9mm buffer and spring with 5.56 hammer
- Thread starter cormann2
- Start date
I'm assuming that you are using this setup for a 9mm AR.
Whether you use a 556mm or a 9mm entirely depends on the type of 9mm bolt carrier group you have and the type of 5.56mm hammer you have.
If you have a ramped 9mm bolt carrier (CMMG/Spike's) then you can use an un-notched (rounded DPMS-type) 5.56 hammer.
(DPMS-type "rounded" hammer)
If you have an ramped 9mm bolt carrier and use a notched 5.56 hammer, you may end up binding the bolt carrier on the notch causing a FTF
(standard "notched" 5.56mm hammer)
If you have an UNramped 9mm bolt carrier (RRA/Colt), then you can ONLY use a 9mm hammer on it
(9mm AR hammer)
Whether you use a 556mm or a 9mm entirely depends on the type of 9mm bolt carrier group you have and the type of 5.56mm hammer you have.
If you have a ramped 9mm bolt carrier (CMMG/Spike's) then you can use an un-notched (rounded DPMS-type) 5.56 hammer.
(DPMS-type "rounded" hammer)
If you have an ramped 9mm bolt carrier and use a notched 5.56 hammer, you may end up binding the bolt carrier on the notch causing a FTF
(standard "notched" 5.56mm hammer)
If you have an UNramped 9mm bolt carrier (RRA/Colt), then you can ONLY use a 9mm hammer on it
(9mm AR hammer)
It's a RRA lower with the 5.56 hammer and RRA 9mm upper, so I am assuming that I have to change the hammer too. I was going to take the buffer and spring out for another build because I have the 9mm buffer,spring and hammer sitting around. The lower is dedicated 9mm.
If you don't want to have your bolt ramped then make ( remove offending notch ) / buy 9mm hammer
With a ramped carrier will work with ALL hammers . Doesn't matter if its a notched 5.56 , because there is nothing on a ramped carrier to catch it . I have used it on everything from Geissele , RRA 2 Stage, LTM 2 stage , CMC etc
A notched 5.56 hammer like the Colt style will result in the bolt getting stuck halfway in battery. You will have to disassembly via BOTH takeown pins to clear jam
Any machine shop can do it for you easily in 15 mins.
As you can see the resetting of the trigger take much more bolt travel. Bolt also contact the hammer further away from fulcrum point.
With a ramped carrier will work with ALL hammers . Doesn't matter if its a notched 5.56 , because there is nothing on a ramped carrier to catch it . I have used it on everything from Geissele , RRA 2 Stage, LTM 2 stage , CMC etc
A notched 5.56 hammer like the Colt style will result in the bolt getting stuck halfway in battery. You will have to disassembly via BOTH takeown pins to clear jam
Any machine shop can do it for you easily in 15 mins.
As you can see the resetting of the trigger take much more bolt travel. Bolt also contact the hammer further away from fulcrum point.
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