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9/22/2017 12:11:25 AM
Posted: 9/25/2005 9:59:30 PM EDT
is this better than say Colt or Bushmaster's?

is there really any diiference in bolts?

chrome BC, what's the benefit to having this?

please spare some brain cells in this direction
Link Posted: 9/25/2005 10:31:30 PM EDT
Hell yah! Inquiring minds want to kow!
Link Posted: 9/26/2005 3:44:19 AM EDT
LMT designed the bolt to ONLY work with M855. Some people get it to work with other ammo but if it does not then you are SOL because you are supposed to know up front it was only designed to work with M855. I would say it is not the better option over a standard Colt Bolt. Colt is better than Bushmaster for numerous reasons but we wont get off track here. A chrome bolt carrier is easier to clean. Thats its only benefit. The LMT bolt is not chromed it is electroless nickle plated. LMT is beatifull and slick and I never had a problem with the one I tested but others have and so I run a Colt bolt and M16 carrier in my LMT rifle for that reason.
Link Posted: 9/26/2005 4:28:50 AM EDT
Are we talking bolts or carriers here? Can a bolt be "load-specific"?
Link Posted: 9/26/2005 8:31:33 AM EDT
Link Posted: 9/26/2005 3:33:42 PM EDT
My 6.8 bolt sheared off the two lugs on either side of the extractor, so I bought a LMT 6.8 enhanced bolt because the lugs are not undercut near as much for the extracter as they are on a standard bolt.

However, the extracter springs are weak and this led to extraction problems. So what I did was to cut an O ring into 3/32 inch "plugs" and drop them into the blind extractor sping holes and then reinstalled the spring. This gave the extracter much more tension (like a defender or "crane O ring" does for a standard extractor). For about 500 rounds now I have had no extraction problems.

If anybody is having extraction problems with an enhanced bolt, you might give this trick a try.
Link Posted: 9/26/2005 4:33:55 PM EDT
[Last Edit: 9/26/2005 4:35:21 PM EDT by edwin907]
There is so many comments on the "enhanced bolt" by LMT that I just had to get one myself.
However, it appears that there has been a re-design of it as it has very different profiles to the locking lugs as compared to when it first came out.

If you go to the Military Morons site there are some pretty good photos of the LMT enhanced bolt.

Compare these with my photos below of the LMT enhanced bolt I received. The difference seems to be in the profile and radius of the locking lugs, but it is very different.

Any comments or experience would be welcome, at least before I test it tomorrow morning in my 20" AR.









Link Posted: 9/26/2005 5:07:16 PM EDT
Link Posted: 9/26/2005 5:17:12 PM EDT
I had heard recent LMT enhanced bolts were of a low finish quality but I did not believe it. The sample I handled was flawless. That LMT bolt is HORRIBLE!!! Dear GOD send it back and demand a refund!
Link Posted: 9/26/2005 5:17:46 PM EDT

I've been using a Bushmaster semi carrier and a Colt bolt in the 20" rifle, but the Colt is my back up bolt for my SHTF A2 and I'm going to try this LMT Enhanced Model with a M16 carrier.

Also, Grant, do you have the LT 17S mount in stock now?

Many thanks as always.
Link Posted: 9/26/2005 5:25:51 PM EDT
Link Posted: 9/27/2005 7:51:13 AM EDT

Originally Posted By DevL:
I had heard recent LMT enhanced bolts were of a low finish quality but I did not believe it. The sample I handled was flawless. That LMT bolt is HORRIBLE!!! Dear GOD send it back and demand a refund!



Haha I'd heard something similar and I to thought that that wasn't possible, that bolt looks like it was made by trailer monkeys.
Link Posted: 9/27/2005 9:23:34 AM EDT
Link Posted: 9/27/2005 12:27:19 PM EDT
[Last Edit: 9/27/2005 12:28:37 PM EDT by Redhook]

Originally Posted By edwin907:
There is so many comments on the "enhanced bolt" by LMT that I just had to get one myself.
However, it appears that there has been a re-design of it as it has very different profiles to the locking lugs as compared to when it first came out.

If you go to the Military Morons site there are some pretty good photos of the LMT enhanced bolt.

Compare these with my photos below of the LMT enhanced bolt I received. The difference seems to be in the profile and radius of the locking lugs, but it is very different.

Any comments or experience would be welcome, at least before I test it tomorrow morning in my 20" AR.

www.pbase.com/edwin907/image/49874555/original.jpg
www.pbase.com/edwin907/image/49874556/original.jpg
www.pbase.com/edwin907/image/49874557/original.jpg



What you have there is newest revision to the enhanced bolt. If you look at the bolt body, you will find a letter "J" stamped on it. The one shown on Military Morons is probably the "I" revision. Yours does look like hell though and I would contact LMT about getting it replaced.

As for function, mine has been 99.9% out of my MRP with the 16"SS barrel. Way early on during the my break-in of the barrel, I had three Winchester 55gr white box rounds FTE during my single shot and clean steps. They weren't stuck. They just didn't come out of the chamber when the bolt cycled. Turns out the extractor had actually ripped a chunk of the rim right off of the case. I figured that it was just a timing issue. Pressure didn't drop fast enough before the bolt cycled. Plus the chamber was really clean during each shot. At the time I was using the enhanced bolt with a standard S/A carrier. I've since fired 50-60 rds of Winchester plus just about every other type of load (including low velocity hand loads) without any problems.

However, just this past weekend I had the same thing happen. Only this time with PMC 55gr. The first and third rounds out of a really clean chamber got stuck. After that I fired another 20rds of PMC and probably 20rds of Winchester without problems. The only thing different is I recently changed the carrier to the enhanced carrier. I'm not too concerned. I'll just have to watch and see if it continues. I really wonder is there is something like a machine mark that is holding onto the brass.
Link Posted: 9/27/2005 1:06:01 PM EDT

Originally Posted By Redhook:

What you have there is newest revision to the enhanced bolt. If you look at the bolt body, you will find a letter "J" stamped on it. The one shown on Military Morons is probably the "I" revision.



Actually, it has a "K" stamped on it, you can just make it out in one of the pictures.

This morning I shot 120 rounds of 75 grain TAP ammo and 60 of Winchester 62 grain R3 using the LMT enhanced bolt with no failures of any kind using a LMT M16 carrier.
Using a TA31F ACOG and bipod single shot accuracy was about .8-.9" with both loads at 100 yards, not bad for my eyes, a very warm chrome lined government profile 20" and a 4X scope with variable wind. And you could very easily hit a 2-3" circle every second (or even a little quicker) for as long as the mag held out.



Link Posted: 9/27/2005 4:01:17 PM EDT
Not to be a stick in the mud, but aren't these bolts an answer looking for a problem? I've never had problems with the standard bolt. If you keep them in good working order by replacing gas rings, extractors & extractor springs, it should stay that way.

While the whole design (on paper) looks very innovative and well thought out, I've read less than stellar reviews from a lot of folks who have them...and btw, when you've NEVER had any type of failure with a regular bolt (and we're talking thousands of rounds of wolf, xm193, Q3131A, ect), 3 initial FTF's with a clean chamber seems like a lot, even if the timing is a little off on the weapon.

Also, the fact that LMT is on what, "K" markings now? I can't help but wonder if those are revision letters, since the MM pic was "I" and a previous poster had a "J" marked bolt. I may be going out on a limb here, but it appears LMT is still working out issues with these bolts.

LMT makes EXCELLENT uppers & barrels, as a matter of fact, I've got a LMT 14.5" M4 Complete Upper on its way ( I almost ordered the enhanced bolt as well), so this is in no way a slam against them.

I'll be curious to see how LMT handles the above pictured bolt with regards to returning & exchanging it, as well as how newer revisions work out. Keep us posted!
Link Posted: 9/27/2005 4:55:13 PM EDT

Originally Posted By TXAGGIECCL:
aren't these bolts an answer looking for a problem?



Looks like it's found plenty
Link Posted: 9/27/2005 6:18:09 PM EDT

Originally Posted By TXAGGIECCL:
Not to be a stick in the mud, but aren't these bolts an answer looking for a problem? I've never had problems with the standard bolt. If you keep them in good working order by replacing gas rings, extractors & extractor springs, it should stay that way.




Standard bolt will often break lugs or break in half at 10K rounds. Do your bolts last 20K+ rounds and "stay that way"? That is the probelm its supposed to solve. Also you sould not have to replace any of the springs EVER until the barrel is so worn out it needs to be replaced because its dangerous.
Link Posted: 9/27/2005 7:14:00 PM EDT

Originally Posted By C4iGrant:
I would suggest that you just go with a CMT or LMT std BCG.

C4


+1

I'm just going to go with my M16 LMT with chromed bolt, Colt, std LMT and CMT BCG.
Link Posted: 9/27/2005 7:34:51 PM EDT
I have one that runs flawless after I broke it in. It was used in a new upper first using WWB. With WWB it was 100%. I then started shooting wolf and had some teething problems. After break in it shoots fine and will shoot wolf all day.
Link Posted: 9/28/2005 5:05:09 AM EDT
[Last Edit: 9/30/2005 8:31:56 AM EDT by Va_Dinger]

Originally Posted By DevL:

Originally Posted By TXAGGIECCL:
Not to be a stick in the mud, but aren't these bolts an answer looking for a problem? I've never had problems with the standard bolt. If you keep them in good working order by replacing gas rings, extractors & extractor springs, it should stay that way.




Standard bolt will often break lugs or break in half at 10K rounds. Do your bolts last 20K+ rounds and "stay that way"? That is the probelm its supposed to solve. Also you sould not have to replace any of the springs EVER until the barrel is so worn out it needs to be replaced because its dangerous.



I think your a little off base. Even these "Enhanced" bolts should be replaced after ten thousand rounds or so. That’s just a good PM practice with any AR. I have never seen anything suggesting they offer longer service time. The real plus is the improved extraction and cleaner operation due to the nickel plating.
Link Posted: 9/28/2005 9:51:16 AM EDT

I cannot speak for the Bolt Carrier but I have three LMT enhanced bolts.

None work reliably in <14.5" guns

However they work flawlessly in 14.5-16 guns with 55-77gr ammo In My Experience.

I have over 7.5K in one of them and no problems the other have far less round counts (2-3K each.)



I use mine in a 20 inch rifle and have yet to have malfunction in 500 or so rounds.
Link Posted: 9/29/2005 10:00:55 AM EDT
Got two when they first came out and both still work perfectly. It was determined they did not run well in sub 14.5 weapons (I discovered that too) but were not designed to so that was no big deal. Apparently LMT did'nt initially tell that to it's dealers. Actually the bolt itself has run great in one of my 10.5 uppers used with a standard colt carrier. It was the enhanced carrier that is the problem with shorties IMO. These bolts have been abused by me and still clean up very well. Both BCG combined have seen around 14,000 rounds.

That being said a standard colt or LMT BCG will do more than enough of a job for anyone.
Link Posted: 9/29/2005 10:22:38 AM EDT
FWIW, I purchased one which is installed in my LMT 14.5" w/ perm G6 upper, (I didn't know it was designed for just the M855 ).

I have never had any problem or bolt related malfunction with any of the Black Hills 55fmj, 68bthp, 69 & 77 smk, Q3131A 55grn fmj, S&B 55 fmj & SS-109, IMI M855, Olympic M855 or my reloads, (from 64grn PP & PP+ to 75 & 77 grn rounds) all of which have been through it at one time or another. To the best of my knowledge this upper has never failed to go bang or eject a round, I have had it and the upper now for over a year. Round count on this upper is probably close to 3K+.

Ran 2 Beta C-mag full loads of Q3131A through it on vacation (testing the C-mag, not the rifle), it never missed a beat.

Sorry for the problems mentioned above by others, but I have been extremely happy with mine and expect it'll remain there for many years to come in my #1 SHTF M4 rifle.

(have no idea what version it is, guess it's one of the good ones though)

YMMV,
Mike
Link Posted: 9/29/2005 11:02:13 AM EDT

Originally Posted By C4iGrant:
I would suggest that you just go with a CMT or LMT std BCG.


C4



I went with the standard LMT BCG with 2 bolts when I got my 16 MRP from Grant, and they have been flawless after 2700 rounds. Not one failure to "Anything"!

Tack
Link Posted: 10/1/2005 2:54:53 PM EDT
I have to ask.......what exactly is supposed to be the benefit of the LMT enhanced bolt and enhanced carrier?
Link Posted: 10/1/2005 4:44:24 PM EDT
Link Posted: 10/1/2005 6:03:40 PM EDT

Originally Posted By C4iGrant:

Originally Posted By dlrector:
I have to ask.......what exactly is supposed to be the benefit of the LMT enhanced bolt and enhanced carrier?



The ability to handle gas better, longer life, better finish, etc. While it works for some (like me) it doesn't work for everyone. You are better off just sticking with a CMT or LMT M16 BCG.


C4



For those of us soaking up information, could you explain why we are better off sticking with a standard bolt?
Link Posted: 10/1/2005 6:29:05 PM EDT

Originally Posted By DDEL:

Originally Posted By C4iGrant:

Originally Posted By dlrector:
I have to ask.......what exactly is supposed to be the benefit of the LMT enhanced bolt and enhanced carrier?



The ability to handle gas better, longer life, better finish, etc. While it works for some (like me) it doesn't work for everyone. You are better off just sticking with a CMT or LMT M16 BCG.


C4



For those of us soaking up information, could you explain why we are better off sticking with a standard bolt?




I have an LMT 14.5" M4 upper with the "enhanced" bolt AND the "enhanced" semi-auto carrier. The main problem I've had with mine is that the enhanced carrier bleeds off too much gas, so the thing short-strokes with almost any ammo, unless I'm using a suppressor. With a suppressor, which increases the amount of gas coming back through the gas tube, the enhanced carrier is GREAT. Otherwise, it's just something I paid way too much money for after falling for somebody's marketing hype.

The enhanced BOLT, is only okay - not great... at least in my experience. I have not noticed that it's really easier to clean than a standard bolt, and extraction is LESS positive than it is with a standard LMT bolt with a "Crane" O-ring installed on the extractor spring. I think the springs that LMT was using in these enhanced bolts were not the best quality. My extractor tension is way less than it is on any of my other standard bolts, with or without O-rings or extra power springs.

I've heard that you can use the detent spring from the rear takedown pin cut in half to make two extractor springs for the enhanced bolt, but I haven't tried it -- just put the enhanced bolt and carrier into a ziplock bag and replaced with a standard bolt and carrier setup. This upper would reliably malfunction at least once every 100 rds, but I have had NO more problems since I put a standard bolt/carrier in it.

Of course, YMMV.
Link Posted: 10/1/2005 7:10:44 PM EDT
I've probably got about 750 rounds of Q3131A, LC XM855, 75 grain TAP, Winchester 223 R3, and Federal 223 55 grain through my 20" with the enhanced bolt. Not a single failure of any kind yet.
I'd have to say the extractor springs in my "K" revision enhanced bolt are pretty dang stiff, at least as stiff as my regular LMT or Colt or Bushmaster bolts.

The government profile 20" CL 1/7 MOS barrel has broken in very nicely, the other day at the range shot a .7" 10 shot 100 yard group with 75gr TAP a couple of times, which for me and a 4X TA31F is outstanding (concrete bench, bipod, perfect weather).
Planning on a MR/T 3-9 illuminated in a LT mount, and I can return the TA31F to my girlfriend's Dissy!
Link Posted: 10/2/2005 5:08:21 AM EDT
Link Posted: 10/2/2005 5:10:00 AM EDT
Link Posted: 10/2/2005 6:45:05 AM EDT
I probably have about 2500 rounds of Q3131A and XM193 through my LMT 14.5" upper with the ENHANCED bolt and std carrier. I've had zero malfs of any sort, and I do really like the ease of cleaning the finish allows.

But, if I was in the market for another bolt, I'd probably save a few $ and go with a regular bolt, they work just as good IMO.

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