Bushmaster Bolt carrier

[Sky]

Was able to trade my Glock for a Bushmaster XM-15 E2S.

We had problems with the Extractor spring being broken either with the first round shot or was broken when the rifle was received. I have a different bolt in the receiver until a new spring is received hopefully in the next few days.

Looking at the Bushmaster bolt carrier it is swedged? In other words you can see approx 1/2 inch of the firing pin when the bolt and firing pin is installed in the carrier.

Is this for weight?

A non-full auto bolt carrier?

Is there any advantage to this swedged type of carrier.

Other (three) bolt carries are not of this design; can only see the end, maybe 1/8 of firing pin when installed.

I remember seeing something about the "Swedged" bolt carriers but could not locate info nor am I sure Swedged is even the proper terminology.

With the swedged carrier does the firing pin get more abuse/carbon or is it pretty much the same as the other carriers?

Bushmaster has a one year 10 day guarantee. ?? Kinda thought that sucks even my lowly Del-Ton has a lifetime guarantee!? Dunno about the CMMGs gonna call.

Just trying to figure out the differences. Thanks

 

[Z-Michigan]

The carrier you're describing was common until the last couple years. That design and the notch in the hammer was required of Colt by BATF way back in the 1960's to make it more difficult to convert an AR15 to full auto. It is not a legal requirement for anyone at this time, and most companies no longer use it. The other design you see is often called "shrouded" and ensures that the carrier, rather than the firing pin, cocks the hammer; that is a superior design. So yes, the firing pin gets more abuse in the design you're looking at, though they do normally work fine.

 

[Sky]

That makes sense.

I clean after shooting so I can live with a bit of carbon. I did notice after maybe 20 rounds by me and another few rounds while trouble shooting the failure to eject and fire that there is markedly more hammer ware on the face than my other ARs with several more rounds through them. Shinny spot appearing on hammer face.

I may just buy a CMMG or Del-Ton shrouded carrier if I have any other problems with the Bushmaster and add a two stage trigger while I am at it. It is just a night time shooter with a night scope but I want it to work and go bang when supposed to.

First experience with Bushmaster but have not had problems with other ARs. Extractor spring for the original Bushmaster bolt should be here next week.

It surprised me when I got on Bushmasters web sight that they only have a one year 10 day warranty.

 

[Tirod]

The cut BCG, hammer, and large collar firing pin are Colt's effort to placate the BATF, along with the different sized take down pins. Moot point, all the full auto upper parts, and the hammer, continue to be legal to use. They are supplied and installed on a lot of other carbines straight from their maker.

It's the lower that is scrutinized, and any attempt to control the hammer which would allow it to be released without the specific act of pulling the trigger. That means a semi auto disconnector that let's go and follows the hammer could be suspect. Colt notched the hammer, and made the firing pin collar large enough to grab it and jam the bolt carrier in a very awkward and difficult way.

Note LEO's are discouraged from using those parts as a double is far better than a catastrophic failure when desperately needed.

Lot's of shooters use the M16 full auto carrier as it weighs more, chambers more reliably, and slows the cyclic rate down a tad. Never having to pry the bolt carrier out of the upper counts for a lot, too. Only Colt did it, why others install the parts in light of the BATF saying the M16 upper parts are no problem, I don't know. Hopefully it's based on price and supply.

The only reason I have a notched hammer is that it came with the LPK, and cheaper kits seem to share that. By and large, the M16 carrier is preferred.

 

[Sky]

O.K. called Bushmaster about the bolt carrier and they said they have not shipped the slotted/swedged bolt carrier for over two years.

Called the shop where I traded for the Bushmaster and the owner (who was told the gun was new when he got it from another dealer) told me he would swap the bolt out for me at no charge..Good guy.....

Now the Bushmaster has the slotted/cut hammer...If I go to the fully shrouded bolt carrier will I need to change the hammer/trigger assembly?

Anyone recommend a adjustable two stage trigger that doesn't cost more than a good horse? Thanks guys I really do appreciate it.

 

[Z-Michigan]

The notched hammer works with any carrier. It just won't hang up the carrier on a hammer follow unless you have the cut type carrier your rifle originally came with.

Your 2-stage trigger options are mostly Armalite, RRA, and CMMG, or a Geissele for more money ($270+ for their adjustable models). I would skip adjustability and get a Geissele SSA for $170.

 

[Sky]

Thanks Z-Michigan!