William iorg do you or anyone else have .307AI load data?

[arjunky]

Just picked up a .307AI Big Bore 94 with dies and brass. Any advice or experience loading this thing?

Thanks,
Byron

[smokenrust]

307AI ???
What is the advantage there? I know 30-30AI makes for some faster boolet

[arjunky]

307AI ???
What is the advantage there? I know 30-30AI makes for some faster boolet

I hope it might get actual .308 performance in the 94. I would think the new 140 monoflex could be pushed to 2,800+. 125's close to 3,000.
I guess I'll find out this winter.
Byron

[Don McDowell]

I don't think Ai'ng the 307 will get you much but a bunch of pressure problems, but the general rule of thumb for the true Ackley Improoved is 5% over maximum of the parent cartridge.

[O.S.O.K.]

I'd look at the starting loads for .308 Win and work from there. Or mid-level loads for .307. Either way, the chronograph is your friend.

Let us know how it goes!

[C. Cash]

I dropped Slim a line.....hopefully he will be along shortly.

[tman]

Be really cool if you could push a 160gr. monoflex to 2700fps. out of a standard .307 94 carbine. Hornaday, are you listening

[william iorg]

I have exchanged emails with two shooters who have 307 Improved rifles, one a TC and the other an NEF Handi rifle. I don’t have any specific load data from these rifles as both correspondents “dropped off the earth” after a few emails.
On the Beartooth Shooters Forum Seattleroadwarrior (Eric) had gunsmith Nonaman convert and then rebarrel at least two 336 Marlin rifles to 307 Winchester. Eric discovered as others have, the Marlin 336 action will not tolerate full power 307 Winchester loads without sticky extraction when loading to the highest-pressure levels.
Eric designed a wildcat based on the 307 Winchester shortened slightly and blown out to the improved case shape. Mr. Nonaman rebarrled one of Eric’s Marlin 336 actions using a high tensile strength barrel and this has proven to be a very successful .30 caliber wildcat for the Marlin rifle. A search of Seattleroadwarrior posts on the Shooters forum will bring up a number of posts on Eric’s “30 Levermaximum” wildcat.

Don’t forget the article by Don Fisher “Half Mile Hits” about Don Bower and his 307 Winchester based wildcats for the 1997 issue of Handguns. An internet search for Don Bower will bring up additional information.

The “reason” for the Improved case shape is to reduce the possibility of lever kick and sticky extraction when loading to the highest-pressure levels. The Winchester Big Bore rifle will exhibit light lever kick on hot days and the first indications of sticky extraction. The case will snap free of the chambers walls with the slightest hesitation when the pressure and velocities are at their highest levels.
The real advantage with the Improved case is the ability to load to these highest-pressure levels while avoiding lever kick on hot days.

For the standard 307 Winchester and 110-grain 30-carbine bullets, I stopped at 2,900 fps because that’s where my best accuracy seemed to be. 45.0 grains of IMR 4895 is the load for my rifle.
45.0 grains of IMR 3031 will come up just short in velocity but will get close to the 3-shot 1-inch circle we are all looking at.
(Note: I load the 30-30AI to a full 3,000 fps with the 110-grain 30 Carbine bullets in the Winchester and the Marlin 336 - the accuracy was there in these rifles. I have shot my 307 rifle quite a lot and its best accuracy is long past. I have a new barrel but have not installed it.)

For the 125-grain Sierra I like 2,700 fps as any faster and the bullet seems very fragile. This velocity for both the 307 and the 30-30AI.
In the 307 Winchester, 43.0 grains of IMR 4895 will give me 2,750 fps and 41.0 grains of Hodgdon 335 gives similar results. 43.0 grains of IMR 3031 come up a little short of the 2,700 fps velocity goal but delivers the goods accuracy wise.

The 130-grain Speer is my favorite light bullet in the 307 Winchester and the 30-30AI. I stop at 2,700 fps in the 30--30AI but 2,850 fps delivers good accuracy.
I am still playing with Alliant Reloder 15 but for quite awhile 46.0 rains of Reloder 15 has been a very good load, 46.0 grains for my rifle.

44.7 grains of IMR 4064 - about a case full and 44.1 grains of IMR 4895 will deliver 2,850 fps.

I am loading the monoflex in the 307 Winchester but a busy summer has prevented me doing very much load development. I will probably stop at 2,550 fps.

You are able to exceed these velocities in the standard 307 Winchester and on cool days there will be no problem. On warm days or if your ammunition has been sitting out on a bench or in a truck, you will feel lever kick. Lever kick is a clear indication of high pressure and any time I feel lever kick, I back off.

Sorry I cannot answer your question with any detail but you should get a start from this and look for Eric’s threads on the Shooters Forum.

[arjunky]

thanks slim, appreciate all the info. I know it will be a month at least before I get to play with loads. I knew you would have a good place to start:-).
Byron

[Blackhawk]

Arjunky,

Any updates on the 307AI?

Johnny

[Marlin32]

Please keep forum posted on any loads you develop on the 307AI.
I have wanted to do it or the 356 for some time. (especially with Marlins for all the pressure reasons Iorg stated)

Have never experimented, not sure if cost benefit ratio is there, at least not enough to put me over the edge to try it.

More interested now in opening up the 338 Marlin Express to 348 or 358.

Have also wanted to do a 32 Improved. Not sure what gain would be there either.

[william iorg]

Greg Mushial from GMDR did quite a bit of load work with the 32 Spl back in the Marlin Talk days.
When Greg loaded the 25-35 with a slow twist barrel and the 32 Win Spl with its slow twist barrel he found both cartridges would produce high velocity with good accuracy when shooting bullets a bit lighter than normaly associated with them. 100-grain in the 25-35 and 125- or 130-grain - I cannot remember now in the 32 Spl.
The joy of the 32 Win Spl appears to be the outstanding accuracy provided by the slow twist for both jacketed and cast bullets.
The toal water capacity as I have it written down is not a lot different over the 30-30AI. I show a total capacity of 45.5 grains of water for the 30-30 AI and 44.9 grains of water for the 32 Win Spl Improved. If I can get the drawing to attach you can see the larger neck dimater makes the shoulder angle come out about 35 degrees. The Improved 32 Special is possible but I think the only way a true Improvement would come about is through the use of lighter bullets than we normally look at. Just a thought anyway.

[Marlin32]

Interesting, not so much improved with the 32.
I have also put my thoughts on opening up the 307 case to fit a .321 bullet a 32-307
or a 32-07 high power special.