6x45 (6mm-223) AR15

Am I missing something here in regards to re-chambering/re-barreling an AR to make it legal for big-game hunting?

How can you go hunting with a Restricted AR?

Wasn't that what Remington tried to do with the R-series rifles that have since been classified as AR variants by the RCMP, or am I just completely out to lunch and missed the bus?

Hoping someone can clarify this.
 
The limitations to the smaller framed ARs being 2.260" -it's a sucky length to be hamstrung to.
Now if you guys jump into the big brother....pretty much sky is the limit.
Base it on taking FN or M14 mags...you might just have something.;)
 
I'm not really seeing the appeal of 6x45 on an AR platform given the range only limitation. For short range, it really isn't giving you anything over the .223 for paper punching and the 300 Whisper is far more interesting. For long range, the ballistics of the lighter .243 bullets at those velocities are unimpressive. I would sooner contend with the bolt and mag change, in addition to being limited on only 5 rd. to get the added performance of something like 6mmAR or 6.5 Grendel. People would probably go for a 6.5 Grendel since its known, you can get brass for it and there is no forming involved.

.20 Practical is another cartridge that would be really interesting if you could hunt with an AR, but doesn't hold much appeal otherwise.
 
Am I missing something here in regards to re-chambering/re-barreling an AR to make it legal for big-game hunting?

How can you go hunting with a Restricted AR?

Wasn't that what Remington tried to do with the R-series rifles that have since been classified as AR variants by the RCMP, or am I just completely out to lunch and missed the bus?

Hoping someone can clarify this.


not missing anything, still can't hunt with your AR in any caliber :mad:

Guys are saying that they would do the conversions IF they could use them for hunting. :(
 
mudgunner49,

Without shortening the case, you will be limited to only the lightest bullets. If you shorten it, velocities with the heavier bullets will be terribly low. There is a reason that both the 6.8 SPC and 6.5 Grendel designers went to cases with larger capacity than .223
 
A bolt action or non-restricted semi-auto in 6x45 has a lot more appeal in my mind, athough, that wasn't what Rick had in mind with his original post.

How about a Mini-14 conversion instead?
 
mudgunner49,

Without shortening the case, you will be limited to only the lightest bullets. If you shorten it, velocities with the heavier bullets will be terribly low. There is a reason that both the 6.8 SPC and 6.5 Grendel designers went to cases with larger capacity than .223

It's not all about velocity - greater frontal area does good things. The 6.8 UCC gets pretty decent velocities with 100-115 gr bullets and it's just a necked-up .223. The cartridge has been around for quite awhile now and ther has been plenty of load development for it.

I envision it for the 0-300m envelope and don't think that is overly out of line - and \i'm no real fan ofthe 6mm cal...


blake
 
6 x 45 can be found in Shotgun News. A short time ago High Standard was offering a package of a 6 x 45 upper and a bundle of ammo.
 
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.....

Rather than cut up the new Remington .243 barrel, I picked up a take-off Sako Varmint barrel that bubba has been gnawing on. 23 1/2" long, lots of meat to work with.

Back to the original post - I think there likely would be a market for some kits. I would be inclined to offer the option of a die set with the barrel.
 
Just ordered a 6x45 reamer. Already have the headspace gauges.
Machining has started on the Sako varmint barrel. Muzzle is threaded for a brake. Fitted a Smith Enterprises unit. Its bore is such that modifications for 6mm will not be required. .243 chamber is gone, shank is ready for threading. Waiting for the barrel nut. Once it is here and installed, the chamber will be cut, headspace set. With the barrel breech finished, the critical length to the gas block can be finalized, and exterior profiling can be done. I am using a .750" clamp on gas block with a short rail for a front sight. This will be a 20" rifle.
Anyone have any suggestions for gas port diameter?
 
You can try asking the guy at ar15barrels.com about the gas port. He lists 6x45 as one of his reamers. If you can't find first hand information about gas port diameter, just start with a very small hole and gradually open it up until you get reliable cycling.
 
Thanks for the lead.
That's what I've done previously - start small, keep opening the port until reliable function is achieved. It is interesting to watch the changes. Breech opens, but no ejection; then it opens and ejects, but doesn't feed. Next step is opening, ejecting and feeding, but it won't lock open on the last round. One size larger, and away she goes.
Given that all ammunition is going to be handloaded, experimentation is going to be required.
For ammunition with which to start testing, I have the tools for 6x47 (based on .222Rem.Mag). I will take sized .223 brass, use the taper expander to open the neck, and then use the 6x47 seater die.
 
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