Just thought I'd share a heads up. I purchased a stainless 4003 sized tube along with caps and wrench for a subsonic 50 BMG form 1 project from gunthreadadpters.com and received nothing weeks and weeks later. Numerous attempts have been made to contact the owner with zero response. The website DID however charge my debit card back in mid May. Not sure if he's still in business, but the website has been updated in 2018, and the card processing is still up and running! I should have known when I didnt receive a response for a request to add 2" to the length. Thankfully, I had the smarts to not file the form 1with his listed specs before having all parts in hand. I will now have to try to recoup the funds with a claim through my bank. Be warned...if you purchase form 1 parts from gunthreadadapters.com, YOU WILL NOT RECEIVE THEM!
Stay safe, everyone!