FYI, I ran some factory Underwood standard pressure 68grain XDs through my Glock 42. I was using a Labradar at an indoor range with side-walls at the shooting bench and had the gun positioned very close to the chrono (like I usually do), and I was getting some double readings due to the concussion. After discarding the really low numbers (e.g. 300 fps), I got a 5 shot MV average of 1233 fps, with a high of 1286 and one very low of 1144, for an ES of 142. I didn’t believe the one low number to be correct, so I shot another five but positioned the gun a few inches farther from the Labradar. Each shot registered and I did not get any extra readings. This time I got a MV average of 1254 fps, high of 1275, low of 1225 for an extreme spread of 50. My Sig P365-380 previously had registered an average of 1273 with a high of 1308, a low of 1233, ES74. Although the Sig’s ES was higher, the low for the Sig was 1233, which was higher than the low of 1225 registered in the second string with the 42, and the high for the Sig was 33 fps higher than the high for the 42. The average was close enough between that two that I think that my junk science testing of the ammo from the Sig P365-380 on a different thread from a few months ago should be valid for the 42.
I also shot some 68 gr. XD handloads through the 42 with a max load shown on Lehigh Defense’s website, and I got a 5 shot average of 1155, high 1159, low 1145, ES 14. This is about 75 fps faster than Lehigh Defense’s factory loaded ammo. Lehigh’s factory ammo was too weak to consistently cycle either the Glock 42 or the Sig P365, but this handload cycles very well in both and is milder than Underwood’s factory ammo. I am going to do my barrier and water jug test with this ammo at some point to see the effect of the lower velocity. Note: Lehigh's XD bullet looks slightly different than the XD bullet loaded by Underwood. I can't explain why.
I also shot magazines of the XD factory and handloads through the 42 and also shot a Sig P365 9mm loaded with Speer standard pressure factory 124 grain Gold Dots with an MV of about 1050 through that gun. The .380 loads have mild recoil compared to the 9mm and are very easy to shoot rapidly. (The Underwoods are louder and slightly snappier than traditional 90-95 grain .380 ammo.) Anyone who thinks they can keep up with these .380s shooting the mini-9mm with duty-grade ammo is either dreaming or has recoil control like a bench mounted vise.
There were no malfunctions with any of the ammo. I also checked the ammo for setback in the 42 and I did not detect any.
I am cross-posting some of this on the .380 thread that I started a while back.
Hope this helps.
MontanaMarine, keep us posted with your results with the +P versions of Underwood XD.
