I just finished cutting out windows in the steel 105MM M115B1 shell case and attached the section M737 TPDS projectile. I am torn on weather or not I should color code / paint the inside of the shell case? Here re a few pics on how it came out.

Overall view showing the 2 window cutout design I came up with.

I cut both nylon driving bands on this side flush on the projectile

I cut both nylon driving bands short about 1 inch to better show how they are attached to the projectile on this side.

Bottom window cutout showing the correct M80A1 ELEC primer

By the way, please keep an eye out for me for any steel 105MM cases in good condition. I am in desperate need of one to three, 105MM M148A1B1 cases with ELEC M120 primers still attached. Apparently, this combo is one of the more common made but driving me crazy trying to find. I would like to make a few more cutaways with some of my other tank projectiles but won’t do it unless I have all the correct INERT components. The cases are easy to find, ones with the correct primers are not :-(

I ended up painting the interior components of the shell case for contrast.

I noticed something I have never seen or heard of before while painting this. If you look at the 12 O’ Clock position of this photo you can vaguely make out 3 letters stamped into the interior of the shell case. The photo did not capture these letters that well but they read PRM. Anyone know what they mean or why they are stamped on the inside of the shell case?