[The Kid]

I have been hunting with a 8.5" Smith and Wesson 29 for a couple of years now, but recently picked up a 629 6" gun to pack around.  Well, to my surprise the 6" gun consistently outperforms the longer barreled gun by at least 50 fps.  Here is an example: 23 grains of Win-296 with a Hornady 240 grain XTP, Federal primer, and Starline brass.  The six-incher averages 1,324 fps while the longer barreled gun goes 1,247 fps.  Same story with lead bullet loads also.  What gives??

 

[pourboy]

Kid- Many things affect velocity. One of the most pronounced differences you will find is that in the barrel/cylinder gap. I've heard (but cannot substantiate), that .001 cylinder gap an cause up to 150 fps difference in velocities. I imagine bore diameter could also play a (smaller) part in velocity as well, but would have to see it to believe it. This would have to be a sort of expansion ratio thing, like you see in the difference between 44, & 45s. Enough rambling. you're probably seeing a barrel/cylinder gap difference here. Enjoy the portability of your 6 incher, life is so much nicer with shorter barrels!!