So what would slugs do? Opinions.

Shot these three groups yesterday, dead calm perfect conditions, second time at 100yards, I found it easy to get to 1" with this Impact X .25 with the 700mm bbl, first time out got 1.200 but had some wind, I was using JSB MK2's at 875fps with a SD of 3, barrel had at least one other long shooting session so it wasn't clean. With these numbers, would like to hear some opinions as to how slugs "might" work in this barrel liner, I know try some and see, I'm NOT adjusting the reg, it's set 135, gun is for long range target, try some slugs or leave it alone? Thanks!
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