I installed my 375 cal Bartlein "T" twist or Gain twist barrel and chambered it in my 375 Snipetac caliber. The barrel starts off at 1 turn in 16" twist at the breech, speeds up to 1 turn in 7.75" at the muzzle,31" long. This barrel is intended for the new style Alum tipped high BC bullets, but for barrel break in I will be using the 350gn Sierra Matchkings.
Viersco Custom repeater action
double helical fluting on bolt
Manners MCS T2 carbon stock
Bartlein stainless barrel, 31"
Detachable 5 shot magazine system
30 moa scope base
8-32x56 nightforce scope
17.25# with Bipod
Starting test results were done during shoot n clean barrel break in.
fed 215 primers
350gn Sierra matchking bullet, seated to touch lands.
2919 Ave fps ES 5 .780 group
2949 Ave fps ES 8 .665 group
3001 Ave fps ES 7 .195 group
This group was fired with no cleaning between shots. Shot 1 was clean barrel, 2-3 and 4 were
in a ragged hole.
I am working up to the top load as I break in the barrel, all of the test loads show no pressure signs. I was shooting 140gns in another one of my rilfes chambered for the same case. I will take my time getting to the top load while break in of the barrel. Once this is done I will switch over to the 370gn Alum tipped bullets and stretch out the range to 500yds.