Gentlemen, Thanks for all the info and ideas. I won't make it to the range until next weekend but I did drop to the the bottom of the load table to get a round that shoud be moving at 2250 fps. I will also pick up a box of 150 Gr. on the way so we will see if those work.
Mete: The bullets are jacketed Speer's and the bore should be clean. I've scrubbed with with a brush and Hoppes until the patches come thorugh clean. As far as I know that's all it takes to clear up lead fouling but if someone has another recommendation I'll give it a try.
BerdanSS: Based on the serial number this Marlin was manufactured in 1962. The bore looks to be in good shape and I know that since the 70s it has only had a few 100 rounds though it.
The load is to be something light and easy for my daughter to shoot and at the same time reach out a bit (200 yrds) for coyotes.
Tom M: The holes in the paper do look longer than the bullets but it is an illusion. I pushed one of the unloaded bullets through and they fit exactly. the bullets are Speer but they don't appear to be separating.
Rangefinder: I have never slugged a bore but I suppose there is post elsewhere in this forum that will provide directions. I did fit one of these unloaded bullets into the front of the bore and there is enough friction that I can't push it in by hand.
Buzzard Bait: I was supprised as well. The main cluster of shots is acutally from 2 different hold points. The top 5 held on the bullseye and the bottom 4 at the lower point of the diamond. That 4 shot group is just over 2"!! I expected performance from tumbling bullets to be much worse.
Rifleman1776: If I had purchased this it would be on the way out the door already but It came to me through by father and I've got to get this figured out so I can pass it to my grandkids one day.