Just acquired a Dan Wesson 1911 after swearing off 1911's a while back. Only large pistol primers I have are 500 (5 boxes) of CCI 350s. Can I substitute safely? Concerns? Suggestions?

You can, Just be aware you may have to back off max loads when using the magnum primers. Accuracy may not be as good or it can be better, Only trial will tell.
I have used CCI 350 magnum pistol primers in some of my rifles with good effect. Just watch for pierced primers when used in a rifle. I've used them for range shooting in my rifles due to I have a lot and not that many standard RIFLE primers.

Hip

Thanks Hipshoot, For me, handgun reloads are for practice only, and therefore never close to max. Of course semi-auto's need to cycle reliably.

Yes. You'll never know the difference.

Agreed. Done it many times during primer droughts

cut back a couple of grs. and work back up, usually one gr. is the difference, but be safe and cut two then go forth if you must...SAme advise for rifle powder between std and magnum..In many cases however its not necessary as the mag primers in rifle seem to raise pressure about 2000 PSI.

I recall on my first mod. 29 44 mag. running out of std pistol primers and substituting mag primers back in the day..all the cases came out trimmed and ready but only half as long at they were before I shot them..sticky cylinder too but hammered it open with my holster end...I came to the conclusion it was a good practice at all!! I noticed also the double action trigger pull was about 5 lbs. harder than usuall...Be sure and test a cylinder full at home..