6.506 vs 280 AI using 140 gr bullets

[3006savage]

Reloader magazine recently did an evaluation on brass for 308 winchester loads. The durability of Nosler brass was dead last out of approx a dozen different manufacturer. Remington, Laupa, and Norma (not certain in that order) were the top three and all loaded nearly double what Noslers loaded. The loads were within sammi pressure levels and were FL sized after each firing.

 

[liltank]

Going nuts with pressures is not a good path for the reloader, but I do wonder what this means in regards to case life with "warm" but safe loads?

Well here is the story, and mind you each rifle is different. My cousin tried the listed max load for Varget. With a 168grn Nosler Custom Comp bullet @ 46.0grns should be safe. Well the first three shots resulted in crushed primers and a sticky bolt. Those three cases then were useless because the primer pockets were stretched. He ended up backing off quite a bit and found accuracy at 43.8grns and has fired them and reloaded them several dozen times with annealing the necks to keep them from splitting. I have Winchester casing doing the same thing. I over pressured and now they are in the junk brass bin. I am very careful to load now with doing pressure testing. I load one round at a time starting with say: 40.0 grains up to 46.0 grns in .5 grn increments. I then shoot one at a time until I start to see unsafe pressure signs. Most of the time I just have the chrony set up to see speeds and find my max load for that rifle. Once I find something I like, then I go back and load groups of 3 in weights I want to test. I find this method easier on brass and less ruined if you go too hot.

Tank

 

[loaders_loft]

that's why every manual says to start low and work up. Never start with a max load. There's the proof right there.

 

[liltank]

that's why every manual says to start low and work up. Never start with a max load. There's the proof right there.

Yep, proof positive, but never hurts to try. It was early in the whole loading thing after years of not doing it. It happens, but then again, all rifles are different. As we all know you can sometimes load over max, but should not be a starting point. That is why you see a lot of people pointing that one load that works for some, will not work for others. Different chambers, different allowances in pressure.

Tank

 

[davkrat]

Why not split the difference with a .270 AI? I have a Rem. 700 in .270 that I have been wanting to rebarrel for years as a 270 AI. Currently it loves the 110gr. V-max which is a pretty good varmit bullet and with the newer Berger .277 available it's right in the same range. I do wish Berger made a larger high BC .277 bullet though.

 

[loaders_loft]

I do wish Berger made a larger high BC .277 bullet though.

There's your answer...

The 7mm and 6.5mm have high bc hunting and match bullets. Surely there's someone out there with a phenomenal high bc match or hunting bullet in .277, its just not well known.

 

[liltank]

There are few makers that will do a high BC .277. Wildcat bullets make a 169.5 and Matrix Ballistics Ltd. will make custom weight bullets.

Tank

 

[OKIE2]

I want to throw in a whole different angle on this thread no one here has mentioned the
264 win mag
6.5 Rem mag
6.5/300 RCM
and all three of them will out do your
6.5-06 6.5-06AI or the
6.5-284
If any of you have read P O Ackly's books he himself said the 6.5-06AI is not worth the trouble over the standard 6.5-06.
And one more very good calibers to look at is the 270 wsm with 130 grainers
and the 270AI
If you want speed go with a 25-06AI with 87 grainers at 3920 fps.
it's only 60 fps slower than the 257 weatherby and does it with 10 grains less powder.

 

[elkaholic]

I want to throw in a whole different angle on this thread no one here has mentioned the
264 win mag
6.5 Rem mag
6.5/300 RCM
and all three of them will out do your
6.5-06 6.5-06AI or the
6.5-284
If any of you have read P O Ackly's books he himself said the 6.5-06AI is not worth the trouble over the standard 6.5-06.
And one more very good calibers to look at is the 270 wsm with 130 grainers
and the 270AI
If you want speed go with a 25-06AI with 87 grainers at 3920 fps.
it's only 60 fps slower than the 257 weatherby and does it with 10 grains less powder.

I would agree that all of the 6.5's that you mentioned are good options, but am confused as to how the 25-06 A.I. could be a good choice and the 6.5-06 is not worthwhile? If anything, using that logic, the 25 should be even less worthwile than the 6.5 A.I. I think the logic in Ackleys original comments about the 6.5 were based on powder availability at the time. i.e. the larger the case, the smaller the bore and the heavier the bullet, the slower the powder needed to create max velocity. With the availability of much slower powders these days, I think we have a totally different situation and in fact have had great success with the 6.5 A.I. personally. I now have a 6.5 Sherman version which is almost as big a jump over the A.I. as the A.I. was over the std. and I have gained 100+ feet per second over the A.I (my opinion and experience)....Rich
P.S. I once read an article that a "well known expert had written" which stated that the A.I. version actually produced LESS velocity in his test than the std. version. He was loading both with the same powder charge!

 

[OKIE2]

"P O Ackly he himself said the 6.5-06AI is not worth the trouble over the standard 6.5-06".

now read my post again I did not say the 6.5-06 was not worth while.
as for the 25-06AI it gains 400 fps over the standard 25-06 with a 87 grainer.
so yes it is worth it.
now both of these calibers are very good ones no one can say they are not.

 

[elkaholic]

"P O Ackly he himself said the 6.5-06AI is not worth the trouble over the standard 6.5-06".

now read my post again I did not say the 6.5-06 was not worth while.
as for the 25-06AI it gains 400 fps over the standard 25-06 with a 87 grainer.
so yes it is worth it.
now both of these calibers are very good ones no one can say they are not.

Didn't mean to ruffle feathers! As I mentioned, Ackley did not have the powders we have now so at that time, he was probably correct.......Rich

 

[McKinneyMike]

"P O Ackly he himself said the 6.5-06AI is not worth the trouble over the standard 6.5-06".

now read my post again I did not say the 6.5-06 was not worth while.
as for the 25-06AI it gains 400 fps over the standard 25-06 with a 87 grainer.
so yes it is worth it.
now both of these calibers are very good ones no one can say they are not.

I have spoken to a few people that have had splitting in the neck and shoulder areas of their 25-06AI's quicker than the standard 25-06's. Has anyone else had any issues with these areas in normal loading?

 

[Ridge Runner]

at the same pressures the AI cartridges gain 2% in MV over the parent case, if your gaining more your pushing higher pressures, average shooters have no way of knowing what they're pressures are, so its a guess at best.
I shoot a 6.5 gibbs with a 29.5" barrel I'm running 140's at 3340 fps and I know I'm pushing it pretty hard. unheard of performance from a 270 win case but it comes at a price. will a 264 win mag do better? probably but brass isn't as cheap and it takes more powder to get it there.
RR

 

[elkaholic]

at the same pressures the AI cartridges gain 2% in MV over the parent case, if your gaining more your pushing higher pressures, average shooters have no way of knowing what they're pressures are, so its a guess at best.
I shoot a 6.5 gibbs with a 29.5" barrel I'm running 140's at 3340 fps and I know I'm pushing it pretty hard. unheard of performance from a 270 win case but it comes at a price. will a 264 win mag do better? probably but brass isn't as cheap and it takes more powder to get it there.
RR

I like the gentle way you mentioned a 2% gain and the equal pressure issue Barrel length of course has a lot to do with the whole equation as you know. To say that an A.I. is 400' better than a std. would take some serious differences in pressure and barrel length! I'm not surprised that you can get 3340 with your Gibbs. My Sherman case holds just a fuzz more than the Gibbs and I can exceed 3200' with a 26" barrel. As you mentioned, that's pushing it. What is your powder and charge with that particular load? I can top 3200' with retumbo 65 gr. RL22 61 gr. and RL25 64 gr.......Rich