AR-bolts: what's the good, bad and ugly on different makes?

Skans

Active member
Are there any genuine differences between all the AR bolts out there? Which ones are good; not good - what to look for in a used bolt?

(I'm not concerned with the Bolt Carrier, just the bolt.)
 

madcratebuilder

New member
The bolt should be made from C158 steel. Many shooter like to see MPI and HPT testing. I don't have problems with untested bolts as long as they are from a reputable supplier.
 

Technosavant

New member
Yeah, Carpenter 158 is the steel to look for. If possible, individual HPT and MPI (High Pressure Testing and Magnetic Particle Inspection) are also preferable.

As for a used bolt, I'd be extremely cautious and would prefer a new one.
 

Quentin2

New member
I also would be concerned about the bolt carrier (unless you already have good ones). There are at least four styles out there and the worst (for example, the Ruger SR-556 carrier) do not shroud the firing pin. Others use improper screws to secure the carrier key and/or don't have the carrier key staked properly.
 

Skans

Active member
I have a perfect condition, top quality chrome M16 Bolt Carrier that I bought about 16 years ago when I wanted to put an A2 upper on my Colt SP1 Carbine. The carrier key has been staked properly. Because I used the Colt Bolt, when I took the larger barrel and A2 upper off to return the SP1 Carbine to original, I no longer have a bolt to go with the bolt carrier.
 

cryogenic419

New member
I had always heard to not swap bolts around.

New bolt with new barrel is OK
New bolt with old barrel is OK
Old bolt with new barrel is bad
Old bolt with a different old barrel is bad

I am sure there are gauges you can check everything with but...if it were my gun and my safety on the line I'd go with new.
 

Gunnutfn49

New member
Im running three dsa bolt carriers that were new, and are running with three dsa complete uppers (16 inch and 20 inch) and have yet to run into any problems with them. (approximately 500 rounds per rifle).
 
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