temperature sensitive

[7 loader]

I guess it is just me but from 5 deg f to 95 deg f I have found no probs with IMR 7828 all of my groups are within a 1.2 I. at 200 yds in my 7 mm mag

 

[str8shoot]

That should be just about right for shooting running deer at 500 to 600 yards with 30 mph cross winds off hand. If I had your skill sets I would use RL powders too.

Jeff

Agreed. Alliant makes great powder for that. I'll stick to Retumbo, H4831sc, H-1000 and Varget for the type of shooting I do. It did not take much long range testing off a bipod and rear bag at still targets and min wind with rl-22 and rl19 at various temps for me to figure this out. 30 degree temp swings will give 100fps swings through my chrony with rl-22.

Maybe off-hand, in the wind, on a moving target would give more consistent velocity?

 

[Clark]

Kombayotch [not his real name] is an engineer that posted some testing he did on temperature sensitivity of powder.

The RL17 and IMR3031 vary 150 fps over 100 degrees F
Varget varies 15 fps over 100 degrees F
AR Comp varies 5 fps over 100 degrees F.
Power Pro 2000 is 180 fps over 100 degrees F
H1000 is in the same class as AR Comp

 

[Lefty7mmstw]

funny, arcomp is basically the new farmula for rl15. Same basic application.

 

[Lefty7mmstw]

Agreed. Alliant makes great powder for that. I'll stick to Retumbo, H4831sc, H-1000 and Varget for the type of shooting I do. It did not take much long range testing off a bipod and rear bag at still targets and min wind with rl-22 and rl19 at various temps for me to figure this out. 30 degree temp swings will give 100fps swings through my chrony with rl-22.

Maybe off-hand, in the wind, on a moving target would give more consistent velocity?

do what works for you. They are coming out of the peanut gallery now. wow.

 

[Outlaw6.0]

....30 degree temp swings will give 100fps swings through my chrony with rl-22....

That sure is a wide swing, enough to make me flinch as well if it were my rig. How much testing was done to come to this conclusion? 2, 3, 5 strings of how many? What was the ES of the original load? How was accuracy effected by the VEL spread?

Don't think i'm trying to pick apart your statement, because i'm not. I'm simply requesting additional data to qualify your results. Anybody can throw numbers on a forum, but those who can prove it generally get a little more attention.

Sometimes I think, the more I read about wide temp swings, maybe it's the cartridge in which it is being used. Heck, I recently read a range report of H4350 running over 100fps faster from one day to the next in a 6.5 Creed' on a hot day. What I don't know, are the rest of the extenuating circumstances.


t

 

[Mikecr]

Only a truth passes all tests
But much like seating depth settings, a truth here may be too difficult for us to see..