LMT 10.5'' which buffer to use??

[WILDBILL]

I am building a LMT 10.5'' MK18 MOD0 Clone and don't know which buffer to use in it, should I use the H2 or the H3 Buffer? I would like to tame a lot of that short barrel recoil and try to get it like the 14.5'' or the 16.0'' if that is possible .

[Robb Jensen]

I'd recommend a H2 with a standard power spring. But I would check to make sure it's cycling well and locking the bolt back everytime by only loading 1 round per mag. If it's not locking back reliably go to an H buffer with the same spring and it should work fine, if not use the standard CAR buffer. Later as the gas port erodes and the cyclic rate increases you can use an H2 or H3 and a heavier rate spring like an ISMI, David Tubb(a more expensive ISMI), or Wolff +10%.

What I find that's working best in my 10.3" LMT right now is a H2 with a standard rate chrome silicon spring. This barrel has about 4K rounds through it now. It was a factory 14.5" LMT and I had it cut to 10.3" and had gas port work.

[C4IGrant]

Since LMT's tend to have smaller gas ports, I think you need to pay attention to what type of ammo your shooting. Like Gotm4, I like H2 buffers, but they don't always work in the LMT uppers.

With mil-spec ball, I can use an H2 and a IMSI springs in most LMT 10.5.



C4

[WILDBILL]

Grant, I was thinking, have you ever tried a H3 in a LMT 10.5'' Upper?

[LukeMacGillie]

Im quite happy with my Mk18, but im only about 4 grand round count into it at the moment. It works fine with or without a supressor and contrary to what I expected has no problems with a standard carbine action spring and H buffer, No O ring on the extractor.

Thats shooting M855 and Mk262.

[QuietShootr]

I have a Colt 9mm buffer and a Brownells standard-weight CS buffer spring in mine. The gun has <checks gun book> 2270 rounds through it of mixed XM193, M855, 5.56 TAP, and a little el cheapo shit just to see if it would run. I have had NO malfunctions to date with this setup. That's right, zero.

However, I also have a KX3, a 5-coil Wolff XP extractor spring with a black Colt insert, and a D-Fender installed. YMMV, but I don't think that stuff hurts.

[grinch]

I think you can get away with the H2 no problem but FYI the military uses the H buffer and I've got 20K rounds with no issues thruogh mine.

[Robb Jensen]

I did some playing with my digital scale this morning and found this out :

buffers
CAR buffer 2.96oz
Bushmaster H buffer 3.75oz
CMT H2 buffer 4.57oz
CMT H3 buffer 5.43oz
Enidine hydraulic CAR buffer 4.34oz (newest type, softer spring rate)
Enidine hydraulic rifle length buffer 5.84oz

bolt carriers (w/o bolts in them)
Colt non shrouded 1/2 circle carrier 8.63oz
Colt shrouded 1/2 circle carrier 8.87oz
Bushmaster non shrouded AR15 carrier 8.92oz.
Bushmaster shrouded AR15 carrier 9.26oz.
CMT M16 carrier 9.46oz
ARES G35 M16 carrier 10.54oz.
Bushmaster gas piston AR15 carrier 10.10oz (w/screwed on solid carrier key like older POF, newest POF ones use integral key like ARES).

[WILDBILL]

GotM4, have you weighted a LMT FA BCG? And Grants, FN Fullauto BCG? I plan on making my LMT MK18 MOD0 all LMT Parts and later building a Stag F-top upper Rec. and a Colt M4 14.5'' barrel and Grants FN FA BCG.

[Robb Jensen]

GotM4, have you weighted a LMT FA BCG? And Grants, FN Fullauto BCG? I plan on making my LMT MK18 MOD0 all LMT Parts and later building a Stag F-top upper Rec. and a Colt M4 14.5'' barrel and Grants FN FA BCG.

There shouldn't be much difference at all in weight between a CMT/LMT/Colt & FN M16 bolt carrier weights. Same with bolts, should be really close to each other in weight.

For your factory LMT 10.5" I'd just use an H buffer for about the first 5-10K rounds and after that then try an H2, by that time the gas port should be eroded enough to where it warrants the use of an H2 or H3 buffer.