I test out the Underwood Ammo 155gr Gold Dot 10mm load in the Clear Ballistics FBI gel block (calibrated to mfg specs) with 4 layers of denim with the Gen4 Glock 20 (factory spring).
Chrono Data (average):
1443 fps, 716 ft/lbs energy
155gr retained weight
.812 average expansion
13.5” penetration
As you’ll see in the video, the bullet holds up pretty well with only minor deformation.
I’d like to see more shots through the Chrony to establish a decent amount of data. Looks as though with those three shots it may be a bit inconsistent with a max deviation of 81fps. That’s quite a bit IMO.
Also more shots into the gel would tell us whether it expands consistently.
Everyone wants different things from a video; some want more shots while others want them to be short and to the point. Unfortunately I can’t please everyone there. Also, if I shoot the block more than once tons of people say “That test it totally invalid because the block is damaged, ect….” [ask me how I know 😉 ]. Again, can’t please everyone here. These tests are just one data point I make to help share information with fellow members of the shooting community; they’re not intended to be the be all, end all tests.
The deviation isn’t due to the round; it’s actually due to the 17lb spring in the Gen4 G20. I have several Gen3 G20s and run heavier springs in them and the same ammo gets about 50fps more and is much more consistent.
I’m a .45acp gal who runs 1911 platforms these days – but I’m going to have to try Underwood as a manufacturer; looks like they’re a good, small business to support.
I’m new to your blog, and I like the way you run a review: simple, direct, concise with no pretense.
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