Ya know....Acetone is used in all sorts of stuff...including cleaning carpets...
what are the chances some was on the carpet that was put into the safe??
The decomposing butt pad is one of several Sig 556 rifles thatt are stored under identical conditions and all are in contact with the same carpet section. The other Sig rifles show no signs of decomposition. I couldn't detect any chemical in the carpet or on the wood floorboards beneath it. This issue has been identified by at least one other Sig rifle owner. I've seen a lot of rubber products dry rot over time but not one fell apart in tacky little bits & pieces.
I'm still waiting on my shipping box to return from Idaho so I can send this on to Sig.
It might have been nicked by a Alien disintegration ray gun during my last tinfoil hat party. Lol
There has been a big problem with rubber on boot soles also, I have run across several , maybe as many as a dozen or so high end boots that look like new but have been in the closet for a few years, upon first glance they look great, but as soon as you wear them and kneel or flex the soles they crumble and break away from the boot altogether. My theory is the Chinese had a bad run of glue and / or rubber some time back.
Chinese rubber and plastic products have been the subject of failure and giving off foul odors for over 15 years. Their tires are probably the best known problem. I don't know where Sig sources the rubber butt pad.
My best guess: "RUBBER REVERSION" ! Though the term may not be familiar, many of you may have encountered it in various stages if you handled a previously "cured" rubber product that changed to have a tacky surface. That tackiness is the early stage of breakdown! It will continue to degrade loosing structural integrity and elasticity until the structure crumbles. Common on footpads on electronics and items with rubberized/coated bodies or parts. Numerous examples can be found, search: rubber becomes sticky tacky. This is a chemical breakdown as opposed to "dry rot" which is caused by environmental/age exposure.
This can be caused by improper chemical composition or improper curing/vulcanization. Mfr may also select chemical composition based on the intend "Life" of the item/part. Its symptoms are a breakdown and seperation of the molecular structure causing the material to revert to laytex. Rubber Reversion also occurs when aircraft tires skid on ice. The rubber breaks down but stays on the tire as opposed to a runway surface skid that sheers rubber from the tire leaving bald spots.
I don't know if Sig will cuncur with the above cause, as long as they fix it!
I had been reviewing Gov/Mil documents from the 1940s. Several covered natural and synthetic rubbers and componds. Most contained test criteria and devices for testing, inadequacy/ failure of test devices. Within that was the term " rubber reversion" which I was describing as rubber decomposition. With the correct technical term, I could better info.
I think I have seen issues like that with other guns. Maybe Beretta and Remington butt pads it was...not 100%. I see failures in bank equipment like you're describing too. Rubber bumpers in roll out drawers and other equipment just melts.