Threaded Steyr M9-A1 failure to return to battery

[Bret]

I have a Steyr M9-A1 that I purchased new a few months ago. It came with a factory threaded barrel. I took it to the range for the first time today along with 50rds of Speer Lawman 147gr TMJ Cleanfire, 50rds of Federal American Eagle 147gr TMJ NT, and 25rds of Speer Lawman 124gr TMJ Cleanfire. There were no issues at all when firing the pistol without my Ti-Rant 9. However, when firing the pistol with the suppressor attached, I did have a couple of failures to fire. After that I noticed that the slide was not fully returning to battery about half the time. It would end up about 1/8" short. Oddly enough, I could just press on the rear of the slide and it would go the rest of the way forward. I even pulled the trigger a few times with the slide back about 1/8" and it fired. I think that the momentum from the striker might have been putting it the rest of the way in to battery. I then removed the suppressor and with the pistol empty slowly rode the slide forward. When I did this, it would stop short about 1/8". So something seems to be providing some resistance right before it should be going fully forward in to battery. I've used the above ammo in a large number of pistols (with and without suppressors), so I'm highly confident that the ammo is not a problem. Any ideas?

[Dionysusigma]

After ensuring it was properly broken-in, first things I would check are lubrication and fouling build-up. Past those, the only thing I can think of is somehow a recoil spring that isn't strong enough (which really shouldn't be an issue on a pistol this new).

[MStarmer]

Did you clean and lube the pistol well before your range trip? I would say run it "wet" for a couple a boxes without the suppressor and break it in.

[Bret]

The brand new pistol was not dirty at all. It did lube it up.

[GNXII]

I know you wrote you were confident in the ammo but, at least try some different manufacturers 115 or 124 gr loads that are a little hotter (NATO Spec perhaps) and, before that, maybe some more unsuppressed rounds to thoroughly break the M9A1 in as suggested by others in the thread. I had an early M9 and it was finicky with 147gr loads initially but with 115 and 124 weights no issue. After about 400 rnds of 115-124gr ammo it ate the 147gr no issues. This was all unsuppressed, btw. Good luck and enjoy!

[liontribe]

I have read they can be finicky when suppressed. No first hand experience, though.

liontribe

[balance]

I then removed the suppressor and with the pistol empty slowly rode the slide forward. When I did this, it would stop short about 1/8". So something seems to be providing some resistance right before it should be going fully forward in to battery.

This is normal on striker fired pistols with precocked strikers. The last bit of slide travel when the slide returns to batter is going to have the recoil spring "fight" against the striker spring, which is cocking the striker in the opposite direction that the slide is traveling in.

I know Walther and H&K came out with stronger recoil springs to run the PPQ and VP9 reliably suppressed.

[Bret]

I shot 50rds more through the pistol using 25rds Winchester 124gr FMJ NATO and 25rds Speer 124gr TMJ CF. The slide went all the way forward after every shot. I'll clean the snot out of it and give it another try. BTW, I checked my Steyr M40 and Steyr M357-A1 by manually easing the slide forward on each to see if it would stop before going all the way forward. The M40 never stopped prematurely at all. The M357-A1 would stop about 1/8" short of all the way forward about 2/3 of the time. It did this with the magazine in or out.