Taming the POI Temperature shift KCMC.

OK guys. Here is a review that has been a while in the works. It has been a bit of a roller coaster, but the storm has been weathered. 

First a bit of a background. This is a GA. Airguns C. Frear tuned Kalibr Cricket Mini Carbine in .22 that I have posted on another thread (will update with links later on) This thing is a freaking lazer. I shoot at no more than 30 yards, so this thing is basically one ragged hole with it's favorite pellets. I got the gun in the Summer of '17 and could not be happier with it. 

One crisp fall day I took Katyusha out to play and low and behold, my POI had shifted, the gun was still shooting in a single hole. Not knowing what to make of it, I just re-zeroed the scope. But by noon the POI had shifted again, single hole. This became a weeks long ordeal trying to figure out what was going on. Scope was changed, same problem. Kept gun in temperature stable environment, same problem. Took the gun in to get a checkup, same problem. Took the Sumo off, same problem. Even changed the shroud to a factory original-non modified shroud, same problem.

Charlie had suggested placing an O-ring between the shroud and the block. His theory was that the temperature change was affecting the Aluminum Shroud at a different degree that it was affecting the barrel. This did the trick! No matter what the temperature did, the POI did not budge. After this I came up with the idea of fashioning a gasket out of Neoprene, this has the same effect, but looks a little bit better, as there is no gap to be seen and it absorbs the shifting a bit more evenly. 

I will try and update this post as I can with pictures and data as I can. Huge shout out to Charlie, he always stood behind his service and there was no doubt that he would make things right one way or another. 
 
I am a new member, and have been bitten by the bug pretty bad. I started this summer with a Kratos, and have had an avenger and now a Wolverine R. I just read your post from 2017 about POI shift and your fix. I shot yesterday in the cold, and had a significant drop in POI shooting at 70 yards. I saw one post about velocity change of 20-25 fps in the cold, and this may be part, or even all, no chrony yet, but I am also wondering if I am having the different metal contraction as you did. 

How has your fix worked out long term. Wondering if this is something I should to to my Wolverine. 

Also, what thickness of neoprene did you use and where did you get it?

Thanks

Sleeper192