Commercial receiver extension and 9mm spacer

AR/M4 AR Pistols & Pistol Caliber ARs
1

I have one of the HK commercial receiver extensions and was considering using it on a 9mm build.

My question before I install it is will I run into any issues with the slanted end on it and using the 9mm Colt spacer? Or is this a non issue?

If it is a potential problem then getting a milspec tube with it’s flatter end is no problem.

Thanks

2

No difference on the inside. Same dimensions.
I’ve swapped buffers & springs between comm. & mil spec buffer tubes and never noticed a difference.