22 MRF = 22 WMR (not 22 WRF?)

spclark

Acquired a very nice S&W Model 48-2 awhile back, barrel's stamped for 22 MRF. Today I came across a reference to the (obsolete?) 22 WRF of similar - but not same - dimensions & NOT INTERCHANGEABLE with the 22 WMR; 1400 fps vs. 1900 fps or better.Somebody please confirm my hope that, in this case, 22 MRF = 22 WMR, not 22 WRF.I've noticed unburned powder in the cylinder bores after ejecting cases - with both Federal and Winchester factory 22 Magnum ammo. I find I must brush out the chambers before reloading so that the fresh rounds seat properly, allowing the cylinder to close cleanly.As crisp as the action is and as accurate at 25 yards (as I have been able to shoot with it) I neither want to ruin the gun (or worse) or have to find what's now collectible ammo, just to shoot a few rounds once in awhile.

spclark

Thanks SaxonPig, you've made my day. I had a hunch the chronology of these two products was as you've confirmed.As for the unburned powder; nylon bore brush on a 6" handle (rides inside the carry case) works just fine. Just have to remember to use it.

TRIGGERSGHOST

The WRF(Winchester Rimfire)is the parent round of the WMR(Winchester Magnum Rimfire)Both have a .224 bullet dia.The 22 Long Rifle has a .222 bullet dia.The WMR is longer than the WRF.The WRF can be fired in the WMR chamber,but the WMR can't be fired in the WRF chamber.Remington also made the WRF type of bullet,but called it the 22 Remington Special.One should not atempt to fire 22 Long rifle bullets in guns chambered the larger bullets,as split cases or rim blowouts can happen.The WRF is again being loaded on a limited basis for older guns.Dead Horse Walking

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JudgeColt

The correct cartridge designation is WMR, but somehow, it is sometimes identified as MRF. The information above is correct. Yes, the WMR has higher chamber pressures than the Remington Special (ballistically identical to the WRF), but I also think it is too long to function in a semi-automatic WRF or Remington Speical action. Two good reasons not to do it. The unburned power is to be expected in shooting a rifle cartridge in a handgun. There just is not enough barrel length to burn the powder. Try some different brands and you may find one that burns more completely. Eject the spent cases with the muzzle in the air and that will help keep power granules from getting under the extractor.

spclark

Thanks: the "muzzle up" technique is a good hint. Debris under the extractor isn't what I find most often - it's debris up in the cylinder bores that needs clearing, before a fresh round is inserted, otherwise the cartridges don't fully seat & interfere with the cylinder closing freely.I'm researching available brands of cartridges right now (also for .22LR for a long-barrel of mine). Anyone have a favorite WMR brand for wheelguns?

JudgeColt

I have probably fired maybe 100 WMR cartridges in a handgun in my whole life, but I never experienced the problem you are mentioning. How can there be that much debris that is so hard that the new cartridge cannot be inserted? Anyone else ever experience this problem? I will have to dig out the Colt Officer's Model Match in .22 WMR and the Colt Peacemaker and try them. Of course, the last time I bought WMR ammunition was about 30 years ago, so my ammunition may not have the same characteristics as yours. (I seldom shoot a WMR because I cannot bear to spend so much per shot when I cannot reload the casing. You can shoot .38 Special about as cheap even if you do not reload. To me, the WMR is the answer to a question no one asked, especially in a handgun.)

spclark

JudgeColt,I'd been surprised by the volume of debris too; I'd owned a .22LR version for years & sold it awhile back, then got to missing it so I bought the WMR version I saw up for sale (kick me; I shoot .44 Mag mostly) & never had a problem chambering rounds in the LR. Fresh rounds WILL fit with some effort; if I load all 6 cylinders it requires some fiddling to get the clean lock up that's guaranteed if I brush out each chamber before reloading.What's the recommended "gap" between cylinder and barrel when the cylinder's locked up? Perhaps mine is beyond spec & leaking some?

JudgeColt

I cannot imagine the cylinder gap is causing the fouling. The spec for the gap is probably about .015" to .006", with about .002" to .003" being considered ideal.

spclark

I've found a couple of web-based suppliers of alternate brands of cartridges; once I can set up a test batch of something other than Winchester or Federal (I use the latter, seems more accurate overall,& cleaner by a bit) I'll see if that makes a significant difference.I'll post the results here for interested parties though it'll be a few weeks.Thanks all for your insights (no pun intended).

He Dog

This will not be the same, but is another point of reference. I have a Gredal P-30 which also shoots .22WMR and it also has a short barrel-don't remember exactly but about 6"+ or -. I do not get significant powder fouling in that pistol. Darn thing is worth too much to shoot any more though.

roundball

I'm very surprised to hear about unburned powder using modern .22 magnum cartridges;I have a rather short barreled S&W .22Mag revolver and it shoots as clean as a whistle..never even had a hint of unburned powder.