Slight problem with my .308 loads in a GAP.

[Tomekeuro85]

I went shooting today, tried SMK's for the first time in my GAP.

Im using the 168's, Varget powder, standard CCI primers, and Remington brass.

Shot at 100 yards

I used 5 gradients of powder, two 5 shot groups per gradient.

41.5gr, 42gr, 42.5gr, 43gr, and 43.5gr as stated in the sierra manual as the max load. OAL was 2.800.

My average group size out of the 10 groups was about .75".

Most of them were between .7 and .8... One group was .3ish one was .4ish

I shot a hunting load (165 gameking) I had from before and three 5 shot groups were under .4" each.

Does anyone know what the problem could be? i sorted the brass and bullets by wieght as well. Obviously there are dozens of potential causes but any in particular, excluding my shooting?

 

[hydro556]

Re: Slight problem with my .308 loads in a GAP.

Problem? What are the symptoms?



ETA- What is the twist in the barrel? Personally, with my 11.25 twist, I had better luck with both 175 SMK's and 155 Scenars than I did with the 168 SMK's. I have noticed a trend in all 3-4 of the 308's for which I have loaded that is similar to the results I had with the GAP mentioned above. That is, that they all seemed to shoot both 155's and 175's better than 168's.

That said, I dont necessarily think you have a problem. It sounds as if you are just starting load development and are getting around 3/4 MOA. I think the GAP can shoot better than that, but that isnt an inaccurate rifle. At least to me.

 

[hydro556]

Re: Slight problem with my .308 loads in a GAP.

Also, I am a long way from being an expert reloader, but from my personal experience as well as from lots of reading, I am of the opinion that sorting (quality) brass and bullets is unnecessary for "tactical" rifle reloading.

I do use only Lapua brass though. I think you just need to keep developing the load and you will get better results. I dont know what your goal is, but if you can hold that 3/4 moa out to a decent range, it should do all you need.

 

[Ol Rob]

Re: Slight problem with my .308 loads in a GAP.

Best 168 SMK load I ever came across was on the front of the VARGET bottle. 46.0 grains. Any length, very forgiving on OAL. 2725 fps @ 2.860"
YMMV Rob

 

[Tomekeuro85]

Re: Slight problem with my .308 loads in a GAP.

I just dont like knowing that a hunting round can get a solid .3 moa and a match round cant beat .75 moa...


Maybe i'll try to work up a bit more powder... I went as high as 44.5 with my old rifle without any problems. I was also thinking to increase the OAL, seeing as the hunting round was all the way out almost touching the rifling.

We'll see hwo that goes. I know this rifle can shoot .3 easy, thats what im looking for with the match rounds.

 

[308sako]

Re: Slight problem with my .308 loads in a GAP.

.

 

[JFComfort]

Re: Slight problem with my .308 loads in a GAP.

Try playing around with your COL, blow out the neck of one of your pieces or brass and put a bullet in it stick it in your rifle to get your chamber dimensions.

I usually seat the bullet .02" off the lands and my rifle will shoot .75-.5 MOA all day.

Mine is no custom GAP but a 700 PSS that has been worked over a bit

 

[Queequeg]

Re: Slight problem with my .308 loads in a GAP.

Try Match primers (210s or BR2s) or another brand of LR primers for one and keep going up in .3 grain increments to 46 grains of Varg., or until you see pressure signs.

Those game kings are damn good bullets! Rem. core lokts aint bad either.

 

[Rob01]

Re: Slight problem with my .308 loads in a GAP.

If you want to see proper max powder charges look on Hodgdon's site in their reloading section. Sierra lists like 41.5grns as max for the 175 SMK and Hodgdon's starting load is 42grns and goes to max of 45grns. As mentioned the listed max for the 168s is 46grns of Varget. I would work up watching for pressure. I'm betting you'll find a better load between 45 and 46 grns.

 

[One_Man]

Re: Slight problem with my .308 loads in a GAP.

match primers, different brass (lapua, win), more varget try 44-46 grs