well at 900 plus or minus a few rounds i think the old set back shilen is all done...this is the barrel from my 260AI thread...i switched to lapua brass and had 2 loads that shot very well...45.1g RL-17 and 48.2g H4831sc...at 700 rounds it was still shooting about a 1/2" to 3/4"...at 750 it open up to about 1" to 1.25" and has just continued to get worse...just waiting on my reamer and ill have a bartlein blank chambered and see what the 260AI is really capable of....

RL-17...



H4831...