6x45 (6mm-223) AR15

alberta tactical rifle

alberta tactical rifle

CGN Ultra frequent flyer
Rating - 100%
114   0   1
Location
calgary alberta
We were thinking it would be cool to try building a few AR15's in 6x45 (6mm-223). This is the .223 case necked up to take 6mm (.243) bullets. It is a fairly easy conversion to make as all the rifle components are the same except for the barrel. Unlike all the other exotic AR caliber conversions that seem to require different mags and different bolt faces.

The 6x45 can push a 60gr bullet to 3000 fps or an 85gr bullet to 2700 fps which is excellent performance for both short and long range shooting. The bigger bullet will of course make bigger holes in stuff. :D Apparently the 6x45 has been around for quite a long time and in the past was a benchrest record holder so it is capable of excellent accuracy.

For more information on this cartridge check out this website http://www.6x45ar15.com

Brass is super easy to come by and there is a huge variety of different bullet styles and weights available. Load data and reloading dies are available from several manufacturers.

We just wanted to guage if there was any interest in barrels or complete uppers or rifles in this caliber?
 
I think it was SGW/Olympic Arms who promoted 6x45 years ago.
The 6x47 round used in benchrest competition in the days before the 6PPC took over is based on the 222 Remington Magnum. Very similar to the .223 based 6x45; basically the 6x47 has a longer neck.
6x45 is a perfectly respectable, useful cartridge. It is essentially a handloading proposition, of course. Easy to do, as you have mentionned. Better than the .223 for hunting larger game, although that is academic for an AR.
 
It is interesting that there seems to be so much interest in the 6.8SPC of which the ammo is nearly impossible to get in Canada and is hobbled by the lack of decent bullets. It also requires special mags (difficult to get) and a different bolt.

Yet a very simple conversion like this 6x45 which requires no special parts or mags is ballistically very similar to the 6.8 and has the benefit of being able to use extremely plentiful and cheap brass and a huge variety of excellent quality bullets seems to generate almost no interest at all. :(
 
This is a great wildcat cartridge that would make the AR an ideal large varmint gun as well as a short range deer gun. Being 6mm it would be legal big game round in all Provinces.

Just our crazy gun laws standing in the way.

Tagged for interest.
 
would be interested, i seen it advertised in SG news for some time now, and its potential is realy interesting, like they say " make it and they will come" . knowing all that's needed is a new barrel, i'm sure a small run of barrels in commonly known lengths 14.5, 16, 18, 20, 24. would sell out quickly.
 
This thread has piqued my interest. I think I will see if I have a decent .243/6mm barrel in my cache that could be used.
 
Apparently you need a 1:8 or 1:10 twist to use the 85 - 90gr bullets. I think the old 6mm Rem barrels were mostly a slower 1:12 twist.

i'm sure a small run of barrels in commonly known lengths 14.5, 16, 18, 20, 24. would sell out quickly.
Click to expand...

From my reading most people are going with 18 - 22 inch barrels but I was thinking this would make a nice hard hitting carbine with a 14.5" barrel. It would certainly be more efficient than a 5.56 with a short barrel.
 
OAL determined by the AR 15 magazines drastically limits bullet selection if you go with a larger bore and the original full length .223 cases

Going with the shorter case Fireball length cases [ eg: .300 Whisper ] allows a much greater bullet selection, with not that much drop in velocity.

Which is why the .300 Apache [ 7.62X45 ] and the newer .30 SPC [ 7.62X40 ] are relatively unknown, while the .300 W is the gold standard.

If you are just looking for max velocity,
with a slim selection of bullets,
use the full length cases.

But if you are looking to up the bullet weight to something significantly more ?useful? [ and a "useful" Ar 15 a pretty well a MOOT point here in Canuckistan ] then again the .300 whisper makes more sense.


Or just do what I did and buy an AR 10.

So just get on with it ...
don't get side tracked by all those other silly AR calibers, or you might never find your way out of the maze.

Start cranking out those .300 Whisper barrels, and bring in a whole bunch of reloading dies for the .300 W. If we get enough AR shooters interested in .300 W, why then maybe some one will start importing the factory loaded .300 W ammo.
And wouldn't that be special???

PS:
Supposedly, Redding makes the best dies for the .300 W.


[;{)
LAZ 1
 
I have a new takeoff Remington SPS .243W sporter barrel. This is the faster twist, should work with any reasonable 6mm bullet. It is 22" long. By the time the chamber is cut off, the barrel could finish at 20".
Only catch is that the barrel is too slender for a .750" gas block. Either a .625" sight base would have to be used, or a sleeve installed. Would probably go with the latter.

Then again I have a couple of .30 barrels.....
 
What I want is a parent case 7.62x39 with a bit straighter walls (like a 6.5 grendel) necked to a 6mm. Would deliver very nice velocities and would be cheap, small and low recoil.
 
Suputin said:
Yet a very simple conversion like this 6x45 which requires no special parts or mags is ballistically very similar to the 6.8 and has the benefit of being able to use extremely plentiful and cheap brass and a huge variety of excellent quality bullets seems to generate almost no interest at all. :(
Click to expand...

If you call it 6X45 SPCMN then you would get many more nibbles.
 
I built a 6x45mm AR upper a few years back. Worked ok but I was not convinced that it was much better than 223 at the time. If I didn't keep mixing the brass up with my 223 brass and if I could have hunted with it I would have kept it. Now if you did 6x45mm conversions to non-restricted black rifles like the swiss then I would be interested ;)
 
What I want is a parent case 7.62x39 with a bit straighter walls (like a 6.5 grendel) necked to a 6mm. Would deliver very nice velocities and would be cheap, small and low recoil.
Click to expand...

The problem with such a conversion is it requires a different bolt and magazine. Also the larger case head results in the bolt being weakened which causes lugs to fail.

The primary reason I am interested in the 6x45 is it requires no special or modified parts other than the barrel.
 
You must log in or register to reply here.
Back
Top Bottom