6mm ARC bolt - are their stronger bolts available?

[Bruce K]

My Lone Star Armory AR15 Designated Marksman Light comes with a LSA TX15 Enhanced DLC-treated bolt carrier, with JP Enhanced 9310 Bolt, enhanced cam pin, and Sprinco extractor spring. In the event of a bolt failure I'd like to know if a new bolt can be fitted in the field, or should I keep a bolt and bolt carrier group together as a replacement?

I have not seen stronger ARC bolts advertised and don't know premium bolts are available or possibe.

Bruce

 

[TheOE800]

Bearing surface where the cam pin resides is smaller than JP, but the bolt lugs are significantly beefier though less chamfered: https://www.sixfiveoutfitters.com/product/ultrabolt-6-5-grendel-6mm-arc-ar15-type-2-bolt-mk136/

 

[TonyTheTiger]

There is almost no reason to carry a spare carrier. I've blown one up but the gun was not field fix-able and it needed way more than a BCG. Any in spec bolt should mate with any in spec carrier.

 

[Bruce K]

Bearing surface where the cam pin resides is smaller than JP, but the bolt lugs are significantly beefier though less chamfered: https://www.sixfiveoutfitters.com/product/ultrabolt-6-5-grendel-6mm-arc-ar15-type-2-bolt-mk136/

Have you used this bolt with success? What issues if any have you encountered if you have used it?

 

[Bruce K]

There is almost no reason to carry a spare carrier. I've blown one up but the gun was not field fix-able and it needed way more than a BCG. Any in spec bolt should mate with any in spec carrier.

Can you tell us the history and background of your ARC bolt failure and what damaged occured?

 

[TonyTheTiger]

Can you tell us the history and background of your ARC bolt failure and what damaged occured?

Not an ARC actually, a 5.56. But the near universal nature of the AR15 carrier applies regardless of caliber.
That particular failure wasn't the bolt, so the story isn't really pertinent to your question, I was just pointing out that a bolt can fail and be field swapped, if something spicy enough happens that your carrier fails you have bigger problems.
But since you asked, I was shooting off a tree, blowing bark and debri everywhere. Had a round not fully go into battery, pulled back on the CH enough to give it another go and it chambered. As I pulled the trigger the thought occurred to me that maybe it didn't go into battery for a reason. Next thing I know my ears are ringing, the remnants of the mag are on the ground and the bottom of the carrier was trying to escape through the magwell. Whatever debri caused the massive overpressure would not have been contained by any bolt no matter how premium.

I also had a 6mm Grendel (virtually identical to 6ARC) bolt fail in the typical way where the lug next to the extractor broke off. 60 seconds and a new bolt (not carrier) later I was back in action.

 

[Bruce K]

Not an ARC actually, a 5.56. But the near universal nature of the AR15 carrier applies regardless of caliber.
That particular failure wasn't the bolt, so the story isn't really pertinent to your question, I was just pointing out that a bolt can fail and be field swapped, if something spicy enough happens that your carrier fails you have bigger problems.
But since you asked, I was shooting off a tree, blowing bark and debri everywhere. Had a round not fully go into battery, pulled back on the CH enough to give it another go and it chambered. As I pulled the trigger the thought occurred to me that maybe it didn't go into battery for a reason. Next thing I know my ears are ringing, the remnants of the mag are on the ground and the bottom of the carrier was trying to escape through the magwell. Whatever debri caused the massive overpressure would not have been contained by any bolt no matter how premium.

I also had a 6mm Grendel (virtually identical to 6ARC) bolt fail in the typical way where the lug next to the extractor broke off. 60 seconds and a new bolt (not carrier) later I was back in action.

Scary. I was asking as the ARC bolt has much thinner walls than the 5.56 and when they fail, hopefully the damage can be resolved with a simple bolt replacement. Your Grendel experience suggests this is the case.

 

[TonyTheTiger]

Scary. I was asking as the ARC bolt has much thinner walls than the 5.56 and when they fail, hopefully the damage can be resolved with a simple bolt replacement. Your Grendel experience suggests this is the case.

Yup. I've seen a few of the 6.5/6mm/6ARC type bolts fail (again, in the normal way that they do, not the one in a million explosive way my 5.56 BCG did) and it's always the same and not dramatic at all.