AR Sponsor
Posted: 3/9/2009 7:23:23 AM EDT
| Is there anyone that makes an upper or conversion in 22 WRM if not why? To me it sounds like a good idea. Jacked bullet, diameter is .224 not .223 like a 22 LR about the same power as 5.7 FN. Ammo cost hear is about $10.00 for 50 rounds. |
|
Quoted:
Is there anyone that makes an upper or conversion in 22 WRM if not why? To me it sounds like a good idea. Jacked bullet, diameter is .224 not .223 like a 22 LR about the same power as 5.7 FN. Ammo cost hear is about $10.00 for 50 rounds. . .22WRM pressure difficult to contain in blowback type action (all .22LR conversions are blowback). It's been done by Ruger and, IIRC, HK but not sure if it can be done economically in the AR. YMMV ETA: At the range a couple weekends ago we found some .17 rimfire brass where some of the cases had bulged out bases (the heads not the case bodies). Not every one but there were several. Not sure what type of rifle was used. |
|
Quoted:
Quoted:
Is there anyone that makes an upper or conversion in 22 WRM if not why? To me it sounds like a good idea. Jacked bullet, diameter is .224 not .223 like a 22 LR about the same power as 5.7 FN. Ammo cost hear is about $10.00 for 50 rounds. . .22WRM pressure difficult to contain in blowback type action (all .22LR conversions are blowback). It's been done by Ruger and, IIRC, HK but not sure if it can be done economically in the AR. YMMV ETA: At the range a couple weekends ago we found some .17 rimfire brass where some of the cases had bulged out bases (the heads not the case bodies). Not every one but there were several. Not sure what type of rifle was used. Pistol rounds like the 9mm, 40, 45 and the 5.7 are all handled by blow back actions. I doubt the 22 mag is at a greater pressure rating than the 5.7 or 40sw. Pat |
|
How thick is the brass on a rimfire case ( rimfire= crushable) as opposed to ANY centerfire case?
Nobody offers a WMR auto at present except MR and thery port their barrels starting right in front of the chamber to reduce pressure. Ruger stopped production because of unmanageable problems. It's probably not just peak pressure, but also duration, area under the curve. My CZ .ZKM-611 semiauto tends to blow cases with Winchester ammo, bulges some others. |
|
Quoted:
Is there anyone that makes an upper or conversion in 22 WRM if not why? To me it sounds like a good idea. Jacked bullet, diameter is .224 not .223 like a 22 LR about the same power as 5.7 FN. Ammo cost hear is about $10.00 for 50 rounds. I did a couple of 22 magnum uppers years ago and still have them because they shoot so nice. The real problem is the magazines –– unless you're good with sheet metal you will have to make do with commercial 7 or 8 round mags. I did a 22 magnum conversion unit and tried it several different barrels. The best was the 1:12 twist barrel and the 1:9 was OK but the 1:7 twist seemed to tear the thin jackets up. some of the newer 22 magnum ammo uses better bullets and might hold up better. I dropped that idea because it depended too much on what barrel would be used. The blowback setup works just fine and somebody already brought up the point that most pistol caliber uppers work just fine that way. That also brings up the point that a 22 magnum upper would most likely need a buffer and spring designed for the 22 magnum round. That is what I did and it works just fine. My 22 magnum 
The mag on the left is a 7 round magazine and the one on the right is a 20. 
|
|
Pistol rounds like the 9mm, 40, 45 and the 5.7 are all handled by blow back actions. I doubt the 22 mag is at a greater pressure rating than the 5.7 or 40sw. Pat Sorry you're correct - I should have said that the cases are the problem - rimfire cases, as we all know, can blow out very easily. We used to blow .38 Supers and even some .45s in locked breech 1911s a couple or three decades ago when we were trying to make major power in IPSC shoots. Then the supported chamber barrels took care of that problem. Of course we then had Super cases end up with no headstamp markings and completely flat (no firing pin mark) primers - and on more than one occasion a comp would go flying down range. 
I know blowback actions can handle a lot more than we think they can - some guys made special barrels for blowback Astras and fired warm light bullet.38 Super loads. Case adhesion, spring tension and slide weight allowed this but this it is definitely not recommended (DON'T DO THIS!!). Perhaps no one does a .22 Mag for the ARs because they don't think there is enough of a market. .22 Mag is cheaper than 5.56 but more expensive than .22 LR. AR-Fan: Very interesting. Which conversion unit are you using? Ciener or 261? |
|
Quoted:
Perhaps no one does a .22 Mag for the ARs because they don't think there is enough of a market. .22 Mag is cheaper than 5.56 but more expensive than .22 LR. AR-Fan: Very interesting. Which conversion unit are you using? Ciener or 261? Mike, I think you hit it on the head about there being a big enough market! I use a highly modified M261 unit for my 22 magnum and my 17HMR uppers. The small capacity mags are Marlin but the hi-cap is a very modified version of a Marlin magazine. |
AR Sponsor