I'm looking for some feedback here. I would like to have a rifle barrel (20"-24") chambered for a .22 cal round. How much more performance can be gained from going with the .222 Mag Imp over the .223 Ackley Improved? My mitigating circumstance is that I also have a 6, 6.5, & 7 TCU so I could benefit from sticking with .223 brass only. However, I don't want to cave in to convenience if I will be giving up a lot of performance.

Does anyone have any experience to add? I'm going to visit Mike's site again to see if it addresses this issue.

Hello B_Koes,

I think it would be hard to tell the difference. The ballistic charts in my Guns and Ammo Annual magazine show both 222Mag and 223Rem at 3240FPS with a 55 grain bullet (factory loads).

With the vast availablility of 223 Rem brass compared to 222RM, I would go with the 223 and not look back.

Just my .02, Bill

( Topic: .222 mag twist? larry b.
New Member
Member # 8887

posted 10-22-2002 05:56

Can anyone tell me what twist rate to get for a .222 mag. I will be using 50 gr. bullets or less. Thanks

Posts: 6 | From: wisconsin | Registered: Jul 2002 | IP: Logged

JBelk
One Of Us
Member # 6472

posted 10-22-2002 07:13

larry B---

One in fourteen is perfect.

I'm a curious guy. Why chamber for a truly obsolete, modern cartride?

The last brass I bought (to make 6x47) was absolutely wretched in quality. Most of it was WAY out of concentricity
and weights were off the scale. I suspect very worn dies and I KNOW the "same lot" of brass was marked on three
different header machines. I had to resell 4 out of 5 cases.

A VERY good alternative is to short chamber, with a 222 RM reamer, by .093" and resize .223 brass in the 222 Rem
Mag FL die that's been shortened by .093. This gives you a nice looking cartride with cheap brass. It also tightens the
base tolorences a LOT. I get 18 full house loads from a tight-necked (.242) case.

WARNING THIS CARTRIDGE WILL LIKELY BLOW UP a .223 rifle!!! It has a BUNCH of excess headspace in a .223
rifle.

I suggest a benchrest tight neck so they cant be chambered in a .223, but I just turn off the headstamp with a
plunge cut that just takes the writing.

Use any 222 or light .223 loading data to start.

I'll do anything to avoid owning a .223. )

And away we go. From another part of Forum

Sorry I didn't get all the post included above The answer was from JBelek Member#6472 Posts 397. the answer wasn't mine. I know better.

tommyn - I'm not sure what that post has to do with my original question. I'm not really considering any other options than the .222 Mag Imp or the .223 Ackley Improved. I would like to know how much more velocity that can be squeezed from the greater case capacity of the .222 Mag Imp.

B_Koes,

The 222 Mag and the .223 Rem are about ballistically identical. If you were to do the same improvement on these two cartridges, you would have ballistically identically results. The 222 Rem Mag has a slightly longer neck than the .223 Rem, but basically and ballistically, It's Sixes...

If there were a difference, it would be so slight as to make the .223 choice a better one, based on the availability of brass. I think...

Malm

I was wondering, especially in light of some of Mike's recent work with the .222 Mag Imp. I am particularly interested in using heavy bullets (70-80gr) and I suspect that the longer neck would help keep part of that boat tail from taking up valuable powder space, but I didn't really know if it was significant. I guess I'm inclined to agree with you...just wanted to know if I would be giving up much.

Speaking of the availability of .223 brass, I have a friend who wishes to return to Vietnam and set up business. I suggested he consider mining. "Mining what?" he asked, why, lead, copper and brass of course...


Malm

The better quality of brass is what I was posting about on the difference between 223AI and 222 MagAI if there was good quality 222 Mag brass it would win hands down.

I have a 24" 222 barrel at Mike's right now waiting on the conversion to 222RMI. I posted a question on his web site under suggestions and he did respond via his new GREAT e-News letter, Mike this is my way of giving you credit for the following:

Quote from BELLM newsletter***sign up on his web site to receive it!!!!

"One question was in regard to what the .222 Rem. Mag. Imp. does in
carbine length barrels v. handgun length. Relying on my friend in MO that
I consider a very good one-man test lab, he gravitated to 50 gr.
bullets at about 3600 fps from 18" barrels. His powder of choice is mainly
AA2520, using around 30.5 gr. 4064 does well also. He said that AA2460
is good with lighter bullets, hitting 4,000 fps with 40 gr. bullets
which was hotter than he wanted to shoot routinely. I don't recall how
much of the AA2460 or 4064 he was using.

As I recall, in 14" handgun lengths 50 gr. bullets do about 3400 fps.

Any of you on the Newsletter list that are shooting the 222 Mag. Imp.
that have loads to add to this, email me. And if you find your results
materially different from this, I'd like to hear from you also"

Thanks,Ken.
Let me add a few points.

One is there are complaints that much of the .223 Rem. brass is pretty poor also, but at least with .223 Rem. you can shop around and buy better quality brass; whereas, with .222 Rem. Mag. you have only one choice.

Tommy is thinking and talking benchrest requirements, which while highly commendable, may not be relevant to the average shooter using conventional loading dies and all their inherent inaccuracies compared to BR inline dies, etc.

Instead of shortening a .222 Rem. Mag. die, what I like is to simply run .222 Rem. Mag. cases into a .223 Rem. die to create a longer necked .223 Rem., aka .223 Rem. 1.850." This is especially helpful in getting the original throat cut out and a new throat cut ahead of the old one... lined up with the bore of course.

Difference in velocity potentials between the .223 Rem. Imp. and .222 Rem. Mag. Imp. have to be slight. There is what, only about .040" difference in body length between the two? I have only done a few of the .223 Rem. Imps. and many more of the Mags, so I am short on experience for a good comparison.

Ref. barrel length, Howard chronographed the same loads through an 18" barrel and a 21" barrel, both of which were chambers I cut, and to quote him, "There wasn't 3 foot a second difference between them." There had to be some difference, no doubt, but you get the point. 3" of barrel gained nothing.

Going custom, I don't think you will give up much of anything with the .223 Rem. Imp. but with heavier bullets especially, the longer neck is a plus. If you were rechambering a barrel, to do the imp. and get the headspace right you would have to go to the longer Mag. case since the headspace on the .223 Rem. Imp. is at least .004" shorter than for the standard, which translated means the .223 Rem. chamber is already too deep for the .223 Rem. Imp.

Mike