What can I rechamber my gun to?

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MikeHaas

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Worn out barrel? Bored/dissatisfied with your current round? Ok, you can buy a new gun or rebarrel your old one. But maybe you can get by with rechambering your existing tube.

So just today I activated a new tool at AmmoGuide: the Re-Chambering Guide. Once you answer a few questioons about your gun, it will search the dimensions for all 600+ rounds in the database and report which one will "fit".

http://ammoguide.com/cgi-bin/aichamber.cgi
(Just press 'Enter as Demo" on the login screen if you don't have an account. Currently, anybody can use the Re-Chambering Guide.)

Enjoy. Mike
 
I tried it, thought it needs work. I input for an 8mm Mauser. One of the most common rifles out there today. You know I have never thought of rechambering an 8mm rifle into a 45 gap. I wonder if it would have feeding problems.
 
...I have never thought of rechambering an 8mm rifle into a 45 gap. I wonder if it would have feeding problems.
Click to expand...
I suspect it would! However, the conversion would probably work in a single-shot pistol.

Thanks for trying to Re-Chambering Guide, but why would I NOT display the 45 GAP or other pistol rounds that are physical candaites for re-chambering? The Guide should tell you what is POSSIBLE - leaving it up to you to decide if it makes sense or not.

All the tool does is see if there is sufficient metal in the existing chamber/barrel to remove to form the new chamber/barrel. It also has some options to allow the user to explore possibilities with or without bolt/extractor mods and/or ability of the action to handle longer case lengths.

And like the tool says in the disclaimer you see if it finds candidates - "ALWAYS INVOLVE A COMPETENT GUNSMITH WHEN DECIDING ON A NEW CHAMBERING FOR YOUR GUN. This program considers ONLY the physical dimensions of cartridge cases and cannot account for the ability or inability of your firearm to safely handle listed rounds" The gunsmith should be able to tell a customer if feeding or other problems might arise from a particular conversion (like it's always been).

Tools can't remove the need for common sense. For example, any .30-30 Winchester can be re-chambered to .30-30 Ackley Improved, but it's not safe to do so with the most frequently-encountered .30-30 firearm in history - the Model 94 Winchester. The Ackley round was developed with bolt-action rifles in mind, NOT for the old lever-action - it generates much too much pressure. We can be sure more than one gunsmith has had to recommend against such a modification.

Mike
 
SO, with only a bolt face mod, I can rebore my 5mm Rem RF to .460 Rowland?

Your program still needs work.

1224.jpg
rcmodel
 
I just wrote out along post on conversions, and lost it when I tried to post it, when it asked me for my ID and password again. I'm not going to write it all out again, but the gist of it was, is there a list of relative strengths of actions, and mods necessary, to aid in deciding what cartridge to convert a particular firearem to? What's safe, and/or what might require such extensive - and expensive - modification as to make the choice impracticle?

I do have a Reminton Model 591 (the clip job) in 5mm Remington Magnum, and would love to be able to put it back on the firing line, by converting it to some now-available cartridge - like the .17HRM - but how do I know if the action will handle it, or would require so much bolt re-working, etc., as to make the whole thing not worth it? I asked a couple of barrel makers, who supply conversion barrels for the Ruger 10/22, if they were doing it or going to do it, and both said no. Too bad. I can do the work myself, including chambering, but first have to know if the idea's even worth thinking about.
 
any .30-30 Winchester can be re-chambered to .30-30 Ackley Improved, but it's not safe to do so with the most frequently-encountered .30-30 firearm in history - the Model 94 Winchester. The Ackley round was developed with bolt-action rifles in mind, NOT for the old lever-action - it generates much too much pressure.
Click to expand...

This would be news to Mr Ackley, if he were still around. He said that the A.I. cartridges reduced bolt thrust due to their minimum taper and were desirable in lever actions as .30-30 A.I. in M94. Another pre-computer simulation writer, H.V. Stent wrote favorably about the combination.

Pressure in a wildcat cartridge is entirely up to the loader and how much powder he puts in.
 
toolman846,

A few minutes on the net revealed that the 5mm Remington Magnum operates at higher chamber pressure than .22 WRM or 17 HMR. Ol Chuck seems a little confused as to whether the .22/17 are 22,000 or 26,600 but gives only 33,000 for the 5mm.
http://www.chuckhawks.com/magnum_rimfire_comparison.htm
So a 591 would be strong enough for the current rounds.

The bad news is that the 5mm is larger in case O.D. and rim diameter. You could safely make the conversion, but might find yourself with a single shot as the magazine might not handle the skinnier .17.
 
The bolt face and extractor are easy, there are casehead dimensions in many handloading manuals and CotW. Feeding from the magazine, you are just going to have to find a writeup or ask around and see what has been done in a particular conversion.
 
rcmodel said:
SO, with only a bolt face mod, I can rebore my 5mm Rem RF to .460 Rowland?

Your program still needs work.
Click to expand...
No, I think the program is correct and you are incorrect. I will explain why and be as succinct as possible.

The program says that, with bolt/extractor modifications stipulated, your 5mm Rem Mag gun can possibly be re-chambered to .460 Rowland. In terms of dimensions only, it sure is possible.

1. The internaL dimensions of the chamber and barrel doesn't prevent the re-chambering. Is the .460 Rowland chamber and barrel WIDER than the 5mm chamber and barrel at all points? Yes. Therefore, one should be able to form a .460 Rowland chamber/barrel by removing metal from a 5mm chamber/barrel. Of course, there are other factors that might prevent this (enough metal to go out that far?) but those factors are outside the scope of the program and left to your gunsmith to determine. The program is just a GUIDE.

2. The action of the 5mm gun seems long enough. Tthe 5mm has a case length of 1.020 inches. The .460 Rowland has a case length of .975 inches. Since the .45 Rowland is shorter, the action length may be long enough. Certainly, case length does not rule out the round as a candidate.

3. Since the program stipulates that bolt/extractor changes are necessary, the switch from rimfire to centerfire is covered.

Now, we all know this is a silly conversion, but you are the person that proposed it. All I am saying is that what my program states is 100% correct.

And think about it - you wouldn't want me, Mike Haas, to exclude any round from the re-chambering candidates list based on what *I think* is compatible. That would mean I am making decisions for you. The goal was to save those who are interested in re-chambering time. AmmoGuide's core philosophy is "Let your computer do the work" - why should you have to check many case dimensions to make sure you are re-chambering to just the right round? The Re-Chambering Guide may show you a candidate you never thought of - THAT'S what it's there for. Not to suggest silly conversions.

I'm also reminded of some of the amazing experimentation I've seen people perform. No sir, I'm not going to remove candidates from that list just because they don't SEEM to me like they should be there. There are too many of you brilliant inventors out there that do wonderful things with some other man's "silly conversion."

Mike
 
The fact remains that the conversion of a 5mm Remington rimfire to .460 Rowland would result in blowing the bolt out of the receiver on the first shot.

The much larger case head of the Rowland, operating at much higher chamber pressure, would present bolt-thrust the little Remington bolt handle locking arrangement could not possibly handle.

Isn't this totally unsafe conversion recommendation seen as a problem?

1224.jpg
rcmodel
 
Quote:
...any .30-30 Winchester can be re-chambered to .30-30 Ackley Improved, but it's not safe to do so with the most frequently-encountered .30-30 firearm in history - the Model 94 Winchester. The Ackley round was developed with bolt-action rifles in mind, NOT for the old lever-action - it generates much too much pressure...

This would be news to Mr Ackley, if he were still around. He said that the A.I. cartridges reduced bolt thrust due to their minimum taper and were desirable in lever actions as .30-30 A.I. in M94. Another pre-computer simulation writer, H.V. Stent wrote favorably about the combination.
Click to expand...
I stand corrected. I was remembering my P.O. Handbook incorrectly.

But my point is still valid - just because a cartridge can chamber or made to work in a gun one cannot assume it is safe. A better example I suppose would be firing .45 Super rounds in a normal .45 Auto. And here, the case dimensions are even identical!

Mike
 
The fact remains that the conversion of a 5mm Remington rimfire to .460 Rowland would result in blowing the bolt out of the receiver on the first shot.

The much larger case head of the Rowland, operating at much higher chamber pressure, would present bolt-thrust the little Remington bolt handle locking arrangement could not possibly handle.

Isn't this totally unsafe conversion recommendation seen as a problem?
Click to expand...
Why should it be? Again, the program is a GUIDE. When it lists candidates, it always includes the disclaimer:

ALWAYS INVOLVE A COMPETENT GUNSMITH WHEN DECIDING ON A NEW CHAMBERING FOR YOUR GUN. This program considers ONLY the physical dimensions of cartridge cases and cannot account for the ability or inability of your firearm to safely handle listed rounds.

Of course, I am assuming a minimum degree of intellegence will come into play SOMEWHERE along the line :) I assume you only pointed out the conversion because it IS so ridiculous, which only helps prove my point.

Now, I don't want to create the impression that I am not open to suggestions. If anyone has serious specific suggestions on how to change the program logic or adjust the disclaimer language, I'm all ears.

Mike
 
Kind of reminds me of the pre-Internet gunzine writer who said he got some strange inquiries. Like whether an M1 carbine could be chambered for .300 Weatherby. He said he showed a carbine and a Weatherby cartridge to his seven year old and got an answer for his correspondent.
 
I'm no programmer, so I don't have a clue.

But there are many factors to consider beside just the physical measurements of the old chamber and the proposed new one.

For instance, a .458 Mag could fit in an Ultra-lite Arms standard length 30-06 action & magazine.
You could alter the bolt-face to fit the belted mag rim.

But if you tried to re-chamber & re-bore the Ultra-lite barrel, the chamber reamer would come out through the chamber walls, and the .458 rifling machine would cut rifling through the sides of the tiny barrel near the muzzle.

On the otherhand, there is no way you could possibly know the measurements of every barrel contour & muzzle dia. ever used by a rifle builder, so I doubt you could program out all the impossible "possible" combinations.

On the other otherhand, almost all conversions are based on action types, strengths & sizes that are fitting to the conversion. And these are known things that are common knowledge to anyone capable of reading a book on gunsmithing, and doing that kind of work.

So why even bother writing a program that potentially offers more erroneous, and possibly dangerous information then correct safe information?

Even the village idiot can order a chamber reamer from Brownell's or Midway, based on your programs recommendation, and blow himself up!

I really admire your effort, but doubt it can ever cover everything it needs to cover to offer safe workable conversions of any known caliber & action.

1224.jpg
rcmodel
 
So why even bother writing a program that potentially offers more erroneous, and possibly dangerous information then correct safe information?
Click to expand...
By your reasoning, no reloading manual should list maximum loads because there can be guns out there that won't be able to handle it.

IT IS A GUIDE! That means it provides partial information - a FIRST PASS TEST to gather information to continue research. The tool produces a list of all POSSIBLE re-chamberings so that one might identify the BEST re-chambering for their needs. Those involved in actually performing conversion work - gunsmiths - are aware of what is an appropriate conversion. If you want to re-chamber a gun to a dangerous cartridge for the gun, the gunsmith will raise the flag. That's what gunsmiths do. (and it doesn't matter where you got the idea)

BTW, NONE of the conversions listed are dangerous. Until one actually speaks of the kind of gun in question, the issue of safety cannot be evaluated and the program specifically does not deal with such issues, warns the user about it AND ADVISES TO SEEK COMPETENT ADVICE REGARDING THE MATTER. So nothing is different, it's just a modern way to select your new round - one that lists ALL possibuilities (even ones you don't want.).

Also, there is nothing that prevents the existence of a 5mm Remington Magnum action that will successfully convert to a .460 Rowland. Nothing at all. None probably exist, but there could be. As a tool used for RESEARCH, the Re-Chambering Guide needs to list all candidates.

Benefits of the program include revealing SENSIBLE candidates one never thought of and providing that "first pass test" to check which rounds might work and which won't.

For example, right away, the Guide showed me one can't re-chamber a .280 Remington to .30-06. I'd always thought that was possible.

Mike
 
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This is an interesting guide and does offer up options I never could have thought of. Is there any way you could add a field for "current action".
Current Action: Mauser 98
Willing to Rebarrel: Yes
I think this would be a great improvement but might take more time then one person has.
 
Sorry, Mike, but that is a very narrow view of "rechambering." Sure you can "rechamber" an 8x57 to .45 GAP, but unless you do a lot more, you would be trying to shove a .45 bullet down a .32 caliber barrel. That might seem a good idea to you, but I think it is absurd and under the wrong conditions someone could be hurt. For that matter, you can chamber an undrilled barrel to any caliber, so if bore diameter is irrelevant, why not advise that also?

Your disclaimers about how it's "only a guide" and consulting a gunsmith just aren't enough to protect you from having your socks sued off if something bad happens.

I was wondering where all the nonsense about impossible "rechambering" was coming from. Now I know.

Jim
 
...Sorry, Mike, but that is a very narrow view of "rechambering." Sure you can "rechamber" an 8x57 to .45 GAP, but unless you do a lot more, you would be trying to shove a .45 bullet down a .32 caliber barrel...
Click to expand...
Uhhh, "Rechambering" normally includes any necessary re-boring and re-rifling to the appropriate caliber. Otherwise, you're absolutely right, the whole thing would be a pretty stupid concept. (Sheesh... this IS a gunsmithing forum isn't it?! :)

BTW, it's not my idea, people have been rechambering barrels for a few years.

Mike
 
...This is an interesting guide and does offer up options I never could have thought of. Is there any way you could add a field for "current action".
Current Action: Mauser 98
Willing to Rebarrel: Yes
I think this would be a great improvement but might take more time then one person has...
Click to expand...
Thanks for the kudos. Indeed, it would be GREAT to include a popup that would list all (or even most) common actions. That way, the website could also include specific info/suggestions on working with that model. Now THIS is someone that "gets it."

And you're right, that kind of feature is a major undertaking, but that's not to say it might not happen someday. I've been developing AmmoGuide for well over 10 years and it's grown from nothing to what it is today just by being a personal labor of love and getting the support of my subscribers I've been privileged to receive. I sincerely hope you enjoy it.

BTW, yesterday I enhanced the Re-Chambering Guide to display case diagrams and added an attribution to Stephen P. Gibbons (thanks again, Steve!) of Steve's Pages who had the original idea for a "Re-Chambering Guide" at AmmoGuide...
rechamber22hornet.gif
http://ammoguide.com/cgi-bin/aichamber.cgi
(just click on "Enter as DEMO" if you don't have an account)

Mike
 
Adding over all case length might help as to what will fit the existing magazine.
Also strength IE pressures, say a 7mm Mag the new 375 Ruger. Over all cartridge length is very close and should work but what about pressure? The cases are almost the same dimensions with the exception of a much larger bore.
I was thinking more along the lines of a rebarrel than rechamber which would be IMO a good option for your program.

This program has it's flaws perhaps but is something new and I for one appreciate it and would like to see even more information, programs, and ideas along these lines.

The ability to do side by side comparisons is good.

Thanks Mike
 
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The literature I have been reading since about 1957 usually makes a distinction between "rechambering" when the caliber remains the same and "reboring" when the caliber is to be larger. Not to mention "relining" to return a worn bore to new or to reduce caliber.
 
Mike said, "Rechambering" normally includes any necessary re-boring and re-rifling to the appropriate caliber."

Says who? Rechambering is rechambering. Reboring and re-rifling is something else again. I doubt many gunsmiths would back that interesting concept, especially if you expect them to rebore and re-rifle the barrel for the same price as running in a chambering reamer.

To me, your statement is silly, but if that is what you mean by "rechambering", then say so plainly and note every case where barrel enlargement will be needed.

Jim
 
Uhhh, "Rechambering" normally includes any necessary re-boring and re-rifling to the appropriate caliber.
Click to expand...

I assure you, the price for cutting a new chamber does NOT include ANYTHING to do with the bore. Mr. Keenan is quite correct.
 
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