Great video, thanks Nick.
You may have seen already that the 6" pellet model only has 2.5" of rifled barrel, the rest is some 6mm bore aluminium airsoft tube. Wingun who manufacture these in Taiwan, have pulled the same trick on the 6" Dan Wesson 715 pellet revolver.
I have fitted a full length rifled barrel to mine and left material on the barrel offcut I used to increase the weight. I also packed the grips with plasticine and old pellets, partly to deaden the hollowness of the plastic, but also add more weight. Unfortunately I have overdone it and will need to turn more metal off the barrel!
It was great to see a side by side comparison with your real M29, especially the unloaded weight of 1125g. Looking forward to your next video.
Too many guns, or not enough time?