Originally Posted by FrontierGander
3 hours? Good lord, it only takes me maybe 10 minutes.
You only need .002" crush fit on the primers to be blow by free.
Have you measured your primers length and then closed them in the action and measured again to see exactly how much crush fit you are getting?
Absolutely. I read your instructions and modified them. Prevailing torque on the retainer actually determines the final fit which is why I set both and a set torque value. I had some issues with one rifle because the breech face was starting to erode from many ignitions. I had to fixture the action in the mill and spotface the recess (above the threads) to provide a square and flat base for the retainer, shim washers and seal ring to rest on. The first was no issue, the second was. 6 hours total, however, the recess was 0.010 deeper prior to spotfacing.
I fully understand CVA's reluctance (and their disclaimer on their website as well as the disclaimer on each packet of shims). It's not a procedure to be undertaken lightly because it can result in spontaneous ignition when the action is closed, if, the retainer crushes the pill. That would be ugly and most likely result in personal injury.
It would be very difficult to determine (accurately) just what the crush is. By that I mean, there is no way to determine (for the layperson) what 0.002 crush on the cup is, because when the action is closed, the cup is not accessable, one reason I bought the CCI's, because they have a copper plated cup that allows you to visibly ascertain if the cup has physical contact with the retainer and what the area contacted is. I set the fit to encompass the entire outer circumference of the retainer, but beforehand, I ensured the retainer was flat and square by chucking both retainers in an appropriate collet, fixtured in the surface grinder and took a cleanup pass across the face.
As a machinist/shop owner and dealing with precision machining everyday, I would not recommend or endorse anyone to modify their CVA is it was in service for any length of time.
The ideal scenario is applying the modification to a new, unfired rifle or a rifle with very limited ignitions. Simply put the blow by from the primer fit degrades the breech face over time and degrades the retainer face as well. New or limited use rifles will not have that issue.
Works like a charm but procedural attention is everything.