I'm pondering my next 223 Rem and have a few questions.

Just for comparison purposes, what's the average MV for 16" and 20" barrel using a 55gr bullet?

What are your favorite types/weights of varminting bullets for a 1/7 and/or 1/9 twist AR-15 and why?

Thanks.

For varmints a 16" would not be the hot ticket.
Velocity loss depends on the load, slower powders will lose more than faster powders. Exactly how much I cannot really say as I do not have a 16" to chrono.
20" or 24" would be the way I would go for varmints, definately 20" if I had to carry it, or shoot offhand.

Sierra Blitzking 55gr.shoots well.
Sierra Matchkings shoot VERY well.

1:9 twist barrels have done well for me with up to 69gr. bullets.

You can shoot the 52gr. Matchking in a 1:8 twist barrel 20" just fine. " overstabilizing " is not an issue with this combination. Shoots great. Someone will most likely come along and say 1:8 is way to fast a twist rate for this light a bullet. But they shoot really well for me in the above combo. ( "well" is sub MOA, in case you needed a number . 20 round groups at 100 yards )( providing the shooter does his part and it's not too windy. )

Travis F.

Didn't Saeed do a test where he progressively cut off the barrel of a .223 to ever shorter lenghts? I always have heard that beyond 18" was the land of diminishing returns with regular "fast" powders in the .223 (H322, H335, etc.)

Varmint bullets and 1/7 twist seems like a bit of an oxymoron for me. Only reason for such a twist would be for 75gr AMAX's or other heavy long bullets, which are not really varmint bullets. For small varmints I'd go with a slower twist. Jeff, as you know I love my Nosler BT's but I am hugely impressed with the performance of Speer TNT's on prairie dogs. They are tremendous! And they are accurate out of my Savage 10FP which is a 1:9 I think. It also shot the 75gr AMAX's darn well.

R