Frank Lopez wrote:Soxfan,
Radial pressures are a concern with chokes and steel shot. However, I don't think so much in this case. The complaint was scoring around the outside of the tube. Radial pressure would act on the inside of the tube.
Roster wrote Magnum Lead loads(harder lead shot and loads containing buffer also) and Steel. The bigger the shot, the bigger the payload and the higher the velocity the higher radial pressures will be.
the scoring as mentioned before no doubt happened when wrenching out the choke.
Regarding the scoring, you are probably correct. I was think he meant scoring parallel to the axis of the tube.
Regarding the radial pressure, this falls in with what I was saying about the CIP recommendations for steel shot, and is entirely possible. For standard proofed guns (not high performance steel proofed), CIP recommends no loads faster than about 1300fps at 2.5meters from the muzzle (roughly 1450 or so at the muzzle), no shot larger than about a US #4 and a momentum (shot weight times the velocity) of less than 12 NewtonSeconds. This last criteria is probably the culprit since Black Cloud loads run about 1650 or so for a 1 1/4oz load which would put it way over the 12Ns requirement. Another thing that might be something of an issue is the shape of the pellets. It would see that these pellets would not "flow" or compress through the choke as easily as a round pellet. But then neither would BlindSide, but Beretta didn't seem to have an issue with them.
I just checked the requirements for High Performance steel from CIP, and it's pretty clear that these loads would not meet those requirements, either.