Seating depth

[andydrose72]

So I have found a powder charge in my 260 that it seems to like. Holding right around half and three quarter minute. This was achieved with the 140 amax just touching the lands. When developing further with seating depth how far are you guys jumping before you consider the load no good and move on?

 

[bjay]

On my custom 260 my touchin land oal 2.885.. load my 139scenars 1.870 thats 15thousand off land and my best group 500yrd 1 3/8 (.263 moa)..i tried INland. Up to .020 but .015 seems what she lyk..so i stoped fixin somethin i think its not broken

 

[Aimsmall55]

So I have found a powder charge in my 260 that it seems to like. Holding right around half and three quarter minute. This was achieved with the 140 amax just touching the lands. When developing further with seating depth how far are you guys jumping before you consider the load no good and move on?

First of all, what's your powder charge, brass type , and what type of rifle??

 

[andydrose72]

It's a savage model 12 lrp. 260 rem, lapua brass, 46.6 grains h4831sc, cci 200 primers, 140 amax seated to the lands currently producing between half and three quarter minute groups.

 

[wchartz]

Most all of my accurate rifles like 20-40 thousanths jump. I have yet to have a rifle that shoots best with the bullet touching the lands although one of my friends who reloads a lot has one that shoots good touching. Don't expect a dramatic improvement in group size by varying bullet jump.

 

[Aimsmall55]

Most all of my accurate rifles like 20-40 thousanths jump. I have yet to have a rifle that shoots best with the bullet touching the lands although one of my friends who reloads a lot has one that shoots good touching. Don't expect a dramatic improvement in group size by varying bullet jump.

Dead on. 20 to 30/1000's with amax.

 

[andydrose72]

Well hopefully its enough to get me down to consistant .5's. If not I guess its time break into my 4350 stash and try that. I may pick up a box of 140 bergers as well. I see no reason why thisgun shouldn't produce like my model 12 fclass did.

 

[bodywerks]

Agreed. I'm right at .020 off the lands with my 140 amax. Anything closer was noticeably less consistent and less accurate.

PCR/XLR/TAC338 http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111453_255_zps1b498f0d.jpg http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111325_951_zps290ebdd0.jpg

 

[JB02]

You have to run a test. Every rifle is different and this changes depending on your bullet/powder combination. I do the following with 5 rounds at 100 and 5 rounds at 400:

- touching
- 0.010
- 0.020
- 0.040
- SAAMI

After that, you can play with neck tension too. Be careful how far the rabbit hole you go chasing that ever elusive perfect load.

 

[andydrose72]

Thank you LCDR. That is kinda what I was thinking. Not sure I can seat to SAAMI as when I did my pressure testing the bullets were seated to the lands and at 47.5 grains the compressed powder was pushing the bullet back out the case a bit. It measured .005 longer after it would not chamber easily like the other rounds. I chose to stop and not fire that one. Never did see pressure signs though.