AI conversion

[243LPR]

Ok,getting the itch for a 6.5x55 Swede but I'd rather go the AI route. If I buy a barrel with the standard chamber,what is involved in making it an AI,other than buying a reamer? Can reamers be rented?

[bootsmcguire]

Reamers can be rented. You would have to put it in a lathe and shave a little off the breech end, and then ream to the AI chamber.

Can't remember the site but there are a couple rental places. IIRC I just googled for it when I went looking before.

Why not just have it built as an AI to start with?

[mike21]

Here's one rental place that's been recommended here before:

http://www.4-dproducts.com/index.php

[scope eye]

I have turned a reg chamber into an AI version many times by renting a reamer, it even comes with the T handle and go-nogo gauges, I would not do a whole rechambering by hand, but when doing just an AI version of caliber you already have, the reamer is in so deep into the chamber, that it guides itself with out any side load, you can feel what you are actually doing, and it is easy to stop and check your work often, I originally did this on a factory Stevens 200 25-06 factory barrel, that I wanted to turn into a fireforming barrel, and if it did not work out lesson learned, but it came out so nice I actually used the barrel, and any barrels I did after that I wasn't filled with as much fear and anxiety, it is actually quite exhilarating to rechamber your own stuff, even more then you feel when you first start making your own ammo.

Dean

This is the place I use

http://www.reamerrentals.com/

[243LPR]

The barrel I'm looking at is in stock and will ship right away. If I order one who knows how long it will take. Reamer rentals doesn't have this one. Midway has it in stock.

[scope eye]

That it what I did for my latest build, I took a finished barrel it was a 6BR, and am having Apache rechamber it, 6 months is just to long await for me,

Dean

When a reamer is not in stock it is probably rented out, put your name on the waiting list.

[yobuck]

ive only one ai chamber in 22/250 ai. my question would be barrel legnth. im assuming a standard say 22" barrel
would no longer suffice with an ai chamber in say a 25/06? in going to an ai chamber, what would be the rule of thumb
increase necessary to achieve max results in say 06 based cartridges?

[scope eye]

You don't half to have a longer barrel to take advantage of an AI conversion, a longer barrel is needed to take FULL advantage, I saw 200 FPS increase just with AI and the same 22" barrel, going to a 26" 12 twist gave me another 400 FPS on top of that.

Dean

[NVBighorn]

I have turned a reg chamber into an AI version many times by renting a reamer, it even comes with the T handle and go-nogo gauges, I would not do a whole rechambering by hand, but when doing just an AI version of caliber you already have, the reamer is in so deep into the chamber, that it guides itself with out any side load, you can feel what you are actually doing, and it is easy to stop and check your work often, I originally did this on a factory Stevens 200 25-06 factory barrel, that I wanted to turn into a fireforming barrel, and if it did not work out lesson learned, but it came out so nice I actually used the barrel, and any barrels I did after that I wasn't filled with as much fear and anxiety, it is actually quite exhilarating to rechamber your own stuff, even more then you feel when you first start making your own ammo.

Dean

This is the place I use

http://www.reamerrentals.com/

So can you achieve headspace in a Savage rifle without turning back the face of the barrel? I've always heard you couldn't but I don't know if that applied to Savages.

[scope eye]

If you are a gunsmith or have access to a lathe, most want to start with a fresh surface, but it can be done I don't know if it is exclusive to savage or not.

Dean

I see what you mean, Remingtons and others that have a recess on the face of the barrel, would need to be set back,
I guess savage being flush do not have to be, I don't know of any others.

[bootsmcguire]

Well the issue you run into is a True Ackley Chamber has the neck shoulder junction .004" closer to the breech end of the barrel than the parent chamber, to accomplish a crush fit when firing the parent case. If you ream a AI chamber into the parent chamber without taking a little bit off the back, you end up with a slightly long AI chamber.

Now a long AI chamber can work if you seat your bullets firm into the lands when fire forming, and then neck size the brass there after or back off your FL die just to bump the shoulder.

The problem you run into is on a perfect chamber your go gauge will stick out of the barrel .125" nominally. Savage bolt faces are recessed .117" on average which leaves you .008". Now, if you ream it perfectly (by hand mind you) to depth you are still .004" long, which means when you headspace with a go-gauge the gauge will only stick out .121" which only leaves .004" between the bolt face and the face of the barrel. And all of that is assuming perfect tolerances. If you ream too deep, if the bolt is deeper than .117", or if the original chamber was deep from the factory by a couple of thousandths. Any one of those could eat into that remaining .004" gap and put the bolt head in contact with the barrel before you achieve proper headspace.

Now like I said above you could just seat your bullets to jam in the lands and fireform to your new chamber, but you will loose the ability to fire factory ammo from the parent chamber in your barrel if you ream it without set back.

If it were me I would rent/buy the reamer and have a local smith rechamber for you. The extra $50-$75 it will cost you is good insurance that its done properly and everything is perfect.

[scope eye]

Well explained Boots, I must have a horseshoe up my WooHoo, to get away with some of the stuff, I have pulled over the years.

Dean

Danger is my middle name, maybe it should be more like,
Dangerous is my middle name.LOL

[bootsmcguire]

Well like I said above, it can be done with out set back, but you end up with a wildcat rather than an AI chamber. If you treat it as a wildcat then you are fine, but when you try and treat it like an AI then you run into issues.

[yobuck]

[QUOTE=scope eye;235725]You don't half to have a longer barrel to take advantage of an AI conversion, a longer barrel is needed to take FULL advantage, I saw 200 FPS increase just with AI and the same 22" barrel, going to a 26" 12 twist gave me another 400 FPS on top of that.

i was aware you could use whatever legnth you chose using. i just question how practicle it might be to not increase barrel legnth
when doing so. im somewhat surprised by your results. i was of the opinion a couple hundred fps gain would be possible over a standard chamber and that with a slightly longer barrel.

[scope eye]

This is how I break it down in round numbers, AI is worth 200FPS, 22" to 26" barrel 200 FPS and increase to 12 twist another 200 FPS
with 70gr Blitz King and 60gr of RL17 3600 FPS from a 22" and with AI, 4" barrel 2"more twist and 64gr of RL 17 4200 FPS.

Dean

[yobuck]

[QUOTE=scope eye;235775]This is how I break it down in round numbers, AI is worth 200FPS, 22" to 26" barrel 200 FPS and increase to 12 twist another 200 FPS
with 70gr Blitz King and 60gr of RL17 3600 FPS from a 22" and with AI, 4" barrel 2"more twist and 64gr of RL 17 4200 FPS.

so if im understanding you correctly, i can rechamber my 22" factory 25/06 in which i shoot 115 gr bullets and increase velocity
by about 200 fps by simply rechambering to ai. if i increase barrel legnth to 26" i will gain about 400 fps in total while still using 115 gr bullets.
an addittional velocity gain can be obtained with the longer barrel by using a slower twist, and a lighter bullet allowing for more powder.
bottom line, 400 fps max for ai and that with a new longer barrel.

[snowgetter1]

Yobuck, I had a 25-06 AI and 200 fps gain with almost all loads is easy. To get the 400 fps gain it was a lot of increased pressure and hard on the brass. Also hard on my ejector. I shot two deer with AI but it was just to explosive. Went back to a standard 25-06. But, fast was cool.

[scope eye]

Yobuck Yes and a few clarification, it is not because you turn into an AI that it is faster, it is because of several reasons 1st it will hold more powder, and if you reached your max chamber pressure, and you still have room for more powder you just use more of a slower powder, which will give you more speed, if you use the same load as you were using when it was not an AI, you will not see any gains in speed but your case life will be longer, the reason I saw so much gain in my case, I had more powder, barrel, twist, and pressure a nice tight custom chamber will always be faster than a factory one.

Dean

[scope eye]

What is your current load with those 115gr, I might be able to give you an idea on what to expect.

Dean

[yobuck]

What is your current load with those 115gr, I might be able to give you an idea on what to expect.

Dean

well first i should clarify im not considering it for my 25/06. i simply used that to illustrate my question.
i am however considering it for a 6.5x06. my son and several friends have standard 6.5/06s. i would be rebarreling
a 700 rem which i own. so rebarreling will happen regardless and no doubt with an 8 twist. decision for me is barrel
legnth and wether or not ai. in any event it wont be less than 24". id not hesitate on 26" if the ai would make that worthwhile.
i will be using the heaviest bullets that shoot well in the gun, hopefully 140s. i recently sold a 6.5 wsm which id built on a savage
and owned for 4 hunting seasons. im not looking at duplicating those velocities. im looking for something i like better and the 06
case looks as though it would work for me.

[scope eye]

If you are a reloader with any experience, there is no reason not to go they AI route, just the brass savings alone are worth the price of admission, not all cartridges respond well or see any gain to AI, but they 06 family is one of the ones that responds to it the most and sees some of the most gains, no matter what barrel length, in fact a excellent way to regain lost velocity from a shorter barrel used for hunting or light weight is AI, with no ill effects and if ever you get caught short on ammo, non AI ammo will work just fine.

Dean

[243LPR]

Well the barrel I ordered is not in stock like I thought. Plan changed and ordered a Criterion from Jim. A little more money but should be worth it.Also have some Lapua brass coming for it. Just need some dies and bullets and warmer weather.

[mattri]

Glad you found what you were after, Jim is great to work with.

As far as the re-chambering goes, let's say that you want a 6.5x55AI. Instead of using a factory 6.5x55 chamber would it be better to use say a 260, so you have the room to cut the proper length?

[scope eye]

AI they existing chamber is easier, but on they other hand once it's in the lathe, it doesn't really make any difference.

Dean

[bootsmcguire]

Glad you found what you were after, Jim is great to work with.

As far as the re-chambering goes, let's say that you want a 6.5x55AI. Instead of using a factory 6.5x55 chamber would it be better to use say a 260, so you have the room to cut the proper length?

If you are hand cutting, the 260 chamber would have you there for awhile and it would be very hard to keep the reamer straight. If you are using a lathe, then either would work, but all else being the same I would probably go with the 260 as a donor just because you would have a bigger window to check when coming up on your target depth and work to it appropriately, but the parent chamber will work fine, you just have to remember to take a bit off the breech before running in the reamer, otherwise you end up with the situation I described above in post #11.