Problem with Savage LRP

[rmkey]

I agree. Yes I ran the powder ladder with H4831sc and found best groups about 1/2 grain below Max in the manual. I did the seating with bullet at .010, .015,025 and .030 and it seemed .015 was best off the lands. This was with Berger 140 VLD. Then I moved to Berger VLD Hybrid, also SMK and Hornady all 140 grain. These are the best bullets I can get so I dont think it is the bullets. The seating test was only with the VLD. The others being tangent I just kept the depth at .015 jump. I have never tried seating into or to the lands. My supply of 4831 was exhausted having used it to develop a 22-250 load with 77 grain SMK and Sirocco 75's. Anyway I understand that supposedly H4350 is the powder of choice for competition shooters in the Rem 260 so that is what I am working with. Problem there is that the load manuals are so different for max H4350. Sierra manual-nothing. Hodgdon lists 39.0-42.0 grains for Nos part bullets. Then Hodgdon recommends 41.5 to 44.5 for SMK 142 grains! Berger recommends a max of 40.8 grains for their 140's! I have read where competition shooters use more than 43 grains. Maybe my view is wrong but when using tangent bullets I dont think they should be seated to the lands? The berger hybrid 140s are what I want to shoot and they claim they are as accurate as their match bullets. To say the least I am a little confused at this point. I suppose the variation in powder charges have to do with the bearing surface of the bullet listed. Maybe I should start over with SMks?

Your Savage 260 should shoot better than that. I suspect your load combination is not quite what the rifle prefers rather than a cleaning issue.
IME the use of a lead sled will not provide an adequate platform for testing I would use a good front rest and rear bag allowing recoil management.
Have you performed a powder ladder test followed by a seating test? In addition a Tangent ogive bullet such as Sierras are much easier to tune than hybrid.
addendum- if you do feel the need for cleaning I have excellent results using Bore Tech eliminator and C-4 Carbon remover