Suppressed SIG Pistol Backsplash?

[boricua9mm]

Hi folks. Recently took possession of an SWR Octane HD and I'm running it on my MP5 and SIG P239. For understood/obvious reasons this introduces a lot of carbon and particulate backsplash into the host firearm.

When running the Octane on the SIG P239 I noticed a significant amount of backsplash on each shot fired. I am using a factory metric threaded barrel and Fiocchi 158gr FMJs, which appear to use .38SPL bullets. I've been running the can dry, but I get a significant amount of gas, carbon and grit (unburned powder perhaps?) back in my face on each and every shot. I wear eye protection, of course, so it's not a big deal at the range.

From what I've read this can result from several factors; host firearm, ammo, suppressor design? Of course the SIG P-Series has a large cutout in the back of the slide for the ejector (unavoidable with the design) and I assume this is where the goodies are spraying from? It's kind of curious since the larger 226 is considered one of the best suppressor hosts, yet lots of folks mention this with the 226 as well. I've shot suppressed Glocks and HKs and did not get peppered the same way, but of course those were all different host-suppressor-ammo combinations.

WOuld shooting the can "wet" help at all? General thoughts? Experiences?

 

[Chopdoktor]

Shooting wet will give you a filthy sewer-water-looking blowback instead of a dry one, as well as a lot more steam/smoke, so keep that in mind. It may cut down on the gas, but you'll get a gross carbon-infused cocktail splashing all over.

Maybe try going to heavier guide rod spring, in order to keep the breach closed for longer, forcing more gas out of the muzzle instead of into your face? I swapped in a .40 caliber spring on my Glock 17, and the blowback is quite minimal with a Thompson Machine Isis. Just a thought. Good luck!

 

[NG VI]

Glocks before the 4th generation used the same recoil spirng assembly for 9, .40, and .357.

Is it a 4th, or are aftermarket non-captured recoil assemblies available with ratings separate for each caliber?

 

[Chopdoktor]

I was running an 11lb spring in the 9mm, before, which cycles fast but unlocks too quick for suppressed use. I have a kit with various weights from Wolff Springs. The stock Glock 9mm/.40 spring is a 16 or 17lb, I believe, in a Gen III. I should have mentioned that; good call. Anyway, I am sure there are various spring weights available for the Sigs, as well. I think mine were only 7 or 8 bucks a piece...cheap enough for some experimentation.

 

[NG VI]

I should've thought of Wolff, I had some of their springs for my CZs 97B and 75D PCR, they make great springs.

 

[boricua9mm]

Follow-up

I ran the SIG 239 again this past weekend, this time the SWR Octane was cleaned and I shot a mixture of Fiocchi 158s and Federal AE 147s. The Federal loads had much less of a sandblasting effect. I could still feel it, but nowhere near as bad as the Fiocchi 158s. The Federal ammo was also much closer to the point of aim, whereas the Fiocchi 158s were impacting about 5-6 inches low at 10 yards

The first outing, I had shot 200 rounds through the suppressor using the MP5 prior to switching it over to the SIG pistol. The booster housing was pretty filthy at that point in time. Last weekend's test seems to show that a cleaned back end along with different ammo yields much better results with far less back spatter. For now, the SIG P239 is running great with the Octane, so I will not mess with the spring weights.

 

[rjrivero]

That's an elegant looking rig!!!