Anybody know the exact diameter of the barrel on the Umarex HDR 50?

[AtmoTac]

I have heard 2 different sizes, .495 and .505

 

[Triglav]

I have heard 2 different sizes, .495 and .505

There are barrel extensions for the HDR, if you can get the bore dimensions on those, you'll also have the inner diameter of the barrel. The extension is probably less than 0.002" in difference.

 

[AtmoTac]

There are barrel extensions for the HDR, if you can get the bore dimensions on those, you'll also have the inner diameter of the barrel. The extension is probably less than 0.002" in difference.

Thank you I’ll look into that

 

[Triglav]

This guy's a well of information on the HDR 50, you should look into his videos, or write to him directly about the bore diameter, if someone knows the HDR piece well, it's him - MadDogAirguns... Link:

https://www.youtube.com/@Maddogairguns/videos

 

[AtmoTac]

This guy's a well of information on the HDR 50, you should look into his videos, or write to him directly about the bore diameter, if someone knows the HDR piece well, it's him - MadDogAirguns... Link:

https://www.youtube.com/@Maddogairguns/videos

Thank you!