firstshot

Took my new F1 Chrony to the range yesterday and checked out the 140 Grn Accubonds on top of Varget. Got the following average velocities from my Rem 700 Mtn LSS 22" barrel using the top three powder charges.

41.0Grn 2,673 FPS
41.5Grn 2,716 FPS
42.0Grn 2,752 FPS

Do these velocitiessound reasonable for a 7mm-08, 22" barrel & 140Grn bullet? What velocities are you 7mm-08 shooters getting from 140Grn bullets?

Anyone know how to check the accuracy of a chronograph?

Thanks

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Roskoe

You could probably get into the middle 2800's with RL 19 . . . .but these loads sound about right for the 22" barrel. Most of the stuff in loading manuals is clocked in a 24" tube.

firstshot

I might just give some RL 19 a try. Nosler shows the max load of 49.0 grns as a compressed load, but Imight nothave to go all the way up to max to hit 2800 FPS.

Thanks
firstshot
--------------------------------------------
Make your first shot count!

Roskoe

As far as checking accuracy of chronographs, I have seen severalchronographs lined up end-to-end along an eight foot 2 X 10, and shot a single round through multiple chronos. They do this at IPSC matches to check power factors. Got any buddies that also own a chronograph?

B-blaster

I have chrono'd max loads with my 7-08 with a 22" barrel with 139 gr Hornady Interlocks and got this:
46 gr IMR4064, 3020 fps tested at 75 degrees
50 gr H414, 2970 fps tested at 75 degrees
49 gr H380, 2940 fps tested at 80 degrees
46 gr IMR4895, 2930 fps tested at 62 degrees
45 gr Varget, 2900 fps tested at 75 degrees
Remember that temperatures at testing do make a differencein velocities so I test them all in extreme temp differences.Using temp insensitive powdersresult in constant velocities at varying temps. Varget tested the same velocities for me at 25 degrees and at 75 degrees whereas the others I listed showed some differences. The stick powders seem to show less differences at temp extremes than the ball powders in my testing.

firstshot

B-blaster

Wow! Aren't some of these a little "Hot". I could only find H414, IMR 4064 & Varget in my book. H414 looked ok but IMR 4064 & Varget seem to way past max. Couldn't find a reference for H380 & IMR 4895. Maybe I'vejust got an old book.

IMR 4064--- 46Grn vs 4.41 book max
Varget -----45Grn vs 41.5 book max

firstshot
-------------------------------------------------
Make your first shot count!