Can it be done? Should it cycle and use regular mags? I could do a 300BLk, but just like something different.

I think the worst part about it is that it is a wildcat round.

I've been considering building a 6x45 upper myself, just can't commit the funds as of yet.

http://www.shop.blackholeweaponry.com/6x45_c514.htm

Is it a round that doesn't need much barrel length like the Blackout?

Part of why the BO does well with a shorter barrel is the increased surface area of the larger caliber. As far as that goes, a .243 bullet wont be as good for that.

It will, however, be much better at long range work. I think the 6mmAR (6.5G based) comes between the ballistics of the 6mm PPC and BR. The 6x45 won't be as good as that, but will use stanag parts.

something like .358 gremlin, .338 spectre, .458 socom would be your best bet in shorter barrels

With some bullets you will have to watch over all length for fitting in the mag, and being wildcat it will be a reload, be that yours or from one of the custom ammo places like Chad's. Dies will be more expensive as well than for standard rounds.

The
6X45 has about 3 grains less powder capacity than the 6mm PPC so will be a little slower than it.

What kind of performance are you looking for in the something different category? To see what kind of performance in a short barrel check out the reloading data for a 6mmTCU and 7mmTCU both are essentially the same case just different shoulder angle than the 223 and 6X45. Hodgdon has both in the pistol reloading section of the reloading data center on line.

Yes sir. Something other than Blackout that has some knockdown power and still runs well in an AR-15. Blackout is a possibility, but I don't mind handloading for something else. That 7mm TCU has my interest.

The problem with the TCU is to get the case right you have to run a 223 case through the sizing die then fireform it to get the shoulder right, have owned a couple 7TCU barrels for the Contender. Neat little round but might be more work than you want for an AR.

I have an AR in 6.5 Grendel and really like it, runs good and ballistics are very good. There are some wild cats off of that case as well 6mm, 30, and 358 that I know of. Could go with one of those and have something different without fireforming. For 6mm it would be just be easier to go with 6mmPPC which shares the same parent case as the 6.5 Grendel and 7.62X39 the little 220 Russian has some nice rounds in its family tree. The difference between the PPC cartridges and the Grendel case is the Grendel case body is .076 longer.

I like the Grendel round enough to have a boltaction in the works.

I have two 6X45mm's currently but have owned four in the past few years. Right now I have a DTech custom AR and a Cooper Bolt gun.

Here is the 6X45 AR. Normally it has a Suppressor on it but it broke and is being replaced under warranty.




Here is the Cooper


The 6X45mm is easy to load for and dies are actually very reasonably priced and it is as simple as running thru the die add primer/powder/bullet and go hunting. This cartridge was used by Bench Rest shooters back in the day is quite popular and I am surprised one of the big companies has not standardized it.
I have shot the smallest group I have ever fired with my old Bull Barreled AR using H335 and the 65gr VMax.

that's awesome