.22 magnum

[zahc]

I just bought a Heritage Arms 22lr single-action revolver (for 99 dollars). It came with a coupon for extra cylinders. It says that you can choose either 22 magnum cylinder or 22lr cylinder. My question is, what could be different about the .22 magnum cylinder compared to the .22lr? The cylinder that is in it, I believe, is intended to be the .22lr cylinder, and there is no machined shoulder in it or anything; it appears that the chambers are straight-walled. So, any ideas?

[lee n. field]

I just bought a Heritage Arms 22lr single-action revolver (for 99 dollars). It came with a coupon for extra cylinders. It says that you can choose either 22 magnum cylinder or 22lr cylinder. My question is, what could be different about the .22 magnum cylinder compared to the .22lr? The cylinder that is in it, I believe, is intended to be the .22lr cylinder, and there is no machined shoulder in it or anything; it appears that the chambers are straight-walled. So, any ideas?

The .22 Magnum dimensions are a bit different from .22LR (I mean, beyond just length). 

Two cylinders on the same coupon suggests that they put the same coupon in the box with .22LR and .22WMR revolvers.

[zahc]

Oh, I guess that makes sense

[Chuck Dye]

Oehler's Ballistic Explorer Ammo Library gives the outside diameter of the .22WMR as .240, that of the .22LR as .224 (the long rifle uses a heeled bullet, the magnum does not,) the outside rim diameters as .290 and .270, respectively.  Other sources provide slightly different measurements, similar differences. 

Firing the long rifle in a magnum chamber would likely lead to gas leakage at the breech, possibly case rupture, unhappy things in a locked breech design, potentially disastrous in a revolver.  Do you trust your eye wear?

[AJ Dual]

Yep.

It would be nice if it were like .38spl and .357mag, but as mentioned above, the dimensions are different.

.22mag is a traditionally neck-seated bullet like larger rounds. So the case has to be a bit larger in diameter than the actual .224 bullet diameter of what are nominally ".22's".

.22LR is heel seated, where the outer diameter of the bullet is identical to the case. The bullet is gripped by a sub-caliber extrusion that protrudes into the case.

http://www.zombiecrisis.org/siteimages/articles/22lr.jpg .22 short and .22LR cross-sectioned you can see how the case grabs into the bullet, rather than the bullet just sleeved into the case. That is the cause of the actual difference. .22mag uses the more traditional seating because it has an actual jacketed bullet, and not just soft lead, or copper washed, and you can't heel seat those kinds of bullets.

[sanglant]

there was a .22 RF between the bb cb short long and LR, and the mag, i think winchester still makes one load for it.

[230RN]

^
Huh!  Following a link in your cited articles, I discovered that there was also a .22 Extra Long cartridge, discontinued in 1935.  Didn't know that!

http://en.wikipedia.org/wiki/.22_Extra_Long