I reload, and wouldn't consider shooting another persons reloads unless I knew them well and had a VERY trusting relationship with them. But even then, the first few shots would be performed by firing the rifle from my old tire set up. I mount the rifle in a 2X6 clamp rig I made and mount that in a tire with a chunk of 3/4" plywood over the rifle, pull the trigger with a string from about 15' behind the rig. I place a piece of paper over the action to possibly mark signs of escaping gas. I developed this habit when had my FFL and was acquiring many old military relics. I needed to know if the guns fired, if they were blowing gas from the actions, and if they would funtion. If the first few rounds went off without apparent issues on the paper and the brass showed no signs of excessive headspace issues I would then fire 2 rounds from the hip before holding to the cheek. After that, with no issues, I would hold to the cheek. BUT, I did this with my ownn, known ammo. Excellent eye protection is of course needed AT ALL TIMES. Even when firing from the tire jig.
I know this sounds like something that warrants a raised eye, but my grandfather was a gunsmith, and this procedure is what he always did when he acquired undocumented rifles. He performed this religiously unless he had great knowledge that the rifle was safe. That said, he was using his own ammo.
Firing another persons handloads is always an iffy event, and as such it should be considered with caution, even if you believe the person to be competent and trustworthy.
I have made mistakes in loading. Fortunately none of the mistakes were of a dangerous nature. But dangerous mistakes are possible with anyone, even a seasoned and responsible handloader. And I never let anyone fire handloads of mine unless I've fired considerable rounds of a batch myself and know the other person's rifle to be in fine working condition. I feel the same about firing other folks handrolls.
Chuck7, I would have popped a few of the bullets out and weighed the charges, weighed the bullets, and then fired a few in a tire jig or other safety device as mentioned, BUT ONLY IF THE WEIGHED CHARGES AND BULLET WEIGHTS SEEMED TO MATCH.
Glad you had no issues with the loads. And I suggest you get into loading. It is very rewarding. Fun too.
At least you now have a batch of brass!