Range Report terrible groups with 155gr .308 rem sps

[maccrazy2]

I had some 155 smk palmas and a max loaded in nozler brass, cci primers and 48.8gr varget. This goes 2825fps out of my 18 in barrel. It is a factory sps with a 1-12 twist. I did load to mag legnth of the aics mag as these will be used in a match so they need to be mag fed.
I shot 2, 5 shot groups of each bullet and both were around 5.5 moa at 100 yards. Then I shot my normal 168 smk load going 2650 and it groups .75 moa.
I have not done any real load development with the 155s yet. I did a ladder test over a chrono when I was seeing what velocity I could get from the 18 in tube. The sierra website had the #2156 155 smk palma listed as .504BC at 2900fps+ before. Now it is listed as 2700fps+. I called sierra and was told it has always been at 2700fps so the website must of had a typo. I made it up to 2875 without any pressure signs but it was over book max and getting to a compressed load so I did not go any further. Once I found out about the typo on velocity I took the ladder test and chose 48.8 at 2825 and loaded some up.
I have put all kinds of commercial ammo thru this gun and handloads of 168's and 175s have all shot very well with varying charge weights. I have never seen a rifle shoot a group as bad as the 155s did. I know I can mess with the load to see what happens but I am changing to .260 this winter so I don't think I will. Has anyone ever come across similar issues with 155s in you rifle?

 

[maccrazy2]

Re: terrible groups with 155gr .308 rem sps

Guess it is just my rifle

 

[MontanaMarine]

Re: terrible groups with 155gr .308 rem sps

I've had some shitty groups pushing 155 Scenar too hard with W748 in my new-ish 700 SPS 308 Varmint. It does well with other loads though.

Here's a target from some testing I did with 155 Scenar, and W748, and RL7. Loads were 2.80" oal, and jumping roughly .150" to the lands.

As you can see, the RL7 loads did fine, the W748 loads were crap.

 

[error4o4]

Re: terrible groups with 155gr .308 rem sps

Factory SPS with an 18" barrel? No matter. I shoot an SPS Varmint with a 26" barrel and a shooting buddy shoots the SPS Tactical with a 20" tube. His has been pretty picky with 155 smk's.

 

[Aimsmall55]

Re: terrible groups with 155gr .308 rem sps

Try some 168 amaxs with 45.3 varget rem 9 1/2 primers seated as long as you can get em and still close the bolt with little or no tension . A 1:12 loves em

 

[Arkhangel5]

Re: terrible groups with 155gr .308 rem sps

Maccrazy,
I too am testing the 155 Sierras, but with IMR 8208. In a R700 26in heavy barrel. I loaded to mag length for initial tries, and the accuracy was terrible, 2MOA at 200yds. Best group was a little over 1in @ 200yds, vel was ~2910fps.

Next test will be seating out further and single loading. Am just trying just because I have the bullets and the powder.

SY

 

[CrispySqrl]

Re: terrible groups with 155gr .308 rem sps

I haven't tried SMK 155 but I have shot nosler 155 44gr Varget and i get pretty good results at 200yds I got about .5MOA my best group for the day but the 168 smk's did seem more consistent. So I plan on doing more load development with them. Chrono is on its way so that will be a big help too.

 

[MitchAlsup]

Re: terrible groups with 155gr .308 rem sps

fourty SEVEN point 8 (47.8 in Win brass, 47.4 in Lapua brass) is a well known accuracy node for std length barrels (20-24) with 155s {secnar Berger, SMK}(still compressed).

 

[maccrazy2]

Re: terrible groups with 155gr .308 rem sps

Thanks guys. I am waiting on a new .260 barrel this winter from krieger. I am just going to stick with the 168s untill I rebarrel.