Sorry if this is the wrong place to make this thread but I have been reading for hours on this inquirey and only ended up more confused.
The two firearms I own and wish to use/interchange a single suppressor onto are a Sig MPX wich came with a non folding pistol brace and a 10.5" AR15 chambered for 300 blackout.

How many tax stamps will I need to use the same suppressor on both firearms?
I keep reading different answers to this question which could be because of inaccurate info or outdated laws.

I am hoping the answer is not 3 tax stamps to do this so anyone that knows the answer to this could please advise me how to ensure I am in full compliance with the laws.

Thank you

Not real sure I follow, but the suppressor itself will be registered and require a stamp.

Any lower that is going to hold an upper with a barrel under 16" in length will require its own stamp.

So if you are running an SBR that is ALSO suppressed, you need 2 stamps.

Lots of important stuff you must know about NFA items. Make sure you know what you are doing. You sure would not want to be in possession of anything without having the stamp first.

Hope that helps

What Greg said is true but I want to hit a different angle as reading over your post, I think you are only going to need 2 stamps.

So first, suppressor:
-Get the stamp, you are good. You can switch the suppressor to whatever firearm you like when you like. Once you get the stamp, you are good to go.

300 BLK
-Since the barrel is shorter than 16" overall length you either have to run a pistol configuration or submit a form 1 and $200 tax stamp fee. Once you get approved, then you can purchase a buffer tube capable of mounting a stock. Until approval, do not buy a buffer tube for a stock much less a stock if you already have a buffer tube. Having SBR capable parts (Buffer tube and stock) in your possession while pending a Form 1 is still considered intent if they are not already on another rifle.

MPX
-With the Sig brace you have a pistol so no stamp needed.


So in total, 1 form 1 for the SBR and the form 4 transfer for the suppressor so $400 in stamps.

As said, 2 stamps, one for the suppressor and one for the SBR.

This is all very helpful thanks guys. I am currently setting up a NFA trust and once I get those papers notarized I can submit form 1 which I was told by the company helping me with the Trust should take about 30 days. So thats good news. However even with the trust the form 4 transfer for the suppressor expected wait time is a year or more. I'm really bummed about that. Its hard to shell out a grand and wait a year to enjoy the purchase but that the laws. Lets hope Hillary doesn't make it into the Whitehouse.

Just an FYI the suppressor wait time is closer to 8 months and the SBR is closer to 3 months. Also with the new 41P/41F rules, you'll need photos and finger prints to go along with your trust along with any trustees on the trust. These rules just went into effect I think July 1st maybe it's July 20th not sure.

as of midnight they went into effect

^^^ This...41F is now in effect!

41F

You will need 2 stamps (1 for SBR and 1 for Suppressor).