Lots of amateur lawyers in this thread. The OP has a very good and reasonable question. listening to half the responses, I'd expect to see several rifles blow up in people's faces every time I go to the range. They are all shooting the reloads that you wouldn't touch with a 10 ft pole.
There are a lot more people able to do professional reloading accurately and reliably than there are capable of rebarreling a rifle. we don't get people saying it is too dangerous to send that job to a professional.
Clearly use someone trustworthy, either confirmed by personal observation or reputation.
I have used Custom Reloads of Dallas for custom loads several years ago, but do not know if he provides load development services. Load development is a lot of work and it won't be inexpensive.
--Jerry
I am not a lawyer but I read once on this website that if you reload ammo for someone and they get hurt you can be sued for injuries. If someone reloads for you do they ask you to sign a release freeing them from damages?