Snow and Bipods

[mslman]

Does anyone know if resting an atlas bipod in the snow (1 foot) of it could cause a vertical POI shift of more than 20 inches? I ask because I was out on a cow elk hunt and all shots from 6.5x284 were about 2o inches high on all ranges shot until I buried my pack and shot from it with bipod legs pulled all the way back in; then direct hit at 503. This rifle has proven to be sub 1/2 MOA out past 800 yards on previous outings. But it was also -5f and I had no way of validating the BR2 solutions given.

 

[effendude]

If the bipod was solid, and only the shooter will know for sure, it should not have a significant POI change. Colder air is more dense and usually shots need more elevation added due to colder temps. Your situation is the opposite of what I would expect in -5* temps.
Scott

 

[Delfuego]

If I don't load my bipod consistently , especially on uneven terrain, I can get a 2/10th mil elevation change even at 100y. I think this would be more likely than the rifle all the suddenly not shooting. It also sounds like you started with a very cold barrel and a very cold shooter. More likely it was weather / shooter related. I think by switching to shooting of your pack that you finally got a good position built with a warm barrel and took care business. But that is pure opinion, glad it worked out in the end.

 

[TikkaSporter]

Does anyone know if resting an atlas bipod in the snow (1 foot) of it could cause a vertical POI shift of more than 20 inches? I ask because I was out on a cow elk hunt and all shots from 6.5x284 were about 2o inches high on all ranges shot until I buried my pack and shot from it with bipod legs pulled all the way back in; then direct hit at 503. This rifle has proven to be sub 1/2 MOA out past 800 yards on previous outings. But it was also -5f and I had no way of validating the BR2 solutions given.

Interesting as I was on a cow elk hunt yesterday also in ~ -10 F temperatures. I used a tripod this time and had no issues with POI in the cold weater (~ 400 yard shot). I have also used an atlas bipod in similar (to colder) conditions in the past without POI issues. That said, I usually test my loads under these conditions (below zero) and use dope that reflects actual/measured bullet velocities in below zero temperatures. And I use 'Extreme' series powders for cold weather hunting.

The problem I usually have with a bipod in snow is the snow depth and the bipod legs sinking in too far to get the needed elevation, or sinking in too far to keep the barrel/bullet path clear of snow, grass, and brush. In the past I have carried an extra shooting bag (Weibad Tacpod) and wedged it between the bipod legs to create some floatation on the snow.

Last year I tried something different and it worked well also. I packed my shooting mat with me on the stalk and laid it out on the snow prior to taking the shot, setting the bipod legs on the mat (835 yard shot).

Possibly your bullet path wasn't clear on the initial shots with the bipod and your bullet was impacting snow/grass on the way to the elk? Only other thing I could think of would be some sort of abnormal movement of the rifle during recoil like the legs jumping or the rear bag sinking/settling in the snow under recoil. 20 inches seems like a lot to be off at < 500 yards.

I did have a problem yesterday with the safety/trigger mechanism on my rifle freezing and being unable to disengage the safety for the shot. I had to dis-assemble and poke/prod at the mechanism with the tip of a loaded round to 'release' the safety, all-the-while the elk herd was bunching up and getting ready to run.