Having a rifle AI

[C.Smith]

I am wondering when you have a rifled Ackley Improved does the gunsmith have to take the barrel off the rifle? Or do they just put the reamer in with it attached?

Corey

 

[FOTIS]

All of mine have been removed. Usually the smith has to set back a thread or so in order up to clean up the chamber.

 

[JD338]

C.Smith

Yes, the barrel will have to be removed.
If you are going to have this done, spend the extra money and have the action blue printed. This will square up the action to the barrel and will help with the accuracy. My M700 280 AI is a tack driver.
What action and caliber are you thinking of?

JD338

 

[nodak7mm]

To have it done correctly, yes. On a typical AI chamber the shoulder jct moves fwd, neck junction & col shortens. Alot of acks are done as you described tho and its not necessarily a bad thing, just not done the way old Parker designed it... (If not mistaken, I think the case neck drastically shortens is the resultant effect.)

Rod

 

[Ridge_Runner]

AI chambers are set to headspace .004" shorter than the factory case, This is why you can shoot factory ammo in an AI chamber to make brass, so the barrel must be removed, and set back a thread or so to clean up the old chamber and re-index the barrel (put the writing back where it was originaly)
RR

 

[nodak7mm]

RR, thanks for pointing that out.. I knew there was more to it, but to dang lazy to go look it up... Sheesh, for having 3 acks, ya think I'd remember that key fact.

Rod

 

[JD338]

AI chambers are set to headspace .004" shorter than the factory case, This is why you can shoot factory ammo in an AI chamber to make brass, so the barrel must be removed, and set back a thread or so to clean up the old chamber and re-index the barrel (put the writing back where it was originaly)
RR

Right on buddy! :grin:

JD338

 

[C.Smith]

C.Smith

Yes, the barrel will have to be removed.
If you are going to have this done, spend the extra money and have the action blue printed. This will square up the action to the barrel and will help with the accuracy. My M700 280 AI is a tack driver.
What action and caliber are you thinking of?

JD338

I have a Tikka T3 lite that I'm contemplating it on.

Corey

 

[jtoews80]

I've got a Rem 700 varmint in 22-250AI and a CZ 602 in 375 ICL Kodiak that is similar to an Ackley. However, I bought both as is and didn't realize that they were intentionally headspaced to 0.004 difference for fireforming. Pretty inpressive difference for very little change in diamensions. Alot cheaper than going to a 223 WSSM or 240 wby for me.

JT.

 

[Ridge_Runner]

I've got a Rem 700 varmint in 22-250AI and a CZ 602 in 375 ICL Kodiak that is similar to an Ackley. However, I bought both as is and didn't realize that they were intentionally headspaced to 0.004 difference for fireforming. Pretty inpressive difference for very little change in diamensions. Alot cheaper than going to a 223 WSSM or 240 wby for me.

JT.

What needs to be pointed out here is, the AI's have about 2% powder capacity increase over the parent cartridges, if you have more than 2% increase in MV, your shooting higher pressure levels than the parent cartridge.
Most folks load the AI's up till they see pressure signs, then back down a bit and call it a max load. and it works, but do not be mistaken, most AI's run much higher chamber pressures than folks realize.
Some things to think about
AI chambers are mostly cut with a custom min spec reamer
Min. body taper prevents the case from acting like a wedge and pushing back against the bolt face.
These reasons minimize and sometimes completely eliminate the first signs of high pressure in alot of AI chambers, most of them show no signs at all till the primer falls out during loading.


RR

 

[Antelope_Sniper]

These reasons minimize and sometimes completely eliminate the first signs of high pressure in alot of AI chambers, most of them show no signs at all till the primer falls out during loading.

Wow. That's a little scarry.

 

[corbin9191]

I dont mean to ask another question on your post, but what are the running prices for having a rifle AI? (25-06 rem)

 

[old #7]

I had my 30-06 ai'd about a year or so ago by a reputable smith and I seem to remember it cost around 125.00.

 

[Ridge_Runner]

These reasons minimize and sometimes completely eliminate the first signs of high pressure in alot of AI chambers, most of them show no signs at all till the primer falls out during loading.

Wow. That's a little scarry.

Its a fact sniper, most custom AI chambers very seldom ever show an ejector pin mark, and heavy bolt lift is rare unless your ruining cases every shot. some show flattened primers to an extent, but primers flattening isn't a real sign of high pressure by itself.
My 6.5 gibbs shows a bit of cratering on the primer from anything above fireform pressures, then nothing till you lose the pocket.
RR

 

[clearwater]

JT.[/quote]

What needs to be pointed out here is, the AI's have about 2% powder capacity increase over the parent cartridges, if you have more than 2% increase in MV, your shooting higher pressure levels than the parent cartridge.



RR[/quote]

This will depend on the case you are working with and the powder used.
I notice a 7% increase in powder capacity in my 7x57AI.
Improvesomething like a 25-35 and you will see even more increase.

 

[30-338]

There is always pro's/con's on building an Ackley and been a long history on the Ackley data. My first Ackley was 7x57AI got my loading data from Speer # 4 wildcat manual and 60kpsi mentioned that was published 1959.

Hodgdon has data that give pressure over the parent caliber for the 280AI.

Here is alittle data from my Ackleys that I loaded to the top of the neck with H-380

222---26.4gr 222AI----29gr

223---29.5gr 223AI---32.3gr I have two of these

22-250---43.8gr 22-250AI---48.5gr

243---54.7gr 243AI---57.5gr

6Rem---54.9gr 6 RemAI---60.9gr I have two of these

280---67.9 280AI---72.3gr New Nolser brass


I've always owned or still shoot the parent caliber so that gives a good base line on velocity and a good chrono helps.

I don't buy the equal pressure never have if I was only looking at 2% increase in velocity you can get than much going to a longer barrel maybe different twist shooting the parent calliber. Most guys that I know who build an Ackley have a good understanding of what to expect they will order a barrel that will help the new chamber.

Varmit Hunter Magazine published good article on the 223AI they used a 27.5 " long Hart barrel. I used a 27" mid 3600 to 3700 fps with 50gr bullets. My 243AI with 80gr bullets @ 3705fps use 2.5gr over my load for the 243.

My or should say my wifes 280AI has 25" 1/9 twist Kreiger the new 280AI will have a Bartlein 5r with 1/10 twist barrel 24" should have it Feb be interesting.

I've shoot pretty close to 25 chamber Ackley rifles and never had a problem but I do agree they are alittle different working up loads. I had one that I just didn't like was a 338x280AI spun that barrel off build the 280AI nothing wrong with the caliber other than just didn't like it. I've always used new barrel when build a Ackley so cann't say how a factory barrel be.

One of my first Br rifles was chambered for the 6x47x40 was the 222mag case Ackley open to 6mm and they shoot lots of 222x35 to 45 was just 222mag case Ackley shoulder from 35 to 45 degree. My 222AI was called in Br circles 222 1/2 proven BR winner.

 

[Ridge_Runner]

Well I don't want you guys thinking I'm saying AI's are unsafe or anything, Millions of guys treat regular cartridges just like AI's, and work up slowly and have very good success shooting loads beyond yhe book max. we all know that different rifles with different barrels, cut with different reamers all handle pressure differently.
I work up a max load for all my rifles, then back off 2-5 gr. depending on capacity and powder used.
I'm just saying most of the time in an AI chamber, when you see the first pressure signs, that case is closer to failure than it would be in the parent cartridge.

Ever heard of the "300 Varminter"?

It is exactly a 300 wsm, that with a 30" barrel runs a 125 gr bullet downrange at just over 4000 fps, the guy making them says its safe, in his action, if he builds it.
Now run that through quick load and see what kinda pressures you'd haveta run to get that speed from a 300 wsm.
I don't know if its safe, but if it is then I don't feel bad pushing a 140 at 3340 out of my 6.5 Gibbs.
RR