What’s the point? What does this bolt give you that a new MP Colt bolt doesn’t, other than being slightly easier to clean?
There is no point. The standard bolt, with the addition of Crane’s O-ring, works perfectly.
According to LMT, the Enhanced bolt has Re-enforced lugs and a dual extractor spring system. The Enhanced carrier has a third gas vent hole to help with pressure. I personally have one one of these for awhile and not had a problem. I have also had several of them returned.
I would say that if you feel that you would benefit from it then get it, but generally speaking, you don’t need it.
C4
Some have had issues with the LMT enhanced BCGs in 10.5" uppers. They were designed for the 14.5" uppers, not the shorties.
I know what they look like, I have one. I just don’t see what they offer over a MP Colt bolt.
Well, supposedly, they improved a few things. Like beefed up locking lugs, with radiused corners, and relief cuts, all to make them less prone to break, especially around the extractor cut. And speaking of the extractor, what does the double spring arrangement do, besides look dead sexy? Dunno on that one, although from what I’ve heard the o-ring/d-ring actually accomplishes the same task, only better.
Might be easier to clean.
Sorry, I failed mind reading and did not know you had one. 
I posted the picture for the benefit of anyone else who has not seen them.
I am an LMT dealer, but I am not a big supporter of the enhanced bolts.
They are pretty pricey for what they offer.
They have some nice features, the coating, the dual springs, sand cuts, better reliefs etc, but a good quality CMT bolt with an O-ring is just as functional.
I stock LMT Enhanced bolts/carriers because someone occasionally wants one, but I don’t push them.
I own one that I ordered with my MRP and it has help it run perfectly since day one, thats why I like them. I have heard that LMT has had some issues with some of the enhanced bolts in the past, but not exactly what type of issues. As Randall said, a good CMT or other quality bolt with the proper extractor upgrades will function just as good. Here are some more pictures (courtesy of Military Morons) for the interested:
Notice the Enhanced Carrier has a different cam track that does not engage the cam pin till later in the reward movement, adding a delay in opening. Unfortunately, none of the above pics capture this feature.
This is to allow residual chamber pressure to drop, ease extraction and reduce stress on the outboard locking lugs.
Looks like there have been a few iterations of the relief cuts to individual locking lugs-- I’m sure I’ve seen them much deeper than that. Although I’ve seen just a few of these.
The raised ring at the end of the carrier, I presume, is to reduce the area of contact where it bangs off on the barrel extension, allowing more room for dirt.
The best thing about the dual spring extractor is that it lets the springs be made longer. Longer springs are happier springs. Woulda been nice if there was some other spring in the system that coulda been drafted to also serve as extractor springs, like safety detent springs or something (too long, justoffered as an example). I’m sure they looked at that during design, it would have made spring availability less of an issue. Anyway-- there seem to be several theoretical advantages in this setup that aren’t translating into it being must-have for ever AR15-ist out there.
Yeah, I know, necropost, but search simply hasn’t worked for me for a while for whatever reason.
I got an LMT bolt assembly in today… ordered it because Bravo Company ran out of BCM bolts, literally minutes before I checked out (got notification yesterday they were back in, figures)
I noticed some odd features on the bolt, it apparently has the same radius on the rear of the locking lugs as is shown here on their advanced bolt. I don’t know when they started doing this, or if all of them have this.
Thanks for the pics, I’ve never seen one before. It looks to be about as relevant as a forward assist to me, though.
they work wonders in some guns. dont get one if you don’t actually need one- and if you don’t know if you need one or not, you don’t need one.
criticism of something you don’t understand is gay.
There is a post around here:rolleyes: with Bill Alexander discussing the enhanced bolt and carrier it was a great post.
I will try to look for it and post you a linky.
BKB pretty much somes it up if you don’t know if you need it then you probably don’t need it.
https://www.m4carbine.net/showthread.php?t=3379
Here it is post #12
The best description of the LMT enhanced BCG that I have been able to find.
just curious, what sort of problems would you see that an enhanced bolt would fix??
I’m running the enhanced carrier but w/ the standard lmt bolt.
Bolt was designed for a longer service life not to fix a problem to say.
the carrier is the part that usually offers the solution to a problem… by bleeding more port gas, it can turn an over-gassed gun into a correctly gassed gun. 10.5s, 16.1s, suppressed, anything that’s overgassed, for whatever reason.
a more durable bolt sort of goes hand in hand with weapons that are over-gassed. plus, as Heavy mentioned above, the bolt further slows unlock- it does contribute to the buffered action of the group.
Thanks…I’m running the enhanced carrier but with the standard lmt bolt.