Temperature effects on pattern

[Birdyblaster]

Hey guys, I've been browsing this forum for awhile and decided to join.  It looks like a great place loaded with good info on all things turkey.  For you pattern gurus out there, how much will temperature affect the quality of a pattern?  I put some Hevi-13 #7's through my Xtrema 2 the other day and was getting around 220 in a 10" circle at 40 yards.  The temp outside was approximately 25 degrees (it's been a really long cold winter).  How much could I expect that pattern to improve when temps warm to say 60 to 70 degrees which is closer to what I expect to be hunting in?

[turkey buster]

What's it choked with

[decoykrvr]

Based upon my patterning results with that shell, I'd expect a 15%-20% increase in the number of pellets within 10" as the temperature approaches 70-80 degrees.  There are a number of different variables which can have a substantial effect on patterns and I've even patterned shells (primarily duck and goose loads) which patterned best at lower temperatures.

[Birdyblaster]

What's it choked with

Hevi-shot choke.  I have a Jellyhead .660 for it that I haven't ran those shells through yet.

[decoykrvr]

With an Indian Creek .660 and temperatures above 60 degrees, I typically get 260-275 in 10" at 40 yards.

[Birdyblaster]

With an Indian Creek .660 and temperatures above 60 degrees, I typically get 260-275 in 10" at 40 yards.

With the same gun and shells I'm shooting?

[decoykrvr]

My 260-275 in 10" are from the 1st and 2nd year production run of the 3" HEVI 13 #7's out of a clean highly polished 21 1/2" barrel on an Ithaca Model 37 Turkeyslayer w/ an Indian Creek .660.  That rig w/ "early production" 3" HEVI 13 #6's yields 206-215 in 10".  I was evaluating the new Winchester Long Beard shells and got an avg. 198 w/6's and 167 w 5's in 10" at a lazered 40 yards.  I run a 10 gauge Bore Snake from the chamber to bore 5 times between shots and thoroughly clean the bore and choke tube w/ solvent after 10 shots.
FYI- the LB #5's were shot out of a Gobblin Thunder .650, not the IC .660.