Looking for a 308 load that stays super sonic past 1000 yards

[genebofunk]

I'm shooting a 1000 yard fun match on Saturday and am trying to come up with a load for the 1000 yard stage. I'm using an m1a with hornady 178 grn AMAX with imr 3031. The hornady manual doesn't give me a formula for this combination. Since this is a recreational match if I need to I can load each individual round rather than them being magazine fed if this helps. Anyone got any suggestions for such a load?

 

[627PCFan]

Look at Hodgdon Varget warm loads @ around 2700 fps. According to Hodgdon, max loads with IMR wont get you over 2650.

 

[LiveLife]

Looking for a 308 load that stays super sonic past 1000 yards
I'm shooting a 1000 yard fun match on Saturday and am trying to come up with a load for the 1000 yard stage. I'm using an m1a with hornady 178 grn AMAX with imr 3031.

For reloading and shooting 1000 yard matches with .308, The Rifleman's Journal is a good reference website, especially for the 1000 yard Palma match:

Part 1 - .308 Palma Preparation and Loading - http://riflemansjournal.blogspot.com/2010/10/cartridges-308-palma-preparation-and.html
Part 2 - Loading the .308 for Palma Matches - http://riflemansjournal.blogspot.com/2010/10/cartridges-loading-308-for-palma.html
Part 3 - 1000 Yard .308 Load Development - http://riflemansjournal.blogspot.com/2011/01/cartridges-1000-yard-308-load.html

The ballistic challenge of a Palma match is the 1000 yard stage. That's where the rubber meets the road and the load either works or it will cost you the match. Somewhere between 901 yards and 999 yards, a bullet fired from a .308 runs into a wall, and that wall is the transonic region which roughly begins as the bullet's velocity drops to 1.2 mach. Ideally, we can remain over 1.3 mach and avoid problems, but that's not always possible within safe pressure limits.



Berger 175, which not only has good numbers in all categories, but is very accurate as shown in the mid-range testing and previous Palma scores with the other rifle. You might ask why I don't go with the Berger 155.5, that is simply because the higher MV required by that weight class of bullet increases the possibility of bullet failure and a lost match. The chances are small, but I have experienced it and don't care for a repeat occurrence. Wind drift differences are minimal, especially when reduced to the difference in a 2 mph change which is as large as might occur without the shooter noticing. The best reason for using the 175 is not reducing drift so much as it is reducing risk. Additionally, the 175 load generates slightly lower chamber pressure than my 155 load and I like having that extra bit of safety margin.

Here are some long-range pet loads - http://riflemansjournal.blogspot.com/2010/01/reloading-western-shooters-pet-loads.html

Mid Tompkins - At Camp Perry, in 1963, Mid became the first shooter to win the Highpower National Championship with the .308. He won it six times, as well as the Long-Range Championship, the Wimbledon Cup and the Leech Cup:
Brass: old Winchester .308, weighs 170 gr., same as Lapua in capacity.
Powder: Varget, 46.0 gr.
Primer: Russian LR Magnum
Bullet: Berger 155.5 gr. Fullbore
Average Muzzle Velocity: 2975 fps
Barrel: 0.2980" x 0.3075" with a 1:13" twist, 30" long

Bob Jensen - Loaded more .308 ammunition for Palma shooting than any other person I'm aware of. Bob, of course, loaded over 300,000 rounds for the 1992 Palma Match, ammunition that was used by competitors from all nations; and before that, he loaded 98,000 rounds for the US Army Marksmanship Unit. Winner of the Wimbledon Cup in 1977:
Brass: Winchester .308
Powder: IMR 4895, 44.8 gr.
Primer: Federal 210M
Bullet: Sierra 155 (2155) 2.80" OAL
Average Muzzle Velocity: 2980 fps
Barrel: 0.300" x 0.308", 1:13" twist, 30" long

Martin Tardiff - One of California's top shooters, Winner of 2009 California Palma Champion and the 2009 Bill Chapman Regional
Brass: Lapua .308
Powder- N-150, 45.5 gr.
Primers - Russian, Lot 1-03.
Bullet: Berger 155 VLD (naked), jam 0.030” into the lands
Average Muzzle Velocity: 2930 fps
Barrel: Krieger, 30” long, 1:13” twist, 0.307” bore, ‘95 Palma chamber

Allen Elliott - One of the top shooters in our area and always does well at Camp Perry and other big matches:
Brass: Lapua, approx. 170 gr. case weight
Powder: Varget, 46.6 gr.
Primer: Russian LR
Bullet: Berger 155.5 gr. Fullbore or Sierra 155 (2156) (No preference) Bergers seated to jump 0.010", Sierras seated to jump 0.020"
Average Muzzle Velocity: 2985 fps
Barrel: 0.300" x 0.308", 1:13" twist, 30" long, Krieger or Hart, no preference

Gary Eliseo - Maker of the Competition Shooting Stuff Tubeguns - among the West Coast's top shooters
Brass: Winchester, weight sorted
Powder:, 46.5 gr. VV N150
Primer: CCI 200
Bullet: Berger 155.5 uncoated, jumping 0.020" to lands
Average Muzzle Velocity: 2970 fps
Barrel: Krieger 0.307" bore, 30" long

Bill Otten - Palma shooter and a member of the US Veterans Team
Brass: Lapua .308, no special prep or selection
Powder: Varget, charge varies depending on the lot, as needed for MV
Primer: CCI BR2
Bullet: Lapua 155 Scenar, no coating, no pointing
Average Muzzle Velocity: 2970 fps
Barrel: Bartlein, 1:12" twist, 0.3075" x 0.298", 30" long

Mike StClair - Palma shooters and a member of the US Veterans Team
Brass: Lapua, weight sorted
Powder: Varget, charge varies by lot, as needed for Average MV shown below
Primers: Federal 210M
Bullets: Sierra Palma Match 2156, 155 gr. for 8-9-100 yards. Sierra 2155, 155 gr. for 300 to 600 yards.
Average Muzzle Velocity: Just over 3000 fps
Barrel: Kreiger, 31" long, Palma Countour, 0.298" bore x 0.3065" groove, 1:13" twist, 4 groove.

John Chilton's F-Class load:
Brass: Lapua, weight sorted
Powder: 44.5 gr. of IMR 4320
Primer: Russian LR
Bullet: Berger 175 Grain Match Target BT, Jump 0.015"
Average Muzzle Velocity: 2810 fps
Barrel: Krieger, 1:12" twist, 30" long

Doug Frerichs's Palma load:
Brass: Lapua, neck turned and weight sorted
Powder: 45.8 gr. of Varget
Primer: Russian LR Magnum
Bullet: Berger 155.5 gr. Fullbore
Barrel: 1:13" twist, 30" long Krieger

German Salazar's Palma load:
Brass: WCC 60 or new Winchester (both weigh approx. 154 gr.), neck turned to 0.0125"
Powder: H4895 44.5 gr.
Primer: Russian LR
Bullet: Berger 175 BT, moly-coated, seated to jam 0.010"
Average Muzzle Velocity: 2835 fps
Barrel: 0.300" x 0.308", 1:11" twist, 29" long Krieger

 

[Canuck-IL]

Note the barrel length all the above loads were used with ... I doubt you can keep it supersonic with a sane load from an M1A.
/Bryan

 

[USSR]

genebofunk,

You will never do it using IMR3031 powder. It's too fast of a powder for a heavy for caliber .30 caliber bullet. I've done quite abit of load development using the 178gr Amax in .308, and you really need to move to either Varget or, better yet, RL15 if you have any hope of keeping the bullet supersonic at 1k. Being that you are using an autoloader with a relatively short barrel - Good Luck!

Don

 

[genebofunk]

For what's its worth my 800 and 900 yard stages are loaded with 41 grns of varget. Then I ran out and all I have left is 3031. Thanks for all the tips. I'm gonna load em up with 3031 and send some hopes and prayers behind them. I don't feel like pulling 40 rounds to scavenge the varget. It's just a recreational match any way. If I manage to post a decent score in the 1000 yard leg I'll let y'all know but my shooting skills are not that great at that distance