Home Forums Hunting & Shooting Ask The Gunwriters Excellent article on Improved Cartridges

Okay, about spit my breakfast on my keyboard. Hysterical.

Thank you; all of my AI's now simply possess "Ackley Improvements." Sounds far more mysterious and elegant.

Sorry to be detained. I had a ditch full of leaves to burn before we are 'supposed' to get heavy rain tomorrow.

Sincerely, I never thot the minimal gains of AIs were worth the expense of chamber reaming and bother of fire forming. I know some don't fire form but that's personal preference.

I read 'this week' here on the fire that the.....

280 AI = 7mm RM performance.

I don't believe that at normal working pressure.


YMMV


Jerry

My 7RM is a 280 AI Improved and 28 Nosler Light. Boils down to handloading IMO, and I'm beginning to run out of give a schit for it.....

I'd believe that.


Jerry

Especially if you Long Throat the 7 !

I'm almost inclined to agree with you on the 7X57, .257 and .250 AI's mainly because SAAMI won't allow data using modern pressures for those cartridges forcing us to go by guess and by gosh working up modern loads for those cartridges. That's been a gripe of mine long before there was an internet. I load for the 7x57 and .257 Bob but have only shot a friend's .250 Sav. while helping him work up reloads for his early Sav. 99. At least with my two cartridges I see no need for improvement. On the 7x57 I load to 7-08 levels and go with that. The Bob is a bit trickier so it's still a work in progress.
Paul B.

^ This

John's article mentions loads for a Better Bob that are just shy of 3" in a NULA 24.
methinks that is a typo, probably a Model 20 w/3" magazine.

long-throating = another dimensional refinement ( improvement )

I love it when you talk Alaskan.

I have not yet seen the issue of Handloader so have not read the article.
No discussion of Improved cartridges is boring.
Certainly two cartridges which epitomize the possibilities of the Improved cartridge shape are the .30-30AI and the .25-35AI. The two cartridges realizing a significant Improvement in performance as a result of higher pressure.

Few of us have read enough of PO’s writing to really understand what his mind set was. PO wrote for the day, not for posterity.

Two of the more interesting articles on Improved cartridges are:

How Improved is it
By William F. Wieman
H. P. White Laboratory
THE AMERICAN RIFLEMAN
DECEMBER 1953


'Improved' Cartridges
By P. O. Ackley
American Rifleman
October 1954

PO in answering his critics left us with two interesting quotes:

“The word 'improved' is an unfortunate choice, and just grew up in connection with certain developments which were made with several objectives. One consideration is increased velocity. Another is mechanical improvement, which results in minimizing certain faults of standard cartridges.”

My all-time favorite PO Quote:

“At the beginning of these comments certain things were pointed out as possible improvements, but nothing was said concerning pressure. Whether the handloader or wildcat enthusiast is right or wrong, he is interested in several things, most important of which are increased velocity and whether the bolt stays in the gun. If he can achieve these two results without serious complications, he is not overly concerned with the actual pressure readings in pounds per square inch.”

powdr
Campfire Tracker

Yes there are some like the 35Whelen AI and the 30-30AI that don't make a lot of sense... powdr

This was posted on P 3 ^^^^^^^^




Apparently opinions vary.

I don't have one on the 30-30 AI.


Jerry

P.O. rechambered my Ruger 77 to 250AI.Been using the same 20 cases since 1982!! [img:center][/img]

Mysterious for sure. A guy at work inherited a "custom 30'06 Mauser". He said it shot great, but did weird things to the brass. I asked him to bring in a fired case and sure enough - "Ackley Improvements"'.

I thought the only way to improve a .25 caliber round was to make it .26 caliber.

Years ago, I used to chat with a gunsmith here in Canada named Ellwood Epps. He and Ackley talked about improving cartridges back in the days when chambers were not created using equipment controlled by computers.

In a nutshell, Ellwood said there were three reasons to improve a case: to clean up the chamber, increase case life and obtain better velocity. Of the three, cleaning up the chamber was the number one reason to improve. Next was case life. Velocity increases ran third.

You have to remember that this was in the days before short and fat were in vogue and most magnums were bottles of champagne. Brass was harder to come by; there were a lot more surplus rifles - including surplus single shots - and civilian industry (Rem and Win) was less involved in cartridge development.

Ellwood sold, repaired and played with a lot of 303 British rifles here. Their chambers were all over the place WRT shape. Some chambers were too long and one firing was all you got from a case. This was unacceptable to him. There had to be a way to fix it.

He consulted with Ackley about improvements. In part, because of the atrocious chambers. He also looked at the 303 cartridge. It was a rimmed cartridge that featured a droopy 19th century design and 16 degree shoulders. The same would be said of the 30-30, the Hornet and others.

Commercial factories like Remington and Winchester didn't have large R&D sections working to change the function and feeding of rifle cartridges. This was back when small gunshops or home experimenters did the lion's share of "R&D".

Ackley started using 35 degree shoulder, as did Ellwood. PO changed to a 40 degree shoulder, while Ellwood stayed with the 35.

Ellwood's primary concern, horrible chambers, was virtually eliminated with a finishing reamer. Like other gunsmiths of the time, he removed the barrel, took a thread off the back and reinstalled it. Then he took a finishing reamer and cleaned up or "improved" the chamber. In effect, it was tighter. A better fit for the unfired cartridge.

He could have simply tightened things up by chambering again in 303 British, but the cases would still distort. It would just take a little longer. Reducing the taper and sharpening the shoulders of the 303, a rimmed cartridge, increased its useful life.

For Ellwood at least, more velocity at the same pressure level was just icing on the cake.

I'm not really sure when "AI-ing" a cartridge was done only for the purpose of increasing velocity, and not to clean up a chamber and improve case life. It seems to me that things got turned around.

A few other things. When experimenters were improving almost everything, there were a lot more rimmed cartridges and single shot rifles around. The feeding problems associated with AIed cartridges were not as much of a problem. In the early part of the 20th century, rimless cartridges took over. Severe tapers and droopy shoulders were great once upon a time, but design requirements changed with increased production and use of the bolt action. AIed cartridges were a logical progression for shooters using smokeless powder and bolts.

Love the 250 whether she's christmas tree or tall timber. Fine cartridge made better by (sorry for the redundancy) improving.

I've never understood the arguments against AI given those two facts. Even if only incremental velocity increases such as with larger calibers, more is more, and the brass will be easier to work with. All good.

He could have simply tightened things up by chambering again in 303 British, but the cases would still distort. It would just take a little longer. Reducing the taper and sharpening the shoulders of the 303, a rimmed cartridge, increased its useful life.



So, when you say cases would still distort in a tight 303 chamber, just what would be the reasoning behind this? GD

The MKIV 303 that we had growing up was a case splitting mofo with anything that wasn't milsurp.

Old, Cordite filled brass had a tendency to do that - made worse by rifles with long chambers. Kind of a one, two punch.

That was the reason I converted my first No 4 to Epps. It was a 1942 Savage 2 groove with a chamber a mile long. Cartridges came out constantly split or separated.