Home made suppresor can experiment

[jtlassila99]

Anybody here make your own suppressor cans at home?

I finally got my ATF Form 1 approved for a do-it-your-self can.

I had purchased this hollow aluminum tube assembly on eBay with plans to fabricate and install internal baffles.

This was for use with my .223 ARs.  I was worried about baffle strikes so I made the baffle holes rather large, close to 9mm.

I test fired this with my 12" barrel .223 AR. It seemed to function well and all bullets hit the target at 50yds in about a 4" group.  I fired 35 shots rather rapidly.  After shooting, the suppressor was smoking hot.   

As to sound, it was quieter, but not quiet for sure.  Without any can, the 12" bbl AR is very loud.

Upon inspection, there's some evidence of baffle strike(s). The internal spacers made of .750" square aluminum tubing, 3mm side wall, appear to have been crushed by the muzzle pressure.

Some of this damage is likely due to the short, 12" barrel and the resulting high muzzle blast pressure.

Initial measurements and plan.  I ended up installing fewer baffles to start with.


Internals after test firing:


Note the crushed baffle spacers:


The eBay piece has a 1/2-28 thread for the muzzle.

[rkr]

I've built a few silencers for airguns and rimfires and managed to make some rather efficient ones. First of all those e-bay/aliexpress "silencer" tubes are poorly made and if you put one on a lathe by threads they will typically wobble quite a lot making them useless things unless you straighten them up. Been there done that and only worth it for airguns.

For firearms the best approach is to build a monocore unit that has a shell around it. They can be easily trued and drilled (hole size = caliber + 1.0-1.5mm) in a lathe thus allowing you to use small hole diameter which is essential in making it truly quiet. One good example of such silencer is the old SAK rimfire silencer which is surprisingly good even if the "baffle" design is not optimal.



For the internal design it is useful to have an expansion chamber first that allows gas expansion and then a stack of baffles that slow down gases as they try to exit the silencer. A rather good example of such monocore design is Freyr&Devik as in following picture:


The tube in picture goes over the monocore baffle stack and thus leaves a big expansion chamber in between the silencer shell and monocore (the first big hole in monocore is open to this chamber).

While rimfire silencers work well with all aluminum construction for centerfires you want stainless steel insert for the first baffle or even stainless steel monocore or those hot gases will eat out your silencer after few hundred or thousand shots. When using aluminum it is also a good idea to anodize it for additional protection.

So, a good and easy to DIY basic design would be Freyr type monocore inside SAK type shell construction. I built one such thing for rimfire use and it was quieter than original SAK (as measured, not by ear) while being 40mm shorter. I did have to play quite a bit with dimensions to get the best out of it but that's part of the "fun" of making your own stuff.

[HJu]

In Finland at the moment building cans for firearms requires a gun part building license 149e per suppressor (law says this, some police say non-comercial suppressors are free to build,  this matter has not been tested in court) . Modifying an existing suppressor is legal without any paperwork if one can legally posses the suppressor. So modifying
22lr suppressors is legal, free and fun. Modifying center fire suppressors is legal but not advisable due to the high pressures while using these suppressors.

The interpretation of the law is changing and because suppressors do not have to have any identification marks it might become free to build suppressors for non-commercial use (again).

Anyway Temu/Aliexpress stuff is fine for airguns and maybe .22Lr. Short barreled .223s may burst the whole assembly and aluminium will be eaten away by the abrasive powdet particles in short order.

If you want a long lasting and safe suppressor for a semi-auto 12" AR-15 I would advise to investigate Silent Steel USA and Surefire for milspec-level suppressors. Both have models that can stand to full auto firing and even models for belt fed machine guns. The firearm is going to fail before the suppressors from these companies.