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Project: Creating a High-Capacity .380 ACP Handgun Supressor Host (Plus a discussion on why 9mm is impractical for suppressing IMO)

1399 Views 8 Replies 3 Participants Last post by  Philipl

Below details the project I undertook to make a reliable/comfortable supressor-host in .380 ACP (natively subsonic); with doublestack capacity

The posts below (other than the 9mm discussion at the bottom), go through my posts chronologically: they show my intial purchase-research phase, purchase, spring-research phase, and spring-testing phase; and do so in the order they were posted originally

I am compiling my posts from to show on here (my more native forums). The rather creative modifications (at least IMO, since there are ZERO after-market ExtraPower springs available for taming the excessive recoil on the straight-blowback Bersa), have made my new "Bersa TPR 380 ACP Plus Threaded" into a 100% reliable supressor-host, that now shoots very smoothly (whoch is entirely thanks to using the heavier Walther PP springs, thay are the same length & coil count as rhe Bersa Thunder/TPR series, but with much greater spring-weight).

More to come as I edit this post with the info!

Part 1: the Order, Purchase, and Planned-Upgrades from BersaPistolsForum

EDIT: I received and upgraded my Threaded Bersa "TPR" 380 Plus (thats 15 + 1 rounds of .380 ACP, which SUBSONIC by nature):

Air gun Trigger Gun barrel Airsoft gun Gun accessory

Does anyone have a picture of the TPR 380 Plus 15rd in "matte finish, silver" and a threaded barrel? If you Google for the model, not one site has an image for it - including where I ordered it from.


Model: TPR380PMX

Bersa TPR 380 Plus
Metal Frame Pistol
380 ACP
3.5 Barrel [Wrong its 4.3" when threaded]
"Threaded Barrel
Matte Finish
Silver [Wrong, nothing silver on it - that's kinda F'd]
Adjustable Rear Sight
Manual Safety
15 Rounds
1 Magazine
UPC 810083200484

Apprently I bought the last one at
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Note: I own a TPR9c, but bought it when the6 didn't offer threaded barrels. Plus most 380 ammo is SUB-sonic, and I wantes something to shoot with a can for as cheap as possible - subsonic 380acp are 30 cents a round currently on Ammoseek so I bought this... apparently it was the last one in stock.

[EDIT: I have removed most of the speculative images of what I thought it would like]

Mine is clearly the "Matte Black" version of the following TPR 380 Plus, but with a threaded barrel as well:
View attachment 2410
Air gun Trigger Gun barrel Everyday carry Gun accessory

But I really want to see or hear about someone else who owns a Threaded "TPR" Plus, or "Thunder" Plus... someone here I am sure has one.

NOTE: The threaded Thunder/TPR actually 4.3" barrels, not 3.5" as on the non-threaded ones.


So the gun worked 100% reliably woith ZERO failures... and that's from trying it straight out of the Blue Bersa box it came in.... and came practically un-oiled as far as I could see. I used 91 grain Tulammo, 95gr Winchester, 75gr Carbon City, 70gr Federal American Eagle Lead-Free Range.... but I have some issues with it, see below past my upgrades section.

Upgrades Completed and Future:
  1. ArmaLaser TR29* grip-activated laser sight (lets me sight rapidly if a can is installed) [installed]
  2. Elongated Thread Protector from Downrange Products LLC (aesthetic) [installed]
  3. Walther PP 18 LB Spring from Wolff springs ( [installed**]
Air gun Trigger Gun barrel Airsoft gun Gun accessory

[**SPRING UPGRADES WILL BE TALKED ABOUT IN NEXT PART] only complaint was that the recoil was snappy/painful, so-much so that the beaver-tail rubbed skin off the web of my hand. I am going to upgrade the springs using Walther PP (not PPK!) either 17lb or 18lb extra power springs. In all my past "straight-blowback" guns that were too snappy, recoil springs have made a HUGE difference (they don't have as much effect, IME, in locked-breach). However I'll be posting those details into the Topic that already exists on the subject.*

*Existing thread: "Looking for the factory recoil spring weight for the Bersa Thunder .380"

Side-Discussion About Suppressed 9MM


9mm Parabellum is a poor caliber-choice for use with a supressor

Only does 9mm Parabellum become supressor "viable" when used specialized, overweighted bullets - the fact that you can't just use standard 9mm ammo you to obtain acceptible sound-supression, I feel should steer people towards natively subsonic handgun rounds like 45 ACP and 380 ACP.

The fact that 99.99% (literally) of 9mm ammunition isn't subsonic, and not truly supressible, makes it a poor choice for suppression in my strong opinion (lest you have an integrally-ported barrell, enabling acceptible suppression via bleeding propellant that thusly slows the projectile. But the fact you require that for suppressing 99.99% of 9mm, means 9mm really isn't a supressor-friendly calliber by nature ...and a barrel ported as-such is something obscenely uncommon).

However, there is a 9mm calibre readily available that IS and ALWAYS has been subsonic in 99% of its loadings, and requires no specialized ported-barrel or over-priced special subsonic loadings, should make it an obvious choice as calibre for a supressor:

9mm Parabellum's smaller 9mm cousin, .380 ACP, is IDEAL for suppression. 380 is subsonic in 99% of ita loadings when 9mm Parabellum is NOT subsonic in 99% of its loadings (by my rough math 99.99% I am adding this project of mine, from the Bersa forums, here to discuss something I feel does not get the discussion it deserves, and now can be addressed thanks to newer threaded 380 ACP handguns that do have 9mm diameter projectiles, but in a TRULY and natively subsonic calber - even in 5 inch barrels a non "+P", and non ultra-light 380 will be subsonic:
380 ACP Results in fps (2010)
Click here for a Muzzle Energy graph for the tests in this caliber.

barrel length​
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This is a post where I rebute one gentleman's claim that the Walther PP springs can't be used - posted on (the sister site to

Addressing the original question:

"What is the weight of the stock recoil spring in the Thunder 380?"

My very rough estimate would be 13 lb.
For a straight-blowback, at least in my opinion, it's recoil-spring is quite under-powered. I think they wanted to avoid the difficult slide-racking that guns like the PPK can have. That's also why they went with a spring that is much longer than neccessary for the frame - which is also why a Walther PP (a much longer gun) has spring that fits in the Bersa and has the right amount of coils.
I just got my new Bersa TPR 380 Plus Threaded - see my post on it here. But I too noticed that recoil is quite snappy, even for a straight blowback. My Makarov never had this much recoil (even before I replaced its recoil spring), and it was in a stronger caliber.

My cheapo Hi-Points also don't anywhere near the felt recoil in the Bersa TPR.

Indeed, as I posted in my new gun thread, the TPR's beaver-tail is literally rubbing the web of my hand raw from both overly-hard impact of the spring, and the un-rounded edges on the beaver-tail. I may smoothe those down, but there is a simpler fix I can user first.

I am going to do what I did with my Makarov, and upgrade the power of the recoil spring to reduce felt recoil. IN straight-blowback designs, increasing the recoil-spring strength is VERY effective at reducing recoil, far more so than in a gun with a locking-action. But you may ask, where am I going to get these springs?

And though indeed it is true that neither Wolff, nor anyone else, sells springs specfically for the Thunder/Firestorm/TPR 380; IIt is also true that Wolff does make springs for a different gun that works perfectly well in the Thunder 380 line - this is confirmed by numerous accounts all over gun forums on the internet, with users stating as much.

So which Gun's recoil spring is it that works? Well, its same recoil spring that this topic's creator mentioned. INdeed multiple forums across the web reveal that the Walther PP Springs (not PPK) work perfectly fine in the Bersa Thunder/Firestorm/TPR 380! And yes, this allows you a way to increase your spring-strength and reduce the felt-recoil in the Beras Thunder 380 line.

Here is one of many threads about this

(I'll add more if anyone feels they need more evidence)

This a post from circa 2017 where you can read an account of the Walther PP springs compatbility with Bersa Thunder 380 (The BOLDED text is my emphasis):

(The BOLDED text is my emphasis):

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I have a post on here somewhere awhile back, talking about them. Not a post I started just commented. What I had trouble with was snappy recoil. It hurt the top web of my hand, and others that shot it as well, not just me. It wasn't hammer bite, because it has a large beaver tail. It was from the beaver tail being too long, actually. And a softer recoil spring than it needed.

So I liked the thing enough I wanted to help it. So I trimmed the beaver tail down shorter, flush with the back of the hammer when cocked, with a cutoff wheel. I then nicely contoured it with a file and sander to blend it all back in to look factory.

I also tried a factory replacement recoil spring in case my factory one was faulty. Nope, they were the same and both in my opinion too soft.
So no aftermarket ones are available, so I found an application close enough to work. The Walther PP "larger" 380 has an aftermarket Wolfe spring available that is heavier than the factory Bersa one. Its slightly shorter and smaller diameter, but it works. And it softens recoil a fair bit, with still being reliable. This lessens the shock to the frame from the slide, and will help the frame last longer.

These two mods were definitely helpful to reduce the recoil, and make it more like what I felt it should be given the cartridge and weight. And its not that I'm that smart, I'm just posting this because I could find literally nothing to mention about these mods or reducing the recoil from these things.

Plenty of BS out there though if you ask about reducing recoil "its only a 380, blah blah" well I'd say most of the tools posting that never actually shot a Bersa side by side with a different make 380 to compare, let alone figure out how to fix it. I'm talking about making them suitable to run a few hundred though at a time for practice, like you should be able to without causing nerve damage over time hahaha

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No promises but I'm pretty sure its this one, the heaviest 18lb one that they offer that I used. And there is a total lack of aftermarket thin grips for these things that would be really nice too. Some plastic checkered or aluminum ones would be sweet.
The Concealed Carry model is the replacement magazine I believe that has the shorter base plate, but still works and holds one extra also

Here is my new gun and the updates thus far (see my post about it) Once I have tried out the 16 lb ,17 lb and 18 lb Walther PP springs, I'll report back on which worked best!
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My is follow-up post on BersaPistolForums reporting on which Walther PP spring worked best, and detaling one modification that was necessary

WOW, it made an AMAZING DIFFERENCE!!! And honestly, I think this change is vital if you are going to run a can on Bersa 380, IMO.

Your mileage may very, as I would guess it voids your warranty. As such I can't give this as a recommendation as something to do, I can only say it worked great for me - though one one additonal change (a super easy one thoygh) had to be done.

HOWEVER, I had make one mod to the last coil on the Wolff springs* - of which, the 18lb one which has tamed the recoil AMAZINGLY made one change. I tried all weights and the 18lb worked 100% and reduced the recoil the most, unsurprisingly.
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tried the 15, 16, 17 and 18 lb springs by the way (As shown above), just to see which worked best on my gun. The 18lb was the best for my gun. Again other people's moleage may vary, bit this matches the reports I have seen elsewhere.

*As stated though, I did make one other change: For some the very last coil on ONE end of each Wolff spring was too small to get onto to the barrel, I don't why they made the last coil that way (Edit:any theories on why I'd like to know...its not like the type of springs that get cylindrically wider on one end, but its just one coil - afaik the Walther PP doesn't need this one tighter coil). But for each spring all I had to do to fox this to take a pair of pliers or two and just losen the last coil and a half a little use force to male the coil imperceptibly larger (bit as little change as it took, it was was enough to the last coil onto the barrel and allow me to compress rhe spring fully without issue - though as others have stated, the springs are tighter on the barrel and you have to kind of work thr onto the barrel the very first time you install them)

Once fix the last coil one end that is to tight, I suggest using a little force to slide the spring onto the barrel, and then yse the slide compress the spring partiall a few times. Then I was able to fully compress the spring on the barrel (as far as my strength would allow, but it not fitting issues after I loosened the last coil).

The only other challenge I had was getting the slide back on the very first time, but it turns put I was just doing wrong as I had with the original-sprong before - for me it sometimes hard to get the slide back on the TPR 380, with both the original and new spring.

I am honestly amazed and the reduction in felt recoil, and as stated, I think this strength spring should mandatory if you are running a can!

I honestly wish I only bought the 18lb spring, not the 15, 16, and 17 lb springs as well... but it was an experiment, and it turned out GREAT!

Admittedly Wolff springs are slightly tighter on the barrel, which could increase friction over time, but so far the spring hasn't even worn off any finish off the barrel, so I am not concerned about that - and I expected that going in, as everyone else on the web had posted that.

Again, this is just my experience and opinion, nothing more.

EDIT: By the way, this is what I was shooting with 100% reliability with the Wolff 18lb spring. The 100 grains are a good choice for guaranteed subsonic out of the longer 4.3" threaded barrels, just fyi
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Exciting project; you've put a lot of thought into this! Thank you for sharing!

The fact that 99.99% (literally) of 9mm ammunition isn't subsonic, and not truly supressible, makes it a poor choice for suppression in my strong opinion
I need to question this premise upon which you based this project, that 99.99% of all 9mm ammo is not subsonic. I guess my question revolves around the 99.99% number. With millions of 147 gr 9mm rounds manufactured every year, how does this factor into this percentage? 147 gr 9mm is subsonic and, during regular times, is as readily available as the other 9mm rounds.
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Excellent question/point!

And yes you can find subsonic readily availble online, thats true, but if you want to use and throw in any odd defensive or random FMJ round in your supressed 9mm round for any reason - you just don't have that convenience that a supressed 380 offers. And sadly the supplies of subsonic defensive HP ammo are both limited and stupidly expensive in 9mm. And the supply of 147gr 9mm in brock & morter stores is almost always sold out, at least in metro area (if the stores even carries subsonic 9mm at all - which is also something I find a problem at gun stores... though that is getting better).

And I do think my percentages are likely accurate. It's just that for 380 ACP, its going to the the case that literally 99% of 380 ammo of any type (defensive or FMJ) is subsonic; and its available from any source, be it online or in-store (at any price), and will always be available anywhere 380 ACP is sold (aka anywhere 9mm is sold) - which is quite contrary to subsonic 9mm, which finding in-stock in stores is unlikely, in my experience - and when found online you pay a signifigant premium for subsonic 9mm.... and you will be hard pressed find subsonic hollowpoints near normal hollowpoint price... if you can them at all. While subsonic 380 Hollowpoints are just normal, and as such there no premium on them.

In fact except for the on the one affordable custom load I found on ammoseek below, which is made from sketchy handloader coatings (stuff normally used for coatings on homemade cast-lead bullets), that ypu dip and dry bullets in (I am not a fan of said coatings), you end up paying more than you do for .380 ACP FMJ when you order subsonic 9mm FMJ (feel free to verify this on ammoseek)

However I appreciate your bringing point, because this is something worth discussing:

...I need to question this premise upon which you based this project, that 99.99% of all 9mm ammo is not subsonic. I guess my question revolves around the 99.99% number. With millions of 147 gr 9mm rounds manufactured every year, how does this factor into this percentage? 147 gr 9mm is subsonic and, during regular times, is as readily available as the other 9mm rounds.
As stated, using is how came up with the number 99.9%, and even then I am may be underestimating that, considering the number of supersonic rounds in inventory vs the limited inventory of subsonic (as shown on a page). The 99.99% became my estimate for supersonic vs subsonic percentage, as most the subsonic inventories that were listed were limited in supply, while most of the listed inventory for supersonic ammo were in quantities in entire magnitudes greater.

Here for example is the first page of ammoseek-classic for in-stock 9mm ammo, sorted by price per round; on which where you can see the grain weight for each round. This is but a one page example, but look for how many subsonic listings you find on there - this is a sample, but again, if also doesn't even considet how much they have in inventory - note, on the entire list there only 1 subsonic option, and even it, the very cheapest subsonic 9mm listing on ammoseek, has a price approaches 380 ACP FMJ (and the ammo on the page is some sketchy cast lead rounds dipped on a hand-loader's coating - the actual jacketed subsonic costs more than normal 380 ACP FMJ):

NOTE: I had to delete the formatted table and replace it with a screenshot, as the vendor-icons in the table exceeded the "20 Image" limit for a forum post
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Note that there is only ONE single subsonic listing in all of the 100 lowest priced per round 9MM listings.

Additionally that one listing was a custom loading, on which they are useing hand-loader's liquid-coating on cast-lead bullets instead of an actual copper jacket, as one would hope for in non hand-loaded 9mm :
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The fact that the loading clearly had to be custom made, and is only offered in a limited amount, in a minimum order of 1000 rounds, speaks to ther rarity in my opinion...

...They list they have 58 of them available on their website website, though admittedly they are in lots of 1000 rounds. However that is nowhere comparable to the other 99 listings with much, much more quantities available in any quantity you want, and at lower prices without being to buy 1000 round lots of lead-cast non-jacketed coated ammo.

The normal FMJ 147gr+ 9mm rounds cost more than FMJ 380 ACP. And the 380 FMJ is more available in actual stores than subsonic 9mm. So online usually the only place to get subsonic 9mm, in my experience.
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I just finished filming a full tabletop review of the TPR380 PLUS X (TPR380PX) that replaces the Thunder 380 Plus X ( "X" designating threaded) - (the full video's not done yet but the preview video is below).

I talk about the recoil spring project I undertook on the Bersa, and it's resounding success as as supressor host once the 18lb Wolff Walther PP spring was installed.

For now here us the preview video about the new Bersa TPR380 line, particularly my TPR380 Plus X:

Once I edit full tabletop review, I will share it as well :)
Interesting essay.

I must whole heartedly disagree about suppressing a 9mm and about how much of what is out there. Personally we have about 6,000 rounds of supersonic 9 mm and about 1500 rounds of subsonic. 500 of those subsonic rounds are Hornady critical Duty 135 grain 1100 FPS (speed of sound 1150) at 363 foot pounds of energy in a ballistic tip hollow point.

Compare that to your table above (I took 95 grain 966 FPS) which gives 197 foot pounds of energy.

I think I will take my 18+1 CZ 75B 9mm suppressed over any of your 380s.

Many people consider the 300 AAC to be one of the best rifles to suppress. However to properly suppress it one must go from a "native" 125 (ish) grain bullet to 220 grains.

Every time I suppress my 9 or 300 I use heavy subsonic bullets.

The rounds are available for $28.34 a box which is about what I pay for my Liberty civil Defense EDC rounds Hornady Critical Duty Ammo 9mm Luger +P 135 Grain FlexLock Box of 25 (
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Note that there is only ONE single subsonic listing in all of the 100 lowest priced per round 9MM listings.
I believe your conclusion is based on a flawed data set. Please know I am not trying to be argumentative and applaud your efforts. However, I reviewed your list and found at least three subsonic rounds. Remember, any 9mm bullet weighing 147 gr will be subsonic. Also, you are looking at the lowest-cost rounds of the spectrum. A 147 gr bullet weighs nearly 50% more than a 115 gr bullet, which most of the bullets listed in your display weigh. These 147 gr bullets will tend to cost more than the 115 gr, even 124 gr, which dominate the list, increasing the cartridge cost and pushing them to the bottom of your list.
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