Bolt flight question
 

I have a 150 lb Horton exp. Problem is I can see the bolt corkscrewing in flight. I'll sight it in at 20 yards then my point of impact changes at 15,25 yards. I have tried carbon and aluminum bolts. 100 and 125 grain heads. Field tip and broad heads, all corkscrew. I have a fairly new string, my limb bolts are tight. I make sure to pull the string back even. My compound bows are easy to fix this problem with some rest and nock tuning. I'm sorta stumped as how to correct my bolt flight. Only thing I can think to do is back out one side or the other on the limb bolts. Is this going to change anything? What am I Missing as how to correct this problem. I can answer any questions to help tune this crossbow. Thanks

Make sure the main mounting bolt for the riser to the stock is tight...
Wyvern

Will check mounting bolts. Do people ever check axel to axel measuerments on crossbows to see if the string or cables may have streched? This is something I never hear talked about with crossbows but know it can be important in performance. Heck I dont know if I can even find the original specs. Nor do I recall ever seeing it listed.

Had same problem BEFORE I went to high FOC arrows with 2" blazer vanes. The 4" and 5'' vanes, when combined with low FOC, were rotating the back of the arrow. Currently using Gold Tip Lazer IIs with 110 brass insert, 2" Blazers, 100 g Slick Tricks. Weigh 405 g, 18.5 FOC. Sweeeet!~