AR15.Com Archives
 223 Remington Ackley Improved
TLMgamecalls  [Member]
11/30/2006 6:51:47 AM
does anyone have this barrel
or know if i can rechamber a 223 or 5.56 barrel with just a reamer
any info would be great
looking to get a little omph out of an AR
thanks todd
mike_mccue  [Member]
11/30/2006 7:39:42 AM
http://www.pac-nor.com/wildcat/


but why? An incremental "improvement" which may help with a bolt action hobby sounds like a pain in the tuckus in a semi auto. How are you going to keep yourself in brass?

mike
ronemus  [Member]
11/30/2006 9:22:44 AM
standard .223 brass can be used with no problems, as can factory .223 ammunition - it will just be fireformed to .223 AI. The AI gives a small increase in case capacity (~1 gr), but the reduction in body taper may make extraction more difficult and cause malfunctions. you'd be much better off with the 6 mm WOP (6.8 SPC necked down to 6mm) if you're looking for a performance boost in the AR-15 platform, or one of the .308-based cartridges if you will consider the AR-10 (my choice would be the .260 or 7-'08); you'd have much better performance with about the same effort as going to .223 AI.
TLMgamecalls  [Member]
11/30/2006 8:06:29 PM
i was hoping to get 22-250 power out of an AR (or close to 22-250 from a 20" barrel)
(without changing brass or mags)
and i could give it a try for for under $250 (barrel, reamer, dies)
the brass just fire forms and any 223/5.56 brass could be used
but before i tryed i was wondering if anyone else had, and what there results were ?
(i'm hoping to get a 6.8 for christmas)



pogo  [Member]
11/30/2006 8:38:40 PM
You would have to set the barrel back a couple threads as the Ackley uses the same headspace gages (and factory 223 ammo), but the inside of the shoulder needs to be cut from metal and not air.

All things considered, I would prefer to start with a new barrel if considering this project.
pogo  [Member]
11/30/2006 8:41:26 PM
One guy I knew shooting highpower with a match rifle uses a 225 Winchester based wildcat. IIRC, it is the same reamer with the rim ground off.

If you are looking for more oomph than the 5% velocity increase I recall for the AI, look at increasing your case body diameter.
AR15barrels  [Dealer]
12/1/2006 2:46:46 AM

Originally Posted By pogo:
the Ackley uses the same headspace gages




Ackley designs always have a sharper shoulder angle and reduced case body taper.
Special headspace gauges are required.
Ackley keeps the minor shoulder diameter at the same place.
This is why the factory ammo can still headspace.
The major diameter of a factory cartridge shoulder IS floating in the air when it's in an ackley chamber.
That's why the shoulders BLOW FORWARD when you fireform...

As for the 225 wildcat mentioned, it could be done pretty simply with 6.8 cases as 225 and 6.8 cases are nominally 0.420" at the base of the case body.
fiend  [Team Member]
12/1/2006 4:27:03 AM

Originally Posted By AR15barrels:

Originally Posted By pogo:
the Ackley uses the same headspace gages




Ackley designs always have a sharper shoulder angle and reduced case body taper.
Special headspace gauges are required.
Ackley keeps the minor shoulder diameter at the same place.
This is why the factory ammo can still headspace.
The major diameter of a factory cartridge shoulder IS floating in the air when it's in an ackley chamber.
That's why the shoulders BLOW FORWARD when you fireform...

As for the 225 wildcat mentioned, it could be done pretty simply with 6.8 cases as 225 and 6.8 cases are nominally 0.420" at the base of the case body.


What don't you know?
TLMgamecalls  [Member]
12/1/2006 5:13:47 AM

Originally Posted By AR15barrels:

Originally Posted By pogo:
the Ackley uses the same headspace gages




Ackley designs always have a sharper shoulder angle and reduced case body taper.
Special headspace gauges are required.
Ackley keeps the minor shoulder diameter at the same place.
This is why the factory ammo can still headspace.
The major diameter of a factory cartridge shoulder IS floating in the air when it's in an ackley chamber.
That's why the shoulders BLOW FORWARD when you fireform...

As for the 225 wildcat mentioned, it could be done pretty simply with 6.8 cases as 225 and 6.8 cases are nominally 0.420" at the base of the case body.



so a standard barrel with an existing chamber could be cut with a reamer to 223 AI
thanks for the info todd
Boatanchor  [Member]
12/1/2006 10:18:48 AM
TLMgamecalls,
I have 8 different Ackley Improved rifles and none of them currently on an AR platform, the biggest problem is that with the case taper blown out they dont feed as reliable, you must be very meticulous sizing your cases or extraction can also be an issue. every Ackley Imp chambering that I have has a -.004" headspace from the parent round so the barrel has to be set back. fireforming your brass is a bit of a headache also but accuracy is normaly quite good but you give up 100-200fps. once fireformed you can gain about 100fps mabey a little more.
B
AR15barrels  [Dealer]
12/1/2006 11:07:17 AM

Originally Posted By fiend:
What don't you know?


Colt model numbers, variations, production quantities and serial numbers.
pogo  [Member]
12/1/2006 10:41:07 PM
BS!... I would not have said that. That is pretty strong stuff for an "it depends" answer. Many other reputable barrel makers think you may have to as well.

Yes, the AI chamber reamer is supposed to clean up the chamber to the case neck junction. It does not always work out that way, from what I gather.

I bought a 223 AI reamer to rechamber a 223 Howa rifle. The reamer came with standard 223 headspace gages, and when I sent them back I got the same ones again with an explanation they were one and the same. As the action length and magazine was used for the 308, I ran the reamer in another 1/4" to make a sort of 222 mag improved.

Typical, from z-hat.com:

When changing to a substantially larger cartridge it may be possible to simply rechamber your barrel. In most cases the best approach is to set the barrel back one thread before rechambering. This insures a clean and true chamber, for best function and accuracy.

We offer a wide variety of calibers and can chamber for nearly any cartridge you can name. specializing in custom wildcat work requires experience. we are Experts at all aspects of barrel work.

Common Questions:

Q: Will you have to set my barrel back for an Ackley Improved?

A: Ackley Improved cases are a perfect example of a cartridge which requires a set back. P.O. Ackley himself recommended this as the correct method of rechambering to his cartridges.

Q: How much will it shorten my barrel?

A: In 90% of the cases we are talking about approximately 1/16th of an inch. It's so little that most shooters can't tell any difference. Gaps around the barrel are a concern for most all clients, moving the barrel back a 1/16th of an inch will not create a noticeable gap.


from rec guns on the 30-06 AI:
What you will get is greater case life and probably better accuracy (the
potential is there if the rest of the rifle is up to it). The question is:
Is it worth the cost and all the difficulties associated with removing and
machineing the barrel. You cannot simply ream the standard chamber into an
Ackley one, as the Ackley case is actually 0.004-0.006" SHORTER than the
factory round at the shoulder to neck junction. This is what allows the
unformed round some degree of gas sealing in the improved chamber.



AR15barrels  [Dealer]
12/1/2006 11:49:03 PM

Originally Posted By pogo:
BS!... I would not have said that. That is pretty strong stuff for an "it depends" answer.


I ONLY said BS to ONE SPECIFIC STATEMENT and certainly not to anything else you were talking about.
You can set the barrel back if you want to, but it's not required.
There is no problem with a couple thousandths of un-cut chamber at the neck junction.
Now, setting the barrel back a turn is an excellent idea for other reasons, mainly to re-cut the throat, but this has NOTHING to do with using standard headspace gauges while cutting an Ackley Improved chamber.

Whoever sent you the standard gauges for use with an ackley reamer was just simply wrong, TWICE.
The manner in which gauges measure simply does not allow the same gauge to be used in two different chambers with dis-similar shoulder angles.
The shoulder angle of the gauge and the chamber absolutely have to match in order to have an accurate measurement TO the shoulder.