260AI Questions.


Well-Known Member
Oct 19, 2008
UP of Michigan
Do I start ladder testing for my 260AI at max 260 loads of H4831SC?

Also I bought magnum primers because I predator hunt in the cold usually 15degrees or colder here in Marquette. Anyway I bought the primers because I thought I read somewhere that use magnum primers in extreme cold, large powder chargers, and ball powder. So can I find my winter load of H4831SC and magnum primers in fire formed cases near the top of the 260 Data?

thanks for all the help. Good luck this hunting season It just started for me here in Michigan.
Last edited:
Magnum primers are not needed but will work.

Start at the listed max for a standard 260, if you are using formed brass that is already blown out to your chamber.

I think my load in my 260ai is 3 grains over book max for the standard 260, with 4831 sc and cci-200. You might want to do pressure testing to find your acceptable working range with that powder before loading the ladder.
You may want to try RL-17 with the heavier bullets. It is my top choice with 140gr bullets. It has also been very temperature stable for me.

I've noticed a lot of people were using RL 17 or similar burn rates on the heavier bullets most people saying that they weren't getting the velocity out of h4831sc. I got a pound and 1000 Magnum primers to use up because I can not find reg Large rifle.
I am using IMR 7828 SSC out of a 30" Shilen prefit on my Savage 10 FCP McMillan. I am shooting the 123gr Lapua Scenar to 3200.. I was planning on shooting the 139gr but got a box of the 123gr at the Alberta Long Range Challenge and thought what the heck...

I have found this to be quite accurate..

I used 49gr as a fire forming load then worked up from there once my cases were all formed..
Warning! This thread is more than 14 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Recent Posts