Help! My muzz(rem.700ml) has shot nothing but perfectly until today! Here's the two things i've changed. 1)I switched to the triple seven(sulfer free) pellets (same 100gr. load) and also it was 90+ degrees outside. My first shot was great and then my gun sat on the hood of my truck(while we shot my buddies gun)for close to an hour. My barrel was way hot from the sun and my next 3 shots were all over the place! What do you guys think could be the issue? By the way my original pellets were normal hodgdons. Thanks for the help.