davkrat
Well-Known Member
I have a basic Shooting Chrony that has given me some strange readings lately. My load in the 7mm Rem Mag is 69.0 grains of H1000 and the 150 ETips. I regularly get an average velocity of 3131 fps and SD of 15. The last time I went out the exact same load averaged 2907 with an SD of 17 for 10 shots. My barrel does tend to copper foul with the ETips and I regularly give it a thorough cleaning. Anything that could cause an extreme drop of 200+ fps in velocity other than a faulty chronograph? These results were only a few weeks apart in nearly identical conditions, around 70 degrees ambient so no extreme temp changes. The fact it was consistently so inconsistent has me scratching my head.
I am shooting a pretty much maximum load out of a 26" barrel so I do not think the higher velocity is outside the realm of possibility of the 7mm Rem Mag and the drops match up very well at that speed.
I am shooting a pretty much maximum load out of a 26" barrel so I do not think the higher velocity is outside the realm of possibility of the 7mm Rem Mag and the drops match up very well at that speed.