Unless you test the loads you don’t know if it makes any difference at all. I do know that over crimping, crimping a shell too deep, will increase pressures. That I tested and pressure shot up over 1,000psi. We think, not proven for certain, that cutting a shell down and roll crimping a load lowers pressure slightly. But again unless you test them you really don’t know. I’ve never tested a Hartin load for pressure so won’t hazard a guess about any effects on pressure. Testing a single load is simple and inexpensive so there are good reasons to know for certain. If you were working up a dozen different loads money might be a factor.
