Inexpensive bulk .22LR ammos often have the most irregular dimensions, including those of the bullet, regardless of whether they are copper plated. They aren't made to the much tighter tolerances characteristic of more expensive .22LR ammo, especially match ammo.Not long ago we took some 22 ammo and measured and weighed several different bulk, cheap brands. The copper plated were the least consistent comparable to just lead. Our guess was it was due to the process of plating. Just my observation
Then Lapua has essentially no competition ... get it up to about 80-85 degrees F. and it's so slippery it's a challenge to hang onto it enough to stuff it into magazines...In his book Ammunition Making, which has considerable information on .22LR ammo including a chapter on "The .22 Match Cartridge", George E. Frost writes "Match ammunition seems to achieve maximum accuracy with a greasier lubricant."
Yes, there's no point in wasting more expensive ammo for fouling the bore. I season with SK Standard Plus before shooting with CX or M+.Fwiw, Devan at the Mesa, AZ test center told me all Lapua and SK labels except Polar Biathlon use the same lube, meaning one can switch from, say, SK Standard+ all the way to Lapua X-Act and back with confidence that no POI shift will occur due to lube