Hola,
Been a while since I have got to post and wanted to bring up a couple of topics.

1. Temperature Sensitivity. I take a 2 gun battery to Kansas every year. One is a Tikka 270WSM and the other is a Sako M597 in 7mm-08. The Tikka has made the trip for the last several years. I do my reloading in 60-100 degree temps in Texas. Do my hunting in 0 to 40 degrees up home. My tight groups go to junk up there. The load in the Tikka (stainless, synthetic) is a near max charge of RL19 behind a Swift Scirocco II. It is good here but varies there. I had not thought of temperature being a possible issue till now I guess.

The question is this. Could it be temperature sensitivity? I would not have thought that RL 19 would be that way. I have done everything else for the most part. Different scopes, tighten action screws, loosen action screws, pressure on at the fore-end, free-float, various COL, ..... This thing will go from 1 MOA at 100 here to 4 there. Driving me nuts. The last caveat is that I have a Winchester in the same set up and it has the same problem. I could slow it down some if that would help. Would it? I have tried all sorts of load and bullet combos.

Is H414 a temperature sensitive powder?

2. I am loading the Sako 7mm-08 for the first time. It has shot factory ammo well. I am begining my tests with 49.0g of H414 and a 139g Hornady Interbond. I am also looking at 49.5 and the max in the Hornady book of 49.9. I also have RL 15 around. Those would be my preferred's to use in this gun. Which would be your choice and what would the velocities be? My understanding is that H414 will get you better velocities but that RL 15 will be accurate and less temperature sensitive. Truth is in here somewhere?

At the end of the day I need to fix this issues of things going to pot when I get up home. I lost a nice buck last year due to this issue. I have used a lot of different combos up there and have never had these issues before.

I appreciate the help in advance.

Cheers,
Jason

What you are seeing could happen with any powder. Hodgdon claims to be less sensitive in their "extreme" line.

I think once you break 50-60 degree temp differences from load testing to hunting, you'll find almost any powder can change your groups.

Ball powders in general, are more sensitive then extruded or flake.
I`ve never had a rifles accuracy go bad from temprature change at normal ranges, but I guess it could happen. The major difference I`ve seen with respect to temps is pressure and the velocities change. It doesn`t in my experiance vary much, although that depends on powders used. R19 isn`t as stable when temprature changes as R15. The Hodgdon powders are better yet IMO, but all do change to some degree. The best one can do is try various loads in conditions you`ll hunt in and use the one that performs best.

Here is a test I ran with R22 in a 6.5x55 a while back in reguard to temp vs vel & pressure...
http://www.24hourcampfire.com/ubbthreads/ubbthreads.php...rch=true#Post1460421