.35 Whelen to AI

[Daveinthebush]

How hard is it to change a .35 Whelen Encore barrel to .35 AI?   It would seem to be about the same as taking a .357 Mag. and converting to .357 Max. with a chamber reamer.

Or, am I assuming it is too easy.

[Nobade]

You can't do this. The barrel needs to be set back and the reamer run in to establish correct headspace. Obviously this can't be done with an Encore. In addition, Ackley Imp rounds aren't really compatible with break open guns, because if they are set up correctly, with enough crush, you won't be able to close it. I see way too many set up too loose, and people all complain of head seperations. Save yourself the hassle, and just don't go there. If you want more power out of that whelen, do a 358 STA or something like that that will clean up the whole chamber and allow you to headspace it. As for the mag to max conversion, it headspaces on the rim so this isn't a problem.

[Daveinthebush]

If it can't be done on an Encore then why does Bullberry, TC Custom and others offer the caliber in their barrel selection?

[quickdtoo]

It can be done, but it won't be an AI that you can shoot factory ammo in, it will be an Ackley improved improved. I'm having a .280 Rem Handi rechambered right now, I discussed this at great lengths with my gunsmith, Wayne York, before he convinced me it was doable. He does 35 Whelen AIIs for Alaskan hunters that want all the case capacity they can get, and he doesn't set the barrel back on their bolt rifles at their request.  Fire forming will require that I load into the lands to hold the rim against the standing breech, but using Nosler Custom .280 Akley brass won't be an issue. I don't have an Encore, but have been told they have a captive extractor, if that's so, fire forming may be easier if the extractor holds the rim against the breech using recommended fire forming procedures, but the improved improved chamber precludes shooting factory ammo in it as a normal Ackley would allow.

Feel free to give Wayne a call or email.

Hope this helps,

Tim

http://home.earthlink.net/%7Eoregunsmithing/index.html

[Nobade]

Yes, I know they offer AI barrels. But I also have seen dozens of them in the shop that have excessive headspace. I'm always getting them in with complaints of "The cases break in half! Fix it!"
If anyone would ever take the time to actually measure the difference between a normal cartridge and an AI one, they would find that the AI needs to be set up .012" tighter than a regular chamber. Yes, I know people set them up looser than that. But by doing this, the cases are stretched at the web on the first firing, and will not hold up as well as they do if the rifle is set up properly. If you make a break open gun this tight, you will have a very hard time closing it on a factory round. IMHO, AI cartridges should only be used in bolt guns. I do have an AR-15 in .223AI, and it does work, but it has a bolt handle to allow it to be slammed hard enough to lock up.
If you want to see if your AI chambered gun has correct headspace, simply load a primed, unsized factory case and fire the primer. If the primer is sticking up at all, it is too loose. It should be tight enough so the primer is flush with the case head. If it is not, you are stretching cases when you fire them the first time.

[rshow]

When i make cases for my AIs i load the cases with primers 10 to 15 grs of unique and fill them with corn meal and compress them with a dowel then put a drop of elmers glue in the mouth to seal it. let the case sit over nite to dry the glue then lube the case so it wont grab the chamber wall when fired. they smell a little when fired but its not to bad. this will make a perfect fire formed case and save on bullets and powder. they are dangerous so dont shoot towards any one. i do mine in my shop while taking a break or having a cup of coffee. Rich

[Nobade]

Yep, that's how I do it too 'cept I use Gulf canning wax. Melt some in a small tin and use an eye dropper to put it in the case. That way you don't have to wait for the glue to dry. 

[EdK]

Why couldn't you simply cut the chamber 0.012" shallower than standard. Granted, the gun might not want to close on factory "unimproved" brass but wouldn't a full length size die fix that? It was my understanding that the reduction in taper of the AI cartridge reduced backthrust and actually increased case life in a TC (assuming case sizing is performed correctly).

All of this is predicated upon a custom barrel of course.

[Nobade]

I'm not quite sure what you're getting at there. Do you mean holding the AI reamer back .012 on a already chambered barrel? If so, you'll get a very strange looking double shoulder. Remember a normal case's datum point is about midway up the shoulder from the neck to the body. An Ackley's datum point is at the neck/shoulder junction. In order to completely clean up the original chamber's shoulder you have to take the AI reamer in enough to generate very gross headspace. This is why barrels have to be set back a full turn and then the Ackley chamber cut. Now if you're talking about just making a custom barrel in AI chambering, sure you can do it. It'll just have to be set up much looser than is correct if you want your break open gun to be able to close. About the only way I know to do it right would be to have two rifles, one a bolt gun and the other a break open. Form the cases in the bolt gun and then you'll be able to close them in the break open. Set the two up with the same reamer and identical headspace and it could work, but not many people want to do that. So they set up break opens too loose, most of the time get away with it, but it's far from being correct and often doesn't work.

[gunnut69]

The problem Nobade is talking about is that the chamber being too long allows the firing pin to push the case to the front of the chamber, as pressure builds the case grabs first at the thinest part,,the front and then when it reaches a certain point the case will stretch 'too the rear' to fill the chamber. The chamber has to be cut as he says to allow fire forming factory ammo.. If one is willing to forgo that benefit of the AI group of wildcats cases can be formed from 30-06 cases by running a fired 30-06 into the AI die and loading a fire forming load as suggested before. I too use wax to retain the filler(cornmeal works well) and the case will fill out nicely and without the stretching at the casehead that causes the early failure..  You will loose the perk of simply firing 280 ammo in the chamber to generate new brass but that's a small price..

[EdK]

Sorry didn't mean to confuse. Was just looking for the correct way to set up in a T/C when building a custom barrel from scratch and without any regard to firing factory ammo in the parent case. Assume all ammo is handloaded specifically for the custom barrel and fireform loads are always used first to blow out cases.

So in summary - not looking to spoil all of the good comments on how an AI needs to be properly set up in a bolt gun - just wondering about the best way to go about it in a custom TC barrel.

[gunnut69]

I think Nobade was simply making the point that to set up an AI wildcat properly, that is to allow the use of factory ammo, it is nearly impossible in a break open gun. The hinge action linits the changes that can be made to allow the AI's their utility. Still if you're willing to fire form all brass using the correct technique, that is by forming with a false shoulder, then the job of conversion is fairly simple.. just run in the reamer 'til the old shoulder is cleaned up. Just remember though that while it may have been made with an AI reamer it does NOT have the attributes the AI's are supposed to have. It is as was said earlier and AIImp. An AI with a bit of excess headspace. Not enough to make firing factory rounds dangerous on the initial firing but surely enough to damage the case and case premature failure by cracking and headseperation. We/re not trying to be mean or elusive but the answer to the original question is it really can't be done correctly. Using a custom barrel one could likely set the chamber up correctgly..although closing with the Encores can be a problem in any case. They sometimes wil FTF if not closed with a certain authority. Add a tight fit of a standard round in the AI chamber and problems will certainly happen. And of course if the cases are prepared properly for either the custom or the rechambered factory, the guns will ork fine.. Just understand that bu creating am 'out of spec' chamber there may well be some liability issues that the smith may wish to avoid. That is--some won't likely take the job.. Good luck.

[EdK]

OK Gunnut and Nobade I concede defeat. Will think long and hard before I follow through on such a project. Nobade: what is your contact info in case I ever choose to get a Whelen bolt gun set up properly? 

[Nobade]

Gunnut, thank you! you can say this much more eloquently than I. Hopefully discusstions like this will help folks understand AI cartridges and dispel some of the misinformation floating around about them. There are even quite a few gunsmiths out there that chamber for them and don't understand how they work.  As for contact info, you can go to www.probed2000.com and find us there. And I do have a 35 Whelen AI reamer that folks are getting great results from. Hoping to get a 375-06 AI reamer soon, I think that would be a fun one as well.

[gunnut69]

Nobade-- How much shoulder is left on a 375-06?!?!?!?!?!  Even the 35Whelan was wildcated Brown/AI to inprove the shoulder for better headspace.. The 375 should be really slim!

[Graybeard]

The .444 Marlin is the same basic case as the '06 with with a rim and a bit shorter. So a more or less straight case but with only the tiniest bit of taper would be a .429". You should be able to have about the difference between .429" and .375" for a shoulder if you minimize the taper. The .375 JDJ is that Marlin case blown out to minimum taper and opened to .375" and it has worked well for many years in the TCs.

[Nobade]

Yep, that 444 case has a rim as well, sure makes it a lot easier to control headspace. On the 375-06, figure the head diameter is about .470, you'll want at least .010 taper to the body/shoulder junction so it'll be .460 there. Assuming about .015" wall thickness at the neck, your neck is going to be .405 so you'll have .0275 per side for headspace control. You will want a sharp, 40 deg. shoulder so you end up with something that looks like a giant 7mm TCU. You could add a little more body taper if you wanted to, but not much. I'm not sure what the real 400 Whelen uses, but you could do it like that one if you wanted, since it works fine with an even bigger bullet. I guess I could make one now without a reamer for it by using the 35 Whelen AI with a proper pilot for the 375 barrel, then a 375 necker and 375 throater. It's a little more work, but you can control the chamber length and throating really closely that way.