Disturbing Chrony Readings
Hi guys,
I spent some time shooting my Condor .22 last weekend at 170yrds over a small lake and noticed that every now and again a shot would fall short of the target. When checking over the chrony I got the following readings:
926 fps
922
927
928
926
894
927
925
927
897 etc etc
I’m shooting 18gr Jsbs at an average of 925fps but get the occasional 895?fps.
What would cause this as I’ve had this happen before but eventuallu got it sorted-how I can’t remember.
Do I play with the power wheel?
Any help will be appreciated.
Thanx Nick
All Replies
Viewing 9 replies - 1 through 9 (of 9 total)
Nobody could be distracted enough to forget to close the breech could they…
Yep, but maybe it’s just my old age 😳
Or could I use the excuse of firing off a couple hundred pellets doing some crony work ❓
Dah 🙄 :3:
Nick,
Sometimes the pellets the experts tell us are going to be so good at long range are in fact not.
Good example is the JSB King, at long range they are very prone to spiraling, as many as 20 % of mine spiraled past 150 yards.
Good luck on your long range shooting.
RC
Thanx RC, that makes sense. What I noticed on the drop was that the pellets that were falling short were landing about 2-3ft in front of the target. I haven’t had this problem with my Talon in .20 as I was dropping starlings reasonably consistently at anything upto 170yrds. I was under the impression that .22 would do better. Something else I found was that the barrel needed a good clean which I did. The weekend before last I tested the .22 barrel after reinstalling and got 2 consecutive 1,5″ groups at 110yrds. At 50 yrds it was around ,5″ or smaller. This is a custom barrel that has also done well before at ultra long range.
I’m definitely going to check on the spiralling, all I want is good accuracy upto 150 yrds. Will let you guys know how it goes.
Nick,
From what I have learned shooting long range with pellets and bullets, I would look as spiraling pellets myself.
When pellets spiral, which almost all have the tendency to do, they reduce their Ballistic Coefficient drastically, when that happens you have a very low shot because more of the profile is exposed to the air and thus its resultant increased drag.
When I started trying to shoot very long range with a air gun and was using a Royale 500 and 25 grain Kings it was a consistent problem. I found that every shot that spiraled that I could see in my scope hit consistently low.
Look at it this way, if you have a 100 yard zero with 18.1 grain pellets at 922 FPS you will have a 170 yard drop of 51 inches. Now if the velocity is 894 FPS with that same 100 yard zero, you have 53 inches of drop. I really doubt your going to notice a 2 inch difference thru your scope at 170 yards unless our shooting paper, even on paper the group would be big enough that 2 inches would be consistent or in the group. If your pellets are spiraling that pellet will land 2 to 3 feet low. Taking a 10 yard zero, because your not rezeroing for the slower pellet, the difference would be 5 inches difference still something you not going to notice that much on a lakebed
It is why I shoot bullets in air guns for long range, they don’t spiral and hold their BC.
Regards,
Roachcreek
Thanx for the quick replies guys, let me mention that I refitted the .22 barrel about 2 weeks ago after shooting the .20 barrel for a few months. Everything is cleaned and lubed as it should be. I’ll check the tophat gap and tophat (which has been lock tighted in place). The power wheel is set at 9-6 so it can’t be inconsistant hammer strikes. I’ll open up and see if any dirt has worked its way into the internals.
Anything else I can check?
Under sized pellets will shoot slower also.
I had this happen and found my top hat gap was too small. A call to AF and they asked me to back it out a ways to see if that fixed it. It did.
There was too much slop when cocked so the top hat to bolt was not sealed well.
Make sure your …
top hat is secure
That your internals are clean so the hammer does not chatter
Be sure to seat your bolt all the way back on top of the top hat until it clicks
And of course be sure each pellet is seated flush to the barrel.
Viewing 9 replies - 1 through 9 (of 9 total)
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Sometimes the pellets the experts tell us are going to be so good at long range are in fact not.
Good example is the JSB King, at long range they are very prone to spiraling, as many as 20 % of mine spiraled past 150 yards.
Good luck on your long range shooting.
RC
Thanx RC, appreciate all the help guys.