I have finally decided to commit to building a suppressor and have set aside the funds for the paperwork and materials. Now, I need to pic a design. I've seen the thread on the form 1 designs. However, starting out, there is a lot of information to filter through. So I thought I would give the specifics of my builds intent to get the fastest and best information.

I would like to build a 6" build similar to the $100 designs with weight being a large factor as I want it to be comfortable for my wife to shoot. I would be willing to substitute with aluminum if it would stand up to the pressures. As of now I want to keep it to 6" titanium with a 1.5" OD to be used primarily on an AR15. I know the builds I've seen show the holes drilled for .308/7.62 builds. I could use this on my .308 build and wouldn't mind. But, how will a 6" build perform on a .308?

I'm not looking for "Hollywood quiet" but want to get optimal decibel reduction out of my build and not waste my money. Can you guys provide some input and suppressor designs to meet my budget and build parameters?

Edit: I am also planning a SBR build and had heard that had been several pieces of legislation to remove suppressors from the NFA list. Is there any anticipated action expected on this legislation that could potentially negate the need to submit a form 1? And would form 1 builds be allowed outside of NFA requirements with the legislation, or would it be only for commercially manufactured suppressors?

Aluminum will not hold up to centerfire rifle calibers.

If you're looking for "optimal decibel reduction", as you say, than go a bit beyond 6".
Can 6" aid in suppression, yes.
Will it yield optimal results, no.

Look more towards the 8" mark. Oodles of Form1 designs out there matching your intentions.

Ti won't hinder performance, but will reduce weight, so look into these parts. Just understand, Ti is going to drive your cost up so get a serious budgetary number together. Also, wait times are at a year, right now, so even saving $30/month will get you a respectable budget by the time you're approved.

Despite what the previous poster said, Aluminum is used everyday in silencers all over the world, even for magnum calibers. This being said, they're designed and made by manufacturers. Businesses that have designed and tested, failed, then redesigned and retested. It is not for the inexperienced home builder, especially not with the current retail parts available. One of the main reasons it isn't used in the US is the hoops people have to go through to buy one. The majority of us look at them as a lifetime purchase. Around the world, they're off the shelf items.

One more thing. You don't need a plan or design to start your Form1. All you need is caliber and length, and even those can be amended (yes, caliber can be changed if the making has yet commenced). Put down 30cal and 10". If you build it to 7" just send the ATF a letter stating the permanent change. (after you've been approved)

If I build the suppressor with .308 specs, can I change it to .223/5.56 later and notify the ATF if I were to decide to purchase a .308 suppressor?

If you've yet to build the form 1, the ATF has been known to allow a caliber change. After building, it's another tax stamp. Personally,  I'd leave the rating alone and just build it to 30cal specs. It would be fantastic on 556 if designed for 308.

I've started listing every form 1 build as 22.  No matter what caliber it is, 22 will go through it, and there is no rule about how much clearance there should be/can be between the bullet and the baffle.

Everything is 22...even if it has a half-inch hole through the center.

@eodinert

I have been thinking on this for a month- and it is ingenious.  Not sure why more people don't do this.  I think I will steal this idea.