Thanks Joe good report! So far I'm getting better accuracy with the 260 brass running 2930-2960fps.
260AI "Palma" brass v 260 Lapua brass
- Thread starter SDDasher
- Start date
I will pass on what I believe to be the optimum .260 Ackly load. Mine is a 30 inch barrel and with 45.6 g of H4350 gets 2950 with Berger Hybrids and Fed210ms with a 3 shot group of .004 over the bullet diameter. This with NO flattening. Barrel life should be good, brass life should be good, life is good. I have a .297 neck, gun is custom.
I shot ten shots at 300 with the Palma brass, BR4's,140 Berger LRBT, 45.5 RL 16, 2960 FPS, 1/2" horizontal, 1 5/8" verticle. 30" Brux, Panda F Class action, .297 neck. I think the verticle may be neck tension. Will work on it some more.
My 260AI likes the LRBT's jammed about 8 thou and I get virtual "waterlines" consistently
I'm jumping the LRBT's; I'll try a jam next week.
I honestly don't think you can shoot a better bullet than the Berger Hybrid 140;s but they require 10 -70 off. Take your time to find out where they work best.
What kind of velocity are you getting from your 7-08 improved?
Laurie, would you mind sharing a bit more about that 7-08 you reference? If you have another thread started on it, pls let me know... Thx!
Hello Mark. I've been slowly working loads up for a 'baby F-Class' rifle for short and mid-range matches in 7mm-08 with a 31-inch barrel and a long-freebore chamber to allow the use of heavier bullets than the 140s/150s that are the norm in sporting rounds restricted to COALs of 2.8 inches or so. (Most bullets in my chamber see COALs up at ~2.95".)
My original game plan was to use the 168gn Berger VLD. To be competitive with an equivalent 6.5 and the higher BC 140s, it had to match or better their MVs, the 7mm 168 and better 6.5 140s having very similar BCs. So, I needed to get 2,800 fps or more.
As with all the best 'cunning plans', the 168 VLD one flopped - the barrel simply doesn't like it irrespective of powder or jump. The 162 AMAX showed some promise, but my early loads were all too low velocity.
So, I spent the back end of last year working on heavier bullets and slower powders. The barrel likes Sierras and has done well with the new 160gn TMK, the old but excellent tangent ogive 175gn MK even better, and has also shot the 180gn MK well, all with Viht N160, but the recoil was getting higher with the 180 than I want with this cartridge, so the 160 and 175 look like being my bullets in this rifle. The relatively low BC 150gn Lapua Scenar-L has also formed the basis of a cracking short-range load - groups very well, good elevations, and light recoil.
As winter closed in I was experimenting with Viht N165 and the 175 SMK in heavily compressed loads in Winchester brass to be able to stuff more powder in than the Lapua cases will hold. It looks promising with initial 3-round batches, but I'll need to see if it stands up in five-round lots.
So far, the reformed small primer Lapua brass hasn't shown any great benefits, but if and when I have to try double-based powders to get more velocity, that should be when this case comes into its own.
Overall though ............... it's easier to get a good straight 284 and shoot 175/180s, keeping loads and pressures down to improve barrel life if needed. The 7-08 is just that bit short of powder capacity. I had considered the 7-08AI and in hindsight, that would probably have been a better option, the extra bit of powder capacity making a real difference.
My original game plan was to use the 168gn Berger VLD. To be competitive with an equivalent 6.5 and the higher BC 140s, it had to match or better their MVs, the 7mm 168 and better 6.5 140s having very similar BCs. So, I needed to get 2,800 fps or more.
As with all the best 'cunning plans', the 168 VLD one flopped - the barrel simply doesn't like it irrespective of powder or jump. The 162 AMAX showed some promise, but my early loads were all too low velocity.
So, I spent the back end of last year working on heavier bullets and slower powders. The barrel likes Sierras and has done well with the new 160gn TMK, the old but excellent tangent ogive 175gn MK even better, and has also shot the 180gn MK well, all with Viht N160, but the recoil was getting higher with the 180 than I want with this cartridge, so the 160 and 175 look like being my bullets in this rifle. The relatively low BC 150gn Lapua Scenar-L has also formed the basis of a cracking short-range load - groups very well, good elevations, and light recoil.
As winter closed in I was experimenting with Viht N165 and the 175 SMK in heavily compressed loads in Winchester brass to be able to stuff more powder in than the Lapua cases will hold. It looks promising with initial 3-round batches, but I'll need to see if it stands up in five-round lots.
So far, the reformed small primer Lapua brass hasn't shown any great benefits, but if and when I have to try double-based powders to get more velocity, that should be when this case comes into its own.
Overall though ............... it's easier to get a good straight 284 and shoot 175/180s, keeping loads and pressures down to improve barrel life if needed. The 7-08 is just that bit short of powder capacity. I had considered the 7-08AI and in hindsight, that would probably have been a better option, the extra bit of powder capacity making a real difference.
Thank you for the update!
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