bent skirt effect?
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bent skirt effect?
The last time I bought pellets I switched from RWS Basics to Rws Hobby. They are a very, very tight fit, not to be pushed in with just the flesh of my thumb. I usually have to use my thumb nail with a good bit of force, and sometimes in seating them I can put a little dent in the skirt. Could this little bend/crimp in the skirt have any significant effect on the trajectory of the pellet? I notice that sometimes I have a good hold and smooth trigger pull and the pellet lands quiet a ways off target. Thanks, todd.
Anything that allows an asymmetric pressure loading on the base of the projectile has the potential (most likely will) to affect accuracy. This is true for firearms as well as air arms. It allows the projectile to "hit the rifling" off axis (crooked if you will) and that causes any number of accuracy robbing affects.
So in short, a damaged skirt will never help achieve full potential, and will most likely result in poorer performance. If that reduction of performance is something you can detect within your ability to hold then you are risking dropping point because of the ammo.
You state you have flyers ... if you are sure of your call on these and you know the accuracy of your gun it's very reasonable to assume the damaged skirts are causing this effect.
If you continue to use these pellets you need to us a seating tool to more uniformly press against the base of the skirt as you seat the pellet in the chamber. This is far better then using your thumbnail.
Or use different pellets.
By the way, are you sure your chamber is clean of any buildup?
I hope this helps.
So in short, a damaged skirt will never help achieve full potential, and will most likely result in poorer performance. If that reduction of performance is something you can detect within your ability to hold then you are risking dropping point because of the ammo.
You state you have flyers ... if you are sure of your call on these and you know the accuracy of your gun it's very reasonable to assume the damaged skirts are causing this effect.
If you continue to use these pellets you need to us a seating tool to more uniformly press against the base of the skirt as you seat the pellet in the chamber. This is far better then using your thumbnail.
Or use different pellets.
By the way, are you sure your chamber is clean of any buildup?
I hope this helps.
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brent375hh
- Posts: 741
- Joined: Wed Apr 17, 2013 8:04 am
- Location: Minneapolis
You know, it might not be that big of a deal.
When I was a kid, I had a .22 caliber pellet rifle (I think it was a Diana Model 25), but we lived overseas in a country where I couldn't get any .22 caliber pellets.
However, I could get .177 pellets.
So I did what any self-respecting 12-year-old would do: I placed the .177 pellets on the ground and smashed them so they'd flatten, especially at the skirts. They'd then fit snugly in the rifle (it was a break-barrel), although some of them would be too big and I'd have to be jam them in with a stick or a nail or something (like I said, I was 12). I probably scratched up the bore, though - I used rocks and bricks to do the flattening, and I'm sure some grit ended up on the pellets.
Anyway, even with all that, they were surprisingly accurate - pretty much whatever I aimed at, I'd hit. Granted, most of what I shot at was the exact size of a rotten mango (usually at between 10 - 25meters), but still, it worked reasonably well even with the extremely malformed pellets. Plus, an added bonus (at least for a 12-year-old) - a good number of shots would come with a 'ricochet' sound "Ka-pwiiiiing", and velocity was definitely faster than the .22 pellets.
When I was a kid, I had a .22 caliber pellet rifle (I think it was a Diana Model 25), but we lived overseas in a country where I couldn't get any .22 caliber pellets.
However, I could get .177 pellets.
So I did what any self-respecting 12-year-old would do: I placed the .177 pellets on the ground and smashed them so they'd flatten, especially at the skirts. They'd then fit snugly in the rifle (it was a break-barrel), although some of them would be too big and I'd have to be jam them in with a stick or a nail or something (like I said, I was 12). I probably scratched up the bore, though - I used rocks and bricks to do the flattening, and I'm sure some grit ended up on the pellets.
Anyway, even with all that, they were surprisingly accurate - pretty much whatever I aimed at, I'd hit. Granted, most of what I shot at was the exact size of a rotten mango (usually at between 10 - 25meters), but still, it worked reasonably well even with the extremely malformed pellets. Plus, an added bonus (at least for a 12-year-old) - a good number of shots would come with a 'ricochet' sound "Ka-pwiiiiing", and velocity was definitely faster than the .22 pellets.
:-)jr wrote:You know, it might not be that big of a deal.
When I was a kid, I had a .22 caliber pellet rifle (I think it was a Diana Model 25), but we lived overseas in a country where I couldn't get any .22 caliber pellets.
However, I could get .177 pellets.
So I did what any self-respecting 12-year-old would do: I placed the .177 pellets on the ground and smashed them so they'd flatten, especially at the skirts. They'd then fit snugly in the rifle (it was a break-barrel), although some of them would be too big and I'd have to be jam them in with a stick or a nail or something (like I said, I was 12). I probably scratched up the bore, though - I used rocks and bricks to do the flattening, and I'm sure some grit ended up on the pellets.
Anyway, even with all that, they were surprisingly accurate - pretty much whatever I aimed at, I'd hit. Granted, most of what I shot at was the exact size of a rotten mango (usually at between 10 - 25meters), but still, it worked reasonably well even with the extremely malformed pellets. Plus, an added bonus (at least for a 12-year-old) - a good number of shots would come with a 'ricochet' sound "Ka-pwiiiiing", and velocity was definitely faster than the .22 pellets.
I dropped an entire tin unopened of H&N Finale Match about a month ago.
Felt kind of bad and pretty stupid - but perhaps it was not in vain: I committed the tin to science!
I went through the whole lot and separated them out into roughly 3 categories.
1) Greater than 20% deformation
2) Mildly deformed
3) Good condition
I found no appreciable difference in performance with just shooting at targets but I didn't vice test it. Still hole through hole groups.
As a half arsed physicist I had a think about and hypothesised the following.
a) The manner of loading with a Morini 162 swages the projectile into the bore creating a seal.
b) The bent pellet that if it is exposed to 100 times the pressure of the atmosphere in a short sharp shock it would blow the skirt open as it traveled down the bore.
Both of these I figure contributed to the lack of change in precision.
Haven't yet tested my theory with hard fact.
I propose the experiment would measure ratio of deformation, velocity and extreme spread. I would pitch deformation ration against velocity in a graph and then relate findings to extreme spread.
TL;DR - Dropped an unopened pack of 15 dollar pellets - no appreciable difference in accuracy.
Felt kind of bad and pretty stupid - but perhaps it was not in vain: I committed the tin to science!
I went through the whole lot and separated them out into roughly 3 categories.
1) Greater than 20% deformation
2) Mildly deformed
3) Good condition
I found no appreciable difference in performance with just shooting at targets but I didn't vice test it. Still hole through hole groups.
As a half arsed physicist I had a think about and hypothesised the following.
a) The manner of loading with a Morini 162 swages the projectile into the bore creating a seal.
b) The bent pellet that if it is exposed to 100 times the pressure of the atmosphere in a short sharp shock it would blow the skirt open as it traveled down the bore.
Both of these I figure contributed to the lack of change in precision.
Haven't yet tested my theory with hard fact.
I propose the experiment would measure ratio of deformation, velocity and extreme spread. I would pitch deformation ration against velocity in a graph and then relate findings to extreme spread.
TL;DR - Dropped an unopened pack of 15 dollar pellets - no appreciable difference in accuracy.
These were shot with RWS Basic (10 shot groups) out of my LP10. My gun didn't like the Hobby's so I stick with the Basic's. The top group is skirts that I squeezed between my thumb and finger as much as I could and loaded. The bottom group is not just a scratch but about a 1/32 notch I cut out of the skirt. I did this because a guy I shoot with said the Basics gave him fliers. He said even the slightest little nick and a good shot would be a 7. BULL! I severely damaged these pelets and couldn't get them out of the 10 ring. I'ts not the pellets it's you.
Yeah, that's about in line with my experience. The difference in group size between the nicest match grade pellets I've tested (JSB SCHaK) and the worst (RWS Hobby - really dirty pellets, so I prefer the Basic which are much cleaner) is about 2.5mm at 10m from a vise, using a Pardini K12, the nice pellets grouping at about 6.5mm and the nasty ones at about 9mm. I never look at skirts. My old eyes are too... old. I load and shoot, the pistol takes care of the skirt shape with the probe pushing them into the bore.
I put once RWS Basic pellets up-side-down and the series was 93, pretty much the same as any other series but with pellets loaded normally. Before, I had tried with even cheaper Gamo pellets who were turned up-side-down and results were worse for just a point (and sometimes two) per series. The difference was that holes were bigger and their edges were more rugged. I guess, it counts only when you reach the 580 threshold.
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john bickar
- Posts: 618
- Joined: Wed May 05, 2004 3:58 am
- Location: Corner of Walk & Don't Walk
I have a similar anecdote:SamEEE wrote:TL;DR - Dropped an unopened pack of 15 dollar pellets - no appreciable difference in accuracy.
Airline monkeys played catapault with my suitcase containing a case of Finale Match pellets, and I recently shot a 580 in training with a tin of the worst-damaged ones (for science!).
Ditto, ditto, ditto.
I have experimented too. Put the Morini pistol in a vice (that's the way we spell it in Oz) and deformed some pellets. They grouped just as well as pristine pellets. I think the pellets are resized as the rod pushes them into the barrel.
When I put a severe notch in the skirt with my fingernail, the group still did not alter much.
Putting pellets in backwards opened the group up slightly and the holes were more ragged but they would have all held the 10 ring.
I have experimented too. Put the Morini pistol in a vice (that's the way we spell it in Oz) and deformed some pellets. They grouped just as well as pristine pellets. I think the pellets are resized as the rod pushes them into the barrel.
When I put a severe notch in the skirt with my fingernail, the group still did not alter much.
Putting pellets in backwards opened the group up slightly and the holes were more ragged but they would have all held the 10 ring.