I am very disappointed in the results of testing this through a variety .45's. Though I don't believe it to be the ammunition's fault on its own, but rather the guns' inability to handle it.
Federal HST .45 ACP 230 gr +P, 950 fps.
I ran (or attempted to) 150 rounds through three of my .45's that are in my carry rotation. A XDS, a Sig Compact Carry Nitron (4"), and a FNX45.
The first round in the FNX locked the slide to the rear. The slide stop was NOT engaging, it had simply frozen in its rearmost position. The slide was not in contact with the next round in the mag, or anywhere near the mag itself (about 1/4" behind the rim). The previous cartridge had ejected normally, and the next round in the mag was in a normal position in the feed lips. It just froze to the rear. I dropped the mag, pulled the slide back (it was already all the way back, so basically just applying pressure), and released it as normal. I cycled the slide manually and could not recreate it. The mag was inserted, slide racked, and fired another round. Same malfunction.... Slide frozen to rear, slide stop not engaged, no mechanical interference to be found. Firm forward pressure on the slide broke it free, and it went into battery. I stripped the gun, and found no foreign debris, damage, or any other reason the slide could be sticking. I still could not recreate the malfunction by manually operating the slide, even aggressively. I loaded the remainder of the mag, and shot through it all without issue until the last round. The slide locked back as normal....but the mag would not drop free, and the slide stop was frozen in the locked position. The mag could not come out even with me pulling on it with decent force. The magazine release was overly stiff, and would not spring back to center. Looking closer at the open slide, the follower had jumped over top of the slide stop tab and bound everything up.
(normal)
At this point I gave up on my FNX. It was obvious it wasn't liking the stuff AT ALL. This pistol has NEVER (not ONCE) malfunctioned on me in the 1500 rounds of standard pressure Ive put through it so far. I also have never seen a malfunction like either of these in ANY pistol Ive ever owned or shot before. If one of these pistols would have eaten this +P like candy, I figured it would have been this FNX.
One magazine into the 1911, I had a bolt-over-base malfunction on the last round. Again, the first BOB malfunction Ive ever seen in this pistol, and the first malfunction Ive seen in this pistol in years (since it was new/ break in). I ran another handful of mags through it with no problem. There was slight evidence of firing pin drag on the primers though. Again, something new for this pistol.
The XDS....the one pistol I figured would be intolerant of this deep dish hollow point +P......ate it up like candy. In all 3 magazine sizes (5, 6, and 7 round variants) it cycled flawlessly in around 100 rounds. Recoil was on the verge of being unpleasant, though I consider myself to be very recoil tolerant. Im sure in less seasoned hands it would be perceived as excessive. It reminded me of a .357 through a J-frame. Follow up shots definitely suffer, though are still acceptable in speed and accuracy for my personal standards. Again, primer drag is evident (also new for this pistol), and primer flow is about as much as Id want to see on a .45.
Top: standard pressure Golden saber 230 gr,
Bottom: HST +P out of the 1911
Right: HST +P out of the XDS....with plenty of drag and flow evident
In the end, Im rather disappointed in how this ammo performed in 3 entirely different platforms. Though, I believe it has nothing to do with it being HST, but rather +P. No pistol seemed to really like it, sans the XDS (except for the primer drag and flow). Slide velocities on all three pistols are way above normal causing malfunctions, and in the case of the FNX, battering the thing to death (which surprised the hell out of me, being the biggest and heaviest slide). It broke my trust in the FNX, and probably won't carry it again until I get a good string of 200-300 flawless shots out of it with standard pressure carry ammo.
I guess I should yield to what the internet consensus has been on .45, that +P isn't needed, and standard pressure 230 gr is the gold standard of .45 acp. I have since ordered another sample of standard pressure HST, and hope everything works out well with it. I am entirely sold on the terminal performance of the bullet in gel testing, and would REALLY like for it to replace my past favorite (golden sabers).