BCG Questions

[Cokeman]

I am in the process of building my first AR. I am looking at bolt carrier groups and am having a hard time picking one. I’m looking at Spike’s Tactical, BCM, Ballistic Advantage, Sionics, and a few others. Are any of these any better than the others? Would I notice a difference between them? Are there any that I am missing?

[elephantrider]

Are any of these any better than the others?

Y-E-S-!

Would I notice a difference between them?

Visually, no, not much difference, except the brand laser markings, or in the case of Sionics, IF you choose their NP3 coated BCG, which looks like NP3

Are there any that I am missing?

Yes. There are many quality BCGs on the market, and many more that are either suspect, or just dog poop, IMO. I think most on this forum would agree that you can't go wrong with BCM, Sionics (NP3 coated, or not), Colt, or Centurion Arms. I would ad that you could also look at ALG Defense, or Forward Controls Design (FCD). The specs might vary a little between some of them, or you might pay a little extra for a non "mil-spec" coating on a couple, but they should all be solid. If you want to take a little bit of a chance on a more affordable 'bargain' BCG, then maybe look at Toolcraft, Brownells "M16 BCG", or Stag Arms.

[officerX]

BCM is my go-to BCG.


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[MorphCross]

For a bare minimum bcg that will check every box look at Centurion Arms.

Sionics with their bare minimum basic bcg is another definite great option.

[ScottsBad]

I have quite a few BCGs. I have some that are not too good and quite a few that are very good Here is a list of the ones I like and use.

BCM My favorite BCGs
Daniel Defense Beautiful machining and works well
Colt Works great
LMT Enhanced Sweet BCG for some rifle configurations, more durable than some

[snackgunner]

Go with toolcraft for $70

[26 Inf]

You can spend as much money as you want buying a BCG. The mil-spec (which folks love around here until it suits them to deviate - as in carrier finishes) for the BCG is:

Bolt: made of Carpenter Technology No. 158 alloy (C-158); should be shot-peened (SP), high-pressure tested (HPT), and magnetic particle inspected (MPI) - if you want to really delve into it you can check to see if the parts are individually tested or batch tested.

Bolt Carrier: automatic carrier made of 8620 alloy; chrome-lined;

Carrier Key: made of 4130 alloy; grade 8 carrier key bolts; properly staked (mil-spec requires(d) perma-tex sealed to carrier - unknown how many do this)

These are the major check-off's that folks list. Most don't list extractor materials, etc. but there are specs for those parts.

Tool-Craft makes a perfectly acceptable product, make sure it is the C-158 bolt though, as they offer them with 9310.

BCM is a manufacturer that goes an extra step for QC: Prior to shipping, all BCM Bolt Carrier Groups are test fired for function. As such, the Bolt Carrier Group will show handling marks consistent with these quality control procedures and they are also a good choice.

Bottom line is, most folks couldn't tell one standard BCG from another if not for the logos.

[MistWolf]

Shot peening is much more important to bolt life than HPT. Without shot peening to stress relief the material, bolts crack more often.

The downside to HPT is that it reduces the number of over pressure events the bolt can handle before it fails by one.

[prepare]

The Toolcraft BCG are $100 cheaper than BCM's. They might be great but I wonder why they're only $70?

[officerX]

The Toolcraft BCG are $100 cheaper than BCM's. They might be great but I wonder why they're only $70?

You get what you pay for.


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