I purchased my first handgun a while back, a model 610, mainly as a side arm to carry for deer or hog hunting, and well just cause...

Looking for ammo and comparing velocities and energy I see most are tested using pistols with 4" barrels. Should I expect similar results with a revolver with 6 1/2" barrel? Better?worse? (I don't have a crono.)

Also, I've seen some references to the gap between cylinder and forcing cone, what is concidered optium gap? Whats too much or too little?

I actually found some Buffalo Bore at Cabelas, on sale and in stock (online) no less...

I can't comment with any authority on the BC gap, but in answer to your velocity question, yes, the longer barrel will give higher velocity. I read somewhere a good rule of thumb is every extra 1/2" of barrel gives 50 fps higher velocity. The reloaders and guys with chronos will have to weigh in.

The longer barrel will get you a bit more velocity than if your same gun had the shorter bbl. However, compared to load data or manufacturers' claimed velocity, it's hard to say. You really just have to chrony your load and gun and see what you get. If you don't have a chrony, then I would say don't worry about it. You will definitely not be handicapped with a 6 1/2", and the paper target or the perpetrator won't know the the difference anyway. Worry about function and accuracy.

For cylinder gap, it depends on who you ask. In general, however, it seems that higher than .008" is considered excessive, and less than .003" may lead to function problems with a dirty or fouled gun. You can buy a feeler gauge for $5-10 if you want to know what yours is.

If the cylinder and barrel gap are similar, then the longer barrel will add probably 100-200 fps.

I consider a barrel/cylinder gap of .006" to be par. .004" is better and S&W allows up to .010" (which is too much IMO).

I have, in the past two years, bought several S&W and Ruger Revolvers. They run within my expectations (the Rugers are near perfect at .004"). Maybe I have been lucky, who knows?

Regarding the velocity expected - only actual testing will give you true results. I have access to a chronograph and it has been a good learning tool.

Dale53