Good morning Moe. I am not KYODE or JAVALINA, but wil add a couple comments anyway.
First off CONGRATULATIONS on the 6mm BR Barrel. While I have never owned or shot a 6mm BR, I am an avid fan of 6mm Handguns. In years past I have had Handguns chambered in both the 6mm-223 & .243 Winchester. Currently I have a 15" VVCG 6mm T/CU that I am working with.
YEP I do like 6mm Handguns, and I think the biggest reason is the availability of different Bullet Weights and Configurations. I have used 55gr. Nosler Ballistic Tips, 58gr. Hornady V-MAX, 60gr. Sierra Hollow Points, 70gr. Nosler Ballistic Tips, 70gr. Hornady SX, 80gr. Nosler Ballistic Tips, 80gr. Speer Spitzers, 80gr. Remington PLHP's, and 90gr. Nosler Ballistic Tips. I have taken everything from Gophers to Whitetails with 6mm Handguns with excellent results. Granted there have been a couple of these bullets mentioned that have been disappointments.
I think one of the major things the 6mm Handguns have going for them is IMPACT VELOCITY. In my opinion this creates more rapid energy transfer and shok resulting in performance all out of proportion to the size of these cartridges and bullets. Now granted that is not all that goes into the equazion, but the Bullets themselves also play a major role in this.
I also think the 6mm BR has about the optimum case capacity for use in Handgun Barrels, and as such should make an excellent choice. Again Congratilations on the barrel. Now enjoy.
Larry