Thanks Greg, was well pleased with that day!!
You may need to wear the barrel in a little more mate, as 100 shots isn't alot, although these big bore wind suckers do foul up quite quick.
I fire through a few roll up *** filters when I notice the accuracy drop off and give it a good pull through every couple of months and then a zero session should have me back to tip top accuracy.
Maybe worth giving your barrel a pull through to get all the muck out and then have a zero session to see what accuracy is like. When you about to re-charge your buddy bottle fire 2 or 3 roll up *** filters through and then re-fill to see if that removes excess lead build up but leaves the barrel leaded enough for optimum accuracy.
Another thing is the Ranger regulated??? If not it maybe worth trying different fill pressures, 240, 230, 220, 210 etc to see if that flattens out your FPS curve. Obviously if its a regged gun each shot should be within a few FPS of one another.
Hope that helps some what buddy.