260 Range Report - Analysis help needed!

[ducks-and-bucks]

260 Tac chamber - 140gr berger VLD Target - 42.0gr H4350 - Lapua brass - Federal Match Primer

28 inch 1:8 twist Brux barrel

95 degrees F ambient air temp in shade at Point of Fire
28% Humidity
961 ft Altitude

Shot 1 - 2926 fps
Shot 2 - 2985 fps
Shot 3 - 2973 fps
Shot 4 - 2979 fps
Shot 5 - 2977 fps

I gave a good amount of time in between shots and checked the ammo temp and chamber temp with a laser thermometer between shots to only shoot the next shot once everything cooled back down to the same stable temp for "more better" results.

What do yall think? First shot was "cold bore" I let the ammo and rifle sit in the shade there for 30 min or so to adjust to the ambient air temp as well. I wasnt expecting higher 2900's though! I was expecting 2800's but this looks like good news, I am happy if it shoots this speed.

Most people have a 26 inch barrel - Do yall think these 2 extra inches in barrel make that extra 100 fps faster? is that what I am seeing here?

This was the "pet load" that I worked up... it's shooting really really well. It's not a max load, but any faster groups started opening up, then I went to max load around 44gr and started getting a sticky bolt... so this is right about where I stand with this rifle as of now..

 

[ShootDots]

If you "scrubbed you barrel down to the metal" ZERO CARBON in it, chances are that you had to foul the barrel for 4-5 shots til it "settled in"... After that your rounds should have stayed very close to your top 3 shot in velocity.. If your next several shots stayed in the 2973-2983 velocity range, your e/s's would be coveted by many reloaders..

Also another thing I should add. If your barrel is just now getting say 100-150 rounds on it, it is very possible that it is breaking in just fine and speeding up a tad. Not EVERY barrel speeds up to a substantial degree, however, canted, as in 5R rifling, is prone to do that. So that, along with your "scrubbed out" barrel, probably accounts for the additional speed..

 

[eric32]

yea looks good on the ES spread have you measured a 10 or 20 shot string yet? If so that will be the ultimate indicator of the load. Also if you compete then at match pace will be a good indicator of the load consistency under those conditions

 

[jcampbellsmith]

That's a very similar velocity performance to what my Remington 260 Rem does. The first cold clean bore shot is slow. However mine are trundling along about 2650 fps in a shorter barrel.

Regards

JCS