In the pre-planning stages, and have a slew of questions...

[mk3guy]

I'll be setting up my trust soon, and would really like try to build a form1 can. Depending where I end up after graduation, I may have access to a modest machine shop, but I want to cut my teeth on a simple design first. My plan is for a simple 5.56 can, using parts from SDTactical, particularly the carbon steel tube and ends, and simple untreated freeze plugs. I've been reading as much as I can on here, and have number of questions, if anyone can help me out.

I understand 7.5" AR is usually not recommended for suppressing due to the blast and gas cutting. With the understanding that it would be a limited life suppressor, would it be feasible to build one from the longer D cell type tube with the steel ends, being that the threads give about 0.5" of contact? I'd be using rockset on the threads. I've only ever run 55gr ammo, and I have no plans on reloading since no one in the area lets you shoot it at their ranges. I've seen videos with full power ammo being used, but never in a 7.5" barrel. Will that make this plan even less likely?
I don't need "hollywood" silence but after years of concerts and drag races without ear protection, I'd like to preserve what I have left in the unlikely event of having to discharge indoors.

I have 2 AR pistols that I'd like to be able to use it on, both barrels already have been threaded concentric to the bore. For simplicity, I'd like to just do direct thread, but in the case of the shorter barrel, would not a brake be a better choice in decreasing some of the damage the baffles might face?

If I decide to do another form 1 in 9mm, can a 9mm pistol can work with a 9mm AR? I understand pistol cans need the booster, and that seems like it would complicate use between 2 different barrel thread pitches without the use of adapters.

Thanks in advance!

[Rich V]

My advice for what it’s worth.


For a 223 a simple 60 degree cone baffle will work much better than a freeze plug and they are not difficult to make. Practice on none silencer parts, make some salt shakers or funnels. Once you have the basics down give the form 1 build a shot.

For a 9mm pistol aluminum is fine for most/all of the parts. The booster assembly should be steel but the rest is OK in aluminum. I would suggest you not try a booster operated can until you have mastered the basics of using a lathe and milling machine.

There are lots of excellent threads on this forum detailing how to design & build good performing silencers. Read up and then ask specific questions.

Good luck
Rich