I looked up the M2 Browning .50 cal gun and know there is the new type with the crank-type quick-change barrel handle, but other than that detail, are there other differences between the guns? Live Resin, as far as I know, only makes the M2A1.

The muzzle is different, and somewhat fragile. The ole threads on the barrel on now interrupting threads, very similar to those on the breech of a 155.

The rear sight assembly is now staked. To change the factory set timing, you must now "unstake" the assembly, as the timing wheel assembly is underneath the rear sight assembly in the receiver. (only 18B's and armorers are authorized to even attempt this, as there's no real reason to)
Brand new, the gun is a tad sluggish, but after several hundred rounds runs very well.

I spent all my time with the old M2HB, it's nice to see they up graded the gun and fixed the 2 major issues, head space and timing only took 80 years. I also liked the M85 never really had a problem with it that didn't come from the ammo feed in the cupola.
The old Ma Duece keeps chugging along.

Tom