Exactly right, Jack! The peak pressure will be the same. The exrta barrel length give the gas more room to expand in, and based on the burn rate of the powder, will cause an slight increase in velocity (all things being equal).
The longer barrel gives some people a better sight radius, however as eyes grow older the sights on the shorter barrels my be more clear and sharpe. There is some advantage that the long bareels have as for less barrel flip due to the lower muzzle pressure. Also there is a little less blast. On the flip side though the shorter barrels don't ride up as much when you sit down ( longer barrels better at crossdraw). Quite frankly, it is really up to what one likes. No animal will ever live to know the difference in barrel length...dead is dead!
Best Regards, James
(Edited by James Gates at 7:42 pm on Aug. 13, 2001)