I came out with these in the mid 80's for guys who wanted to button their piston or compression tube but had no tools. An old customer called and asked me for some and I forgot I use to sell them before the internet days-by word of mouth only.
You get 6 buttons for $6
They run about .250" OD.
Degrease piston or comp tube etc. ( Brown button side too)- rubbing alcohol works fine
Use instant glue only like Krazy Glue Etc. Watch dollar store glue-its often old and no good. (CYANOACRYLATE ADHESIVE)
Glue Brown side down- full coverage of the button. Maroon side is the side you see when installed. Hold 20-30 seconds until glued. Do not over glue. It is no good to set a button on a pile of glue- use as little as possible. Gel instant glue sometimes is too thick.
Sand with 220-320 grit to size required- Fitting it till its snug or somewhat less.
If you have a buffer-use it to size-If not hand sand Maroon side as above.
Works best with wet edge- apply moly or clear tar if its a comp tube.
Thats it- No drilling or milling. Just degrease, glue, hold, fit, and its ready to use.
I put 6 buttons on a .22 R1 and gave up looking for wear after 20K shots. So they last really a long time or forever.
**Sorry no shipping discounts on these. We can not send them in a standard envelope because in the past customers claimed they did not receive them or the USPS tore up the envelopes. Gone is the economy button, seal, and trigger shipping from customer abuse. We use bubble mailers and track the parcels and that is not a simple 40 some cent stamp. It takes as much time, paper and ink to send a few buttons as it does other parcels that are much bigger. Especially when these go to a foreign country with customs forms and the red tape involved.