Toughest BCG's in your opinion? 5.56/308

[Creedmoor]

Well, it DOES depend on the type of chrome, but right now, I would say:

1. NASA's research (well, LRC in Cleveland for NASA).
2. My brother, the Man of Steel, who runs a steel plant for AIT in PA.
3. Eugene Stoner.

But, if your objection is based on "distinction without difference" especially for Title I guns, then it is likely valid.

I mean the greatest AR makers in the world at Colt don't use chrome, so . . . why should any of us?

Ok, I was always of the understanding that military firarms were parkerized or coated in a material that held/absorbed lubrication to keep lubrication where its needed.
I'm not sure chrome and some of the other modern finishes do that as reliable as what Colt and FN use.

 

[Kirk Freeman]

Ok, I was always of the understanding that military firarms were parkerized or coated in a material that held/absorbed lubrication to keep lubrication where its needed.
I'm not sure chrome and some of the other modern finishes do that as reliable as what Colt and FN use.

Early AR-10s/AR-15s (heck, I think a couple of the AR-16 prototypes had chrome bolts) had chrome bolts up to mid-production M-16A1s.

The chrome tech then was less than optimal so switched to parkerized.

 

[Refrigerator27]

We used to hear a lot of trash talk about Palmetto BCG's. Not so much anymore?

Where did you buy your o-rings? Are there are other BCG parts we should keep on hand for in case?


.

Hopefully I didn't come off as trashing it however, I think their rifles/parts are very good, there's just better options for the same price now. They still have some QC issues apparently which was seen with their AK variants they were putting out. The good thing is they are willing to learn from their mistakes and fix them, and most importantly listen to the consumer base. That's a sign of a good company.

I got them from a local FFL, don't remember the brand but any website has them (primary arms, midway, brownells). I personally keep an extra set gas rings as its designed to be the first thing to fail. Nothing else aside from that. I've seen people keep an extra bolt and extra extractor springs and what not.

 

[Creedmoor]

Early AR-10s/AR-15s (heck, I think a couple of the AR-16 prototypes had chrome bolts) had chrome bolts up to mid-production M-16A1s.

The chrome tech then was less than optimal so switched to parkerized.

I'll read up on the topic, now i'm curious because I was issued a few A1's in the 70's and 80's and I dont recall any of them having chrome bolts. But I am old.
Thanks

 

[Fordtough25]

We used to hear a lot of trash talk about Palmetto BCG's. Not so much anymore?

Where did you buy your o-rings? Are there are other BCG parts we should keep on hand for in case?


.

I've had good luck with PSA BCG's, they look to be toolcraft made. As long as the staking is done well.

 

[JEBland]

I thought he liked Monty's? That's why I bought all them.

His personal Centurion AR has a factory chromed BCG:


I think that BCG options are so varied and so consistently good (in the sense that if it has a good reputation, it's probably pretty good), that like triggers it's hard to go horribly wrong. As a non-expert, I think It's a good time to be a consumer for BCGs.



For those less in-tune with SmallArmsSolutions and wanting some history, discussion of pros/cons, and just some good ol' BCG discussion, SAS has a series on it (Part 2 is on AR10s and excluded here):

 

[Kirk Freeman]

His personal Centurion AR has a factory chromed BCG:

Kirk learning new things:

 

[Airtevron1]

Summary of Final Rule 2021R-05F | Bureau of Alcohol, Tobacco, Firearms and Explosives

Definition of “Frame or Receiver” and Identification of Firearms On April 11, 2022, the Attorney General signed ATF final rule, Definition of “Frame or Receiver” and Identification of Firearms, amending ATF’s regulations by removing and replacing the regulatory definitions of “firearm frame or...

www.atf.gov

I dont see this as wide sweeping , mostly about the 80% stuff

 

[DDadams]

I dont see this as wide sweeping , mostly about the 80% stuff

Did you not read the second part below the 80% first section??

"

Proposed New Definition of Firearm “Frame or Receiver”​

Under the proposed rule, a “frame or receiver” is any externally visible housing or holding structure for one or more fire control components. A “fire control component” is one necessary for the firearm to initiate, complete, or continue the firing sequence, including, but not limited to, any of the following: hammer, bolt, bolt carrier, breechblock, cylinder, trigger mechanism, firing pin, striker, or slide rails.

Any firearm part falling within the new definition that is identified with a serial number must be presumed, absent an official determination by ATF or other reliable evidence to the contrary, to be a frame or receiver."

 

[Airtevron1]

This will now require a sn.

0% Billet AR-15 Lower Receiver

Our 0% billet AR-15 lower receivers are essentially solid aluminum bricks ready to be forged! Buy this 6061-T6 aluminum slab online from 80 Percent Arms.

www.80percentarms.com

 

[indysims]

Where did you buy your o-rings? Are there are other BCG parts we should keep on hand for in case?

I think it's smart to carry a bolt repair kit (gas rings, extractor, extractor spring/o ring, cam pin, extractor pin).

I also keep a complete spare bolt, firing pin, and firing pin retaining pin, because it's easier to just swap out a complete bolt then try and rebuild one while at a class or event.

All parts of a milspec (non enhanced) BCG should be interchangeable.

Micro Best makes BCM's BCG you can get them from PK Firearms for about $40 less than BCM, but they are not in stock currently.

 

[bwframe]

I think it's smart to carry a bolt repair kit (gas rings, extractor, extractor spring/o ring, cam pin, extractor pin).

I also keep a complete spare bolt, firing pin, and firing pin retaining pin, because it's easier to just swap out a complete bolt then try and rebuild one while at a class or event...

What kind of bolt repair kits do we like? A good online source?

I have always liked the idea of having a spare BCG on hand for classes and such. That said, my SHTF bag needs lighter field repair stuff.


.

 

[MindfulMan]

What kind of bolt repair kits do we like? A good online source?

I have always liked the idea of having a spare BCG on hand for classes and such. That said, my SHTF bag needs lighter field repair stuff.


.

Here's a kit on Midway.

CMMG Bolt Rehab Kit AR-15

These are the exact same parts used by CMMG for all of their rifles and kits. All CMMG products meet or exceed Mil-Spec standards. Kit Includes:...

www.midwayusa.com

 

[Megasaki]

Makers- Colt, FN , or Diemaco.

Finish- Chrome

I think only Colt made a bolt and Carrier in Chrome finish.

 

[DadSmith]

Best AR15 BCG Finishes - Pros Cons and Recommendations

AR15 bolt carrier groups are available in a variety of finishes including Phosphate, Black Nitride, & Nickel Boron. Find out which is right for your upgrade!

www.spicetac.com

I thought this was an interesting read.
The DLC treated I may well be using in new builds, and old builds when in need of replacement.

 

[hANNAbONE]

SHARP's DLC coated...

even ON SALE NOW.!! save $20.00 and free ship

Xtreme Performance Bolt (XPB) Carrier Group in DLC

The Sharps Xtreme Performance Bolt (XPB) Carrier Group Complete is comprised of our patented Relia-Bolt™ and our Balanced Bolt Carrier. Both are machined out of S7 tool steel. The XPB undergoes a 24-hour thermal cycle proprietary heat treatment and is finished with DLC (Diamond-Like Carbon) coating.

www.srcarms.com

 

[natdscott]

My 1,000 yard upper holds a Rainier Match, with a hand-selected bolt.

ETA: I think it's just phosphate, since I wanted the bolt to wear in, which it has done (but I can't find the receipt). DLC and some of the other coatings interfere with the lug bedding process, and some very well-known individuals in the industry would support me when I say that many spicy coatings on AR BCG are like fishing lures: more about being sparkly to fishermen than they are about catching fish. With a good web developer, it works like a charm.

For sheer strength (pun intended), there's nothing harder on an AR bolt than shooting long range with it except long strings of automatic fire (enough to overheat the bolt and carrier).

I DO think that there's some sound reasons for some of the geometrically-improved bolts though.

 

[DadSmith]

SHARP's DLC coated...

even ON SALE NOW.!! save $20.00 and free ship

Xtreme Performance Bolt (XPB) Carrier Group in DLC

The Sharps Xtreme Performance Bolt (XPB) Carrier Group Complete is comprised of our patented Relia-Bolt™ and our Balanced Bolt Carrier. Both are machined out of S7 tool steel. The XPB undergoes a 24-hour thermal cycle proprietary heat treatment and is finished with DLC (Diamond-Like Carbon) coating.

www.srcarms.com

That DLC has me interested also. Is it a new treatment in the last few years or has it been out a long time and I'm just now learning about it?

 

[Tombs]

Has anyone ever worn out a bolt carrier? Really?

Carrier keys, sure, bolts, sure... But the carrier!?

That said, I prefer chrome lined internally and phosphate. DLC coating on the bolt would be great, as would chrome.
The carrier rides in aluminium, it is far harder than the aluminium is. I don't really see any advantage to putting a ridiculously hard finish on the outside of the carrier. I'd rather have a porous finish that absorbs a lot of oil to preserve the upper from wear.

 

[natdscott]

Has anyone ever worn out a bolt carrier? Really?

Carrier keys, sure, bolts, sure... But the carrier!?

That said, I prefer chrome lined internally and phosphate. DLC coating on the bolt would be great, as would chrome.
The carrier rides in aluminium, it is far harder than the aluminium is. I don't really see any advantage to putting a ridiculously hard finish on the outside of the carrier. I'd rather have a porous finish that absorbs a lot of oil to preserve the upper from wear.

Incorrect. The carrier rides in what is typically Type III anodizing. That's a helluva lot harder than the underlying aluminum: north of 60 R(c), and up to 70.

Even hard chrome is just right at those figures.

I have personally "worn in" bolt carriers, for sure.

Worn out, well no, I haven't seen that. The cam slot could though.