The Firing Line Forums - View Single Post - AR-15 Barrel Length Change

Ifishsum · January 4, 2020, 07:50 PM

I bet you will have to go down in projectile weight. The first year and a half I shot Highpower was with a 1:9 (20") and 69gr SMKs were the heaviest it would shoot well. Challenging at the 600yd line, especially with wind but do-able. At least for my skills at the time. Not to say that it isn't worth trying 77s if you already have some loaded up...nothing really to lose. Apparently a few have been able to get Hornady 75gr HPBTs to work in the 9 twist, I bought some planning to try them in that barrel but ended up getting serious with a new upper with a 7.7 barrel so I never did. Still wore that first barrel out shooting 53gr and 69gr SMKs at reduced distance matches.

January 4, 2020, 07:50 PM	#5
Ifishsum Senior Member Join Date: September 15, 2005 Location: Oregon Posts: 1,033	I bet you will have to go down in projectile weight. The first year and a half I shot Highpower was with a 1:9 (20") and 69gr SMKs were the heaviest it would shoot well. Challenging at the 600yd line, especially with wind but do-able. At least for my skills at the time. Not to say that it isn't worth trying 77s if you already have some loaded up...nothing really to lose. Apparently a few have been able to get Hornady 75gr HPBTs to work in the 9 twist, I bought some planning to try them in that barrel but ended up getting serious with a new upper with a 7.7 barrel so I never did. Still wore that first barrel out shooting 53gr and 69gr SMKs at reduced distance matches.