Question: was just told that I could not use a DPMS pattern 308 BCG in any DPMS 308 barrel

[Armordude]

OK

I was just told that I could not use just any BCG with just any barrel. He said the reciever # is engraved into the bolt to be sure you dont mix them up.

I was told this when I asked to have my just built DPMS 308 SASS chamber checked and head spaced(BCG bought here Nickel Boron BCG Bolt Carrier Group 308 DPMS AR10 : AR15 Parts at GunBroker.com )

Barrel is a DPMS 18 inch SASS barrel from Midway

The smith said it would not work unless they were matched at the factory and you could not mix and match.

In everything I have read NEVER has this been mentioned EVER.

Have I missed something or should I look for a new smith?

How say you?

 

[biner626]

I call BS! Find a new smith. He's giving you the... I don't want to eff with it answer.

 

[FMJBT]

Find a new smith. Anyone that ignorant should not be trusted to work on rifles.

 

[Regalkismet]

He is clueless.

 

[ORD]

+1 on clueless (or at least VERY poorly informed or suffering from a complete inability to communicate to his customers).

However...there is at least SOME truth to at least what I THINK HE MAY BE TRYING TO SAY (I'm REAAALLLY trying to read b/w the lines here, but I'd still find someone else).

The headspace on an AR type barrel can't really be adjusted to match just any bolt unless it is a short-chamber that can be opened/reamed some. If it is a FINISHED factory tube (like the DPMS LR-308 SASS you referenced), then you are more or less stuck with the barrel as it is...again with the exception of possibly being able to open it up somewhat if it is too short. Either your new NiB bolt will headspace within the acceptable range or it will not. This is one of the reasons that companies who sell barrels and bolts for various AR platforms offer to sell you a bolt at the time you buy a barrel. They don't do any "smithing" to make it fit...they just "plug & play" with bolts until they get one that headspaces properly. Just one of the reasons that if you are building an AR, regardless of make/model, that you provide your bolt to whomever is doing your barrel work BEFORE the barrel is finished. 99% of the time (or more), with AR-15s at least, you'll be fine running just about any mil-spec bolt with any barrel. With all the variations in the .308 AR market, even within a specific sub-division of the market like the LR-308 platform...you can get into trouble sometimes with getting any bolt, especially a NP3, NiB, Chromed, (generally coated) bolt to heaadspace properly depending on how tight the barrel was chambered to begin with as you get into tolerance-stacking issues.

In your case...while the smith can certain check to see if the bolt/barrel combo achieve a proper fit within the acceptable range for the cartridge (assuming its a 7.62 NATO/.308), but adjusting or "fitting" the bolt to your barrel...not so much.

Make sense?

As for someone who can check it out for you...if you are planning on owning/building/re-barreling any more .308 ARs down the road, spend the money on a set of gauges for the investment will pay off in fairly short order. I think I got my set from Brownells (long ago) which was a Clymer or Forster (can't recall off hand) set of go, no-go and field gauges for around $65-70. I know that I buddy of mine just got a set from Fulton when he ordered a barrel last month and they are nice for the money too...here's a link to those: Headspace Gauge Set, f/Chamber: Go, No Go & Field, .308, 3-piece

Good luck!

 

[biner626]

...if you are planning on owning/building/re-barreling any more .308 ARs down the road, spend the money on a set of gauges for the investment will pay off in fairly short order. I think I got my set from Brownells (long ago) which was a Clymer or Forster (can't recall off hand) set of go, no-go and field gauges for around $65-70. I know that I buddy of mine just got a set from Fulton when he ordered a barrel last month and they are nice for the money too...here's a link to those: Headspace Gauge Set, f/Chamber: Go, No Go & Field, .308, 3-piece

This is good advice!

 

[wagonpilot]

You can also rent headspace guages.. I rented the ones for my 6.5 creedmoor build from these guys, Elk Ridge Reamer Rentals (800) 996-0426 ... cheap, fast and easy to do.

 

[LRRPF52]

I have yet to see an AR barrel that is marked to match the receiver with a serial number or code. The smith is either not familiar with AR's, or is BS'ing you. I can't count how many barrels and uppers I have seen separated from different manufacturers, to include DPMS LR-308 and AP4 series.

With a self-loader, there are (-) tolerances on the bolt face depth, as well as the extension, with a margin of combined error for both. They run a little sloppy, not like a bench rest custom action. Within the first few rounds, the dimensions often settle-in due to the pressures. ORD's advice is unusually thorough in this regard.