Cold weather and 17hmr
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I've known for a lot of years that 22lr typically shoots very poorly in cold weather. Anything below 55F and it tends to start doing pretty badly. This is due to many factors, not the least of which being the lubricant used on the bullets.
Today I wanted to see if 17HMR was affected also. It was 15F out so it was plenty cold to test. I hauled out my best shooting lot of CCI 17gr TNT, and ran a few rounds through my TS Customs 40X in 17HMR. The first 50rnds was pretty rough, as I had to chase the POI around a bit as the rifle, and ammo cooled to outdoor temps. This wasn't unexpected.
However, once about 30-40 minutes passed, everything started to settle down for the most part. There seemed to be a significantly higher number of flyers than I recall seeing when I was lot testing the ammo. This could be caused by the temps themselves, or possibly simply the difficult wind I was working in. There was about a 3-5mph wind that was shifting from 8:00 to 4:00. There was a light dusting of snow happening while I was shooting, so that really helped me lock into the condition. Even with that help, these little 17cal bullets just don't take very much of a breeze to toss them all around. Anyway, it was fun little experiment, and while I don't think it performed as well cold, as it does in warmer temps... it's obvious the 17HMR isn't as effected by cold as 22lr.
Three individual 5-shot groups @ 50yds.
It was shooting OK, but the POI shifted around a fair bit to start. Again, not unexpected, as this is normal with most any rifle when you don't have it previously zeroed in the cold. Especially rimfires.Here's the last two groups of 5 shots @ 50yds. Really started doing good again once it settled down.
Were it not for that one that got out, that would be quite the bug hole.
It just doesn't take much to cause those 17 holes to look far apart. Really nice groups being shot, but they'd look so much more impressive if they were .22 in size. lol
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Somewhere I read and I'm not saying this is true Hodgdon Lil'Gun powder is used as a propellant for 17 HMR. My experience with Lil'Gun is limited to Blackout sub's and 458 Socom loads for 300 grain bullets and up. A long way from a .17 HMR. The Socom guru's claim temperature affects Lil'Gun so maybe the 17's get a little warmed up in the chamber but at 15 degrees how much can the chamber heat up? Doesn't Lapua make a 22 round with a different priming compound for shooting in freezing temps? I don't have that problem where I am it's usually so hot you need to keep the ammunition in the shade.
