Rugers are known for tight champers. I'm not hating on Ruger, I'm just saying that they are known for tight chambers. You might want some evidence, so, to wit:
In Cowboy Fast Draw, Belle ad I own several .45 Colt revolvers. Pietta, and Uberti in several flavors, and a couple of Ruger New Vaqueros. We bought some laser cartridges for practice, ad while they'd work right out of the bubble pack in the others, in the Rugers they would't completely chamber. The fix was simple, with an emery board, reduce the case mouth just a bit ad the lasers would fit the cylinder.
I load .308 Win for several rifles. My daughter owns a Ruger American. Ammo that will fit in the Savages or the Remingtons will chamber very tightly in the Ruger. I've learned to seat bullets for her rile just a bit deeper, a hair under SAAMI length for best chambering in the Ruger.
We have a couple of old Ruger Model 77s in .25-06. Likewise, tight chambers.
Which brings me to my Ruger LCP. Nice little gun, but factory ammo simply will not completely chamber. The slide stops ever-so-slightly before going fully into battery. I suppose I could find a suitable mop, fill it with jeweler's rouge or valve compound and polish the chamber, but I'm loathe to do that.
My preferred solution is to take a few minutes and run the factory ammo through a Lee Factory Crimp die. A while back, I loaned the Elsie Pea to a friend to try out, and later got it back. Recently I learned to my horror that I was out of ammo, so I stopped by the store to pickup another box. Good, hollow-point ammo. And, I spent 15 minutes at the bench.
In just a few minutes I had run that bx of ammo through the die and filled the magazines. Everything works, ad we're ready to drop the little pistol into my pocket come springtime.
Rugers have tight chambers. It's a good thing to know.