Hi all, I'm fairly new to reloading, and just tested a .308 load that I came up with using the "ladder method". It's a 175gn MK with 41.4 gns of RL15. I tested 10 loads and got an ES of 64. I FL resized and trimmed and chamfered the necks. I'm using CCI BR-2 primers. What should I pay most attention to next if I want to reduce my ES?

Hello savageshooter,
I got the tip of sorting the brass by weight.
I mainly use Norma brass and the weight difference in 7x57 Mauser is about 2 grains.

I have no idea if this will help but if the difference is located in the wall thickness it should improve your ES by sorting by weight.

As a rule, I find the most consistent vel when the powder is slightly compressed.

Others on this board have far more experience than I, and they will surely provide more tips.

All the best

Jens

Forgot to mention that I was using BlackHills match brass, but didn't do any sorting. I'm wondering if attention to cleaning the inside of the neck and neck thickness is the key. I don't know where all the case prep items stand on the scale of most to least importance.

Very unconventional approach, but here it goes...

Don't use a chronograph for load development. It isn't necessary, and can be quite distracting.

If the Audette method played out properly, your load should be a good one.

Forget the chronograph for the moment and see if the load passes the "OCW" test. That's "optimal charge weight," I call it. My website link is in my signature line, where I explain it better.

Anyway, load 41.1 grains of RL15 in one case, 41.4 grains in the next case (normal load) and 41.7 grains in the third case. Shoot all three of these varied charges into the same group at 300 yards, and see if they hold MOA. They should actually hold a bit better than MOA, since you're only varying the charge about .75%...

If they will not hold MOA under the low charge/high charge conditions, it really doesn't matter what the velocity is, as the load is not optimized.

If they do shoot MOA at 300 yards (with the -.3 and +.3 charges in the same group) you've probably got a great load.

Then chronograph the load to see what the velocity is. If it isn't satisfactory, you may want to go to another powder, because if the charge of RL15 is truly optimized, adding more RL15 to the recipe will destabilize the load.

For what it's worth, the M118LR military sniper load uses 43.4 grains of RL15 behind the 175 grain Sierra Matchking. That's a hot load--I've tried it and I don't believe it is optimized. I wouldn't recommend trying this load, as I had hard bolt lift on two different rifles with 43.4 grains.

My best groups from RL15 with the 175 SMK have come with 42.8 grains of powder, but I did not test that load in the manner mentioned above.

Let us know what you discover...

Dan Newberry
green 788

Thanks Dan. I guess it would be a good idea to re-verify using the Audette method. I've been shooting at 200yds due to the continually windy conditions at my range. I incremented charges by .2 grains each. I found the loads from 41.0 to 41.6 were within .25" verticle dispersion. Three of them were touching. It's funny though, looking at my target again the load at 42.8 was also touching, but after that I had changed targets. It does imply that I was getting back to that part of the barrel whip though, and may be a second range to look at further.

If this is a long range load then turn all the necks and otherwise prep the brass and separate them by weight. This just eliminates another variable.

Of course if the necks don't vary it's not necessary but just skimming them with a tight fitting arbor won't hurt. It's hard to believe they are perfect.