Crosman Model 451


Colt 1911A1 (.45 ACP)

Crosman Model 451 (Military 45 Auto)
Replica Of:
Colt 1911A1 (.45 ACP)
Made In:
22, lead pellets, 6-shot rotary magazine
Air Source:
CO2, 12 g Powerlet
Recommended Pellet or BB:
H&N Match-Kugeln (13.4 gr)
Weight (lb)/Length (in):
2.8, 9.0
Body Material/Finish/Grips:
metal, black, plastic
Barrel Length (in)/Material/Rifled:
4.75, steel, yes
Trigger Action:
Trigger Pull (lbs)/Adjustable:
6.0 (SA), no
Sights (front/rear):
fixed, fully adjustable
Velocity (fps):
not specified
Sound Level (dB):
Thickness of Pellet Holder (in):
Manufactured Dates:
70%, yes (copy), no
Serial Number:


Comments: This is a true semi-automatic from the Golden Decade of Crosman CO2 pistol production. Concurrently produced with the Model 451 were the 600, Mark I & II, 38C, 38T, and the SA-6. The Model 451, marked as the Military 45 Auto, is the rarest of all the Crosman CO2 pistols produced during this period. This hefty all metal gun (the grip panels are plastic) was manufactured during part of 1969 and 1970. This complex design used an unusual horizontally rotating 6-shot magazine. The first shot requires cocking the hammer by hand. Gas pressure pushes the slide back against the hammer, cocking it after each shot. Since some of the gas is used to cycle the slide and rotate the magazine, the 451 doesn't get as many shots from a 12 gram CO2 bulb as other models do. This gun gets about 30 good shots from each cylinder. This pistol has a good kick and is fun to shoot, but loading pellets takes a lot of patience. While generally quite reliable, the 451 has a fragile cast metal hammer that is subject to breaking with hard use. The Crosman 451 is still the only semi-automatic, true single-action, CO2-powered, blow-back pellet pistol ever made. The Model 451, along with the Model 600, represent in my opinion the high water mark in Crosman air pistol innovation and engineering.

Pyramyd Air Report on the Crosman Model 451.
Owner's Manual for Crosman 451 (.pdf)

Performance: Measurements were made on 11/19/06 at a temperature of 68 F and 14' elevation. A ten shot string was fired from a bench rest at 15' using H&N Match Kugeln pellets (13.4 gr). The highest velocity measured was 322 fps, the lowest was 287 fps (average of the 10-shot string was 307 fps). A six shot string fired with open sights grouped at 0.70". Click the thumbnail below to see a larger image. Click here for a description of the measurement methods.

Test Firing Record:
April 15, 2007 - Tested with RWS Hobby pellets.

Right Profile:

Front View:

Right Side Markings:

Left Side Markings:

Rear View: This pistol has a hammer safety. To engage the safety, pull the hammer back about 1/8" until the first "click" is heard. To fire the first shot after loading pellets, the hammer must be cocked manually. After the first shot, the hammer is cocked by the blow-back action of the operating slide.

Loading Pellets: To load pellets, first engage the safety. Push the magazine cover button forward, which pushes the operating slide up. This allows the magazine to be rotated using the knurled edge. Pellets are loaded into the magazine skirt first. Be sure to push the magazine cover button back after loading in order to cover the chambers of the magazine and to lower the operating slide.

Loading CO2: Although the threaded knob at the bottom of the grip is not very attractive, this gun has one of the most effective cartridge piercing mechanisms of any CO2 gun I've seen. Unscrewing the knob lowers the whole bottom plate of the grip and releases the cylinder. Tightening the knob pushed the cylinder against the piercing pin. The right hand grip will not stay on unless a CO2 cylinder is inserted.



 Copyright 2011