Home Forums Hunting & Shooting Gunsmithing I was thinking about this....

While on a mountain top south of Jackson Hole last week and should have been concentrating on big mule deer. Anyway, I have a job in the shop that needs rework. It is presently a 223 AI that the client wants converted back to a standard .223. Everyone knows it takes some figgering to find how much to set it back without just removing all of the chamber section.

Here is my idea. Is it possible to find a set of transparencies that we could overlap to determine this? They could be double sizew or triple size to make the measuring easier and then we could convert this to actual size.

Maybe someone already makes these. I don't know.

Jim

Jim
Perhaps because I have a math background and no metal working background, it seems awfully easy to do the math and awfully tough to get ACCURATE templates, that can be measured ACCURATELY. Well-defined measuring points and a probable need to do the rechambering in thread increments seem easy for me to deal with???

Also, it seems that testosterone would make the average rechamber bigger rather than smaller, so only the occassional job would go the other way. It seems a table of conversions would be easier to build than a template. Just my perhaps naive opinion...
art

My 'smith has done it (rechambering a 223AI back to the std version) so it can be done. Alot of factors determine success though.

MtnHtr

Jkob,



The fired cases from my 223 AI are so straight, that it would essentially require cutting off the barrel enough to remove the entire body section of the case.



Ted

I realize the whole AI chamber would have to be removed, but that is not the problem or the solution. I just thought it would be easier to overlap a few transparencies and be able to readily see how much needed to be done. Take the case of the 308 to 30-06, I have done that one too, but had to figure how much to take off and piss around with some dimensions before doing it.

Sorry, I am not following you.



Would it not be a simple function of shortening the barrel a tad more than the length of the AI case from the base to the shoulder, then threading and rechambering?



Ted

Ted
This case is pretty simple, but others could be interesting to figure, assuming barrel length retention is an issue.
art

You wouldn't have been part of the horde of folks I saw near Ramshorn Peak would you? <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" /> LOTS of folks hunting that country opening week.

We headquartere out of Camp Creek Cabins east of the junction and went in the trailhead at big Granite I believe. It was a 2 1/2 hr ride in and then found all kinds of hunters. When you pay for a one on one hunt, you expect to be kind of exclusive in the area.

Sounds like the USFS ground I was on. If I remember right, Granite Creek is on the other side of the Mtn than I was.

Whenever you have an existing chamber that has less body taper then the desired re-chamber, the only way to properly re-chamber is to wack off the whole chamber. This is the opposite of a 30-06 to .308, as the 30-06 has more body taper then the 308.

No disrespect ment, but if you don't understand the math involved in comparing chamber dimensions, I wonder about your abilities to run the lathe?

You could just set it back a thread or two and cut a new shoulder, but you won't end up with a .223 chamber. Sure, it'll chamber and fire .223 ammo, but the case body will have signifigant growth, and be signifigantly sized after eacher time it's sized. You'll basically have an ai body, with a standard shoulder, and a slight step at the transition of the differing body diameters.

I have to ask. .223AI to .223 -- why?

Ya know guys, it is really amazing what some guys can read into this. It don't make a [bleep] if a guy wants to go from an AI to a standard. It don't matter if he wants to go from an '08 to an '06 or the other way around. What matters is he wants it and I am here to help. I have a generous math background and have used the trig tables on numerous occasion to figure out the differences in these cartridge comversions to remove only the minimun amount of chamber for the new one. If you will go back and read my original post, you should, and I say should, understand the impetus for my question was to find a quick and easier way to do this. Thanks to all who responded with a viable, intelligent response. JIM

If he wanted to have his 300 win mag re-chambered to a 30-06, could you do that too by setting it back a thread or two? That is same deal as getting rid of an ackley chamber, you can't put metal back, you have to wack off the hole chamber, otherwise it's a cluge job.

If you're familiar with the dimensions of the various chambers, then that is obvious.

GEEEEEEZ....no $hit, now why didn't I think of that????

I feel your pain, but I'm not aware af anything that might help. Last time I did that particular job, IIRC, I took an even .800" off.

Simple really, just take a decent CAD program, lay out a 223 standard 2d drawing, thenon a different level, draw up a AI drawing overlaying the 1st. Now just shift the 1st over till it would clean up. measure the distance from case head to case head. nuttin' to it! <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" /> You could get the dimensions from many loading manuals.

How about using the cartridge drawing tool in RCBS 2.88 and printing the drawings onto flimsy paper (onion skin) or onto transparency stock?
Probably not as exact as a CAD program, but I bet it would give a good approximation.