A few years ago a friend of a friend bought one of these, definitely bulldog brand m4 type, but unsure of model, even though I'd warned him to speak to me before buying anything, he didn't listen, spent about £150 on what was being marketed as a "ready to play starter gun", & then played a few games.
It went bang pretty soon after, I get asked would I look at it, but told him you'd be better returning it under warranty, can't remember the reason he then gave me but apparently returning it wasn't an option, so I agreed to have a look at it, repair if possible, failing that salvage whatever I could.
He drops it round in a bag, remember at this point I've not seen it, & knew nothing about it.
OMFG🤯
It was like a child's toy you'd buy for £15 at an obscure Sunday market, other than being m4 shaped it had nothing remotely like what we would call an m4, even the most basic rifle that the cheapest recognised manufacturers might sell looked like a systema in comparison.
It didn't strip per se, just lots of screws up & down the body, & even though I was disgusted by it & was struggling to control the bile at the back of my throat, I went ahead & took it apart, in the forlorn hope I'd spot something simple that could be put right & not break this fellers heart, knowing what he'd paid.
An hour later I told him to come & get it, handed him his bag & said sorry, couldn't be fixed, when he asked was anything salvageable I pointed that all the little screws were in a sandwich bag, & he might find a use for them one day, but everything else, even the mag & battery, should be binned & if he ever bought again without talking to me first, he was to delete my number from his contacts.
Seriously, they are an abomination & should be banned from all insured sites & buyers neutered, it's the only way to reduce their numbers.