Robinson Arms XCR - what caliber

[ccwcanada]

How does the 7.62 compare to the 6.8 then, in terms of trajectory and energy?

Guess I can go look it up, but if someone wants to post that here in the meantime....

http://www.ar15.com/lite/topic.html?b=3&f=121&t=271627

Here is a great link comparing 5.56 NATO, 6.5 Grendel, 6.8 SPC, and 7.62x39.

Wish I could get the 6.5 now.

 

[diemaco]

Just from Remington's claims...

"Remington likes to compare the ballistics of the 6.8mm SPC with those of that time-proven deer slayer, the .30-30 firing a 150-grain bullet. Accordingly, the 6.8mm Rem. SPC produces 23 percent more energy at 100 yards, 36 percent more at 200 yards, and at 300 yards, the 6.8mm SPC still retains 1,072 ft-lbs of energy compared to the .30-30's miserly 565 ft-lbs. The 6.8mm SPC is 4" flatter at 200 yards than the .30-30, and in rifles of identical weight, the recoil of the 6.8mm SPC is 30 percent less."

Most of the ballistic charts I've seen show the 6.8 to be roughly equivalent to the .243 though so I'll back down on that one...

Jeff

Guess it depends where you get your data. The difference in energy at 100 yards is insignificant from what I've seen. Also, data for 300 yards is silly, neither cartridge is ideal for 300 yard big game hunting. IMO energy alone is a poor indicator of killing power as it places too much emphasis on velocity. The .30-30 makes a bigger hole aswell.

 

[Stranger]

Don't buy one! buy two (different ones)!

I was thinking along the same lines as OP... and ordered one in 223.
....

and for the price of a 7.62 caliber conversion kit you can have a nice CZ858 with 4 mags... non-restricted and capable of 3MOA any time.

s>

 

[ccwcanada]

And they're supposed to come out with a 6.5 conversion kit too.


So I say 5.56 for now, and get the 6.5 kit later.