About to start playing with the 139's,

H4350, likely around 42.6 grains, CCi 200 primers, 6.5 Creed.

Thinking starting maybe .020 back,

Just wondering if these are known to prefer any certain setback.

The 139's I've developed loads for have not been finicky at all. I always start at .02 off max mag box length and go from there.

JG, if I recall your shooting a Tikka, Your limited by mag length rather than by the lands?

Yes Kenneth. I'm still off the lands at max mag box OAL. I don't recall how far but it isn't much.

Kenneth, prudent to start off at 41

Understood, Been shooting the 140 Berger Vld and worked up to 42.9 with no issues,

It certainly clearly shows a preference for 42.6 with the Bergers, I'm just assuming this barrel likes around 42.5 with the 139/140 class,

And yes, starting around 41.5 working up in .2 increments, 10 loads from 41.5 to 42.9

I questioned the upper 42 grain loads myself, most reference materials say I'm too hot, but numerous other people have stated the same results in their guns.

It shoots the Bergers so well, I'm not real sure why the need to continue on looking for improvement,,,,

I went to the range today and used 2.820" for all of my 139gr Scenar loads.

Started at 41.0 grs of H4350, 41.5, 42.0 and 42.5. All with 5 shot groups. Federal gold medal large rifle match primers, Hornady 1x fired brass.

My 2 best groups were at 41.5, which gave a nice round .76" group. The 42.5 gr load gave a .83" group that tended to be vertical. Factory loads seem to do the same.

I did not check velocity yet.

The primers were a wee bit flatter with the 42.5gr load but nothing that made me not want to use that load again.

Those groups matched the accuracy that the factory 143 ELD X is giving me. Those are running 2655 fps out of a 26" barrel X Bolt.

I guess the next order of business is to play with COAL after I check velocity.

Interesting that no scope elevation adjustment is needed with the above loads and the factory ELD X load. Hand loads shot about 1/2" to the right though.

This is one bullet that doesn't seem sensitive to seating depth IME.

My experience being in a 1:8" Tikka T3 .260 Rem and a 1:9" .264 Win Mag. The .260 is just under max mag box length ~2.800". The .264 shoots great anywhere from a kiss to 0.040" off lands.