.308 200-grain bullets and fast powder

[Ilya S.]

Hello guys.

Now Im waiting a 32" 10 twist heavy palma chambered for 200.20x hybrids.
Yesterday I tested 200.20x bullets (0.050 off the lands, coal is 3.110) for pressure sights and recoil difference on my factory 26" 12 twist barrel and our analog of IMR3031/H322 powder - "sunar 308", have a exellent speed, good Extreme Spread with no pressure sights - 2600-2615fps. But it was a 10 shot group with magnetospeed without any accuracy control and POI spotting.
So I have two reloading questions :
Could the fast powder like IMR3031 or Hodgdon H322, with this bullets, give me a good accuracy ? Or its strongly reccomended to use slower burning powders like IMR/Hodgdon 4895, Varget and Vihtavuori N140 ?
Anybody tested heavy bullets like 190 or 200 grains in .308 with imr3031, h322 ?

Best regards,
Iliya S.

 

[jim_k]

Almost all long-range shooters are using either Varget (#1) or H4895. These powders shoot more consistently when the temperature changes. IMR3031 and H322 are excellent powders, and they are two of my favorites. H322 is also good when the temperature changes. With 3031 and 322, the velocity will not be as high as with 4895. The powder will not determine the accuracy in any application, in my experience. The accuracy and the size of the groups depends on your load development. Of course, for long range shooting, more speed is better, due to speed giving less wind drift. I test bullet seating depth from 0.010" off the lands to 0.120" off the lands. I start with 0.010" off the lands, and load five cartridges. I do the same for 0.030", 0.050", 0.080". I shoot those, then pick the one that has the smallest group, especially the vertical part of the group. Then I test for seating depths close to that, and pick a seating depth. Then I do the same sort of test for powder charge, using the chosen seating depth from the first round of tests. Then I pick my load, check it with the chronograph, and verify my drop chart at various ranges, out to my maximum. I also use QuikLoad and the optimum barrel time chart from the Long Family site to start the load development process. For long-range shooting, I recommend Strelok Pro from Igor Borisov. He updates frequently, and has developed a great program for the cellphone. Everything should be Ochen Khorosho after that. (That's about the limit of my Russkiy yazik.)

 

[Ilya S.]

The powder will not determine the accuracy in any application, in my experience.

Its what im want to see. 10x. On my new 32 tube velocity will be 2650-2665 fps with .015 jump like guys tested it in fall 2016. It was only pressure/velocity test with specfic coal/cbto for new .190 freebore chamber. On facrory Rem700 PSS 26" barrel freebore is .280.
You bring me a good idea to test 0.010-0.015 off the lands from factory barrel, but 12 twst doesn't inspire trust.
Im using Applied Ballistix Mobile, its perfect for my tasks. Let me expand your limits, with new word - "Zaebis" what means the highest form "Ochen Khorosho"

ps
Im using Redding Type S Match die set with .336 bushing and 55.65 H2O capacity(fireformed) Lapua LR primer brass, and KVB-7 primer (Its also known as "murom", "wolf", "tullamo" in U.S.)

 

[jim_k]

Thanks for the new word! If your barrel has 1:12" twist, I think the heaviest bullet you will be able to trust is the Berger 168 grain VLD. However, with 2900 fps velocity, that will shoot 1,000 yards just fine.

 

[T-shooter]

Hello guys.

Now Im waiting a 32" 10 twist heavy palma chambered for 200.20x hybrids.
Yesterday I tested 200.20x bullets (0.050 off the lands, coal is 3.110) for pressure sights and recoil difference on my factory 26" 12 twist barrel and our analog of IMR3031/H322 powder - "sunar 308", have a exellent speed, good Extreme Spread with no pressure sights - 2600-2615fps. But it was a 10 shot group with magnetospeed without any accuracy control and POI spotting.
So I have two reloading questions :
Could the fast powder like IMR3031 or Hodgdon H322, with this bullets, give me a good accuracy ? Or its strongly reccomended to use slower burning powders like IMR/Hodgdon 4895, Varget and Vihtavuori N140 ?
Anybody tested heavy bullets like 190 or 200 grains in .308 with imr3031, h322 ?

Best regards,
Iliya S.

I wanted to get the maximum range out of my 22" .308 bolt gun. I went with Varget because of the temperature stability. I loaded these for maximum velocity, not accuracy. The load was Hornady match brass that had been fired once in the same rifle. Neck turned, using .001" interference fit. I used the Hornady ELD 208 grain bullets set .025" off the lands. I get an average of 2,435 fps at the muzzle. I only have room to shoot out to 450 yards but have been able to get multiple 6-8 shot groups under 1/2 MOA. I never worked up the load except checking for pressure signs. The COL averages 2.968" - 2.970".

 

[memilanuk]

...but 12 twst doesn't inspire trust.

A 12 twist wouldn't be my first choice for bullets over 175 gn, but the 185 Juggernaut brought home the bacon (gold) for the US FTR teams in 2013, using 12 tw Kriegers barrels.