I have read on this forum that a 10mm case will deform in a .41magnum cylinder, but what if I had a cylinder custom made? could I convert a .41 magnum to 10mm with out changing the barrel. would .400 to .41 be to large of a difference?

Yes.

Ruger has built their Blackhawk revolvers for years as .357/9mm convertibles and a lot of folks say that accuracy is so-so with the 9mm cylinder and that's only a difference of about .002 to .003.

Don't waste your money.

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John 3:16
WAR EAGLE!

Absolutely not!

The 10mm (.400-401") is small enough to fall through the .41 (.410) barrel. The cylinder would have to be modified to use moon clips and then would not be usable with the rimmed .41 Magnum.

Just tried a Hornady 10mm in my 657. Wouldn't quite fall through, but it pushed through the barrel with less resistance that a tight cleaning patch would give.

The .41 Magnum is far superior to the 10mm, what would be the point even if it were possible?

Muley Gil, I am surprised at your answer. Obviously you read this as .001" difference, it is .010, a lot of difference.

"Muley Gil, I am surprised at your answer. Obviously you read this as .001" difference, it is .010, a lot of difference."

Yes, I am aware of the difference in bore diameter.

The question was "would .400 to .41 be to large of a difference?"

My answer was "Yes". I was comparing the .002-.003 difference of the .357/9mm convertible to the proposed .41/10mm (.400), stating that if the Blackhawk could give so-so accuracy, the .41/10mm would really rattle going down the bore.

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John 3:16
WAR EAGLE!

I guess that would depend on the performance and accuracy you were looking for.

bob

Well, I think this is a dandy project. No need for a custom cylinder - S&W made 10mm cylinders for N-frames for the Model 610. Just order one of those and install it in your Mod. 57. You'll then have a "pinto" 10mm/41.

I think you guys are missing his point. I think he wants a revolver that will shoot the bullets without spinning them so there's no rifling marks for the forensic's guys to trace back... The 10mm bullet "gliding" along on the surface of the 41-cal's lands ought to still fly fairly straight for a little distance, and that's all handguns are good for, right?











Sorry, couldn't resist!

Back in the 80s I experimented with using .401 dia. 10mm bullets in .41 mag and .41 AE brass that was necked down to hold the smaller bullets. Accuracy was so poor I'd have to say 'no' it won't fly straight enough for even a handgun. In fact, at three feet accuracy was so bad I killed my Chrony with a direct hit, even though I was aiming extra high.

Somehow I detect a bit of sarcasm in some of these answers.
40 S&W in M610's happen all the time. 10mm down a M57 tube? Well.... as Borat might say: "Maybe, she'sa not so hot." Sorta reminds me of this girl I knew back in high school. But I digress. -S2

Yeah, but you necked down the brass, which was your mistake... If he uses a 10mm cylinder, the brass will fit right, and the throat will fit right and help guide the 10mm bullet on it's initial journey before it gets to the barrel. This guidance will make sure the bullet will already be steady and aligned before it gets to the .41 barrel...
















Sorry, again! You know all of this is tongue-in-cheek, right?

I apologize. The way I read it was yes it was possible.

Maybe, but it doesn't have to be. You might be on to something there. I don't know how much difference it would make with the bullet yawing in the cylinder before entering the forcing cone. They wouldn't turn much, but how much is too much?

I had made some full cylinder length shotshells for the .41 magnum out of .30-30 brass, which after fireforming I used a .40 S&W sizer to resize the narrowed front portion of the brass. I wonder now if a .401 bullet could be safely seated and fired from it.

I wonder whether this question has ever really been answered. Ruger single action convertibles would be the perfect platform for this endeavour, no moon clips necessary...

Everyone is worried about accuracy and ignoring velocity! The reduced bore dia would allow the forcing gasses to escape around the bullet so much I would be worried about the possibility of sticking a bullet in the barrel, depending on barrel length and softness of the lead! Before I spent money on a custom cylinder I would seat a .401 bullet in a 41 Mag case, shoot it over my chrony, and look at accuracy!
jcelect

It is possible, but you have to hold the revolver side ways (gangster style) which makes it difficult to use the sights.not being able to acquire a proper sight picture is what causes accuracy degradation in this case,as well as earths rotation not being factored in properly (due to the sideways thing)

Sleeve the the Model 57's cylinder throats for a tight fit with .401" bullets. From the other end ream the chambers to about .490" forward to the start of the throats. Face off the back end of the cylinder for clearance to weld on a washer that covers the chambers. The washer has to be thick enough to drill and thread for muzzle loader percussion cap nipples. Cast your 200 grain 10mm bullets out of pure lead and a lightly compressed charge of FFFg black powder will bump the bullet up to fill the grooves.

I leave it to Alk8944 to work out the details.

Ruger made a single action conversion for Buckeye Shooters Supply in 10mm and 38/55 a few years ago.From what l read accuracy was very good.

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SWCA#2288
SWHF#407

Possibly not germaine to the topic, but several years ago I fire-formed several dozen .45 Colt cases from some .38-40 and .44-40 brass. I loaded 10mm lead bullets in the .38-40 cases and some .44 (.429) lead bullets in the .44-40 cases and fired them in a .45 Colt. I used fairly light loads, I think I used 6 to 7 grains of Bullseye. Surprisingly, I was able to keep all the shots on paper plates at 15 yards, and most of them were not even keyholed. In every case, the bullets used were far more than 0.010" too small. Once, entirely by accident (and I have written about this incident here earlier), I accidentally fired a cylinder full of .32-20 cartridges in a .38 Special revolver. That day I was firing two similar M&Ps in different calibers. Again, all of the bullets stayed on the paper and I didn't even know what I had done until I ejected the fired .32-20 cases. All were split.

I have heard stories (possibly untrue) that back in the Old West, it was not unknown that if a cowhand or outlaw couldn't get .45 Colt ammo, he might use .44-40 or .38-40 in his .45 if that was the only ammunition available. And I know from personal experience that it for sure would work in a pinch.

After all that I think it would be cheaper to buy a S&W Model 610.

So: do you hold it canted to the left or to the right to counteract the rotation? What if you’re firing due east or west? Way too complicated for me...I’ll stick with the .41 Mag for my 10mm needs.

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50 Years of DSOTM

38/40.


38/55 is a rifle round the length of a 30/30. I do not believe one would fit in a Blackhawk cylinder.

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I always take precautions

No problem at all to shoot .40 S&W in a 610; no benefit at all to trying to shoot 10mm in a .41 Magnum.

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NHI, 10-8.

Aplo is correct. It had separate cylinders for .38 WCF & 10 mm. Unlike the .41 Magnum & 10mm the .38WCF and 10 mm cartridges us the same diameter bullets.

It matters not which compass point the barrel is pointed towards, in the Northern Hemisphere the Coriolis force will cause the bullet to drift in a clockwise direction. From the shooter's perspective it will drift to the left. That was accounted for while firing battleship projectiles and in the design of later 19th century rifle volley sights. It is plainly visible in the U.S. 1873 .45-70 Trap Door rifle sight. However, Hollywood actors holding their pistols side ways while pretending to be gangsters might get by without adjusting for the Coriolis force.

The lateral Coriolis effect depends upon the direction you fire the bullet - along a line of latitude, a line of longitude, or some direction in between. And also where on the earth you are standing. It has no perceptible effect except at ranges considerably greater that any handgun would fire. It becomes much more significant for long-range artillery fire than for small arms fire. As a practical rule, it can be ignored at range distances less than 1000 meters. BTW, the Buffington wind gauge rear sight used on the 1884 Springfield trap door rifle does not correct for the Coriolis effect, but rather for the aerodynamic effect of the bullet spin. The bullet tends to drift in the direction of the spin, sort of like a baseball curve ball or a golf ball hooking or slicing. It is more significant for fat slow-moving bullets, like the .45-70.