on a rifle, if rebarreling to an Ackley Improved case. Back in 1959 I had a 25/06AI made up (dumb, gunsmith tried to get me to buy his model 70 in 270, but being young and having read all the BS about the 25/06). Anyway, had trouble getting it to feed, would , in fact, let a case "jump out" of the action, and he had to modify the feed rails, twice, to get it right. He wasn't some jerk, knew his stuff, and told me, you almost always have to modify the rails to get an AI to work, as just the difference in case shape. Since then I've heard others, who I presume had someone build them an AI, say, no you don't. But presume they never asked the gun maker. My rifle, at the time was a 1903 Springfield action.

Anyway, the question is, how often is it necessary to modify the feel rails, to make an AI round feed right? Or does it kind of depend on the round. Had one guy tell me that going from a 260Rem to a 260RAI, doesn't really need I as case shapes too close. Thanks..

BTW, got my first deer with the 25/06AI, 117gr Speer, I think, and like 60grs of 4831, which I now know was more than it should have needed.

I have two improved cartridges on bolt actions; one a 35 Whelen on a 1917 Enmfield that feeds a bit stiff but I've never gotten up the nerve to styart grinding and filing.

The other is on a 98 Mauser, a 25-o6, and the extractor would hang up when chambering,but not seriously. I did some filing and polishing on the guard rails, forward, that 90% fixed the problem. It looked to me that the cartridge, moving forward, didn't lift early enough, which made sense, and hung up a bit on the ramp. Since the bullets were the same whether it was improved or not, I opted to work on the rails rather than on the ramp.

I think I'll leave the Enfield as is; I replaced it with a .338 and haven't used it for 15 or 20 years. I'm getting too old to haul out an elk anyway.

I was hoping some of the gunsmiths I've seen remarking on other things here would see this and reply. A 35 Whelen pretty much still has the case shape of an 06 (like my 338/06 does), but thicker bullet might cause a problem. Hoping to get some other input. Thanks for yours.

Read this thread, if you haven't already.

http://forums.accuratereloadin...9411043/m/9301061152

Buy Duane's booklet.

Thanks, but doesn't answer the question about reworking the feed rails to make an AI round, feed right, and therefore mess up the action for anything else, as can't then go back and use it for the original round. But interesting read, and in fact, will probably buy the book, though I have an ACCG smith in PA that I'm friends with.

Tyson...got your PM...Like to help out, but I just can't provide drawings or instructions on a one off project like this, but I would say that I only start out with properly proportioned bottom metal ..the rest is seat of the pants try and try..something like knowledge based on experience , art and a bit of luck.

I do not take on feeding issues unless it's part of a complete custom build..i.e. I'm not in the business of general gunsmithing .

Ackley did move the shoulder out on many of his improved rounds. So, the answer is "probably yes". Some had retained the original shoulder position.

Got a Electronic Digital Vernier Caliper?

Google both the standard & AI caliber wiki to compare shoulder positions & diameters. If no luck there, then measure the AI round and compare with std. factory measurements on wikepedia.

quote:

Originally posted by tysue:
on a rifle, if rebarreling to an Ackley Improved case.

Anyway, the question is, how often is it necessary to modify the feel rails, to make an AI round feed right? Or does it kind of depend on the round. Had one guy tell me that going from a 260Rem to a 260RAI, doesn't really need I as case shapes too close. Thanks..

As a rule, AI cases should feed through the parent mag box and action with no hiccups. I would tinker with the box first. Cheaper part to replace if it gets messed up. Adjust the lips of the box to push the base of the round to the center of the well as it reaches the release points milled into the receiver.
Learned it the hard way.

Ok, I will chime in, only because I have milled out a lot of Mauser and Enfield receivers to feed cartridges with less taper and bigger bullets than originally designed for.
How often is it necessary, you ask?
Often.
How is it done? With a ball end mill and a die grinder.
I do it like the Pinball Wizard won games; sense of smell.
As DW said; it is an art, not a science.
And I can't work on a rifle that someone else built; they should have done the complete job.

An afterthought- One of my old hunting buddies loves Remingtons and has several AI cartridges; all chamber perfectly according to him, and he should know.

Maybe it's because it doesn't hang up on the extractor Like a long extractor can.

quote:

Originally posted by kendog:
As a rule, AI cases should feed through the parent mag box and action with no hiccups. I would tinker with the box first. Cheaper part to replace if it gets messed up. Adjust the lips of the box to push the base of the round to the center of the well as it reaches the release points milled into the receiver.
Learned it the hard way.

I should pay better attention. I see the OP has a 1903, no stamped box to adjust or fiddle with. OOps

Jerry, your friend's 700 feeds because the sheet metal magazine box controls the feeding
and there are not integral contours milled into the receiver as there are in Mausers and Springfieds for example.