Load for the SPS Tactical

[freezingduck]

I bought a SPS tactical a year ago, i have put about 2000 rounds downrange with it.
1500 of it is with 150gr factory Norma jaktmatch.
It shoots .5 moa at a 100 with this ammo.
I reload for the 6,5x55 and get consistent .5 moa using a diopter with my sauer 200 str.
so i loaded up 50 rounds from 40-44,5gr vihtavuori N-150 using 168gr sierra match kings.
i struggle to get below 1,5 moa with this load.
I thought the 44gr went the best, so i loaded up 6 rounds with 44 gr, sent it downrange only to see two more 1,5moa groups.
tested the norma ammo at 450 yards, 3 inches.
does anyone have any reccomendations or loads with vihtavouri and the 168gr sierra MK?
its a 1/12 twist.

 

[glock24]

Re: Load for the SPS Tactical

The powder of choice here in the States for 308 Winchester and 168g/175g bullets is Hodgdon's single base Varget powder. I understand however that you'd rather use Vihtavouri powders due to availability. Viht makes great powder, you just need to find the right one.

What I'd recommend is that you use the Viht powder that best matches the burn rate of Varget. From Viht's own burn-rate chart , it appears N150 is significantly slower than Varget. I would suggest that you try the faster burning N135 or N140 instead. Your results WILL be much better. With the short barrel of the SPS Tactical, I'd lean toward the N135 powder myself

 

[freezingduck]

Re: Load for the SPS Tactical

When I started out reloading for the .308, i looked it up on reloaders nest, and the N-150 was by far the one with the most loads published, thats why I went with the N150.
Does anyone have any good loads on the N135?

 

[freezingduck]

Re: Load for the SPS Tactical

how far down from max load does you guys start, with the N150 I started at the minimum and worked up with .5gr increments, and the first five loads was way underloaded with black necks.

 

[glock24]

Re: Load for the SPS Tactical

The black necks are a sign of low pressure, as the case isn't sealing against the chamber. This is the result of slow powder and a short barrel

N150 may work fine in 26" barrels, but it's not ideal for your SPS-T.

Personally, I'd start with 40.6 grains of N135 and work up in 0.3 grain increments. Go slow, and watch for a sticky bolt and ejector marks on the case head. You'll know when you've reached your pressure limits.

I found this while digging around the SH reloading depot;

<span style="font-style: italic">tikka t3 tactical - 24" barrell - 1/11 twist - 308 win
170 Lapua lock base
42,5 g VV N140
OAL 2.85
primer CCI BR2
</span>

 

[freezingduck]

Re: Load for the SPS Tactical

I will get a box of N135 and start all over from scratch.

hoping for better results