I'll be trying an XM-8 out Sunday at Camp Robinson, Arkansas this Sunday. Among other things, I'm going to try to hang onto some fired brass and a couple of GI rounds- I have a project or two in mind.
Interestingly, one other goodie on hand may be an Australian F88 AuSteyr reworked for the 6,8mm cartridge- the F88 has a quick-change barrel, and the replacement of the bolt with one with the larger face for the 6,8 is no problem. It should be interesting to see how well the cartridge fits in the L88 magazine, which is NOT a M16-type mag.
They have all the normal requirements such as reliability and durability. Also handy to carry and I always liked the ability to keep topping them off from loose ammo without worrying about mags. It also saves space and weight.
I bought a Marlin with a Redfield receiver sight around 1984 then when I sold it I kept the sight. I later got a Winchester model 94 and noticed the sight fit it as well. The combination of peep and hooded front is both fast and accurate. Nearly as good as a scope withought all that weight and bulk.
They have plenty of power for shooting people and that flat pointed bullet is effective.