Why no Jr Carabine in .223???
- Thread starter Cirrus8
- Start date
The JR may not be designed to handle the pressure, but, others have been designed to handle the pressure easily. Ruger did a 44mag.
Canadian_Zuk
CGN Ultra frequent flyer
- Location
- Pickering, Ontario
44mag is a straight walled pistol cartridge, not a shouldered rifle cartridge. The difference between 36,000 PSI(44mag) and 62,000 PSI(223) is quite substantial.
Ok, I didn't know the mechanics were more based on a semi auto pistol, then AR's. Nowi can see why it is not on the market. Still sad that we can get anyrhing close to an Ar in 223, whitout slapping some plastic stock (tapco,promag) on a semi auto. I know some will chime in and say go with the Bushmaster or XMR but I dont have 2500$ to splurge.
Man I just feel that if a canadian manufacturer would build this kind of rifle in 223, he would make serious $$$$$.
Rant over lol
Thanks for the info.
Man I just feel that if a canadian manufacturer would build this kind of rifle in 223, he would make serious $$$$$.
Rant over lol
Thanks for the info.
Canadian_Zuk
CGN Ultra frequent flyer
- Location
- Pickering, Ontario
Get a Keltec SU-16 and dress it up. takes LAR mags, can look almost AR-ish, can be found for $6-700 used on the EE. Folds in half for storage.
I agree there is a difference between a 44mag and a 223, all I am saying is a blow back design is possible for the 223, just not a JR. It is possible to have a blowback chambered for rifle rounds that are high pressure. Look at some of the machine guns chambered in 303, 30-06, 8x57 and 50cal, they are high pressure (the mg34, mg42 and Browning 50cal are blowback).
Canadian_Zuk
CGN Ultra frequent flyer
- Location
- Pickering, Ontario
You are right, rifle cartridge blow back firearm are not unheard of, but they are usually roller delayed and not straight blowback (HK33 for example). All the WWII guns you refer to above used oilers to overcome case friction issues, kinda messy in a sporting rifle. Another issue is the recoil spring would have to be incredibly stiff and also the bolt would have to have much more mass than what a pistol cartridge would require. It may require Hercules to cycle the action open 
Alberta Tactical Rifle Supply is workin on that Non-res ar-style .30 cal rifle. Could check that out. Don't think they're doin their first run in .223 but from what i've seen they'll chamber it in any caliber that'll fit in a .308 mag. Might be wrong, check out the thread in their subforum for more accurate info if you're interested.
You are right, rifle cartridge blow back firearm are not unheard of, but they are usually roller delayed and not straight blowback (HK33 for example). All the WWII guns you refer to above used oilers to overcome case friction issues, kinda messy in a sporting rifle. Another issue is the recoil spring would have to be incredibly stiff and also the bolt would have to have much more mass than what a pistol cartridge would require. It may require Hercules to cycle the action open
The Armor Militant-99 Anti-Material Rifle or AM-99 is a recoil-operated, semi-automatic .50 BMG caliber anti-material rifle designed by weapons manufacturer ...http://www.google.ca/url?sa=i&rct=j...CvMKjnxml7cx9oOyASCroNoA&ust=1411690252837048
You are right, rifle cartridge blow back firearm are not unheard of, but they are usually roller delayed and not straight blowback (HK33 for example). All the WWII guns you refer to above used oilers to overcome case friction issues, kinda messy in a sporting rifle. Another issue is the recoil spring would have to be incredibly stiff and also the bolt would have to have much more mass than what a pistol cartridge would require. It may require Hercules to cycle the action open
Here is another...http://en.wikipedia.org/wiki/Barrett_M82
This isn't real. That's a fantasy board. If you read it carefully, it's gas operated.
MG42 and all G3 families are roller delayed. A non delayed recoil operated (like JR) high pressure cartridge gun has been done, do exist and been tested in battle. Several actually. But as you go through the list, M82 included, they tend to be heavy and sometimes cumbersome like Canadian_Zuk said. I'm probably incorrect, but the I think the main difficulties would be making the rifle weigh well while making the bolt weight function with as much as the myriad of .223 out there
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Canadian_Zuk
CGN Ultra frequent flyer
- Location
- Pickering, Ontario
Recoil-operated is not blow back, it is delayed blow back. And the AM-99 you linked is a gas operated semi auto.
Canadian_Zuk
CGN Ultra frequent flyer
- Location
- Pickering, Ontario
M82 is recoil operated, not blow back.
When the gun is fired, the barrel initially recoils for a short distance (about 1 in or 25 mm), before being securely locked by the rotating bolt. After the short travel, a post on the bolt engaged in the curved cam track in the receiver turns the bolt to unlock it from the barrel. As soon as the bolt unlocks, the accelerator arm strikes it back, transferring part of the recoil energy of the barrel to the bolt to achieve reliable cycling.
On a blowback firearm, like the JR carbine (the topic of this thread), there is absolutely nothing locking the bolt shut. The recoil spring and the weight of the bolt is all there is.
Blastattack
CGN Ultra frequent flyer
- Location
- Winnipeg MB
There are no straight blowback operated firearms of any sort chambered in .303, 30-06, 8x57 or .50 BMG. There are many machineguns that are Short-Recoil operated or Roller Locked, but none that are blowback. Some German machineguns are Roller Delayed Blowback operation, but that is not straight blow-back. The most common Roller Delayed automatic is the MP5 as well as the G3 rifle and it's derivatives. It is practically impossible to create a functional blowback firearm chambered for a high pressure bottle-necked round, the physics challenges (and weigh concerns) make straight blowback a pointless endeavor. However it works exceptionally well for straight walled pistol cases of most shapes and sizes.
