Todays arrow vanes are supposed to be soft and supple. Right? Recently, I was setting up my 10 Point Turbo S1 crossbow and new Oracle X scope in below freezing snow and cold weather because I was tired of cabin fever. You too!
My crossbow arrows, set up with Swhacker 231 practice heads were not grouping as well as I’d like in this freezing weather.

What could be the problem, I thought? My new Oracle X scope needs electronics to run but the stats say my scope should be fine down to minus 15F. Could limbs and cams be affected? Maybe. But, the very next few days, temperature’s were in the high 40’s and mid 50’s. Accordingly, my fears melted away as groups tightened to my expectations even out to 45 yards. Very nice indeed!
I did not set up an experiment to prove my theory. However, I was shooting a 3.5 inch helical fletch, longer than usual thus it made sense that if the plastic helical fletch was rock hard from the freezing cold, it could have difficulty in the narrow launch ramp and bump during the spin. I switched arrows with a 1 degree offset and a shorter 3 inch vanes. With temp’s in the 50’sF they flew great, almost identical to my longer warmer helical vanes with practice swhackers. Thus, I believe my frozen helical vane issue was temperature driven. Perhaps switching to the 1 degree offset and shorter vanes is the way to go? Time and many arrows will tell.
UPDATE
Today, March 9th Temperatures were a balmy 35 to 37ºF. I have field points which I have weighted to mimic my Swhacker 231 heads. In addition, I shot both 3 inch 1 degree offset vanes and 3.5 inch helical vanes at 20 yards and at 35 yards with my 10 Point Crossbow/w Oracle X Laser rangefinding scope. The results were that both vane types and offsets at this temperature shot exactly the same even at 35 yards in image below.

The takeaway here is that really cold vanes below 32F can affect crossbow arrows during launch.
Secondly, that the helical fletch is not necessary with Swhackers as there is very little blade to plane. However may add steering value with traditional broadheads.
Good Shooting!