Doc7
Member
Hey all,
I built my first AR a few months ago and so far it has run great although that's only a couple hundred rounds of the Federal lake city XM193 ammo. I have a JP Enterprise A2 front sight with integrated adjustable gas block. I single loaded rounds while opening the gas block slightly until I achieved BCG lock on an empty magazine and then a little beyond, per instructions. I haven't had any malfunctions since the intentional ones with the port undersized.
I am more curious than anything else; when I get a chance to shoot some 69 gr SMKs (Black Hills) and 77 gr SMKs (Federal Gold Medal Match) is the adjustable gas port likely to cycle the action or not? I don't understand an AR enough to know if the increased bullet weight will make a predictable difference or not. I understand powder charges are different so it's not like we can say definitively one way or another without testing, but if you had to guess, what would you predict?
I do understand that the final upshot of any adjustable gas block system is that it has to be tuned to a specific ammo eventually (or left wide open, or at least open enough to cycle all ammo tested), but this is more for curiosity for an upcoming one-time informal group size match with a buddy of mine. He will be using a bipod and 4-16x scope whereas I may only use a sling and a 3-9. However, I have a Geissele SSA-E vs his milspec trigger, which I think makes the biggest difference, as well as a higher quality barrel.
I built my first AR a few months ago and so far it has run great although that's only a couple hundred rounds of the Federal lake city XM193 ammo. I have a JP Enterprise A2 front sight with integrated adjustable gas block. I single loaded rounds while opening the gas block slightly until I achieved BCG lock on an empty magazine and then a little beyond, per instructions. I haven't had any malfunctions since the intentional ones with the port undersized.
I am more curious than anything else; when I get a chance to shoot some 69 gr SMKs (Black Hills) and 77 gr SMKs (Federal Gold Medal Match) is the adjustable gas port likely to cycle the action or not? I don't understand an AR enough to know if the increased bullet weight will make a predictable difference or not. I understand powder charges are different so it's not like we can say definitively one way or another without testing, but if you had to guess, what would you predict?
I do understand that the final upshot of any adjustable gas block system is that it has to be tuned to a specific ammo eventually (or left wide open, or at least open enough to cycle all ammo tested), but this is more for curiosity for an upcoming one-time informal group size match with a buddy of mine. He will be using a bipod and 4-16x scope whereas I may only use a sling and a 3-9. However, I have a Geissele SSA-E vs his milspec trigger, which I think makes the biggest difference, as well as a higher quality barrel.