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300winmag OCW Test: Help

Jig Stick

Gunny Sergeant
Full Member
Minuteman
Aug 27, 2010
1,438
5
45
Pittsburgh PA
Im planning on doing an OCW test for my new gun. Its a 300winmag, McMillan Adj A3-5, BAT heavy repeater action, Kreiger Barrell, Jewel Trigger, Badger bottom metal, Cerakoted. Im shooting Hornady 208g Amax 0.001 off the jam. I shot this target with 70g of Reloader 22:



I got a few targets like this, dead on, but with vertical stringing. My buddy told me that this is a tell tale sign of needing more powder? Do you guys agree?

Max load in my manual for this bullet is 74 grains. Im trying to determine where to start my powder charges for the OCW. I was thinking of doing the following:

71g
71.5g
72g
72.5g
73g
73.5g
74g

Would you guys use smaller increments? Or is this ok to start with? I only have 25 pieces of brass on hand so this is about the max amount of differing charges that I can test today. Any help would be greatly appreciated
 
Re: 300winmag OCW Test: Help

How far away was your target ? My 300 win always shot well (Savage) I re-barreled at 2K rounds. After re-barreling it still shot well but didn't shoot exceptional until I got real picky about the brass I used. I think .5 gr increments will get you close. I know my rifle used to shoot well with 72.5-73.5 gr of RL-22 but I have found that H-1000 works alot better with the heavier projectiles. I shoot the 208 Amax at stuff that doesn't bleed and 210 Bergers at the stuff that does. I have found that the OCW/Ladder test works the best the farther away you can get, for me on a very calm, cool day. I think it is tough to do a test like that with the 300 win, everything gets hot in a hurry so you need a long time to get it done. I am not against them but I shoot a new load or loads over a few days at different yardages and when I get one hitting near the Point of Aim very consistantly, I get out the chrono. Set your target at 300, try the .5 gr increments, make sure your brass isas good as you can get. Good luck
 
Re: 300winmag OCW Test: Help

Im using CCI magnum primers and virgin Winchester brass. The range that I routinely have access to in only 100yards, and thats what I shot that target at. On occasion I have access to 400yards. I just want to get close to an optimum charge. Im probably going to use H1000 for my hunting loads, with Barnes Triple Shocks. Ive had good luck with those for hunting. But right now Im working on my target loads, which is why Im using R22.
 
Re: 300winmag OCW Test: Help

Check your brass to ensure you have then grouped to size, some guys weigh, some guys measure internal volume. I have found that at 100 yds finding the optimal charge is tough because you won't find much variation at that range. I bet you will from 72.5 -73.5 gr of RL-22. I am always faster with a Fed 215M primer than I am with a CCI.
 
Re: 300winmag OCW Test: Help

here are the results of my OCW test. It was 90 degrees outside, 0 wind, mirage was decent. Shooting at 100 yards off a harris bipod and rear bag.

70g Reloader 22, 208g AMAX, Virgin brass,CCI 250 mag Primer, 0.15 from the jam. I accidently seated these too deep and used them as foulers:



71g Reloader 22, 0.005 from the jam



71.5g Reloader 22, 0.005 from the jam



72g Reloader 22, 0.005 from the jam



72.5g Reloader 22, 0.005 from the jam



73g Reloader 22, 0.005 from the jam



73.5g Reloader 22, 0.005 from the jam



74g Reloader 22, 0.005 from the jam



This is what I am shooting with. A Bat Heavy Repeater Action, McMillan Adj A3-5, Krieger 1:10 26inches, Badger DBM, Jewel Trigger, Badger Rings, Leupold Mark 4 M5 ERT with TRM reticle



Any opinions on what powder charge you think is best would be great. I also think that the 208g Amax likes some jump, atleast in my gun
 
Re: 300winmag OCW Test: Help

Amongst about a dozen rifles that I've personally developed loads for the 208 Amax in, every single one of them shot the best at 0.015-0.020" jump.

They all shot terribly (1+ MOA) when jammed.

I have worked with several 300WM's and the best thing since sliced bread seems to be H1000. It gives great velocities, a pretty full case, and temp stability.