Hello all, have an interesting question perhaps someone here can help me with. I have a few Browning Hi Powers in both 9mm and .40 S&W and stumbled across an AAC .40 S&W specific suppressor. I figured it would be fun to try out so I got a bar-sto threaded barrel for my .40 Hi Power.

The barrel works great and is magnificently accurate however when I use my suppressor I keep getting failures to feed. Without the suppressor it runs flawlessly. After doing a little bit of research it appears that my spring weight may be too high and many have recommended going down in weight to improve reliability when using a suppressor. I can find a lot of information for 9mm Hi Power running suppressors but none on .40 Hi Power.

So I did some quick math and it seems most people using 9mm Hi Power are going down in spring weight by almost 47%. That would mean for a .40 S&W Hi Power I should be running a 11-12 lb recoil spring....that seems very very low.

Any suggestions from the hive would be greatly appreciated.

Who made the piston; AAC? Is the piston spring fresh, or is it worn? That might be a quick and easy first check. Is the piston the correct one for the can?

If the recoil device and spring are set up correctly, is it failing to unlock/cycle, failing to extract, failing to eject, failing to strip the next round off the mag, etc? There's a lot to the cycle of operations and without a lot more details it's kind of hard to troubleshoot...there's plenty of pressure in the cartridge so I can't imagine that it would fail to cycle, unless you don't have a recoil device on the can, or the spring that generally covers the piston is super weak?

FWIW I have a suppressed 9mm BHP and I didn't have to go to a weaker spring at all; it's still got the spring that Novak shipped it with, which is already pretty over powered...runs just great with any of my 9mm cans on it.

The piston, can and entire assembly was made by AAC. The can has roughly 200 or less rounds through it. It works fine on my Glock 23 and 45 chambered in .40. Zero issues, the only issue is the browning hi power.

As stated previously, I'm experience failures to feed. The Bar-Sto barrel is full supported and has a shallow ramp. This doesn't cause and issue when the gun is fired without the suppressor but once I do its "jam city".

Ok, so just failures to feed? Sorry, I missed that. With a round in, it fires and cycles, ejects, and then presumably gets hung up...where? Pushing the round out of the mag, does it get a 3 point jam, does the round get half way in and the slide just stop, etc?

It's sounding like you need more spring, not less. It needs to overcome the weight at the end of the muzzle when closing the slide. I'd probably look at getting a stronger spring from Wolff? Should be an inexpensive test?

The pistol will fire and eject the spent casing, the next round ends up almost vertical  with the nose of the bullet stuck on the roof of the barrel's chamber and the rest of the cartridge rammed in between the slide, magazine and barrel.

Reading about similar issues on Silencertalk with Browning Hi Power's in 9mm, it was advised to go to a lighter spring. I assume the logic is nothing would hamper the slide going fully reward. Many users on that forum had been of the opinion that the slide didn't have enough momentum to go fully rearward due to the gasses being slowed down by the suppressor.

I don't know if this is correct but apparently it had worked for some.

However, I also read on this forum that the Sig 226 needs a stronger spring when running suppressed in order to prevent premature slide wear.

Please post a picture of your suppressed HiPower...

If it's firing and ejecting, it doesn't need a weaker recoil spring. The recoil spring might already be too weak and can't pull the slide back quickly enough.

My BHP as worked over from Novak shipped with pretty stout recoil spring that they replaced the factory one with (admittedly mine is only a 9) and I've never had a failure of any kind with mine shooting with a can on, with a super stout recoil spring in it.

Try a stronger recoil spring from Wolff. It's only a couple of bucks. While you're there, try a softer one. If you're out more than $10 total I'll be surprised.

Are you greasing/oiling the booster?

My G19 turns into a jamomatic once the piston gets dirty

My 1911 on the other hand trucks through anything not caring.

Go figure

I cleaned up the booster a bit more today. Wish they made a nylon brush that really got in there. I will try again tomorrow. Thanks for all the help.

I've given up on this project.

I've tried a combination of different bullets weight, shapes and sizes. With recoil springs from 22lbs down to 17lbs. This thing just won't run suppressed.

Well, before you give up - how old are your magazine springs?

If they're kind of weak, that might be an issue too...

If you've been using them pretty steadily for years, it's possible that they're weak enough so that the gun will function without a can, but maybe it's just not got enough spring to get rounds up fast enough with a can on it? It's all I can really think of, since you've already verified the can works on a .40 Glock, and you've gone through a bunch of recoil spring weights...

Otherwise, that really sucks The .40 should be a pretty good platform to suppress since 180grs are already subsonic..

Edited to add - if there's any three platforms I'd like to try in .40, it's a BHP, a 1911, and a full Sig 226, which is hopefully nicer than the compacts. I've got a 229 that's "meh" with .40 and .357 Sig, and I've got a USP in .40 that's a little bit nicer but still not great. And a G35 that again - not bad, but not something I'd take to the range for fun. I'm hoping a BHP or 1911 would break that round into the "fun" category for me..

That could be it, when I took the gun to the gunsmith to get my barrel fitted he took the liberty of getting a new magazine and charging me $60 bucks for it. I've never had a problem with any of the original mags but even with his new mag I couldn't get the suppressor to fire.

I wish .40 Hi Power had a different follow I could use because this bar-sto barrel is cut at such an angle it really invites failures to feed. However, in my search I couldn't find any Hi Power followers for .40 that had a more aggressive angle for reliable feeding. Between the boxes of ammo and springs from Wolff, this project is getting a little bit pricey so I'm just going to throw in the towel. The biggest issue, I can find little to no information on suppressing the .40 Hi Power. There is scant information on suppressing the 9mm HiPower but barely any on the .40.

I must be a glutton for punishment. I took out the Hi Power again today and yesterday. I tried the 22lb wolff spring again with some ammo and was getting a failure to feed every other round. Then I tried some Colt solid copper hollow points, I believe they are 155 grains and only had one failure to feed for each magazine. I only tested two magazines so I got two failures to feed but it did feel like an improvement.

I took your earlier suggestion and ordered some magazine springs. Time will tell if these make any difference.