Notes on fireforming Ackley Improved cases

[Wayne Smith]

I was reading P.O. Ackley's loading manual the other day it it struck me that he strongly supports using full loads to fireform his cases. In fact, he states that if a light load is used it can shorten the case and change the headspace of that cartridge. This is potentially disasterous. He states cases and shows pictures of rifles blown up by this practice.

This only applies to rimless cases that headspace on the shoulder. With rimmed and belted cases it doesn't matter if the shoulder is set back.

This is old, and needs to be renewed as a warning.

[5Shot]

I have never used light loads to form, but it is good information to keep in mind.

[Sig556r]

I use medium loads to fireform 7.6x39 brass to 6.5Grendel with excellent results...not a big fan of the cream of wheat filler

[Tom W.]

In my 30-06 A.I. I fire form w/ 13 gr. Red Dot and a 150 - 170 gr. cast boolit.....

[stubshaft]

In my 338-06 AI, I form cases from 270 brass. I neck them up to 35 cal and create a false shoulder to headspace on. 16 grs. of Red Dot with COW and a tissue square to top it off forms them perfectly.

[GBertolet]

To fireform my 35 Whelen Imp, 10 gr of Bullseye, COW, and tissue to keep in place. Swab bore and chamber often, as COW is messy. Fired into a stack of magazines in the basement. Works great.

[M-Tecs]

I know I am going to need flame proof pants after this but the P. O. Ackley reference books are the only ones I have not kept and I have hundreds. Just too much stuff that the claims fell short or were flat out wrong. At one time I drank the cool aid but after chambering a couple of dozen AI's in 7 different cartridges I have developed a mild to strong dislike for most of the AI's

[5Shot]

What didn't you like?

[M-Tecs]

I am currently out of town due to my father's health issues. I only have my phone so long answer's are a challenge. Velocities in the books tended to be very optimistic and the velocity gains when improved tend to fall short of P.O's claims. Of the ones I have done the 280AI seems to be the best. The 22-250AI is the one I like the least. Campared to my 220 Swifts the 22-250AI is very dishonest. Pressure and accuracy nods are very narrow with the AI verse the Swift.

[TNsailorman]

Most of the ballistics claimed in the old days were wrong, both by developers, writers and others. They did not have reliable chronographs in those days and used mostly calculations that some mathematician had come up with. I corresponded with him in the early to late sixties and he told me in one letter that the most effective of his improved cartridges was the .257 Roberts AI. He claimed to be able to get almost .25-06 velocities out it when the same length barrel was used. The fact is that most of the later "experts" have a world of equipment and firearms available to them that did not exist way back when. All too often writer would play with the findings of their article by comparing a personal favorite with some other caliber that they want to disparage and quote velocities and data arrived from different rifle with different barrels lengths and powders and bullets. The computers have done a lot of good cleaning up a bunch of these guys and knowledge is greater these days also. This site is a good example of a wealth of knowledge that exists today. In the past there just wasn't any experience, knowledge or gun tinkers in one spot of even available as you can find right here on this site. I have been a happy camper ever since I found it. james

[5Shot]

I am currently out of town due to my father's health issues. I only have my phone so long answer's are a challenge. Velocities in the books tended to be very optimistic and the velocity gains when improved tend to fall short of P.O's claims. Of the ones I have done the 280AI seems to be the best. The 22-250AI is the one I like the least. Campared to my 220 Swifts the 22-250AI is very dishonest. Pressure and accuracy nods are very narrow with the AI verse the Swift.

I agree with all that...the improved cartridges gain VERY little, and I have the king of the letdowns...the 35 Whelen AI. What I do like is that the shoulder reduces case stretch, and it looks cool. There is nothing to lose, almost nothing to gain, but if you want one, you want it. I have never had a factory 35W, so I already had dies, and case forming is a non issue.

[Tom W.]

That's why I have two, 30-06 and 30/30 , both A.I now. I only kill paper. haven't hunted in several years due to health problems, but like to have something different......

[GBertolet]

I had the same experience as 5Shot did. I went to have my rife rebarreled to 35 Whelen, and the gunsmith said he had a 35 Whelen Imp reamer, which would reduce case stretching, and the sharper shoulder would give a better headspace, over the standard Whelen. So I went with that. No way to know what the standard 35 Whelen would have done ballisticly in my rifle, but with the Imp version I can break 2700 fps with the 250 gr Speer Hot Core bullet in a 24" barrel. A moose and caribou both went down, like they were hit with the hammer of Thor. The rifle now is mostly used with cast bullets at the range.

[Budzilla 19]

Full power loads and engrave the rifling with the bullet!!!! Never had a failure doing it this way. But I’ve only done .280 AI so far. More coming later as funds allow

[5Shot]

I had the same experience as 5Shot did. I went to have my rife rebarreled to 35 Whelen, and the gunsmith said he had a 35 Whelen Imp reamer, which would reduce case stretching, and the sharper shoulder would give a better headspace, over the standard Whelen. So I went with that. No way to know what the standard 35 Whelen would have done ballisticly in my rifle, but with the Imp version I can break 2700 fps with the 250 gr Speer Hot Core bullet in a 24" barrel. A moose and caribou both went down, like they were hit with the hammer of Thor. The rifle now is mostly used with cast bullets at the range.

That is exactly why I ended up with my first 35 Whelen AI...that was the reamer the smith had.

[SvenLindquist]

Most AI results in P.O.s' books cannot be duplicated until you go to longer barrels.

Case forming with fast powders, COW and a TP wad works just fine.

You can also shoot non AI factory ammo in an AI chamber IF the chamber is correct.

His books are great reading BUT like most 50 year old info its age should be considered.

And lets never forget that tapered cartridges always feed better. That's why the brilliant Brits made the 300 & 375 H&H look the way they do.

[rockrat]

I have two. A 30-06 AI and a 223AI. The results were good with the 06, but the 223 version was a big improvement. 3600fps with a 55gr vmax out of a 24" barrel. My '06 will go 3100fps with a 168 Zmax, but I do have a long barrel on that gun--29"

[Rich/WIS]

Have a 30/40 AI and fire form with a moderate load of Blue Dot and a 170 cast. The rifle is a Ruger No 3 and the gain in case capacity is about 5 grains of IMR 4064. This puts it between 308 and 30/06 in capacity so significant gains in power are possible in a strong action like the No 3. Unfortunately to utilize the gains means a significant amount of recoil and my standard fun load if pretty wimpy, about 1600 fps with a 311291. For deer I load a 150 gr J bullet to about 2600 which is effective and not too punishing on me.

[GBertolet]

I am drifting a little on this thread, but I find decent loading data for the 35 Whelen Imp almost nonexistant. I asked the gunsmith if he had any data, and he said no. He said most of his clients settled on using 4320 powder though. So that's what I did. This was back in 2001. There are likely better powders now. It was suggested by the gunsmith, that I start at the maximum for the std Whelen, and work up. 56 gr was max for the 250 gr bullet. I incrementally worked up to 63 gr, where I finally started to see pressure signs of lightly cratered primers. YIKES, those P17 Enfield actions are sure strong. Bolt lift and extraction was easy, and minimal effort required to resize the cases. After taking a moose and caribou in 2001, I decided not to further push my luck with those loads. I have shot only cast bullets since in the Whelen.

[5Shot]

I am going to work up some loads with RL17. According to Quickload it should give the best velocity of available powders with 250 grn and heavier bullets. I'll know more after the snow is gone. My initial tests in the fall matched the QL prediction quite close for velocity.