ShipScript has been an eBay Community volunteer since 2003, specializing in HTML, CSS, Scripts, Photos, Active Content, Technical Solutions, and online Seller Tools.
If you are referring to the programmable bots as drunk monkeys, it might be true that they could be called by any label. If an item is listed in the wrong category, or if the title mentions items banned by eBay policy (like AR-15), the eBay bots/monkeys may remove the listing. Keep in mind that not everyone is skilled in weaponry, and heads-down programmers may be the least skilled in real world trinkets. I would recommend checking the category in which the item was listed to make sure that an accessory is not listed as a weapon.
Oh, and don't consider an item purchased on the eBay site to be immune from eBay policy or future eBay filters. The site rules, and the bots/monkeys, can change at any time.
As a heads-up warning, it seems that once an account has had a listing taken down for an eBay violation, a flag is set to check for future violations, or for attempts to circumvent the violation by using alternative titles. Many of our members recommend abandoning any effort to relist an item that eBay has removed, even if the removal was unwarranted, since multiple violations will result in suspension of the selling account.
If it was this item, and you used the same title when you relisted this ended auction, then the problem may have been that the title implies you were selling a complete rifle, not just a bolt shroud.
I'm surprised that this auction wasn't caught, but I guess they didn't get to it in time. You need to avoid possible confusion like that up-front. At this point, if you change it, it will look like you're trying to do an end run around the ban.
I agree with @shipscript 's warning, that once your account has been flagged, it is likely to happen again. It's better to avoid arguing with the bots, because it's not a debate. They are always going to win.
