MCR Howa 308 OCW load test 165 IB

[zupatun]

Went to do load development with the 308 using win brass, Federal 210 large primers and 165gr interbonds and loaded with Varget. Temps were from 90 to 93F outside. 450ft above sea level. Chrono data was taken by a ProChrono set up 5 feet away from the muzzle.

Kevin Cram of Montour County Rifles installed the 26" Broughton 5.5contour 5C barrel and trued everything up. Bell and Carlson Medalist stock bedded with Devcon and a home-made Kydex cheek rest.

I have got to get a better portable setup. My plastic table is kinda rickety and on the rocks where I'm shooting it's hard to find a spot where it isn't solidly placed...it's also narrow so I used a rear monopod...needless to say I had to work to keep myself, the table and crosshairs from moving...other problem was I left my chairs at the house (40 miles away)...so we had to drive my Jeep up to the back of my table and sit on the bumper--every time my boy gets up it throws off my sight picture etc...needless to say groups up to 2MOA were the worst and around 1moa the best...no optimal for testing, but at least all the shots were made in the same condition.

The groups settled down at 44.5gr and the second at 46.9gr.

the lower group had an average of 2773fps and and ES and Sd of 35 and 16.7.
The group at 46.9 had an average of 2882 and ES and SD of 37 and 16.4 respectively.

Primers for the higher load were cratered a little, but no more than the Federal factory 165gr hunting rounds I used to sight things in. In fact the factory rounds leave some ejector hole marks on the brass and the signs on the 46.9gr of Varget were less than the 165gr factory rounds from Federal--just beginning to show...

Velocities seem high...

I used 4 shot groups.

My Tikka used to like 44.5gr of Varget, but I didn't have any Chrono data.

Matt

 

[ICANHITHIMMAN]

I enjoyed your thread but you have broken the unwritten rule of rifle thread posting! You forgot pics of the rifle man

 

[zupatun]

I only had a little time to post earlier...will get to it when the kids get to bed...if I make it. Looooooooong day.

 

[zupatun]

I looked at the 46.9 and 46.1 rounds from the test. I could see one ejector mark and slight cratering. Here's a pic:

The factory rounds I used to sight in were similar--Federal 165gr (power point?). Bolt lift on both the factory and 46.9 grains took a little effort. Here's a pic:

Strange thing is during barrel break-in I was using Winchester 150gr super X rounds and most all of them had much worse cratering, stiff bolt lift and very easily identifiable ejector marks on each round...got less towrd the last few rounds:

Next step is to load some around 44.5 and around (below) 46.9 and see which groups better. I'll do this at the range (100yd) and then follow up with longer tests at 300+ on my piece of land I hunt.

On the bipod:

 

[ICANHITHIMMAN]

Great rig very nice Kevun built my HOWA as well

 

[OKIE2]

I read your post 2 times and you never said what powder you used.
But I would say you have a lot more testing to do your group of 1.2 is 3 times what my cheap savage rifle shoots with
168 amax and 39.5 grains of imr 3031 2550 fps.
It shot a 10 shot 0ne hole group at 100 yards

 

[zupatun]

Varget, Sorry. Fixed it in the first post.

 

[trebark]

I read your post 2 times and you never said what powder you used.
But I would say you have a lot more testing to do your group of 1.2 is 3 times what my cheap savage rifle shoots with
168 amax and 39.5 grains of imr 3031 2550 fps.
It shot a 10 shot 0ne hole group at 100 yards

I agree you have more testing to do. Both your accuracy and your ES/SD need to improve. Even if you find a load that's .5moa at 100 yards, but has an ES of 31 (your best ES), you need to reduce the ES to 15 or less.

 

[zupatun]

I agree you have more testing to do. Both your accuracy and your ES/SD need to improve. Even if you find a load that's .5moa at 100 yards, but has an ES of 31 (your best ES), you need to reduce the ES to 15 or less.

Exactly what Kevin said in a PM...definitely a problem from 600 to 1K...magnified at 1K...

Along with the next set of reloads I'm also going to suss out a box of Federal Match ammo. The tube still doesn't even have 100 rounds through it yet either....

Thanks all,

Matt