Anybody loading the 30-06 AI today with any of the new slow powders. I have a yen to turn one of my 06's into an AI, and think with some of the new slow reloading powders, it could be an even better performer, than in the old days.

Jerry

quote:

it could be an even better performer, than in the old days.

Any improvement at all would be an improvement as in the old days there was no gain whatever in the AI version of the .30-06

Problem with converting an existing 30-06 is to do it correct you need to set the barrel back. Second to try and use slower powders menas a longer barrel.

Took QL and the 30-06 & AI with a 165 accubond in a 24". Told it to use up to 115% of case capacity and a max pressure of 63000.

QL chose MRP and giving the highest velocity in both 3067 30-06 and 3113 for the AI. N560 was second with 3023 and 3083. All reached 63,000 right at the 115% limit.

Your 06, time and $$ but I sure wouldn't fool with it. Something like the 30 Howell by AHR will at least forcast a 100+fps gain. AHR can run the reamer in your rifle, sell you the brass($1 each) and dies (around $80). Wayne with AHR posts on here as Bitterroot.

I put mine together back about 2006 with "Ackley Improved User" mentoring me. He probably knows more about Ackley calibers via hands-on experience than anyone I've ever conversed with. Search his and my posts on the subject.

I push the 180 AB/BT to 3000 fps with a compressed charge of Rel 25 from a 26" Lilja 3-groove. My top vel was over 3100 fps, IIRC, but my node was 3000 fps.

Alan

I turned a new Rem 700 CDL 30-06 into an AI and have been very happy with it. As mentioned before, it is critical that the smith knows how to do it properly. Set back is a must. I bedded mine and dropped it into a McMillian.

I don't have my data with me (at work) but 165, 180, and 200 grainers all shoot .75 or under with IMR4350 but best accuracy and velocity I've had is with RL25. Mine does not like the lighter bullets.

I have just under 1000 rounds through mine and should eclipse the 1000 round mark by the end of summer. Still glad I did it.

Why does the barrel have to be set back to go AI, and why not jump straight to the 30gibbs?

I like the idea of a 30 Gibbs also, but I am very curious as to why the barrel needs to be set back for the AI. My understanding of this mod, is no complications?

Jerry

quote:

I like the idea of a 30 Gibbs also, but I am very curious as to why the barrel needs to be set back for the AI. My understanding of this mod, is no complications?

A proper AI chamber is shorter than a std. To do it properly the barrel should be set back one turn. It was designed that way so that a std case is a "crush" fit. I'm sorry I don't remember how much shorter off the top of my old head. (.006 shorter comes to mind but please check it)

Not saying that there aren't a number of AIS out there that were simply cut by running the reamer in without setback. However if done that way you actually have a wildcat not an AI. While you MIGHT get away with firing std cases in it you might also have an excess headspace issue.

If you choose to not set back simply plan on not firing std brass in it without using a false shoulder or bullet in the lands to give you headspace. Problem would then be when you sold it as an AI to the next person.

I shoot my PDK wildcats. Pretty much a Gibbs with a 40deg and using 280 brass. A 30 Howell will give you just a touch more capacity than the gibbs with a longer neck.

What he said. The bbl is set back so you can still fire standard rounds in the improved chamber safley.

I have a 257 AI, it basicaly matches a 25-06, but part of the reason it can is simply because there is less bolt thrust with the minimal taper. There is considerable pressure but the design "hides" it. The 257 is one of the best calibers to do that with but I would never do that to my 06. Not enough gain to justify IMO.
I also would go with the Gibbs version. But after having been there and done that Ill just stick with the boring, efficent old plain vanilla 06. Ive come to like the taper for feeding purposes and one chambering (as opposed to shooting standard and improved from the same rifle) for consistancy, fireforming is a pita.

Thanks for the good info, Paul. You talk about the days gone by, it was my understanding, the the junction of the neck and shoulder, were the same between the std case and the AI, which made firing the std round possible without any problems. Don't remember anyone talking of setting the barrel back then, but???

Here's some numbers that Earl Etter wrote about, pretty good I think, and this is what peaked my interest.

These numbers are from a 22" Barrel:

64IMR4350/150 Sierra/3192fps

62.5IMR4350/165 Sierra/3100fps

62IMR4831/180 Nosler/2967fps

Looks like quite an improvement over the std 06, velocity wise anyhow.

Jerry

quote:

These numbers are from a 22" Barrel:

64IMR4350/150 Sierra/3192fps

62.5IMR4350/165 Sierra/3100fps

62IMR4831/180 Nosler/2967fps

Jerry, the AI was designed to allow std cases to be safely fired. The AI chamber was just a touch shorter to insure the std case was a crush fit. While many are built without setback it doesn't make it right. Can you get by with it sure just treat it like a true wildcat.

I shoot mostly AIs or my own PDKs both have minimum body taper. Like Wstrnhuntr says the design hides pressure. On the chambers I did do pressure testing on 70,000+ could be obtained. However a fraction of a gr would take me from no sign to blown primer.

Also comparing an AI to factory is an apple and orange. That is one of the reason the Roberts & 7x57 show such huge gains. You are comparing a load of 51-55,000 to a load of 65-70,000. On a 30-06 with a max pressure of 60,000 taking it ot 65,000 gives you 60-70fps by pressure only. If a 270 can be loaded to 65,000 no reason a 30-06 can't be in a good rifle.

Watch jumping onto a band wagon based on one article or one persons claims. Just as a reference point I ran your article numbers through QL (yes just a calculation)

64gr of 4350 behind a 150 was 62,540 and 3039fps
62.5 of 4350 and a 165 was 65,297 and 2953fps
62grs of 4831 and a 180 was 67,328 and 2894.

The calculated velocity were 70-150fps slower than the article. Not saying he didn't get those results.

If you want an AI go for it. If you want to maximize your capacity for the same $$ think Gibbs or Howell.

quote:

Originally posted by Jerry Eden:
Thanks for the good info, Paul. You talk about the days gone by, it was my understanding, the the junction of the neck and shoulder, were the same between the std case and the AI, which made firing the std round possible without any problems. Don't remember anyone talking of setting the barrel back then, but???

Ill try to explain the bbl setback a bit more. When the chamber is altered to AI the proper way to do it is to ream it enough to completly alter the shoulder angle, this changes the headspace, and as paul said you want a "crush fit". That way the standard case with its shoulder will still headspace on the new, steeper AI shoulder within the chamber. If you rechamber without setting back the bbl you would probably end up with sort of a double taper shoulder in order to get a standard case to still have safe headspace as the shoulder forward of the datum line would have to remain unreamed.

Hope that helps.

quote:

the AI was designed to allow std cases to be safely fired. The AI chamber was just a touch shorter to insure the std case was a crush fit. While many are built without setback it doesn't make it right. Can you get by with it sure just treat it like a true wildcat.

If one does not want to set the barrel back a thread, he'd be better off chambering for the .30 Gibbs...

I like the Gibbs cartridges, they seem like a more worthwhile alteration and the numbers Ive seen are impressive. But case prep and fireforming for them is even more work than an AI.

As hard as it has become for me to find time to play with such things thesedays I think Id just as soon get a 300 wsm and go hunting.. Cool hobby if youve got the time though.

quote:

I like the Gibbs cartridges, they seem like a more worthwhile alteration and the numbers Ive seen are impressive. But case prep and fireforming for them is even more work than an AI.

If you want a gibbs and don't have the time to foreform brass there are two easy ways to get there. First simply have bitterroot rechamber your 30-06 to 30 Howell. BAsic shape as the Gibbs shoulder just a touch more forward and 2.6" brass. AHR sells both headstamp brass and dies for a very good price. Or if you still want a Gibbs simply buy 30Howell brass run it in your gibbs die and trim.

As you said simplest way if you want more than the 30-06 run a 300 wmag die in your 30-06 open the botl and go shooting. If you have a shorter action go with the wsm in your 308.

One of the reasons why I am considering doing this modification, is the screw around factor. If I can get a reamer, under economical circumstances etc., I'll do it. I learned long ago, that all cartridges have a usefull value, and I don't get real hot about wither I have the best one or not. But you have to admit, if you have an extra rifle, and can get a reamer, it would be fun to do it yourself.

Jerry

4D has both the 30 Gibbs and 30-06AI for rent.

http://4-dproducts.com/display...group=Rifle+Calibers