Form 1 questions

Yes, it can be legal to make a silencer. For everything Form-1, from silencer designs that are easily made, to filing forms with the BATF, to 3D modeling. Remember, you must have an approved BATF Form-1 to make a silencer. All NFA laws apply.

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Ekacpuc
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Joined: Fri Jul 03, 2020 9:39 pm

Form 1 questions

Post by Ekacpuc » Fri Jul 03, 2020 11:23 pm

New to the forum, been collecting parts for a build. Will be for a 7.5” 300 blackout. I’m hoping to build a can strong enough to survive supers and subs. I reload so the possibilities are endless. I have some background in metallurgy but not specifically titanium. I understand enough to get in trouble and overthink things.

I have a 7.5” tube made of titanium from diversified machine, some ss cups, cherry bomb flash hider.

First i planned on a 2” blast tube and the possibility of a stainless first cone (blast cone)with titanium for the rest. My question pertains to the expansion rates between the metals. It’s my understanding that titanium expands almost twice the rate as stainless. With the only stainless in the can being the blast baffle (blast tube is titanium) is there much of a worry of anything getting damaged due to expansion? My thinking is since the stainless expands less the cup stack will loosen up. What I’m not sure about is since the tube will see less heat than the cones if it’ll expand enough to allow the stack to loosen vs the titanium cups expanding a lot causing excessive pressure against the ss. Prob overthinking but don’t wanna damage the tube as it’s the part that’s registered. I intended all titanium as I’m also building a 9” stainless can too but with such a short barrel it is my understanding that while grade 9/5 titanium will take more heat than SS (304) the ss is more abrasion resistant.

Next where is a good source to figure out muzzle pressure? Iirc based on a source I can no longer find the 300aac running 1800 FPS is about 13k PSI.


Any ideas on how much the space between the cones influence turbulence? I saw someone used a program to figure it out but I couldn’t locate the thread again. Still looking.


Is there going to a be a big difference between grade 9 and 5 titanium for cones? Was thinking radial. I’m not good enough to machine my own so I’m stuck buying my own. For now... I have access to a machine shop and have been tinkering with the lathes and mills.


Might be it for now. Thanks if anyone can provide any answers.

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mcrump
Senior Silent Operator
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Joined: Fri Aug 07, 2015 3:36 pm

Re: Form 1 questions

Post by mcrump » Wed Jul 15, 2020 10:00 am

Low pressure configurations should be different from high pressure configurations both in type of baffle, length and baffle spacing. You would be much happier designing two suppressors, each dedicated to the host rifle.
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748
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Joined: Mon Aug 06, 2007 11:58 pm
Location: Anythinggoes, NM

Re: Form 1 questions

Post by 748 » Thu Jul 16, 2020 8:09 pm

Pistol usually have big blast chamber, one reason is for a recoil booster.
RiflesGo Straight into cones or baffels.
I had a much longer post about titanium versus stainless the bot check deleted it.
So much has changed since my last form 1

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