Wanted to get some chronograph results and see how the Underwood 220gr hard cast works in a Glock 29.
I decided to compare the spread of hits of the 220gr HC between my 1911 with its Bar-Sto barrel and my third generation Glock 29. The G29 is standard, except for a metal recoil rod assembly with a standard 17lb recoil spring.
I placed the target at 30 yards and shot slow strings with my hands resting on a shooting bag. Took lots of time to make sure my sights were aligned consistently. Each square on the target is 1x1". The group in the upper left is from the Glock. The better centered group is from the 1911. Proves in my mind that the Glock barrel does stabilize the 220gr ammo. Then I shot the Glock at a distinguishable formation on a berm about 60 yards away, standing off-hand. The hits were comfortably close to the target, showing again, the bullets stabilize.
Here are the chronograph results
Altitude: 3221 ft, Temperature: 48 degrees, Barometric pressure: 26.9 inHg
10mm Underwood ammo -
Glock 29
180gr XTP : 1263, 1266, 1255, 1253, 1299 : avg 1267 ft/s
200gr XTP : 1133, 1120, 1141, 1153, 1170 : avg 1143 ft/s
220gr HC : 1075, 1082, 1084, 1104, 1094 : avg 1088 ft/s
1911 4.25" Barrel
180gr XTP : 1271, 1265, 1269, 1299, 1253 : avg 1271 ft/s
200gr XTP : 1181, 1187, 1199, 1183, 1167 : avg 1183 ft/s
220gr HC : 1152, 1153, 1165, 1156, 1161 : avg 1157 ft/s
Target attached: