One blank is slightly longer, with a full length bullet crimp. These blanks are commonly use for SMG blanks. These blanks will eject in 1911s that have had their ejection ports modified by milling out the front of the ejection port.
The shorter blanks, will eject in all 1911s. No modifications are needed to the slide.
I am currently using Atlantic Wall Blanks’ 45 auto pistol blanks. I met up with Rob (AtlanticWallBlanks) at Camden and was able to field test the blanks for him.
The blanks he supplied me all appeared consistently formed, crimped and clean upon inspection. All of the primers were properly seated. The bag of 50 contained 50 blanks. Rob also gave me a handful more blanks to test out to see if they worked.
The blanks headspaced properly in my barrel, (the shoulder was properly formed and the right length). I fired 14 rounds (2 magazines), one slow fire, one rapid fire in my 1942 Colt 1911a1 (885XXX) with a ww2 production GI magazine (R). All rounds fired consistently, ejecting and feeding consistently as well. No stoppages, failure to feeds, failure to eject or stovepipe problems. My 1911a1 runs well with live ammo, and I did not anticipate any problems running blanks.
The blanks were not excessively loud, or excessively powerful. I felt the volume to be appropriate for pistol blanks, and safe for use in pistols.
I was using the blank barrel pictured above, with a .154 set screw installed. The recoil spring I was using has an unknown number of rounds on it, and I assume it to be weak. I fired the blanks without the barrel link installed. Otherwise, the gun is stock, no further modifications or alterations needed.