7mm Berger 168's & 180 targets

[barefooter56]

barefooter56, my 5 velocities were 2988,2992,3003,3005 & the high shot was 3022. As far as pressure goes, I have no heavy bolt lift, primers look good but I am getting a very slight extractor mark on a few cases. I'm using Norma brass which I've heard is softer, temps have been in the mid 70's while shooting, been told by a few people that it's a pressure sign and a few people saying not to worry about that! What are your thoughts! Thanks.

Rogmay,
You mean ejector marks ? NORMA can be soft and you say the primers look good ( edges still rounded not squared off , no cratering starting?) I would say you may be getting close so if you do work up the load. I would suggest .1 increments. Do you have either the Extreme Spread or Standard Deviation numbers besides the velocities ?

 

[Rogmay]

]Barefooter56, yes I do mean ejector marks, and as far as the brass goes the edges do look rounded when looked at closely and there might be slight cratering, I'm attaching three pictures from loads of 65, 67 and 69 grains of Retumbo. I guess as far as extreme spread by looking at my velocities it would be 34 FPS and as far as standard deviation goes, not quite sure how to calculate that one out !

 

[Rogmay]

Here are the other 2 pics! (Hopefully)

guess the pic thing isn't working so great!

I'm done!

 

[Rogmay]

Clownbuster, just finalized load for my 7mm and did the same box test as you with my VX-6, 3 shots in center, 16 clicks down and rt, took one shot, adjusted 32 clicks back to the left, shot once, then back rt 16 clicks and up 16 and shot 3 more! Also did one with my 6.5 with a Vortex PST on it! The Leupold was good, not quite as good as your ATACR, but I'll take it, the Vortex was off a little as well, about as good as my Leupold!

 

[barefooter56]

View attachment 62692Here are the other 2 pics! (Hopefully)

guess the pic thing isn't working so great!

I'm done!

Rogmay,
You are kind of hot there man. only 1 picture came through but I think I would back off a little on the load. What was the temperature when you shot these? I think on the ES and SD we need to know so if you could run these loads across the chronograph again so we have more solid information please. That would be great!

 

[Rogmay]

Barefooter, temp was around 75 to 80° when I Shot these, I backed the load from 69 down to 67 grains Of Retumbo and extractor marks disappeared, bolt lift feels real easy, primers I can see are now rounded on edges! Hopefully should be good to go! Thanks for the input!

 

[barefooter56]

Barefooter, temp was around 75 to 80° when I Shot these, I backed the load from 69 down to 67 grains Of Retumbo and extractor marks disappeared, bolt lift feels real easy, primers I can see are now rounded on edges! Hopefully should be good to go! Thanks for the input!

Rogmay,
Good move.