Form one suppressor build


March 10, 2010, 12:42 AM
So Im getting ready to mail my package off this week for my suppressor build. Ive got a few questions. Is it OK to start buying the materials? I understand that I cant start construction until I get the approval back but I would like to get materials on hand to see what Im working with.

Next. I'm building a .30 cal suppressor. What is the ideal suppressor bore? Im looking at something like somewhere along the lines of .3125/ 7.9275 (5/16) just for ease of materials procurement. Would this be ok? Or do yall think it would let too much gas by the bullet? .30 cal is actually .3091 according to Wikipedia, so this leaves me .0034 margin of error for baffle strikes. Mmmmmm....too close? I guess I could ream the completed suppressor out a little bit if necessary .....


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Zak Smith
March 10, 2010, 01:24 AM
Uhh, by your math (0.3125-0.3091)/2 is 0.0017" per side clearance. That's way too little and unsafe. Remember that besides the clearance you need, you also need enough to handle any runout on the whole suppressor assembly on the barrel.

Also consider that 6.5mm shot through a .30 caliber suppressor still suppresses very well.

Use 0.020" per side (ie diameter 0.040" larger) as a starting point.


March 10, 2010, 03:03 AM
Yeah, I generally go nearly .375" on .30 caliber silencers. You're thinking in FAR too tight tolerances.

March 10, 2010, 09:08 AM
Use 0.020" per side (ie diameter 0.040" larger) as a starting point.

Thank you Zak.


Yeah, I generally go nearly .375" on .30 caliber silencers. You're thinking in FAR too tight tolerances.

Thank you PTK.

Now that thats cleared up, did you guys give any thought to the first Q in the OP?

March 10, 2010, 10:15 AM
My 762-sd is .405" at the muzzle but they do that just to be safe if some hack threaded the barrel wrong. My form 1's are pretty tight but I still have .020-.025" around (for a total of +.040-.050).

You can buy all you want it's just barstock and tubing but don't go making "shot glasses" or anything like that, your too close to do it wrong now.

March 10, 2010, 03:22 PM
Yep, buy materials all you want.

March 10, 2010, 06:10 PM
Yep, buy materials all you want

I really just want to play with machineability of different materials. Maybe Ill make some custom bolt handles for a few AKs or bolt guns out of extra bar stock to see whats easy to work with. No shot glasses though.

March 12, 2010, 07:26 PM
Sweet, this just made my day!

I found this pic on Arfcom looking in the krink forum. Someone wanted to see pics of a "real" krink suppressor and I found this. I am building this suppressor for an AK. Ive been racking my brain looking for ways to pull this off without having access to a lathe. If the reds thought this desighn would work it should be fine for my general use.

I could whip this up in a few hours!

Id like to hear your thoughts on this desighn vs a k baffle design.

Zak Smith
March 12, 2010, 07:58 PM
It'll be better than nothing, but worse than almost any centerfire rifle suppressor currently on the market here in the US.

March 13, 2010, 07:48 AM
...without a lathe, and you figure it'll only take a few hours? Optimistic.

Also, as noted, that is a LOUD can. US tech surpassed that in the 70s with SIONICS silencers.

March 13, 2010, 11:34 AM
Oh yea, Im real optimistic. But Im a good craftsman and have been known to amaze even myself sometimes....ha. Shoot, I silencer like that one up there, I honestly think you would have to not try to make it in under a few hours. (except the knurling)

But ok, thats two no go's for the commie diesgn.Guess I Need to run down to Harbor Freight and start pricing benchtop lathes...........

March 13, 2010, 04:59 PM
I think you should get the best lathe you can afford and have room for. Think of it as a lifetime investment. I am not the one to ask for about advice on whcih lathe to buy, except to say that you will not be well served by a mini lathe. I did not like the one I used. Make sure the bed is longer than the largest sielncer you will ever make, and that the spinkdle bore is wide enough to do some barrel work like cutting threads. The smaller lathes might only have a half inch bore and that is no good for working on most rifle barrels.


March 13, 2010, 08:31 PM
I went and looked at the "best" benchtop lathe Harbor Freight had for $499. Needles to say I was not willing to spend my money on it.

Still scratching head.........

Think of it as a lifetime investment

Trying to convince my wife at the moment

March 13, 2010, 10:04 PM
I went to the local gun show today and theres a guy there that always has a booth set up. Its always full of suppressors and MGs so I took the opporotunity to talk shop with him. He showed me one .30cal suppressor today that I was really impressed with. If my memory serves me correctly it said something like HVT on it. Anyway, It had removable end caps and stacked k baffles. The price was $490. That really got my gears turning.

Anybody got any info on this particular one.

March 13, 2010, 10:50 PM
That's a stupid low price if it's actually a Gemtech HVT; mine cost a couple hundred more.

It does *not* have removable end caps.

March 14, 2010, 12:03 AM
It does *not* have removable end caps.


Ill be going back tomorrow.

Follow up report coming soon.

March 14, 2010, 01:02 AM
I learned more about my limitations recently as a silencer builder. My Browning HP stopped working at the range. I had made a silencer for it a while back, but did not know how to make a recoil booster (linear decoupler). So I made the silencer as light as I could, used a cut down 8 pound spring and exceeded the manual load limit for 147 grain bullets. After about 300 rounds the spring guide is deformed and the slide refuses to cycle at all. Until I can figure out for sure why it happened, I will not be using a silencer on my Hi-power.

On the other hand, my 338 RUM silencer works very well, even if it is made from 3 pounds of steel. I like those bolt guns, hard to mess up. :)


March 14, 2010, 04:16 PM
OK, went back to the show today. The suppressor I mentioned above was NOT an HVT. It said "CGI" on the side, apologies for the mixup.

Coastal Guns Inc.

Needless to say........I bought it. $524 out the door (well, not literally) I got the CGI LRT.

The guy selling them in his booth runs a class III shop about 30 minutes from here so I felt comfortable purchasing from him.

We talked suppressors for well over an hour. He showed me Shurefires suppresors, Gemtechs and AAC and at half the price the CGI was just as solid and well made, if not nicer than most. Obviously it has a lifetime warranty. Removeable end cap was a plus to me even though I know its been said to be not a necessity. I like the idea of being able to remove the K baffles for cleaning so when I get done shooting my AK, Mosin or romAK PSL I can ensure the corrosive residue is removed from it. Mainly it will live on my FN SPR 308.

I still am doing a F1 to build my own, but for $490 bucks I couldnt pass it up.


March 14, 2010, 06:03 PM
K baffles can be hard to remove if fouling has built up after prolonged use. I am finding that out on my 9mm and 22lr take apart cans. They require soaking in solvent to soften the gunk so the baffles will budge.


March 14, 2010, 06:38 PM
They require soaking in solvent to soften the gunk so the baffles will budge.

I would think Kano Kroil might be good for this. I love that stuff. But it stinks.

March 15, 2010, 08:42 AM boggle my mind. You're talking about building a silencer without a lathe (because $500 for a lathe is "too much") but expect to have it A) hold together upon firing, and B) actually sound decent.

How will you get the bore concentric to the threads? That alone is worth the $500 cost of a cheap mini-lathe.

I'm simply stunned at your willful ignorance.

March 15, 2010, 11:40 AM
I'm simply stunned

Cool, because Im actually quite stunning.:evil:

go back up and read a few threads, I ended up buying a suppressror, but thanks for the bashing.

your willful ignorance:what:

I do appreciate your prior advice you gave during the whole conversation though. Ultimately I did end up purchasing a manufacturd suppressor. As far as building one on a form one. Yes, I still am going to be persuing that route. If you'll read post #13 you will see that I am considering purchasing not just a cheap lathe, but a decent one. ( trying to convince the wife part )

this guy makes simple suppressors without a lathe. AND hes using an ARC welder:what:. to install simple washers into the tubes. they seem to work decent.

March 15, 2010, 11:55 AM
Looking at this one:

I could make suppressors AND golfball cannons all day with this one.

I was not "willing" to spend my money on a harbor freight lathe because of the quality of the machine. Id have no problem buying quality equipment.

March 16, 2010, 07:52 PM
Mini-lathes from Harbor Freight are made by Sieg, same as those from Grizzly, MicroMark, and several other manufacturers. They're fundamentally sound, but they DO need some "tweaking" (i.e., some elbow grease!) to bring them up to their full potential. (A good place to get info is Of course, you can buy a similarly-sized mini-lathe from Germany or Austria and you'll probably be good to go right out of the box . . . for 5x - 8x the price and questionable parts and accessory availability.

I'm working on a MicroMark 7x14 right now . . . it's a bit rough around the edges, but I'm sorting that out and am confident that in a moderate amount of time it will be a useful tool.

Of course, a mini-lathe will NOT do the work of a larger machine but not all of us have room/budget for a Clausing, South Bend, or other "name brand" full size lathe. So the mini-lathe fills a niche. (especially when one of the requirements is that it be "man portable." )

A recent thread at the silencer talk forums detailed use of a mini-lathe to build a Form 1 can, so it's possible.

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