Is there a difference in accuracy in the dissipator rifles with 16" barrels versus the 20" length rifles?

Does the 4" make a difference on paper?

Thanks

at longer ranges the greater velocity of the 20" will drop/drift less.

I love the dissipator but at longer ranges the 20" rules the roost. But for that I have a 20" Armalite AR-10T

Thanks

If you mean Bushmaster (real) Dissipators, they are just a carbine barrel with full-radius (rifle) sights:


You get the same performance as with a carbine.

If you mean the DPMS-style 16" rifle-gas barrel, I have no idea, and I defer to the posts above - more distance = more drop form lower muzzle velocity.


No one has a real pic of the DPMS barrel with no handguards online that I can find.  It has rifle gas system on a 16" barrel, and they open the gas port up more for reliable cycling with less barrel past the FSB.  Here's the barrel I mean (at Del-ton):
www.del-ton.com/detail.aspx?ID=42

This has probably been asked a bazillion times, but what the heck:

Why doesn't the Dissapator just use the rifle-length gas system? Would the gas port have to be enlarged or somesuch?

ETA: OK, I see in engineer2001's link that DPMS makes what I was talking about; Is there a technical reason Bushmaster doesn't do the same?