I bought an A2 stock. it came with a cap that screws on the buffer tube to keep it all together for storage. that was very handy.
it's plastic. now it's worn out. needs replacement. you can get caps like this but they are metal and cost like 25 bucks. anybody know of a common bottle cap that works this way?

it's plastic. now it's worn out. needs replacement. you can get caps like this but they are metal and cost like 25 bucks. anybody know of a common bottle cap that works this way?