30-06 Ai

[guntech]

not wanting to take away from the discussion but what is the general feeling on whether or not the 30-06 is worth AIing

There is no way or predicting how much gain there would be from one rifle to another. In Ackley's testing he found a big difference in what would appear to be identical rifles. They were consecutively serial numbered 30-06's with the same length barrels and he chambered them identically for the 30-06 AI. With identical loads the two rifles chronographed something like 150 to 200 f/s difference to each other ... one rifle performed much better than the other..

I think the 30-06 AI will usually get better velocities with the light range of bullets up to 165's. Much less of a gain with the heavy ones.... that's where a magnum case works much better.

With the high cost of AI dies it makes one hesitate...

 

[Riflechair]

pretty much turns your .30-06 into a .308 Norma Mag.
Its a great round.
Might have some cycling issues because of the extra steep shoulder angle though. Great for the 200gr bullets otherwise I would not go the extra mile to do this.

 

[Mystic Precision]

I have played with the 30 Gibbs and it proved to be accurate and tolerant of elevated pressures.

There is no free lunch so if you want increased performance for a given case capacity, you ramp up pressure. Not entirely bad since the 30-06 is rated the lowest for pressure of its family. If you just raised it to the level of a 270, you will already see significant gains. Go towards magnum pressures and that is the results you see wildcatters getting.

At magnum pressures, a standard case will not show overt pressures signs except maybe a more flattened primer. Just about any action today is used for both standard and magnum cartridges so more then strong enough for this type of 'hot rodding'.

What I have found is tapered cases grow/stretch way too much when pressures are elevated (still safe in absolute terms by the way), so I see significant gains by going to an AI or low taper sharp shoulder case shape.

Also, accuracy is "better". Why, I don't really know but I have rechambered barrels and the AI chambers tolerate the elevated pressures while retaining accuracy. The orig case lost accuracy at lower pressures (based on case characteristics).

With my Gibbs, I was able to reach 2900 to 2950fps with my moly 165gr SST (24.5" pipe I believe). This is a vast improvement over all other -06's rifles I have owned. Not saying there aren't '06 rifles that can't match this. Just I have never owned one (most loose accuracy around 2750 to 2850fps).

I am pushing 162gr molied Amax to 2900/2950fps from my 24" Shilen in my 7 Mystic (my version of the 280AI). And 139gr naked Lapua at 2900/2950fps out of my 6,5 Mystics (my version of the 260AI) and 30" Gaillards.

Is this a significant gain? Is it worth the case forming hassle? If you like wildcatting and experimenting, you bet it is.

Personally, if I was building a light mountain rifle and still needed some reach, I would build a 7-08AI on a 22" pipe and load to 'BR' pressures. With 162gr SST or Amax, I would be good for a very long ways out on deer and sheep and have a significant ballistic advantage over medium cased 30cals.

Jerry

 

[dan belisle]

Dave Henry has some of the Gibbs reamers I believe, check with him. - dan

 

[762nato]

With the 22-250 and 06 AI you do not need special dies, regular Lee collet and seater dies work fine. No extra cost.

Andy

 

[ACKLEY ABE]

Dan: You didn't mention the .06 Ackley that you now have , that I would like back some day......

Anyway I've had two. One of which: 180 gr speer. 2992 fps. I liked it, or should I say them. The second one that I owned was not as accurate as the one that I had sold, so, it went down the road.

 

[Leeper]

In an attempt to show reduced bolt thrust with a 303 Epps, I was unable to do so.
In rifles with good chambers and no mechanical flaws, I have seen no reduction in case stretching.
If you want more than a 30/06, build a 300 magnum. A 30/06 AI will not equal a 308 Norma. Neither will a 30 Gibbs. Even a 300 WSM is a better choice. If you have no pride!
Breech thrust with a 45/70 or a 45/120 is high, not because the case is tapered (it isn't very tapered) but because it is a pretty large diameter case. Thrust is exactly the same for the two cartridges if loaded to the same pressure. Regards, Bill.

 

[Casull]

Breech thrust with a 45/70 or a 45/120 is high, not because the case is tapered (it isn't very tapered) but because it is a pretty large diameter case. Thrust is exactly the same for the two cartridges if loaded to the same pressure. Regards, Bill.

Bill, that was my logic too. But increasing velocity with the same bullet did increase apparant thrust. Though with the much greater case size pressure should have been reduced.

 

[guntech]

But increasing velocity with the same bullet did increase apparant thrust.

Increasing velocity is usually done by increasing pressure... and should result in some sign of increased pressure... Brass expands and stretches rather than sliding back in a chamber. The bolt simply stops the brass from stretching back any farther. I don't think of thrust as much as pressure... as far as pressure against the bolt, I don't think case design matters if the pressures are equal....

 

[Casull]

In this case it was "springing" off the face of the action. Causing cases to setback more, giving more expansion and mishaped cases.

 

[p-17]

I've never tried any of the AI cartridges, but I understand some cartridges give better results from improving than others. Everything I've heard suggests that the .30-06 really doesn't benefit that much.

In any event, with modern powders and bullets, I can't see the problem with the regular .30-06. A good case in point is my own Rem 700 Stainless Mountain Rifle with a 22-inch barrel. With a 168-grain Barnes TSX pushed by 64 grains of Vihtavuori N560 out of a Winchester case, I'm getting solidly 3000+ fps over the chronograph; and at 200 metres, I'm getting about .75 to one inch for the first three shots. That is effectively equal to the classic 7mm Remington Magnum performance. A few weeks ago that rifle knocked a large Muley buck right off his feet on a shot across a large draw from 300 yards.

My advice to anyone trying to soup up the .30-06 is to try N560 and the Barnes TSX first (assuming you're not using a rifle like a Garand). You may discover that you have all the rifle you need right now.

 

[H4831]

200 gr. vel.

You get other benifits, reduced bolt thrust, never have to trim a case again. I had an 06 AI, most signifigant velocity gain was in the heavier for class bullet weights, 200 gr Sierra @ 2650(actual on a chrony) with no pressure signs.

Andy

An old Norma powder loading chart shows a 30-06 load with their slowest powder giving their 200 gr. bullet, a velocity of 2684. The old Norma books are the only loading books I have ever seen that give accurate figures on velocity. I was using Norma powder, extensively, forty years ago. In more recent years I had an Ohler 33 chronograph, and checked their load. I copied their 200 gr bullet load and instead of 2684, got a reading, 12 feet from the muzzle, of 2673! I increased the load ½ a grain, which is a nothing with very slow powder, and the reading with the 200 grain Nosler, was 2690! Still completely normal pressure signs. Big deal, those blown out, "improved," calibres.