Underwood 10mm Hard Cast in Clear Ballistics Gel


Test Gun: Colt Delta Elite
Barrel length: 5 inches.
Ammunition: Underwood 200 and 220gr Hard Cast
Test media: 10% Clear Ballistics Gel.
Distance: 10 feet.
Chronograph: Caldwell Ballistic Precision Chronograph G2.
Five shot velocity average: 1191, 1139fps
Gel Temperature 74 degrees

This test has to be one of the biggest pain in the ass test I have ever done. This is the third and last in the Underwood woods loads. The 10mm is probably the most recommended woods carry round for semi-auto pistols and for good reason. The 10mm is a powerful round capable of sending heavy bullets at high velocity giving deep penetration. However, as we have seen in the past test with the .45, .40 and 9mm provide a very good alternative.

With the 200gr loading, I got an average velocity of 1191fps with a high of 1200 and a low of 1183fps.

Ten yards off hand five shots 200gr

The 220gr round had a four-shot velocity (chorny problems) of 1139fps with a high of 1162fps and a low of 1108fps.

Ten yards off hand five shots 220gr

When shooting the 200gr load on paper at 10 yards I was having issues with the slide locking back with a loaded magazine. I decided to modify the slide lock to prevent this from happing. Once completing the modification, I had no more slide lock issues. I remember committing when I tested the Double Tap hard cast loading should not be necessary. However, if I wanted to shoot this type of ammo I guess it was necessary for my gun.

I also had two failures to eject with both the 200 and 220gr loadings. I have never had this happen in this gun before but I’m not convinced it was an ammo issue.

In the bare gel, the first found of the 200gr hard cast hit the gel at a velocity of 1189fps and 58.5 inches and had a recovered weight of 195.4 grains. The second round has a velocity of 1204fps and penetrated to 58 inches. The recovered weight of that bullet was 196.7 grains.

I had many issues shooting through the sheet metal. I tried three rounds and all of them curved to the left and exited the about midway through the second block.

I had similar issues with the 220gr bullets. Where the 200gr penetrated straight in the bare gel both of the 220gr bullets took a significant curve to the left also. Luckily I had shot both of them on the right side of the blocks or they wouldn’t have been recovered either.

 The first shot in the bare gel had a velocity of 1146fps and penetrated to 60 inches. Recovered weight was 217.7 grains. The second round’s velocity was 1160fps and penetrated to 59.75 inches. Recovered weight was 216.6 grains.

With the 220gr shot through the sheet metal, I had very similar problems as with the 200gr loading. Three rounds were shot and only one was recovered. The one recovered bullet’s velocity was 1172fps and it penetrated to 25 inches. Recovered weight was 202.4 grains. The second round curved upward and exited the top of the block about midway through the second block. The last round curved to the left, just like the 200gr bullets, and exited about midway through the second block.




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