AR modifications

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Officers'Wife

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I debated on putting this in gunsmithing & asked if it be moved if more appropriate there.

Is it possible for a rimmed cartridge to function in the AR platform? It would be nice to have a modern semi-automatic rifle to let my Winnie retire. On the more extreme side it would be fun to have one in .303 Brit so I could shoot it on the range when hubby has his .223 AR out... Or would that just be mean?
 
It is possible--after all a .22 LR is a rimmed cartridge and adaptors have been made to fire them in std. AR's. It might also be possible to fire a .22 WMR from such an adaptor (don't know whether someone has made one or not). However, to feed larger caliber rimmed cartridges, you would need to borrow ideas from the VEPR, Bren, or so on on magazines, bolts, etc. and that feeding mechanism might or might not fit within the confines of a standard AR lower and bolt head.

It could be done but would require extensive modifications to the bolt, probably easiest to do in a single shot with magazine feeding problematic, and might have ejection problems.

The easiest way would be something like what Ruger did with its precision rifle series based on the AR platform.

Or you might find or make a rimless version of a .303 (or other rimmed cartridge such as the .30-30) and try to develop one around that.
 
The usual solution is to get a similar round to the one you like that was made for semiautos. 7.62x39 and .300BO are pretty close to 30-30, so the market for a 30-30 design is not really there. As far as .303 goes...just look at an AR-10 in .308. Not the same, but pretty close.
 
I debated on putting this in gunsmithing & asked if it be moved if more appropriate there.

Is it possible for a rimmed cartridge to function in the AR platform? It would be nice to have a modern semi-automatic rifle to let my Winnie retire. On the more extreme side it would be fun to have one in .303 Brit so I could shoot it on the range when hubby has his .223 AR out... Or would that just be mean?

Anything is possible. Not everything makes sense. Given enough time and/or money and skill this shouldn't be hard. That said, why not get your own AR? As others have said, there are plenty of calibers besides 223/556. But if range use is your main use they probably make the most sense.

Now if you really want to be "mean" to your hubby, put an AR together yourself without him knowing. It might be a fun project to do the lower, then the upper then surprise him at the range. Stripped lowers, lower parts kits and sticks are cheap. Stripped uppers are also cheap, barrels can be had cheap to expensive and hand guards are all over the place. Plus you could do it in neat colors!
 
It is possible--after all a .22 LR is a rimmed cartridge and adaptors have been made to fire them in std. AR's. It might also be possible to fire a .22 WMR from such an adaptor (don't know whether someone has made one or not). However, to feed larger caliber rimmed cartridges, you would need to borrow ideas from the VEPR, Bren, or so on on magazines, bolts, etc. and that feeding mechanism might or might not fit within the confines of a standard AR lower and bolt head.

It could be done but would require extensive modifications to the bolt, probably easiest to do in a single shot with magazine feeding problematic, and might have ejection problems.

The easiest way would be something like what Ruger did with its precision rifle series based on the AR platform.

Or you might find or make a rimless version of a .303 (or other rimmed cartridge such as the .30-30) and try to develop one around that.

I have considered .30 carbine, even so far as to discuss it with the local gunsmith. However, I have shot the 32-20 since I was just barely a teenager and have a good understanding of the flavor of cartridge's uses and limitations. Add the fact that eventually I am going to have to retire my 92 Winchester as it is well over 100 years old there is a romantic element to the idea the cartridge will still "carry on" the work that served my great grandfather to myself so well.
 
The 32-20 would fit an ar15 envelope using a modified 7.62x39 bolt and maybe a .312 barrel blank adding a barrel extension after reaming chamber. Extraction might be an issue and feeding from a mag/semi operation difficult. A single shot manual model using a side operating bolt upper and std lower with a blocked mag might be possible. It would look like an ar but be a hi tech single shot 32-20. You might even be able through trial and error to rig a manual feed mag.
 
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Such a radical caliber change would not really be a "modification" in the normal sense of the word. This would be something unique (and rather impractical, IMO).
 
Why not get a newer 32-20 lever gun? Or just keep shooting yours. It's really hard to truly wear out a non-automatic firearm.
 
There are a couple of important parameters that dictate what can or cannot be chambered in an AR pattern rifle. The first is cartridge length, the second is rim diameter. While the .303 British rim diameter could work with a short mag bolt in a .308 AR, the overall length exceeds what will fit in a .308 magazine by 1/4".
 
But then you have specialty AR platforms like the OMEN that shoot .300 Win or .338 Lapua. So I guess the short answer is that they could probably make a .303 Brit AR but it would be a high dollar specialty rig and capacity would be limited because it is difficult to stack rimmed rounds in a straight magazine well.
 
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