Tikka T3 Stainless action.
Tikka Super Varmint Stock.
Lothar Walther 26" 1 in 8 twist barrel.
Throated to shoot the 69 Grain Sierra Tipped Matchkings.
Oversized Bolt Knob.
Ase Utra CQB sound moderator
Stainless Optilocs
Sightron 8-32x56 LRIRMOA Scope.
Built by Dave Folwell at Bowtec
Been over to Garland today to do my first load development with my new 8 twist 22-250rem. Since collecting the rifle the weather has been horrendous, so I booked in to Carlton Moor on Monday evening to see how it grouped. However, I came home from work this morning to find the weather at home was quite mild with very little wind so I headed over to Garlands for a few hours.
I have been playing with Quickload for while trying to find a good bullet/powder combination, after trying a few different permutations I settled on the following.
Sako Brass
Federal 210m primers
Sierra 69 grain TMK bullets
RS60 Powder
COAL 2.542"
After running Quickload I decided to try 0.010" off the lands with powder charges from 36-39.6grains, increasing in 0.3 grain increments. I was a little sceptical of the velocities quickload was predicting, they seemed a little to high to me, so I started with a really low charge of 36 grains and went from there, I was trialling 3 shot groups at 116yds on the Garlands range.
After getting the new scope on target I was ready to go, the first 2 groups were poor, they were 0.9" and 1.3", to say I was disappointed is a massive understatement. I didn't get too disillusioned though, I had a lot more testing to do and on the third group the size shrunk to 0.500" so things were looking up.
Whilst the group sizes weren't great the velocities were very surprising, all groups tested were 30-100fps faster than quickload was suggesting, 36 grains of RS60 was pushing the 69grain STMK's out at 3300fps, 37.2grains was pushing them at 3400fps and my chosen charge of 38.4grains gave me 3 shot velocities of 3640fps, 3641fps and 3635fps which totally blew me away.
All groups between 37.8grains to 39.3grains were sub 0.520", I have decided to settle on 38.4 because it was the middle group of 3 groups which were 0.400", 0.250" and 0.350".
As I was leaving another guy turned up with a chronograph, I asked him if he would let me compare the velocities given on my chrono to his, I put the two chronos in tandem to compare and was pleased to see a slight variation of 20fps with my chrono giving the slower velocity.
Obviously you cannot take this load and put it straight into your rifle without proper load development but RS60 is a great powder in 22-250rem using the heavy bullets and well worth trying if you have a suitable 8 twist barrel.