It has been too long since I have had the time to shoot and cool weather is upon us here in AL. I was trying to remember what the coldest temps we used to shoot our 850's @ without a major decrease in accuracy. If I recall correctly it was around 45 degrees or so....

I just found out there will be a state championship FT match again in our state on December 5th. I would like to take the 850 depending on weather.

I have bone stock 177 & 22 cal 850s. I have spring kist from Roland that I could install if that would help with the cooler temps.

Thanks

~GOD BLESS~

john

Hi John, I've shot down to 40'ish and still took a squirrel out at 25yards.
thats as cold as I've gotten with it.... not very I guess.
The spring only really helps when its hot, over 80 degrees. It might add a few
fps at lower temps but nothing great.
Roald.

The 850 Store

CO2 Liquid/Vapor phase:
90 F....1200 psi
80 F....969 psi.
70 F....853 psi
60 F....747 psi
50 F....652 psi
40 F....567 psi
30 F....491 psi
20 F....422 psi
10 F....361 psi
0 F.....306 psi

It is over 80 degrees today and supposed to only be a high of 58 on Sunday. Got to love our weather this time of the year. It is not uncommon to have some days in December that are consistently over 50 degrees.

I'll shoot some this weekend and start keeping a record of the temps. I thought I remembered we did shoot it when it was cooler/cold so looks like I may be OK if it is above 35.... Since it is for FT I'll be looking for repeatable accuracy not so much fps. Ofcourse I really do not need the accuracy since I am not that good at FT : O

Ray the match is in Alabama - Heflin, AL. Let me know if you need more detail.

Rich - Thanks for the info. That supports that I may get consistency if the temp is stable. Just have to adjust my POI that morning.

~GOD BLESS~

john

You might also chrony at different temps and run those numbers through chairgun. If you're being completely anal about it, you could hardcopy the chairgun plot with MOA lines for various velocities and simply select the closest one to carry with you on the day of the match - I've done that and it works fairly well. Remember too, that you can pick up some extra heating and velocity by having the gun in the sun as much as possible.

I shot CO2 in a couple of matches this summer in Idaho - didn't do too badly. I've since done the HPA conversion - that's a lot better

test you can do. I used 20 yards for this one. Go out early when temps are low in morning. Shoot on target noting temperature. Then wait a few hours when temps are higher and repeat test.
I did this and note POI is in same area even though temps were 13 degrees apart (3/4" circles)....I did this off my hunting sticks before going hunting as a quick check.....but you should do it off a bench for tighter groups...

For FT practice,get a Gamo Squirrel drop target..it comes with reducers for kill zones like ones used in FT matches..

[IMG][/IMG]

I use ballistic software as Ray suggests to make range cards...but good idea to verify calculated data on actual target at different ranges..

I like the simplicity of the target with the temps written down.

I'm thinking I'll try to throw together a shooting bench this weekend and then get started shooting again. My old set up is a pair of saw horses and 6 peices of laminate desk top pieces I scrunged from a dumpster. Plop some sand bags on top and it is steady as a rock. It is also always in the way so I need something easy to move.

I'll get a target sheet together. I don't have a chrony at this time but I would like to get one.

We mounted some gamo targets and steel back plates in the trees and I have about 4 more ground targets as well (some wood some more gamo). The pic below has two mounted on a 2X4 that runs in the foreground and one higher up and farther back by itself on the left is a gamo rat.



I will most likely be without a computer until Monday.

Everybody have a great weekend and shoot safe!

~GOD BLESS~

john

Earlier this week I shot my .22 cal Co2 rifle over the chrony. Gun was modded per suggestions on this forum and avergaed 703 fps in the mid to upper 70's.

the day I chronied this week it was 51 degrees F. and the gund averaged 654fps.

Matt H.

http://www.frontiernet.net/~mhall

We had a chance to shoot this past weekend. It was about 60 degrees and the weekend before about 50. I really did not notice too much of a POI shift, however, the 50 degree weekend I was about out of gas (using 9 and 12 OZ tanks)

They certainly performed well - especially considering I haven't used them in awhile.

~GOD BLESS~

john

My approach to these 850's is to "stretch" everything out...heat,cold,shooting long distances,etc..

When I hunt with my CO2 850 in cold weather,I try stalk squirrels to reduce range...one of these days,I'm going out with my CR1377C,and try getting even closer...lol..takes much more time,but sure helps getting stalking skills improved..

For long shots,I practice on small rocks out 60 yards...you learn about your rifle fast that way...and quickly learn to read the wind...