[nerdwithagun]

I have to be very careful here in saying what I “know”. For all intensive purposes, I know nothing when talking about guns as there are so many people who know more then me.

That said, would a 68-75gr 5.56mm coming out of that size barrel have enough speed in 25-50 yrds to still fragment and have more destructive power then a .45 acp out of a carbine?

[Sea Parrot]

If hollow point or soft point sporting ammo was used, those bullets would upset out to 5-6 hundred yards. Military hard ball ammo is designed specifically not to fragment at any range. (per geneva convention specs. The 5.56 military bullet may tumble inside a soft target like human flesh.

Fragmentation is a bad thing for ammo it one wants penetration, and is normally reserved for varmint hunting.

The 5.56x45 versus a .45 acp is apples and oranges, but both can kill a person dead, as in very dead.

[ctdonath2]

At 6.5”, it’s not moving fast enough to fragment.

Read this: http://www.razoreye.net/mirror/ammo-oracle/

If you didn’t, do.

Upshot is 5.56 ammo is very finicky. It may do wondrous things when happy, but the happy zone between weight, velocity, barrel length, fragmentation, etc variables is very small - and the gun at issue here is well outside that happy zone.

Oh, and no suppressor manufacturer will warrant their work if you put their can on this thing. 10.5” is minimum.

Take the hint from FN and their P90: they identified the application, then designed a solution from the bullet up.

[ExpatGator]

In general, rifle rounds go so much faster than pistol rounds (even out of carbine bbls) that they cause a lot more damage even with lighter bullets. There is a point at which damage reaches an equivalent level considering faster rifle velocity vs. increased bullet weight/larger hole of average pistol round. Bottom line: any small arm that dependably delivers ordnance on target (standard rifle or pistol caliber) will accomplish the mission.