Home Forums Hunting & Shooting Handguns Underwood 68 and 90 Grain 9mm Standard Pressure Xtreme Defender Chrono Results

MontanaMarine recently posted some chrono results with Underwood 9mm+P 68 grain Underwood Xtreme Defenders. I indicated that I would try some of the standard pressure rounds in 68 grain and 90 grain versions.

Here are my chronograph results with Underwood 9mm standard pressure Xtreme Defender 68 grain and 90 grain ammunition in a Sig P365, Sig P365 XL, and Ruger PC Carbine. Because I only bought one box of each kind of ammo, I only fired 4 rounds of each in each gun. I was using a Labradar chronograph.

In doing this testing I wanted to check for bullet setback because I have found that Underwood 68 grain XD .380 ammo sets back on the first chambering. I noticed that these 9mm cartridges in both bullet weights have a very stout crimp on them bordering on roll crimps. I brought my calipers to the range to check for setback.

68 grain XD, factory rated for 1700 fps MV :
Sig P365 (3.1 inch barrel): (1) 1610; (2) 1661): (3) 1661; (4) 1646. Avg. 1643: ES 51
Sig P365 XL (3.7 inch barrel): (1) 1663: (2) 1737; (3) 1687; (4) 1656. Avg. 1686; ES 80
Ruger PC Carbine (16.12 inch barrel): (1) 2104; (2) 2160; (3) 2131; (4) 2160. Avg. 2139; ES 56

Notes: I started with a loaded magazine in the gun with the slide/bolt locked back and released it using the slide release/bolt release. I had a failure to chamber with the first round of the ammo in the P365. It dinged the nose of the bullet. It fed on the subsequent chambering. It also fed fine 2 other times using the slide release. No other failures to chamber or feed occurred in testing with any rounds in both bullet weights.
The bullet did set back about .003” when releasing the bolt of the Ruger PCC. The rounds chambered in the P365 and P365 XL did not set back.
There was only a 43 fps difference in the average MV between the Sig P365 and the P365 XL. The P365 results are impressive for a short barrel. The P365 was noticeably snappier, though.

90 grain Xtreme Defender, factory rated for 1400 fps MV:
Sig P365 (3.1 inch barrel): (1) 1288; (2) 1324: (3) 1290; (4) 1267. Avg. 1292; ES 58.
Sig P365 XL (3.7 inch barrel): (1) 1380; (2) 1393; (3) 1399; (4) 1343. Avg. 1379; ES 56.
Ruger PC Carbine (16.12 inch barrel): (1) 1596; (2) 1642; (3) 1588; (4) 1639. Avg. 1615; ES 53.

Notes: No bullet setback issues were observed after chambering from slide/bolt lock.

I got a chance to shoot some rounds against 3 pieces of 22 gauge steel, a piece of 2X6 and water jugs.

68 grain 9mm XD from Sig P365


68 grain 9mm XD from a Ruger PC Carbine


I may need to shoot the 68 grain XD rounds again to see if I am just placing badly centered hits on the targets or if the rounds just tend to deflect a lot after hitting barriers.

90 grain 9mm XD from P365 XL


If I were to carry a 9mm XD round for self-defense in a handgun, I think I would prefer the 90 grain. But, I am not unhappy with standard pressure 124 grain Gold Dots, so I don’t see a reason to switch.

My real takeaway from all this is that the 68 grain XD in .380 is rather impressive for it's diminutive caliber. It's my thread, so I guess it's not thread drift.
.380 68 grain Xtreme Defender from Sig P365-380, previously posted:

Nice tests, thanks for sharing.

I was having some chrono difficulty the day I did my chrono test, but comparing our results, it seems there is very little difference between the 68gr standard pressure and the +P.

Yes, your 380 has some teeth with the 68gr Underwood XD.

2139 out of that carbine is no joke.

I'd like to see what that does to soft armor.

Cool tests. Thanks for posting.

I think I can put one more shot on the undamaged piece of IIIA panel that I previously shot with Mackay's hard cast 9mm ammo. I just didn't have time to try it yesterday. If I manage to do that, I will post.

Very cool 👍

Those XDs are nasty little bullets. I load the 95gr in 32 H&R and 327 Fed. I haven't done video, but one out of a 327 does a lot of milk jug carnage for the size of the cartridge.

Good videos.

I think it's interesting how the differences in barrel length affected muzzle velocity differently with the two different bullet weights. Just 6/10 of an inch of barrel made a surprising amount of difference with the heavier bullet, but not so much with the lighter one. It kinda says, it takes the heavier bullet a little longer to get going, but once it's there you get what you get.

I'm going to repost my velocities with the 68gr +P here, just to show how similar they are with Cheyenne's numbers with the standard pressure,

3.4" Glock 43X - 1666
4.0" Glock 19 - 1775
4.5" Glock 17 - 1813 avg
6.0" Glock 22 - 1937 avg
16" Ruger PC Carbine - 2135

It's pretty impressive to me, that a 4" 9mm with this ammo is getting speeds faster than the FN57 out of the typical 40gr ammo and roughly 4.7" barrel.

It looks like that stuff would be fun in my S&W FPC carbine. That thing is a ball to shoot.

The shot against a piece of IIIA body armor was a fail, although it went farther than the 148 grain +P hard cast that was fired into the other side of the same panel. It probably would do some CPR on a person behind it if not put a hole in them. Here is the video. ETA: It might have gotten through on a center shot through a big piece of armor, but I don't know.



Note that this was a panel purchased from Midway USA and may not be representative of high end professional body armor.

I also shot one of the 90 grain standard pressure XDs from the carbine against the same array MINUS the body armor. That round got into the front of the piece of wood. When I had previously fired a Buffalo Bore 147 grain +P hard cast against the same array (also without armor), it stopped after denting and putting a small hole in the second piece of 22 gauge steel.

I really don't know if I see any benefit of this ammo in 9mm. It is very expensive to buy and test. I also have tried to load some 68 grain XD bullets in 9mm cases using Lehigh bullets (which appear to be slightly different than the ones in the Underwood ammo), and I can't get enough tension on the bullets to prevent setback. The Underwood factory rounds appear to have a bit of roll crimp on them.

YMMV