7mm Mauser Ackley Improved

tahoe2 · January 15, 2014, 01:17 AM

Here goes, I have a 1931 Spanish Carbine 1916 Pattern Model 1893, it shoots really decent (2"-3" @ 100 w/iron sights) but the chamber is a little blown out.
Rather than sink a bunch of money into it.(buying a new barrel and paying a gunsmith to install it).
I was thinking of cleaning it up with an Ackley reamer, and I would like to hear from someone who has one or has shot one (7x57 AI).
I did a search but couldn't find anything. Thanks to all who participate.

HiBC · January 15, 2014, 08:03 AM

I shoot a .257 AI.Parent case is 7x57.

I do not know what you mean by "blown out" with the original chamber.Elaborate?

What particular problem are you having?There may be other approaches,such as handloading to compensate.

There are some lo=buck threaded/chambered bbls,see Midway/Brownells.

Ackley Improved ctg's,of course CAN be modestly loaded..but its sort of like "bored and stroked".Which may be in the spirit of hot rodding.

Nothing wrong with a sound 93 Mauser for lower to moderate pressure loads,but it would be a poor choice to hot rod with.

Myself,I'd leave it a standard 7x57 and enjoy...and I like Ackley Improved's

tahoe2 · January 16, 2014, 01:45 AM

HiBc, what I mean by blown out; is the fired brass is about .010" (ten thousandths) over-sized at the shoulder, and reamed out to AI would clean that chamber up.
Since I already reload, I could actually keep the same velocities and reduce pressures

to preserve the old girl.
Since it is a 93 action I keep pressures down around 40-44,000 CUP, If I need to ramp it up, I'll just use my 280 Rem

I have plenty of other rifles, I would just like to keep her running without breaking the bank.

HiBC · January 16, 2014, 05:40 AM

There is a version of "improved" that retains original shoulder angle.RCBS improved,maybe.You might check Huntington.

A smith may have a reamer,or maybe you can rent,but a reamer will be around $100,and the set of semi-custom dies will not give you much change from $100.

Numrich,Sarco,E-bay might find you an original.

Look to see what the house brand at Midway has in a step contour mauser replacement bbl,threaded and chambered.

That may give you some ideas to work with...its your ball game

tahoe2 · January 16, 2014, 10:28 AM

midway "cheapos" are out of stock, Numrich has 17-1/2" barrels (used) for $52 bucks, there is still the issue of "Go-No go" gauges,
and if the barrel needs to be turned at the shank, I do not have a lathe.
I was trying for least amount of work and dollars to keep it shooting. I just hate to have a rifle sit and not get used.

Clark · January 24, 2014, 11:46 PM

I don't have a 7x57mmAI, but I do have some formed brass from when some guy died.

I have a couple 257 Roberts AI rifles I built.
After wasting 10 years with that cartridge, I just ordered the 257 Roberts reamer.

Ackley improved is not worth the effort for me, which is ironic because Ackley's books are some of the only good publications I have found on the subject of guns.

James K · January 25, 2014, 12:04 AM

The 7mm AI is reportedly a very good cartridge and the plan suggested would probably work fine. The only drawback is that after spending time and money, the rifle is still an 1893 Spanish Mauser.

Jim

Lucas McCain · January 25, 2014, 12:26 AM

If your shoulder on the 7x57 is already blown out, how do you know the barrel metal is not already compromized?

Jimro · January 25, 2014, 12:30 AM

Instead of wildcatting the chamber to the AI version, simply neck size your brass. The brass has already been fire formed to fit your chamber, and neck sizing will prevent the shoulder area from being over worked.

Cheaper solution as it only involves purchasing a 7mm neck sizing die.

Jimro

F. Guffey · January 25, 2014, 11:38 AM

Quote:

Here goes, I have a 1931 Spanish Carbine 1916 Pattern Model 1893, it shoots really decent (2"-3" @ 100 w/iron sights) but the chamber is a little blown out.
Rather than sink a bunch of money into it.(buying a new barrel and paying a gunsmith to install it).
I was thinking of cleaning it up with an Ackley reamer, and I would like to hear from someone who has one or has shot one (7x57 AI).
I did a search but couldn't find anything. Thanks to all who participate.

Tahoe2, It is assumed the 7mm57 Ackley Improved reamer will clean up the the 7mm57 chamber. The shoulder of the improved version moves forward at the case body/shoulder juncture and the shoulder/neck juncture moves back, meaning the Ackley version has a longer neck, The difference in neck length allows the shooter to fire form cases, when fire forming the 7mm57 case head spaces (is held to the rear) by the short neck , When chambered the 7mm57 the shoulder/neck juncture is formed when chambered ‘if the reamer removes all of the old chamber’. Then when fired the rest of the shoulder and case body is formed.

And then? The case shorten from the case head to the end of the neck, not to be confused with Bart B. and his cases getting shorter ever time he shoots/fires them. When the case fills the chamber the case body expands, when the case forms the shoulder the neck is pulled back. I have no ideal what happens in the chambers of Bart B., when I form cases my cases get longer from the shoulder of the case to the case head.

I have no choice when forming 30/06 cases to 30 Gibbs, when I neck the case up to form a shoulder the case shortens .035”, when I fire to form the rest of the case the case shortens an additional .010” from the end of the neck to the case head. But, the case gets longer from the shoulder to the head of the case, the difference in length between the 30 Gibbs and 30/06 from the shoulder back to the case head is .202”, what got shorter? The case neck, the neck of the 30 Gibbs is .217” +/- a few.

I form cases, I form cases to the chamber first then fire. Forming cases shortens the length of the case, the part of forming that bothers me is the neck gets shorter, I want the case to comer the chamber. When forming cases I choose linger cases, I use 280 Remington cases when forming 30 Gibbs cases, there is no way I can miss, the 280 Remington case is longer than the 30/06 .051”.

Forming 7mm57, the 8mm57 is a better choice, I have the dies to form 30/06 to 7mm57 and 8/mm57, There is no way I can miss when sizing a case to the long/blown out? chamber.

http://masterton.us/Spanmauhome

I have a few cock on close Mausers, I do not shoot them, I have too many rifles that have a third lug etc., and improved gas handling.

F. Guffey

Jim Watson · January 25, 2014, 04:14 PM

Converting to AI is not just a matter of running in a chamber reamer through the action with a long handle. Although I am sure it has been done.
The AI should be rechambered after the barrel is set back so that if you shoot standard loads to fireform, the headspace is .004" below Go for the parent round.

If you send a fired case and your regular sizing die to the maker, they will usually be able to make it match at low or no cost.

Buzzard Bait · January 25, 2014, 04:22 PM

Some where I have read,,,, that some early mausers have swollen chambers along with the barrel shank and the receiver. The cause was the proof loads used at the time. While the guns seem to function ok it can cause grief when trying to remove the barrel.

William T. Watts · January 25, 2014, 05:42 PM

Jim Watson is spot on, if an AI improved chamber isn't cut in that manner you can't fire standard ammunition without the danger of a case rupturing/ splitting! "Buzzard Bait" also has a valid point too, I have a 1898 Argentine series A serial number (the first lot of rifles shipped to Argentina) action that I rebarreled to 338/06.. I have shot less than two boxes of ammo thru it and now it has developed head space because the steel is too soft. An 1893 mauser is unsuitable for what you have in mind! William

tahoe2 · January 28, 2014, 01:35 AM

Thanks for all the pertinent information, I definitely appreciate it. I certainly don't want to create an unsafe rifle (especially since it is my son's).
I guess if we want to shoot it, I will have to re-barrel it.

Due to the 1893 action I keep pressures down around 40,000-44,000 Cup,

January 15, 2014, 01:17 AM	#1
tahoe2 Senior Member Join Date: August 13, 2011 Location: Seattle area Posts: 661	7mm Mauser Ackley Improved Here goes, I have a 1931 Spanish Carbine 1916 Pattern Model 1893, it shoots really decent (2"-3" @ 100 w/iron sights) but the chamber is a little blown out. Rather than sink a bunch of money into it.(buying a new barrel and paying a gunsmith to install it). I was thinking of cleaning it up with an Ackley reamer, and I would like to hear from someone who has one or has shot one (7x57 AI). I did a search but couldn't find anything. Thanks to all who participate. Last edited by tahoe2; January 15, 2014 at 02:11 AM.

January 24, 2014, 11:46 PM	#6
Clark Senior Member Join Date: December 4, 1999 Location: WA, the ever blue state Posts: 4,678	I don't have a 7x57mmAI, but I do have some formed brass from when some guy died. I have a couple 257 Roberts AI rifles I built. After wasting 10 years with that cartridge, I just ordered the 257 Roberts reamer. Ackley improved is not worth the effort for me, which is ironic because Ackley's books are some of the only good publications I have found on the subject of guns. __________________ The word 'forum" does not mean "not criticizing books." "Ad hominem fallacy" is not the same as point by point criticism of books. If you bought the book, and believe it all, it may FEEL like an ad hominem attack, but you might strive to accept other points of view may exist. Are we a nation of competing ideas, or a nation of forced conformity of thought?

January 25, 2014, 12:26 AM	#8
Lucas McCain Senior Member Join Date: March 7, 2013 Location: Callaway, MN Posts: 361	If your shoulder on the 7x57 is already blown out, how do you know the barrel metal is not already compromized? __________________ If you have time to do it twice, then you have time to do it once right and put your name on it

January 25, 2014, 12:30 AM	#9
Jimro Senior Member Join Date: October 18, 2006 Posts: 7,097	Instead of wildcatting the chamber to the AI version, simply neck size your brass. The brass has already been fire formed to fit your chamber, and neck sizing will prevent the shoulder area from being over worked. Cheaper solution as it only involves purchasing a 7mm neck sizing die. Jimro __________________ Machine guns are awesome until you have to carry one.

January 25, 2014, 04:22 PM	#12
Buzzard Bait Senior Member Join Date: June 25, 2008 Location: Republic of Texas Posts: 502	early high pressure proof loads? Some where I have read,,,, that some early mausers have swollen chambers along with the barrel shank and the receiver. The cause was the proof loads used at the time. While the guns seem to function ok it can cause grief when trying to remove the barrel.

January 15, 2014, 08:03 AM	#2
HiBC Senior Member Join Date: November 13, 2006 Posts: 8,286	I shoot a .257 AI.Parent case is 7x57. I do not know what you mean by "blown out" with the original chamber.Elaborate? What particular problem are you having?There may be other approaches,such as handloading to compensate. There are some lo=buck threaded/chambered bbls,see Midway/Brownells. Ackley Improved ctg's,of course CAN be modestly loaded..but its sort of like "bored and stroked".Which may be in the spirit of hot rodding. Nothing wrong with a sound 93 Mauser for lower to moderate pressure loads,but it would be a poor choice to hot rod with. Myself,I'd leave it a standard 7x57 and enjoy...and I like Ackley Improved's

January 16, 2014, 01:45 AM	#3
tahoe2 Senior Member Join Date: August 13, 2011 Location: Seattle area Posts: 661	HiBc, what I mean by blown out; is the fired brass is about .010" (ten thousandths) over-sized at the shoulder, and reamed out to AI would clean that chamber up. Since I already reload, I could actually keep the same velocities and reduce pressures to preserve the old girl. Since it is a 93 action I keep pressures down around 40-44,000 CUP, If I need to ramp it up, I'll just use my 280 Rem I have plenty of other rifles, I would just like to keep her running without breaking the bank.

January 16, 2014, 05:40 AM	#4
HiBC Senior Member Join Date: November 13, 2006 Posts: 8,286	There is a version of "improved" that retains original shoulder angle.RCBS improved,maybe.You might check Huntington. A smith may have a reamer,or maybe you can rent,but a reamer will be around $100,and the set of semi-custom dies will not give you much change from $100. Numrich,Sarco,E-bay might find you an original. Look to see what the house brand at Midway has in a step contour mauser replacement bbl,threaded and chambered. That may give you some ideas to work with...its your ball game

January 16, 2014, 10:28 AM	#5
tahoe2 Senior Member Join Date: August 13, 2011 Location: Seattle area Posts: 661	midway "cheapos" are out of stock, Numrich has 17-1/2" barrels (used) for $52 bucks, there is still the issue of "Go-No go" gauges, and if the barrel needs to be turned at the shank, I do not have a lathe. I was trying for least amount of work and dollars to keep it shooting. I just hate to have a rifle sit and not get used.

January 25, 2014, 12:04 AM	#7
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	The 7mm AI is reportedly a very good cartridge and the plan suggested would probably work fine. The only drawback is that after spending time and money, the rifle is still an 1893 Spanish Mauser. Jim

January 25, 2014, 04:14 PM	#11
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,543	Converting to AI is not just a matter of running in a chamber reamer through the action with a long handle. Although I am sure it has been done. The AI should be rechambered after the barrel is set back so that if you shoot standard loads to fireform, the headspace is .004" below Go for the parent round. If you send a fired case and your regular sizing die to the maker, they will usually be able to make it match at low or no cost.

January 25, 2014, 05:42 PM	#13
William T. Watts Senior Member Join Date: January 20, 2010 Location: Central Arkansas Posts: 1,074	Jim Watson is spot on, if an AI improved chamber isn't cut in that manner you can't fire standard ammunition without the danger of a case rupturing/ splitting! "Buzzard Bait" also has a valid point too, I have a 1898 Argentine series A serial number (the first lot of rifles shipped to Argentina) action that I rebarreled to 338/06.. I have shot less than two boxes of ammo thru it and now it has developed head space because the steel is too soft. An 1893 mauser is unsuitable for what you have in mind! William Last edited by William T. Watts; January 25, 2014 at 07:58 PM.

January 28, 2014, 01:35 AM	#14
tahoe2 Senior Member Join Date: August 13, 2011 Location: Seattle area Posts: 661	Thanks for all the pertinent information, I definitely appreciate it. I certainly don't want to create an unsafe rifle (especially since it is my son's). I guess if we want to shoot it, I will have to re-barrel it. Due to the 1893 action I keep pressures down around 40,000-44,000 Cup, Last edited by tahoe2; January 28, 2014 at 01:55 AM.