9mm hammer/bolt for FA LMT lower?

[Josh-L]

I have a buddy that has a full auto LMT lower. We built him a 9mm upper but I've never done a full auto setup before. All the different hammer setups and ramp/don't ramp the bolt crap confuses me. Anyone have any ideas on what to do? Can he run his LMT full auto 556 hammer and just ramp the bolt or leave it un ramped or what?

[22_Shooter]

I have a buddy that has a full auto LMT lower. We built him a 9mm upper but I've never done a full auto setup before. All the different hammer setups and ramp/don't ramp the bolt crap confuses me. Anyone have any ideas on what to do? Can he run his LMT full auto 556 hammer and just ramp the bolt or leave it un ramped or what?

-You can't run a notched 5.56 hammer with an unramped bolt.

-You can run a "rounded" 5.56 hammer (like the DPMS hammer) with an unramped bolt.

-You can use a 9mm hammer, with the bolt ramped or unramped.

All that being said, a ramped bolt will make things run smoother, regardless of which way you go.

I'm not sure what kind of buffer your buddy's got, but obviously a 9mm buffer would be best. Also, a lot of people recommend the KNS pins for 9mm setups. Supposedly the blowback design is harder on all the pins. Even more so, if you're going FA.

[Robb Jensen]

A full auto 9mm (if using Colt type 9mm upper) uses the same hammer as a full auto 5.56mm does.

[Josh-L]

-You can't run a notched 5.56 hammer with an unramped bolt.

-You can run a "rounded" 5.56 hammer (like the DPMS hammer) with an unramped bolt.



Do you know what the LMT FA trigger is?

[22_Shooter]

A full auto 9mm (if using Colt type 9mm upper) uses the same hammer as a full auto 5.56mm does.

Correct. The fact that M16 hammers are rounded like DPMS hammers slipped my mind.


Do you know what the LMT FA trigger is?

See above.

Being that it's an FA hammer, you could run it with an unramped 9mm bolt. Ramping would just be an option, not a necessity, in this case.