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Old July 02, 2019, 00:16   #2
FALaholic #: 1441
Join Date: Oct 2000
Location: USA
Posts: 947
I have built more than 1000 G3’S.
Here is what you do press the barrel into the trunnion stopping about an 1/8 before flush then insert the bolt and carrier group and try to lock it up watching the bolt gap ( at this point the gap will be huge and bolt will not lock up)
Bolt gap is the space ( looking at the bottom of the bolt and carrier asy ) the gap between the rear of the bolt and front of carrier keep pressing the barrel slowly the more you press the tighter the gap gets keep checking the gap with an automotive feeler gauge until the gap is at 22 thousands ( yes this is above spec) but once you drill and pin barrel to trunnion and shoot a few rounds the gap will settle in around 18 thousands depending on how well you drill the hole.
Remember you are not just pressing in the barrel but you are setting the head space as well.
Also if you press the barrel in to far you will not have any gap at all and will have to start all over.
There is a lot more to think about before pressing in a barrel like are you using a used trunnion used barrel that have holes already drilled. or all new parts

Pm me your phone number i will call you tomorrow
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