Trying some IMR4064 in my 308 F/TR, getting 5 shot groups consistantly under .75 MOA at 100 meters with 168 grain matchkings. My question is how much difference will I see when the weather warms up this summer? Is IMR 4064 very sensitive to tempeture change and if so approx how much will I need to adjust my charge weight when the tempeture goes from 3 degrees C to 30 degrees C. The load the rifle seems to like best is 45.8 grains with the bullets just kissing the lands.
Imr4064
- Thread starter moeben
- Start date
Would you shoot a 308 factory loaded cartridge in your rifle at a temperature of 30 degrees C?
If you would, then I don't see why you would be concerned about firing your handloads, which do not exceed loading book amounts of powder.
The loads in the loading books which are marked, "Maximum," will give about the same pressures as will factory loaded cartridges for that calibre.
I am not concerned about exceeding pressures I am concerned about the affect on accuracy, mostly vertical spread. if there is a signifant change in pressure then there will be a change in velocity witch will affect vertical POI. I am wondering if anyone has used this combo and what did they find with changes in velocity as the tempeture increased.
Thanks
Thanks
First off I use a lot of IMR4064 in 22-250, 308, 30-06 and 45-70 and do not find it overly temperature sensitive.
If your particular load has such a narrow "sweet spot" that a few fps faster or slower will noticeably affect the accuracy you should be looking for a different load anyways.
I have seen many great loads developed in the spring that won't shoot in the summer.
Try your load with another half grain. If the groups goes to hell, you know you are too close to the limit and will have to back off for the summer. If it still works, you should be ok.
Try your load with another half grain. If the groups goes to hell, you know you are too close to the limit and will have to back off for the summer. If it still works, you should be ok.
burnt_servo
CGN Ultra frequent flyer
- Location
- right in the middle of b.c.
like " BOO " ,
i have used imr 4064 in alot of cartridges , 6.5x55 , 300 savage , 303 british , 30-06 , 45-70 , 45-120 .
i've never noticed anything out of the ordinary in terms of it being tempeture sensitive .
just for safety's sake , if i work up a load in cold weather , when it's warmer / hot out i'll do it all over again , just to avoid a possible overload situation that happens when it's warmer out and things ignite and burn a bit faster .
i have used imr 4064 in alot of cartridges , 6.5x55 , 300 savage , 303 british , 30-06 , 45-70 , 45-120 .
i've never noticed anything out of the ordinary in terms of it being tempeture sensitive .
just for safety's sake , if i work up a load in cold weather , when it's warmer / hot out i'll do it all over again , just to avoid a possible overload situation that happens when it's warmer out and things ignite and burn a bit faster .
