Where to next??? OAL or powder type?

[twintips16]

Hows it going guys!!

So this is my first post in the reloading section.... So eat me up!!! lol

I have been reloading for about ten years now and have never reloaded for "accuracy".

In the past i have loaded for several different rifles in the same caliber. I have always had to reload for friends and family and had to find loads that would work "good" over a broad spectrum of rifles.

I have never had a problem achieving 1 moa accuracy over all out of all the rifles. But i have never had the chance to reload for one rifle and fine tune it.

My question is where do you start to fine tune loads with a rifle.

The rifle in question is a custom made 7mm WSM. Im shooting the 160 accubond right now but have some bergers in route as i speak(180's and 168's)

I would like to make the accubonds work but am not settled on it.

I guess my post boils down to asking what first.

Do i mess with the OAL and find a seating depth that will work better with the rifle? Or do i load a bunch of different powders to see if it prefers one over the other.

I was thinking of loading 5 groups of 7 rounds each, and each group with a different OAL by .025. Same powder and charge. Shooting two groups of 3 with each one and seeing if there was a "sweet spot".

Would that be a bad first move?

 

[varmintH8R]

My personal opinion is that OAL is a good place to start. Once you nail down an OAL range for each bullet type it typically won't change dramatically powder to powder. Hope that makes sense - different powders will give different results but your OAL "sweet spot" should be about the same (for each bullet).

I recommend measuring OAL to the bullet ogive, and always relating it to how far the bullet sits off of the lands of the rifling. This will help you better understand the different preferences of different bullets and will make your precision loading more repeatable.

As far as your 5 group test, it should work but you may want to reduce the changes to OAL. For instance, seat:

Touching the lands
10 thou off the lands
20 thou off the lands
30 thou off the lands
45 thou off the lands

See what your results are and load up a second set refining the range with the most promise. There is also a sticky on Berger OAL at the top of the reloading forum that is excellent.

Good luck

 

[ICANHITHIMMAN]

Berger's are a different animal, it requires a different approach. First you need to do a pressure test at the max COAL you can run in your rifle(mag box if you don't have an extended or don't want a single shot), work up slow look for signs of pressure. When you reach the book mag load stop.

Next you need to load up for a 24 round seating depth test, 4 groups of 6 rounds fired at a range of 200 meters or more. This test gets you close as you will see one of the groups will be much better than the other 3. You will need 4 different seating depths that can be found in the article I have linked in my signature line.

Now the accubonds are a little simpler, you will need to do a ladder test, I suggest 3 rounds at ever charge weight from min to max. You again will see a pattern some loads will be better than others. Seating depth will not matter much with these bullets, if you get a load close to what your looking for you can try switch primers.

Remember with all these loads we are looking for a balance, if you have a chronograph use it in your load testing. Fire all the loads over it, we are looking for the lowest ES, SD we can get!