So, by chance I got a heavily discounted HDR 50 and its kind of fun to shoot but nothing to get excited over, and nothing I had intentions of getting ultimately so if this duds out, so be it. I have the modification build worked out, but I can't find the information I need to determine optimal length and what additional power will be added by reducing the bore (or none that makes a lot of sense to me anyway lol, I'm by no means an airgun enthusiast so the maths are alien to me where I do find what I think is the info). The info I do have is a review I found where 183 grain lead balls where shot, 11 joule model w/ removed block no barrel extension) with an average around 170fps , 13 FPE, 17 joule average, this is the only decent test with lead I could find. The barrel extension kit I found boasts 2x - 3x joule improvement (claims 11j + power kit will be 30-40 with 4" extension) I cannot confirm these claims but that seems heavily inflated to me. I know that reducing the bore is also going to increase velocity, but I'm not sure that matters, or what if any of what I am explaining matters at all here lol. Anyway, the barrel material I am working with is 12" long, the .50 cal barrel CLAIMS adding 4" onto 4.7" basically doubles the joules. Again, seems off to me, but how can I determine at what point I've added too much barrel IE friction to be helpful? Will be fitted to .37" 105 grain round nose pellets if that matters.
Thanks in advance for any tips or information on this
Thanks in advance for any tips or information on this