Every time you shoot a center-fire rifle suppressor, you wear it out a little bit. It takes thousands of rounds and most suppressers will outlive most barrels, but it will happen eventually. And using a shorter barrel will be louder and will wear out the suppressor faster.
And some suppressers are only rated for certain barrel lengths. For example, the Surefire 5.56 Micro is a very small can so Surefire says it only should only be used on barrels 14.5" and above. And the AAC SDN-6 is a .308 can, but AAC says you can use it on a 300 Win Mag if you're shooting it out of a long enough barrel (I think they said 26").
0331: "Accuracy by volume."