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AR Conversion kits

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shakti

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Hello friends

Are AR conversion kits still legal in MA?
If one were to look at a 16.1" barrel, should the muzzle break be welded?

Any restrictions you are aware of?

Thank you
 
Sorry for the lack of clarity. There is no specific caliber in mind.. it could be a
- 5.56 to 9mm
- 5.56 to 22LR
- 5.56 to 5.7

Basically one of the CMMG videos that was on you tube that was fascinating. Hence the question.
 
shakti said:
Sorry for the lack of clarity. There is no specific caliber in mind.. it could be a
- 5.56 to 9mm
Click to expand...
9mm won't fit down a 5.56 bore. 5.56 won't fit in a 9mm chamber
shakti said:
- 5.56 to 22LR
Click to expand...
this exists, e.g.
www.brownells.com

Bravo SS .22LR Conversion Kit w/ 3-10rd Magazines | Brownells

The CMMG Bravo AR-15 .22LR Conversion Kit allows you to practice your critical shooting skills while using economical .22LR ammunition.
www.brownells.com www.brownells.com

shakti said:
- 5.56 to 5.7
Click to expand...
5.7 won't fit down a 5.56 bore. 5.56 won't fit in a 5.7 chamber

Unless you're talking about uppers. In which case, yes you can buy a new upper and install it on your lower, especially if you follow all applicable state and federal laws. You might also need special magwell adapters...
 
You wouldn't usually 'convert' from 5.56 to 9mm. That's more like you need a bigger barrel and bolt, and usually recoil operated. So you'd need a different upper. Then there's the problem with mags/lower compatibility you'd have to solve.

5.7, why bother? Unless you get the special nylon ammo it's ballistically the same as .22 magnum.

.22 conversions are the most common. They'll foul up your gun pretty bad and are pretty inaccurate so I always ran dedicated .22 guns. The Tippmann is awesome.
 
shakti said:
Sorry for the lack of clarity. There is no specific caliber in mind.. it could be a
- 5.56 to 9mm
- 5.56 to 22LR
- 5.56 to 5.7

Basically one of the CMMG videos that was on you tube that was fascinating. Hence the question.
Click to expand...
You can do the CMMG 22LR conversion from 5.56. I like mine and have had zero issues but I only feed it CCI Mini Mags. Super cheap, super fun. You want a 1/9 or slower barrel twist, no faster.
 
shakti said:
whether changing uppers was legal
Click to expand...
Changing uppers is legal as long as the assembled firearm is legal to possess.

For example, swapping a 16” 5.56 barreled upper for a 16” .22 barreled upper is fine.

Swapping a 7” barrel onto that same lower isn’t fine. Regardless of caliber.

The original manufacturer def of firearm as declared on 4473 is important. You can go from pistol to rifle but not tifle to pistol and SBRs are federally regulated.
 
allen-1 said:
The original manufacturer def of firearm as declared on 4473 is important. You can go from pistol to rifle but not tifle to pistol and SBRs are federally regulated.
Click to expand...
That's why one builds from a stripped lower. 4473 just says "firearm" on it since it hasn't reached its final configuration.
Mine can be anything legal they feel like being on any given day.
Well at least in a free state.
 
shakti said:
If one were to look at a 16.1" barrel, should the muzzle break be welded?

Any restrictions you are aware of?

Thank you
Click to expand...
If the lower is post ('94) ban and the barrel is threaded then yes to pin/weld of the muzzle device as threaded barrel falls under the AWB ridiculousness...
 
shakti said:
Sorry for the lack of clarity. There is no specific caliber in mind.. it could be a
- 5.56 to 9mm
- 5.56 to 22LR
- 5.56 to 5.7

Basically one of the CMMG videos that was on you tube that was fascinating. Hence the question.
Click to expand...
CMMG has a 9mm upper that fits on top of a AR lower with the only change being a 9mm AR style mag. This is an easy conversion. Nothing illegal about it. That is if you pin/weld a muzzle break or a thread protector. Even if the barrel > 16”, you still need to eliminate the threading on the barrel to prevent installation of a flash hider. 9mm does not need a muzzle break so I would see if your gunsmith can pin the thread protector that comes with the upper.

For other conversions, I’m not familiar with any uppers that work with a regular AR lower. I’ve seen plenty of lowers with a Glock mag well but that’s not what you were thinking about, correct?
 
40 Creedmoor fan said:
CMMG has a 9mm upper that fits on top of a AR lower with the only change being a 9mm AR style mag. This is an easy conversion. Nothing illegal about it. That is if you pin/weld a muzzle break or a thread protector. Even if the barrel > 16”, you still need to eliminate the threading on the barrel to prevent installation of a flash hider. 9mm does not need a muzzle break so I would see if your gunsmith can pin the thread protector that comes with the upper.

For other conversions, I’m not familiar with any uppers that work with a regular AR lower. I’ve seen plenty of lowers with a Glock mag well but that’s not what you were thinking about, correct?
Click to expand...

That upper is also available in .22 from CMMG.
Or you can go with their conversion BCG which goes into a standard AR.
 
It looks like this thread was a bit premature ... I asked CMMG and they said their barrels are threaded and they would not ship the upper to a restricted state :(
 

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