"While he was packing I looked at the gun. The only thing I pointed out to him was that barrel was a little loose in the front of the slide and maybe he should take it to the gun shop instead of calling."
Was it loose as in you could move it with your fingers or did it just look like there was a lot of clearance between the barrel and the slide? ¼" seems an incredibly big gap. The space between the top of the muzzle to the slide shouldn't be more than 1-1½mm. The barrel/slide lock-up should be very tight and solid when in battery. It should be very difficult, if not impossible, to move the muzzle of the barrel around when the slide is fully forward. Maybe there really is something wrong with his particular SIG.
The hole for the barrel at the end of the slide is a bit big as compared to the barrel itself to provide some clearance when the slide retracts under recoil and the barrel tilts. There is no barrel bushing.
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It just hit me, were you examining the barrel with the slide locked back or fully forward? If locked back, the barrel will seem to be 'loose'.