i had the same issues with my 10T in 6.5 cm, after 1600 rounds i figured the barrel seen it's days, was almost ready to order a new barrel, so i figured either i will ruin this barrel or help it, JB bore pase did not quite get the carbon out, so i chanced a 600 grit valve grinding compound in the first 6-8inches of the throat area, i stroked for about 3-4 minutes vigorously, and then i finished it with JB bore paste, took it to the range and in the meantime before i done this procedure i was trying different bullets some times decent groups, most not, so i hit the range and i only shoot 200yds most of the time, best i was getting was maybe 1 1/4 to 1 3/4, my few loads were rather good, back to the loading bench i loaded the sierra 140SMK 40.8 H4350 and i am a happy camper, don't have to get a new barrel, i am near 5/8 mostly 3/4" i know its me now i use to have to give this gun a death grip, now i shoot it free recoil, last week i had 3 shots touching 4th and 5th were out to the 3/4". and since i done this the barrel cleans within 6 to 8 patches a few with a brush, before i done this it was a nightmare to clean, took forever .


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