I have been trying to "tighten" up the groups I was getting w a new to me '03 Sporter clone. In general, I was getting 2.5" groups at best. Some of this was the shooter getting used to a new rifle plus experimenting with the bullet, load etc.
I have had excellent results with my other 03 rifles with 311284 and 16.0 grains of 2400 without fillers, but while I was getting grouping in this rifle, I thought it was capable of a tighter pattern. To make a long story shorter, I had read a comment by Larry Gibson that he considered fillers anytime the load density was less than 80%. I'm working from memory here Larry, I hope I got that right. So I tried it today, and the targets above show the result of a 10 rd string at 100 yards ( first target is after the first 5, my spotting scope wasn't giving me a good picture of the group so I took a walk down range). fwiw I was shooting iron sights, Lyman 48 rear and a 17a front w aperture.
Even w the flyer I am happy with the group, you can literally cover the 9 shot cluster with a quarter. This is the best group I have shot to date with any of my 03s.
The only thing different in the load today was that I used a 1.0 grain dacron filler...
installed per Larry's and others instructions in the sticky on fillers and related post comments.
The load details are:
LY 311284, Rotometal #2 alloy, sized .310 (nose measures .300)
2500 lube
LC 68 Match brass, neck sized
WLR primers
16.0gr 2400
3.26" oal (bullet seated out to the edge of the first grease groove)
Now I have to get back to my NOE 311291 and find the best combination for it.
I find fillers tedious to make and install, but after today I'm convinced they make a difference.