winter/spring/summer fps
Hi all,
I did my .25 matador tuning during the winter and had it set to 886 fps…
Spring is here (about 75 F) and speed have increased to 898 fps.
What can I expect for summer when temps are around 86 F?
Thanks, Q
All Replies
Viewing 14 replies - 1 through 14 (of 14 total)
Could it be due to being more broke in?
Is the 8 fps per 10 degrees linear?
Just saying.
Often internet conjecture transitions to into internet fact too quickly.
I’m just saying the 8fps per 10* is just an unscientific generalization based on my not so specific test parameters.
For my 22 long, HST at 6oclock for low 100 temps(115 regged shots),8oclock for mid 60s low 70s( current temps)(appx 100 shots), 10:30ish for high 20s low 30s(appx 90 shots). All strings right in the 885 fps mark with SD in low 2s and max spread of 9-10 fps.
Hoot,
You pull yours hard any season and for any reason.
First time I noticed the temperature drop affecting my velocity was with the Ranger 45.
I had it running at 790 or so with 410 grain bullets, then in the first part of June, I went up to my old mountain place and it was snowing and in the 20’s. I was sighted in for 100 yards here in the warm tropics but I was about to find out up there things were going to be a lot different.
I had 3, 12 inch gongs I had set up years before that I used to shoot at with my Sharps rifles off hand. I took careful aim with the Ranger and hit a full foot low. Repeated the process three times, then after being educated, I sighted it in for the colder climate.
Lesson learned was to sight in whenever there was a temperature change when hunting something you really want to eat.
With my Haley 257, the difference between 40 degrees and 65 degrees is 40 FPS with the 81 grain bullet and 60FPS with the 105 grain bullet.
Regards,
Roachcreek
… What can I expect for summer when temps are around 86 F?
Thanks, Q
First, Where is it only 86 F in the Summer?
Second, while I don’t wish to give out all my shooting secrets…have you tried pulling the trigger harder in the Winter?
Just a thought.
12 fps increase isn’t much.
Could it be due to being more broke in?
Is the 8 fps per 10 degrees linear?
Just saying.
Often internet conjecture transitions to into internet fact too quickly.
Didn’t think of spring. Good call.
It must be the two springs, heat expands the spring, same HST cocking length means more energy to strike. What about the one in reg? I don’t know.
Definitely. All that combined sure does it.
I figure it combination of lube thickening ie;Orings in reg not sliding as quickly, denser ambient air for pellet to push through-Higher humidity when cold.
One of my springers ( HW 97) was really sensitive for cold and lost lots of fps when it got cold. Although springers are more sensitive for deviation in temps the chills seem to affect PCP guns as well.
wow, thats quite a difference… 890 to 820.
sure, quite big difference between 20F and 100F but I never thought changes in speed would be that extreme.
Interesting
Yup. Your estimate 10dgr/8fps isn´t far off.
My experience while completely unscientific. Tuned R3 22 long in summer with low 100s to around 890fps with 115 regged shots. Come winter with average High 20s temps it dropped to mid 820fps. Increased HST appx 3/8 turn to get speed back but shot count dropped to appx 90 regged.
I’m gonna go with appx 8fps for every 10 degree change.
I do all my chrony strings in back corner of garage with gun normalized to outside temps.
Around 1500 ? 😀 😀
Viewing 14 replies - 1 through 14 (of 14 total)
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I’m not talking high/low temps but rather average summer temperatures during a 24 hr period… high temps would be just above 100 F.
Q