Hot barrel was hammering…why

[sacklunch]

not smart enough to contribute much, but you folks always point me I the right direction.

Had a weird day at the range today. Lower end of my “node” if you believe in such things on this charge weight. I couldn’t recall if I had done load dev on this rifle with my supressor or not. So I backed it down .2 gr (6 creed, Lapua brass, 105’s) guessing that keeps similar speeds as unsupressed. I took bad notes, I know.

Hit my original great loads FPS, but rifle was walking all over the place. Decided to just kinda burn it down with 15 rounds on a hot barrel…result was just a hammer, all touching, one ragged hole.

Did the hot barrel increase speed and get back what the rifle likes with the can on? Was considering bumping back up .2 and .4 and seeing the results.

Jsut curious any theories behind why it only wanted to group when hot? I did put the chrono to it. Load dev (pretty sure unsupressed) was 2985…suppressed now and backed off .2gr was 2985, but it didn’t want to group cold to luke warm.

Gap contour barrel.

 

[Hawk in WY]

Hot barrel or hot shooter?

I think we know the cold bore shot is also often a cold shooter shot.

The reverse could also be true.

 

[supercorndogs]

Sometimes barrels won't shoot cold and onky want to shoot when hot. The converse also happens sometimes. ⁰

 

[diggler1833]

Barrels are individuals.

I also agree that the shooter can frequently provide that variable input that messes with results in a strange way.

Best thing you can do is to try it again and see if your results from the last range session are repeatable. I once had a factory Remmy 5r barrel that would tighten up after the bore was fouled with about 20 rounds...and like a moron, I kept cleaning it until I figured out that it liked to be shot dirty.

 

[sacklunch]

I never shoot my 6’s as bad as this was grouping. Checked torque on everything when home, gtg. It’s a 20# 6 creed, was just very strange it wanted to walk all over for 15 slow fire rounds and followed up with 10 rounds in a ragged hole when hot, wasn’t sure if that hot barrel sped it up? If so guessing that I’m on the low end with this load for OBT?

 

[sacklunch]

Sometimes barrels won't shoot cold and onky want to shoot when hot. The converse also happens sometimes. ⁰

What’s weird is during load dev, there wasn’t a charge it didn’t like and was pretty impressive repeatable accuracy hot or cold, I attributed that to the heavy contour.

Yesterday was just strange and I was trying to hypothesize why

 

[Whytry85]

How long between shots? Rounds could’ve cooked in the hot barrel creating higher velocity.

 

[DairyDictator]

Not saying it's impossible that it's the rifle, but I haven't seen any of my rifles change that much over the course of .2 or .4gr of powder without some serious other changes.

Sounds like you might shoot better when you're not thinking about it so much. Also, as long as you weren't letting the rounds sit in a hot chamber, they don't have enough time to soak heat so the velocity increase would be minimal.

 

[clark33]

You probably stopped thinking so much, I’m also a fan of larger sample sizes when shooting groups. 3 rounds doesn’t tell you much, 5 is better, 15-20 of the same load tells you a whole lot more. I bet most people would be surprised how similar groups would measure out if they shot 15-20 of each charge weight in their load dev.

 

[Wannashootit]

Did the hot barrel increase speed and get back what the rifle likes with the can on

Makes sense, could be. Heat expands the barrel (from inside out obviously=bore), stiffness is reduced, and harmonics change. Could be any or all of the above contributing to it.

I'm sure you know strings like that will toast the throat (and accuracy) in short order with what's already a burner in the 6 Creed.

 

[eklarsen]

Sounds like you stopped thinking and started shooting, sometimes its the archer not the arrow.