Does the M4/SPR fit the LMT 12" piston?

[NetJunkie]

I know this has been discussed but I can't find it in search. Will the M4/SPR fit or does it hit the piston end?

[AlanD]

I emailed LMT perhaps 6 months ago and they replied that an M4/SPR would not fit.

[Walker Precision]

The SPR/M4 requires about 2.5" of unobstructed barrel behind the muzzle to properly fit. The 12" LMT piston barrels are just over 1.25" to the gas block. An M4-2000 or an M4-1000 will fit, but will prevent the piston from being removed without removing the flash hider or pulling the barrel.

[AlanD]

Chris,

Thank you for the info and photos.

Alan

[Walker Precision]

No problem. Hope the info is helpful.

[openbolt]

An M4-2000 or an M4-1000 will fit, but will prevent the piston from being removed without removing the flash hider or pulling the barrel.

This information is incorrect. I own a 12" LMT CQB piston rifle in 5.56mm and the M4-1000 AAC can. I think I was the first person to figure out that you can seperate the piston and push rod from each other while it is inside the upper. What I do:

1) Remove the can.
2) Pull the upper from the lower.
3)On a bench flip the upper upside down so the op-rod is visible, grab the op-rod with a smooth jawed pair if needle nose pliers, gently pull the op-rod from the piston. The two parts will now be loose/seperated. Keep rearward pressure on the op-rod while manipulating the gas plug out from the front of the piston housing.
4) Then just let the op-rod run forward under it's own spring pressure. Done deal.

This process is even easier if you want to go to the trouble of pulling the Q/C barrel.

When I discovered this I reported this procedure to AAC's Mike Meyer as well as Gene Swanson over at LMT. Both were grateful for the tip.

Hope this helps,

openbolt

[Walker Precision]

Thanks for the info.