260 ackley real world.
- Thread starter ollie
- Start date
I have been getting an easy 200fps gain from the 260 to the AI. Same bullets, same powder and same barrel. I dont know how much more of an increase you could ask from any AI. I have been shooting 140g bullets at 3000fps with R19, have had them as much as 3060fps in some testing but i wanted to back off some. The 260AI from a 30" barrel is flying side by side with the 6.5x284 you cant get that from a standard 260.
Not saying you don't, but, a 4% increase in case capacity in the 260AI would give one roughly 40-60 fps more than the standard 260. This is the reason for not having the 308AI. After all, the 308 case is just about as improved as one can get 
The 260 is for all intents and purposes a necked down 308. To get 200 fps more, how much have you increased the pressure ???
The 260 is for all intents and purposes a necked down 308. To get 200 fps more, how much have you increased the pressure ???The 260 shooting 140gr Noslers at 2850 started to show a flatter primer and the AI at 3000 shows no pressure signs, 3060 started to show a flatter primer also.
I just picked up some H4831sc last night, cabelas didnt have the Amaxs i was looking for, but i will do some tests with Nosler and Amax with R19 and 4831sc. I will have to find another chrono though.
I just picked up some H4831sc last night, cabelas didnt have the Amaxs i was looking for, but i will do some tests with Nosler and Amax with R19 and 4831sc. I will have to find another chrono though.
I get those kinds of velocities from my 6.5x55BJ, but it has a much greater amount of case capacity than the 260AI. 14% +. The additional pressure it creates is substantial, and was tested quite thoroughly by it's designer. The pressure testing was done in a controlled environment. I wouldn't bet MY eyesight or life on a primer to tell me whether or not pressure is excessive. Only voicing my opinion.
All that i have seen is flatter primers, not even totaly flat, and i backed down from there untill i got my best groups. No bolt lift problems, primer pockets arent showing signs of wear after 5 fireings of that load and not a single mark on my case heads. I dont know what to say but im not worried a bit. The 30" barrel helps with the last 40 or so fps over say a 26".
No problem, just voicing my limited experiences.
Been shooting a 260AI since the days it was a 6.5/308 acklified wildcat . Tried RP when the 260 brass came(disappointed),switched to 243 Laps rather than the previous 308 and am going to try the Lap 260 brass next.(Lapua brass just works....better)
Have had great results in accuracy and speed using 140Amax , 142 SMK's , 139 Laps and 140Bergs.
Ran powders from RL19,RL22,H4831sc,N550, and now RL17.
I've found it an extremely easy cartridge to load for.
Some of my fastest speeds have been coming from RL17 maintaining my objective accuracy requirement,but
have always fallen back on H4831sc for overall LR consistent performance so far.
If speed was not in play ,some of my tightest aggregate groups for midrange have come from RL22 at a lowered speed node.
Barrel life has been better than others using the 6.5/284, in my experience of over 14 barrels now. A few years back I even managed to shoot a perfect 600 in an ISU match on a barrel with 2500 rounds on it.
Real world (it's a little more work than some will like) but I think worth the effort.
A great balanced cartridge IMHO.
Gord
Have had great results in accuracy and speed using 140Amax , 142 SMK's , 139 Laps and 140Bergs.
Ran powders from RL19,RL22,H4831sc,N550, and now RL17.
I've found it an extremely easy cartridge to load for.
Some of my fastest speeds have been coming from RL17 maintaining my objective accuracy requirement,but
have always fallen back on H4831sc for overall LR consistent performance so far.
If speed was not in play ,some of my tightest aggregate groups for midrange have come from RL22 at a lowered speed node.
Barrel life has been better than others using the 6.5/284, in my experience of over 14 barrels now. A few years back I even managed to shoot a perfect 600 in an ISU match on a barrel with 2500 rounds on it.
Real world (it's a little more work than some will like) but I think worth the effort.
A great balanced cartridge IMHO.
Gord
Im glad to hear you have had some good experiences with H4831sc.
Do you have any load data your willing to share for 140gr amaxs?
Do you have any load data your willing to share for 140gr amaxs?
Rock
On a new chambered barrel, I start at 47.5 of the H4831sc with bullet at (not in) lands with ccibr primed ,Lapua formed brass.
Work your way up to find your speed/node requirement.I've found some barrels have found even this starting load "warm".
Cross uses a match load of 48.6g and I also found it a good load for speed,accuracy and low deviations.
Have fun,stay safe.
Gord
On a new chambered barrel, I start at 47.5 of the H4831sc with bullet at (not in) lands with ccibr primed ,Lapua formed brass.
Work your way up to find your speed/node requirement.I've found some barrels have found even this starting load "warm".
Cross uses a match load of 48.6g and I also found it a good load for speed,accuracy and low deviations.
Have fun,stay safe.
Gord
Holy buckets, im on the low side then, 47g was where i stoped. 48.5 is a fullll cases. i was just about to walk out of the door to do a second ladder test from 46.0 to 46.8.
46.5 shot great and 47 shot like crap, 46.5ish must be my lower node. Soon as in done with this post i will load some more rounds for some pressure testing.
THANKS for the heads up.
46.5 shot great and 47 shot like crap, 46.5ish must be my lower node. Soon as in done with this post i will load some more rounds for some pressure testing.
THANKS for the heads up.
Well i just got back from the range with some great results.
I tried loading some rounds above 47g or H4831sc and it got tight. Just for some pressure testing i tried 47.2, 47.5 and 47.8. I litteraly had to force the bullet into the 47.8 to be seated to the lands, i didnt think i was going to shoot it but once i tried the first two with no pressure signs i figured i would try. 47.8 didnt even flatten the primer slightly but put a little extra sheen on the head of the case. This is all with 140gr Amaxs.
Back to the original ladder test. 46, 46.25, 46.5, and 46.75. They all shot around 1.5" groups at 300 yards except the 46.5 i got an amazing 3 shot group measuring just under .4" center to center, the group can be covered by a dime. It was an excelent night for a test, not a breath of wind. From 100 yards had a 3moa drop, im not sure about velocity but i would like to know.
I planned on doing some reloading of my choice load after the test in the club house but a gun safty class was going on, and a group came by to do some clay shooting while their kids were in the class. So i took off without doing some extra shooting of that load, but i will be back.
I tried loading some rounds above 47g or H4831sc and it got tight. Just for some pressure testing i tried 47.2, 47.5 and 47.8. I litteraly had to force the bullet into the 47.8 to be seated to the lands, i didnt think i was going to shoot it but once i tried the first two with no pressure signs i figured i would try. 47.8 didnt even flatten the primer slightly but put a little extra sheen on the head of the case. This is all with 140gr Amaxs.
Back to the original ladder test. 46, 46.25, 46.5, and 46.75. They all shot around 1.5" groups at 300 yards except the 46.5 i got an amazing 3 shot group measuring just under .4" center to center, the group can be covered by a dime. It was an excelent night for a test, not a breath of wind. From 100 yards had a 3moa drop, im not sure about velocity but i would like to know.
I planned on doing some reloading of my choice load after the test in the club house but a gun safty class was going on, and a group came by to do some clay shooting while their kids were in the class. So i took off without doing some extra shooting of that load, but i will be back.
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