I used my Miroku-made A5, 3 inch two seasons ago. I used Longbeard 5's. I tried Remington Nitro Turkey, Fiocchi, and Federal turkey loads in patterning, all 3 inch, of course. Settled on LBs. Great pattern for my gun. I use my sons 870 now. But I was confident to 45/50 yards with those LBs in the A5. I would have taken a head shot at 50 one day (that's all I could see), but I let my friend shoot him - I had one already that day and my friend was by another tree a bit closer to the turkey. No bragging, but I tested it to 50 yds. and I had complete confidence in LBs in that Browning. Might go back to it. I missed a tom at 8 yards last season with the 870!
I know the sentimental attachment to older firearms, especially those from an ancestor. My younger son insists he will shoot his first turkey with his great-grandfather's Model 12 16 gauge. That's why I carry the boy's 870.
Good luck