LMT MWS - receiver extension question

[andy t]

I have MWS ban complaint receiver extension. I would like to replace this RE with a standard carbine RE. However, the recoil spring is about 15.8" long - much longer than one for an AR15. Will it work in regular AR15 RE, or do I need to get a special one? The buffer is marked H3.

Thanks!

[rdbse]

The standard MWS receiver extension (collapsable SOPMOD stock) is a little longer than a milspec AR-15 receiver extension due to the longer bolt carrier in the MWS. I will take some measurements and post them shortly.

[andy t]

Thank you!
I also found MWS stock options thread that helped me.

[rdbse]

Here are the measurements from my MWS compared to my standard milspec receiver extension.

MWS buffer tube = 7.875" (milspec = 7.25")


MWS relaxed buffer spring = 15" (milspec = 10.75")


MWS bolt carrier is 1.25" longer than standard M16/M4 bolt carrier


You might consider contacting Clint at Heavy Buffers to help with the correct buffer/spring/tube combination. I have one of their HSS buffers. http://heavybuffers.com/reference.html

Also, I believe other members have modified their receiver extensions so you might check some other threads.

[andy t]

Thanks again. I ordered his heavy buffer and modified recoil spring so that I can use standard carbine RE.