I Call Shenanigans!

[BsChoy]

I took my chrono out today for the 2nd time and was severly dissapointed! My 8x57 150 grain mauser rounds that I loaded with 47.0 imr4064 were going an average of 2450 fps!?!?! The IMR online resource has them going 2305 or so with 36.0 grains! I know everything you read must be taken with a grain of salt but come on! Gotta try the H4895 i bought toady maybe that'll help

 

[scrat]

thats odd its usually the opposite.


Same time usually they use test barrels to come with these figures. Test barrels can be totally different from your gun. So htye are just starting points and every gun will be different and i guess thats why they say to adjust aroudn 10% from the begining then adjust accordingly.

 

[Cosmoline]

Your results sound about right. The IMR sounds a little inflated. If I remember my JS loads, once I got down in the low range of 4064 the velocity was down closer to 2,000.

 

[Shoney]

Before you go off "halfcocked", please give the vital statistics of your weapon/components and those of the test weapon.

Make
Model
Barrel length
Case
Primer
Bullet Mfg.
Air temp on day you tested

How do you know what batch their powder was from?
Any idea of their elevation above sea level? Or yours?