Using 44 magnum reamer to cut chamber in 44 Spl?

[Fishoot]

Now that the virus scare has me socially distanced, maybe I can use the time on some long standing projects. Does anyone have experience using a 44 magnum reamer to cut a chamber for 44 special by cutting the chamber short of the rim cut, then cutting the rim with a lathe bit? I have done it with a .357 magnum and foresee no difference, but its better to know of any pitfalls. I have some old #1 rolling blocks to do. Thanks for your consideration.

[Outpost75]

I'm not the best person to answer this, but I don't see why not.

If John Taylor reads this I would trust his judgement implicitly, as he is a current practicing gunsmith, I am sure has done this before, and he would be aware of any caveats which might apply.

[Chill Wills]

I think you are right about being able to short chamber the 44 Special and single point the rim. That is within my ability too.
How are you at cutting square thread? I have not tried it yet but I know it is not as easy or even the same procedure as cutting 60 degree V thread.

Like you, I should use this time to grind a HHS lathe tool for Square Thread and cut and fit some with scrap steel.

I have two Danish Rolling blocks actions and you are right, a 44 Special would be a fun single shot rifle on a Roller.

[Winger Ed.]

I don't see why it wouldn't work, just be careful and don't go too deep with it.

[John Taylor]

It will work fine, just make sure of the depth. You will need a reamer designed for a rifle chamber and not a revolver chamber. If you use one for a revolver then the throat will need to be cut separate.

[Martin Luber]

Are you concerned that it couldn't handle a factory mag case should someone discover that it fit?

Plenty of specials fired in mag chambers, can't stat the degradation of precision though

[Chill Wills]

Are you concerned that it couldn't handle a factory mag case should someone discover that it fit?


You misunderstand. The chamber cut with a 44 mag reamer would not be full depth and would not chamber a 44 mag case.

[DougGuy]

It will work fine, just make sure of the depth. You will need a reamer designed for a rifle chamber and not a revolver chamber. If you use one for a revolver then the throat will need to be cut separate.

In addition to this, there are two distinctly different sets of specs from SAAMI for 44 rem mag, one for a revolver and a different one for a rifle. Diameters are different. Rifle specs are larger than revolver specs.

[Martin Luber]

You misunderstand. The chamber cut with a 44 mag reamer would not be full depth and would not chamber a 44 mag case.

my question is why not cut it to a 44 mag and shoot specials or mags in it? As to any differences, you could compare the SAAMI specs for dimensions particularly for taper. Good luck

[M-Tecs]

pages 54 and 54 https://saami.org/wp-content/uploads/2019/02/ANSI-SAAMI-Z299.3-CFP-and-R-Approved-2015-12-14-Posting-Copy.pdf

page 143 for rifle 44 Mag. https://saami.org/wp-content/uploads/2019/02/ANSI-SAAMI-Z299.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

I only own one 44 Mag rifle and that is a Browning B92 that is .433" verse .429". That is a pain in the rear since it doesn't like any jacketed bullets I've tried.

http://castboolits.gunloads.com/showthread.php?350053-New-1894-Marlin-in-44spl-44-mag-bore-diameter

I don't use solid pilot reamers but if you do note that pilot size is an issue.

Depending on your skill level and equipment this is one that is very doable to single point the complete chamber.

Personally I would go with the .429" barrel.

[Chill Wills]

my question is why not cut it to a 44 mag and shoot specials or mags in it? As to any differences, you could compare the SAAMI specs for dimensions particularly for taper. Good luck

Hello Martin,
The high pressure of the 44 magnum would be a good fit with single shot actions like Ruger's #1 or even Winchester's highwall singleshot and others but the weaker action of the #1 rolling block and a lot of others of the early BP era might not hold together when loaded to maximum by some future owner. That, even tho the current owner may understand its limit and load safely.
Knowingly creating an unsafe rifle comes under the category of cruel jokes and negligence.

I hope this helps.

[Fishoot]

First, thanks to all for the help and encouragement. I have found the help I have gotten here to be top notch! I have cut a 38 Spl chamber in a number 1 rolling block with good results, but was about to bid on used .357 mag and 44 Mag reamers that were cut for rifles, not cylinders. I wanted to be sure I was on the right track before laying out the cash and not missing something.

Chill, You are on the right track. Yes, I was concerned about .357 or 44 magnums being used in one of my old time rolling blocks by some innocent (if there are any left) user down the road. I wanted to be sure the block would not close on one of the longer rounds. As for square threads, I have cut lots of 'em. They are easy to do with a correctly ground bit. I will send pictures of my rim recess cutters to anyone that is interested. I do not use square threading bits, although they might work. I use something that looks more like a diamond when viewed face-on. I will send more pics via email upon request if there is any interest. I run my cutter into the chamber with the same angle used to cut a chamber with a chambering reamer...straight in to rim depth; and then cut outwards, as in single point widening of a drilled hole.258802

[Chill Wills]

First, thanks to all for the help and encouragement. I have found the help I have gotten here to be top notch! I have cut a 38 Spl chamber in a number 1 rolling block with good results, but was about to bid on used .357 mag and 44 Mag reamers that were cut for rifles, not cylinders. I wanted to be sure I was on the right track before laying out the cash and not missing something.

As for square threads, I have cut lots of 'em. They are easy to do with a correctly ground bit. I will send pictures of my rim recess cutters to anyone that is interested. I do not use square threading bits, although they might work. I use something that looks more like a diamond when viewed face-on. I will send more pics via email upon request if there is any interest.

Yes. I would be interested in learning about your diamond shaped cutter and how to set up for using it. My limited trial plunge cutting a square thread, using the ground profile tool with flat face produced a lot of chatter and would try to suck in the cutter as well. I am sure my novice skill set and light South Bend lathe have a lot to do with that.
Please feel free to PM me with your home email and maybe we can talk where it is easy to send pictures with no limit. Thanks for the offer!

[john.k]

Before grinding a tool for square thread ,try to find a decent brand of HSS....IMHO ,a lot of chinese HSS sold by hobby shops tends to crumble at sharp edges,and is useless for threadcutting.....ie Fagersta,Poldi stahl,Jessops,etc.

[Outpost75]

It will work fine, just make sure of the depth. You will need a reamer designed for a rifle chamber and not a revolver chamber. If you use one for a revolver then the throat will need to be cut separate.

A reamer which John has is called .44 Magnum NRA and has a shallow, gradual forcing cone departing directly from the case body, with no ball seat. This was developed and tested by NRA Contributing Editor LTC Ellis Lea, (USA, Ret.) An article in American Rifleman in the early '80s showed useful improvement in T/C Contenders and Marlin levers when rethroated with that reamer. I have a .44 Magnum single-shot which John built for me on a Beretta 412 .410 shotgun action which is very accurate with lead bullets, using a 1:20" twist Green Mountain barrel.

[DougGuy]

A reamer which John has is called .44 Magnum NRA and has a shallow, gradual forcing cone departing directly from the case body, with no ball seat.

I bet this works really well in a rifle, but a revolver cylinder is too short to take advantage of it. I throat auto pistol barrels long, with enough freebore for the boolit to exit the case mouth and be guided square and concentric by the freebore before the boolit engages the leade ins of the rifling. It's like a Taylor Throat but for an auto and it works great,