• Quick Shot Challenge: What’s the dumbest shooting myth you’ve heard?

    Drop it in the replies for the chance to win a free shirt!

    Join the contest

Sierra 155 palma OAL problem

High Binder

Resident Tribologist
Full Member
Minuteman
Jun 18, 2008
493
25
Occupied Colorado
Guys, I'm unable to find OAL when loading Sierra 155 Palma because the beginning of the rifling is a bit further than the brass will allow for seating. So should I just seat the bullets just enough to hold them in the neck or what? most of my other rounds seat well and end up around 2.985" these ones being so streamlined are just a mystery to me.

700 PSS .308
Nightforce 5.5-22x50

Thanks in advance!
 
Re: Sierra 155 palma OAL problem

I presume this is the new S155MK, model 2156? If so, it has a *very* short bearing surface (0.230" or so) and isn't really meant to reach the rifling in a gun like yours - Rem 700 VS/PSS etc. tend to have very long lawyer-mandated throats. The good news is that a lot of these bullets will shoot very well jumping a *lot*. One old thumbrule for seating depth is to try and keep at least 1/2 caliber of bearing surface in the neck. I'd try maybe backing your seating depth down to that point and give it a whirl.
 
Re: Sierra 155 palma OAL problem

As Monte said, these bullets need to be jumped. I ran on them at the lands and my 1/4 MOA rifle went to a 1 1/4 MOA rifle.

Jump them 40 or 80 thou; longer if you have to in order to keep them in the case.
 
Re: Sierra 155 palma OAL problem

Thanks guys, I was worried I was fucking it up. I trim my brass to 2.008" and then sat these (2156) right at .202". So it looks like if I follow the half diameter seating I could push out another .048" which would still give me a pretty good (>.150") jump.

Thanks for the info guys!