Ummm, your bayonet would be a bit stubby on a carbine gas system...
Yes, but that is why it is there....really.
Stubby? Yes, but the hoards in Haiti were sufficiently intimidated by "stubby" a time or two.
And Colt M4's routinely break/crack bolts...really. This ain't hearsay. This was extremely rare with the old 20in rifles but fairly common today.
M4's are also famous for the dreaded "bolt over base" malfunction that will ruin your day. I believe the high port pressure causes this.
Ummm, the USGI standrad issue M4 has a 14.5" barrel, the govt has never used a 16" barrel....really.
I wouldn't say "routinely" but yes they do break, however the service life is well above anything we need to worry about here, though I do carry a spare Colt bolt. Also you're talking 14.5" barrels not 16"s. Yes the extra 1.5" makes for more pressure on the bolt but after firing thousands upon thousands of rounds in a 16" carbine, I'm not skeered.
If the "bolt over base" is bolt bounce, that is why we have H and H2 buffers with loose weights inside, run a soldi buffer like the 9mm buffer and see what happens.
