Yes, the short barrels seem to recoil less...
Probably due to the bullet exiting sooner and all that extra burning gas dumping out the muzzle brake rather than pushing the projo further down a barrel.
I've read that the 'optimal' barrel length for a .50bmg cartridge is around 42"
Most of the lightweight guns are around 29". My Serbu rifles are 29 and 30" and have no trouble driving a 750gr projo to the 1000yd targets at ~2650fps.
My UltraMag50 has a 22" barrel and it drives the same ammo to only ~2450fps.
Not the ideal performance envelope for an AMAX target round, but still a great .50 plinker out to 5 or 6 hundred yards.
The Serbu 22" Carbine is a real comfortable shooter too with it's efficient brake.
Here's one being shot at one of the SoCal shoots at Lytle Creek: