[FlatDarkEarth]

I've thought of a potential issue with the 6.5 and caliber swapping. It seems to me that an ideal combo would be the 6.5 (great BC's for range and retained energy) and the 7.62x39 (higher caliber and decent energy for close-in social work, super cheap for plinking and trigger time).

The issue comes in with which sights to put on such a combo rifle. I'm thinking I'd pick something like an Leupold 2-6x36 MR-T to start taking advantage of its long range potential with 6.5. But something like a EOtech seems more appropriate for the 7.62.

So, what's to do? You wouldn't want to swap sights with each barrel change would you? ...especially if the swaps were fairly frequent, right? Would it be possible or necessary to buy two separate uppers? I know, *gasp*, why would I think of such a thing, especially on a forum for a barrel swapping weapon. For comparison, I've done a cost rundown of what it would take to make an AR lower with two separate uppers with these capabilities and comparable features (op-rod, side charging handle, etc...): it's almost twice as expensive!

 

[gr8santini]

I like my Trijicon TR21R. At 1.25X magnification, it's almost as fast as a red dot, with the ability to dial it up to 4X for longer shots. Mine has the post with triangle reticle. They're coming out with new models that have a more traditional illuminated crosshair.

 

[blankman]

I can't be of much help, but I am interested in hearing some opinions as I had the same thought.

Which btw whoever reads this I do not own an XCR yet because I am waiting(impatiently) for either a 6.5 or 7.62 hint hint

 

[marinewmu911]

The TR21R is also a favorite of mine, but instead of looking at getting to very expensive uppers, look at getting QD (Quick Detach) mounts for your sighting systems. ARMS, GG&G, Nighforce (I think), LaRue all make QD stuff. Most have little to no loss of zero so combined with the barrel swap getting back on target would be about as quick and easy as it gets.

 

[stanc]

I've thought of a potential issue with the 6.5 and caliber swapping. It seems to me that an ideal combo would be the 6.5 (great BC's for range and retained energy) and the 7.62x39 (higher caliber and decent energy for close-in social work, super cheap for plinking and trigger time).

The issue comes in with which sights to put on such a combo rifle. I'm thinking I'd pick something like an Leupold 2-6x36 MR-T to start taking advantage of its long range potential with 6.5. But something like a EOtech seems more appropriate for the 7.62.

So, what's to do? You wouldn't want to swap sights with each barrel change would you? ...especially if the swaps were fairly frequent, right?

I sure wouldn't want to. I like your basic concept, but it's really dependent upon the 6.5 conversion being available, and so far there doesn't seem to be any sign of that happening.

However, assume that it eventually becomes reality. If by "long range potential" of the 6.5 Grendel you mean distances of 800-1000 meters, does the XCR possess the accuracy necessary to hit targets that far away? If the combination of rifle and ammo is only good enough to hit consistently at 600 meters max, then perhaps an ACOG or similar optic would be good for both calibers?

 

[dont_tread_on_me]

What would be so difficult about switching optics if you have quick detach mounts for each optic in each caliber? It would take less time than changing barrels.Much less cost than buying a complete upper which would make little sense unless you want a PDW upper.

 

[Cid1911]

One of the features about the XCR that I really liked is that it's possible to quickly change your weapon from a CQB setup to a quasi-D.M. type weapon in minutes with QD mounts on the same receiver. I'm in the market for a 18.6" barrel and when I acquire one, I plan on getting some QD mounts for a 3-9 variable scope and zeroing the scope with the longer barrel. I'll keep my GG&G throwlever mount equipped eotech zeroed with the short barrel.
Remember F.D.E. your not dealing with an AR anymore

 

[hunter s gatherer]

You can also keep both mounted: the AGOG in the usual primary position and get a 45 degree offset mount for a dot. I have also seen
a one-over-the-other on LaRues site. That looks too high to me though.