OzFclass

G'day all,

I have been building a Remington SPS Tactical up over the last few months. The ammo that I will mainly use is the NRAA loaded 155gr SMK ammo. I want to make up a range card for it. I need to know what is the velocity of this ammo at a given barrel length. Im using a 1:12" twist 20" Remington Heavy Barrel. Has anyone got a MV for this ammo load at say 26" or 30" or whatever so I can work out what MV will be approx out of my barrel.

Thanks a bunch guys.

Shaun

I believe that this ammo runs at about 2950fps from a 30" barrel.

Shaun,

Interpolation is a pretty imprecise method of determining what the velocity will be in your barrel. The ammunition has been asembled with the assumption that the majority of barrels it will be used in are 28" plus, which is one reason why AR 2208 is the powder used.

Beg, borrow or steal a chronograph - or build your drop table from results achieved shooting over measured distances.

John

Ok then cheers guys. Thats give me a bit to think about.