I have minor problems with Jamison's brass. I have 400 cases of each, .44-77 and .44-90 - 2-5/8 bn.
Cases are short and rim thickness varies quite a bit. About 40% I could not close the breach because the rims where to thick. This brass was made for the Shiloh.
Like I said this is minor and something I can fix. Short brass by a few thousands is not a problem in my concentric throated lead bullet chambers. Heck the .44-75 Ballard case is 2.5" and I shot some by mistake in the .44-100st that has a 2.6" long case and at shot very good in that rifle.

Base diameter variances are a problem that lead to case separation like I have with Starline brass.
For straight wall cases I'm switching to Norma. I been using it for the .45-2.4 and I used it for the .45-3.25 when I had it and I have not had any kind of case failure short of damages from loading. Norma is very good brass.