No issues with the many rounds of 45ACP I've fired through mine suppressed or unsuppressed but its a factory IMI UZI. Check your welds if you're worried but if it was rewelded they likely did a good job and it will hold up for it's average life expectancy.I have a full size uzi the back of the receiver has been rewelded by vector about 8 years ago my question is does shooting 45acp in it harm the receiver more than 9mm