Weird pellet flight at 100yd

[Raider03]

I had the same problem with my impact, after 50 yards my JSB 25 grains would hook a big spiral. If you ever watch TEDS Hold Over in some of his old episodes he had the same problem, he tried all different velocities and I don’t remember his results. Anyway I switched to H&N barracuda match pellets and the problem went away. I have shot them from 890 to 940 FPS and no spiral trajectory. I even asked FX about why my gun couldn’t shoot the 25 grain JSB pellets and they couldn’t give me a good answer, I believe the technician said the barrel support orings where bad or something like that. Anyway, give the barracudas a try and I bet your problem will be solved. Good shooting

If it is the support liner support o-ring using a carbon fiber sleeve would help.

 

[alpineboard]

700 slug liner and carbon sleeve is on the way, will see what shows up.

 

[Dairyboy]

Any grain weight recommended for the HN Barracuda Match?
Yes , the Ted hold over videos, interesting. Lots to digest.

1000fps= .095 bc
1100fps= .180 bc

Don't trust that at all. No offense to Ted, like his videos but there's no way the BC doubled by raising 100fps. Don't expect that with whatever your shooting.

 

[Centercut]

Don't trust that at all. No offense to Ted, like his videos but there's no way the BC doubled by raising 100fps. Don't expect that with whatever your shooting.

Bingo. The oddest part of this is that HE HAS THE LABRADAR AND NEW FX OUTDOORS crony, so at any time he could have calculated the BC with those two units vice the worst way to calculate BC. It just doesn’t make sense and leads me to believe it was just to get people talking and generate churn…

 

[Bramezy]

If it is the support liner support o-ring using a carbon fiber sleeve would help.

Nope, carbon sleeve didn’t help me. I found stability and accuracy at 940fps. As soon as the wind picked up i lost all control and that pellet went crazy.

 

[alpineboard]

Barrel OD=0.315", carbon sleeve ID=0.317" and OD=0.460", Cape Fear spacer ID= approx 0.465" to 0.470", Sleeve was a nice smooth resistance slip fit, am not using any adhesives until I think it is needed. The carbon sleeve needed lots of cleaning of the ID. Appears to be a linear drawing material removal process by the evidence of the fines left in there. But after cleaning it is smooth as glass mirror polish or maybe their cleaning method leaving linear streaks.
50 rounds thru it last night, got some tight groups at the end, at 50 yds, had a few 1/4" to 1/2 " out, 920 to 930 fps, with a HN 27 slug.
Trying for 1 hole at 50 yd, then go to 100 yd. The right target things started settling in, new barrel, end of 50 shots.
What I did discover in the barrel swap, was that indexing is a big factor, with the new 700 1:16, was at the end limit adjust with the scope on both elevation and windage and on the Xring, with index at 12 noon, so I went CCW to 10 oclock with index, and the prior sighted in on X ring shot moved 12" down, but I had the elevation clicks available to bring it back up, as I was at my end limit.

 

[alpineboard]

Understanding slug flight path, originally I was thinking this slug flight of the flyers was a strait line or an arc in a some what strait path. After watching this video, Mr Aim Small, states that he gets the slug going so slow, that he sees the slug spiral. This got me thinking, what does he mean by that. No one can see the 30,000 rpm spinning, so I concluded he is seeing the slug "corkscrewing, spiraling".
Now I get the big picture, when a slug is a flyer, it is corkscrewing, and can go any where on the o'clock face, and how far off is a function of how much the corkscrew radius is. Or is corkscrewing/spiral in a small radius and veering off its strait path.
So the goal is to find the correct twist, and velocity, slug weight that will be the least corkscrew radius.
Also have been at 50 yd, trying using 23 grain hn slug, 700 mm heavy barrel, 120 bar, 915 fps to 920 fps. And 27 grn hn slug, 120 bar, 890 fps, need more time with this.

I wish Mr Aim Small could go out to 50yd, and 100 yd.

 

[alpineboard]

Possible wrong #'s from prior posts?, Order of operation is multiply not divide. Spin rate is very fast.

You are being redirected...

Muzzle Velocity fps X (12/twist rate in inches) X 60 = bullet rpm

 

[dizzums]

one of the inherent problems with airguns is the short pronounced arc flight path .. you spin the projectile to keep it stable, but that same spin keeps its muzzle exit orientation the same along the curve of the arc .. in other words, way out its still pointing straight or parellel to the muzzle but falling fast and the nose isnt following the flight path .. shoot it faster and flatten the curve lol... or, you could likely find a balance that makes it work better by adjusting the speed ~10 fps at a time until it likes the whole thing ..