from there. If the ammo is part of an out of spec lot, Hornady will likely take care of it. I would inspect the back of your bolt lugs where they interface with the barrel extension though and look for deformation. If there is deformation, your bolt has probably increased the headspace to the point it’s out of spec and needs replaced.
 
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EDIT: what I mean to say below is you need more information. There’s a number things you could try such as different factory loadings, measuring the OAL of one of the rounds your having issues with and comparing to Hornady’s load information or customer service, or what I described below.

A Hornady bullet comparator, modified case, a set of calipers, and Hornady 105 gr BTHP from a pulled round or new box of projectiles would allow you to measure your chamber in relation to that projectile ogive. Then you’d compare your measured “jam” base to ogive length to the factory ammo and see if it’s longer than your measurement. This or take it to someone who already has the tools to help you out.

For what it’s worth, a short throat isn’t necessarily a bad thing especially in an AR that’s normally limited in COAL by the magazine. I wouldn’t even say it’s an issue and was probably a deliberate design by Proof in their chambering and I assume other Proof barrels are similar in chamber dimension.

Get your measurements and go from there. If the ammo is part of an out of spec lot, Hornady will likely take care of it. I would inspect the back of your bolt lugs where they interface with the barrel extension though and look for deformation. If there is deformation, your bolt has probably increased the headspace to the point it’s out of spec and needs replaced.
That makes much more sense. Thank you I’ll work my way through that list.
 
I have 2 Proof 18" barreled AR barrels shooting hand loads with Hornady 108 ELDM, at COAL 2.288" with no problem.
I've never shot a factory load in either Proof barrel, and never shoot with a suppressor, so brass comes out much cleaner.
Clean the chamber at closer intervals, when shooting suppressed, may help.
Could just seat a few .010 deeper and shoot them, and the check remaining loaded cartridges for some variation in COAL. This has been well documented to be a problem with early lots of Hornady factory 6mm ARC ammo.
If the bullet is sticking in the rifling enough to pull the bullet upon extraction, .010” may be enough to stop the bullet from pulling but it wouldn’t be nearly enough to get the bullet out of the lands. I suppose the bullet in the lands isn’t an issue in of itself, the sticking part is. Either way the man doesn’t have a press.
 
You can seat deeper with a vise, but not much as pressures rise quickly. Just square the heads with the vise jaw, make sure the bullet tip is not deformed badly...but I wouldn't do that. You can seat with a Wilson inline die too, smack with your hand or a plastic hammer, no press needed . I'd just buy a press and reloading dies ...Lee is so cheap and works its hardly worth discussing.
I have fired just one factory round in 50 yrs. Still have 19 in the box. No sympathy for those who spend a ton of money on factory ammo, and its non adjustable, uncontrolled variables, of general match, or general hunting ammo. I doubt if anyone ever set a benchrest record with factory ammo. If you shoot, learn to reload, cheaper, more accurate, and total adjustability, to fit your chamber, your rifle, your shooting endeavors. Nothing complicated, easily learned...just do it. It opens a whole new world of possibilities. Should have bought a reloading press before a suppressor, now ya know which is more important.
 
Hornady will replace the ammo if it is one of the early lots. The 105's should only measure 2.200 OAL
 
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