.243 upper on a Ruger SR556

dhc-6

New member
I have a Ruger SR556 that I would like to buy a .243 upper for, do I have to change anything on the lower in order to make it work with a new upper? Thanks for any info.
 
Thanks, I was not aware that I would need a new lower, t hanks for the info. What calibers interchange on the .223 lower?
 
There are literally a 100 calibers for the AR15 lower, about half are wildcat or other custom calibers.
The change to the AR10 lower starts with the .308 length brass.
 
This list was posted on another forum:

AR-15, without bolt modification
.17 Remington
.20 Tactical
.204 Ruger
.221 Fireball
.222 Remington
.222 Remington Magnum
.223 Remington (5.56x45mm)
.223 Remington Ackley Improved
6x45mm
6mm Whisper
6.5mm Whisper
7mm Whisper
7mm TCU
.300 Whisper (.300/221, .300 Fireball)
.338 Whisper


AR-15, with bolt modification
223 WSSM
5.45x39mm (.21 Genghis)
243 WSSM
6mm PPC
6mm BR Remington
6.5mm PPC
6.5mm Grendel
25 WSSM
6.8x43mm SPC
.30 Herrett Rimless Tactical (6.8x43mm case trimmed to 41mm and necked up to .308; the 6.8mm version of the .300 Whisper)
7.62x39mm
.30 RAR
300 OSM
.357 Auto
.35 Gremlin (necked up 6.5 Grendel to 35)
.358 WSSM (various names, but all are some form of a WSSM necked up to 35 caliber, some are shortened to make them big game legal in Indiana)
.458 SOCOM
.50 Action Express
.50 Beowulf


AR-15 using a simple blowback operation
.17 HMR
.22 LR
.22 WMR
9x19mm
40S&W
10mm Auto
45ACP
 
Originally Posted By: dwayThis list was posted on another forum:

AR-15, without bolt modification
.17 Remington
.20 Tactical
.204 Ruger
.221 Fireball
.222 Remington
.222 Remington Magnum
.223 Remington (5.56x45mm)
.223 Remington Ackley Improved
6x45mm
6mm Whisper
6.5mm Whisper
7mm Whisper
7mm TCU
.300 Whisper (.300/221, .300 Fireball)
.338 Whisper


AR-15, with bolt modification
223 WSSM
5.45x39mm (.21 Genghis)
243 WSSM
6mm PPC
6mm BR Remington
6.5mm PPC
6.5mm Grendel
25 WSSM
6.8x43mm SPC
.30 Herrett Rimless Tactical (6.8x43mm case trimmed to 41mm and necked up to .308; the 6.8mm version of the .300 Whisper)
7.62x39mm
.30 RAR
300 OSM
.357 Auto
.35 Gremlin (necked up 6.5 Grendel to 35)
.358 WSSM (various names, but all are some form of a WSSM necked up to 35 caliber, some are shortened to make them big game legal in Indiana)
.458 SOCOM
.50 Action Express
.50 Beowulf


AR-15 using a simple blowback operation
.17 HMR
.22 LR
.22 WMR
9x19mm
40S&W
10mm Auto
45ACP


Well that pretty much sums it up!!!! LOL
 
Holy crap. I would love a heavy 16" barreled, fast twist AR in 6mm BR or 6 PPC. My wheels are turning now. Feeding the 6BR has always been tricky when converting a short action bolt gun with a .243/.308 bolt face to a .223 magazine well, but that's what I ended up with in my profile pic. How do they mod the bolt? Do you just buy one or do you have to get them cut and welded? How much would that cost?
drool.gif
It's been a while since I did my model 7 build, but we had to change out and put a custom follower in the magazine. How do they handle that. Oops, sorry to thread jack.
 
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Originally Posted By: BLACKRIVER4X4Can't get much more detailed than that!

That's a good starting list but they miss a whole bunch of chamberings. I've spent two days in the desert shooting and am too tired to add them tonight..lol

Greg

Holy crap!! This post is 4 years old!!

 
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