I measure my guns occationally.
Pistol case sup margin web *Pressure rating
Patriot 45acp .... .180"..... .180" .... 0" ....21,000psi
Colt 1911 45acp .225 .180 -.045 21,000psi
Para Ordinance 45acp .235 .180 -.055 21,000psi
Glock 20 10mm .250 .180 -.070 37,500psi measures .275, .280, gunzone quotes me at .306"
Glock 22 40sw .235 .180 -.055 35,000psi
Beretta 92S 9mm .163 .160 -.003 35,000psi
Beretta 92S chamber wall .1" thick
Kel-Tek P11 .190 .160 -.030 35,000psi
Glock 19 9mm .190 .160 -.030 35,000psi
Star Firestar .165 .160 -.005 35,000psi
CZ52 9mm .145 .160 +.015 35,000psi
Tokarev 9mm .160 .160 0 35,000psi
CZ52 7.62x25mm .185 .185 0 42,000cup
Tokarev 7.62x25mm .170 .185 +.015 42,000cup
Berretta 1934 .380 .170 .175 +.005 17,000cup
Kel-Tek P32 32acp .250 .150 -.100 20,500psi
Savage 1917 .240 scribe, .265 bulge
P3AT Gen I .270"
P3AT Gen II .275"
I can see my list is not up to date. The LCP is in the same category as the P3AT.... 1100 fps 90 gr is the most I can get.
If I scribe the feed ramp line on a case with a needle, the measurement I get is always bigger than when I measure the edge of a case bulge, by ~ .010"