Now that the election has concluded and we know that the Republicans control both chambers of Congress and the White House, we have some very realistic odds of getting pro-gun legislation passed. Specifically, the Hearing Protection Act (HPA) to remove silencers from the NFA. One of the primary backers of the legislation is the ASA (American Suppressor Association). The ASA is to Title II firearms silencers as the NRA is to Title I firearms. They could use our membership and financial support to help drive the push to pass the HPA. They also have a form on their website that you can use to reach out to your Congress critters about the HPA.
http://americansuppressorassociation.com/hearing-protection-act/

I'm going to join as a life member ($1,000) using their payment plan ($250/year for 4 years). I encourage others to also find ways to support the ASA and support the passage of the HPA. We can do it if we try!

Thanks G4L will take a look at their membership/contribution options.
https://store.americansuppressorassociation.com/

They have one and three year memberships in addition to the life membership options you mentioned as well.

I think they've been pretty active in various state houses working towards repeal of suppressor bans (IA, MN) and also legalizing hunting with suppressors in various states.

Some recent posts by the ASA on prospects for the Hearing Protection Act in 2017!!!
http://americansuppressorassociation.com/blog/