GTA
All Springer/NP/PCP Air Gun Discussion General => Air Gun Gate => Topic started by: Jman on September 14, 2010, 04:46:51 PM
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With a new pellet rifle will I need to do something to the barrel besides clean it well to get notches in the pellet skirt? I believe the notches help the pellet spin increasing accuracy correct? I cant remember when I got my Big Cat a long time ago if the first couple of pellets I shot through it and recovered had the notches, but the pellets I do now out of the same gun have them. Ive probably confused most of you, but hopefully someone will get what im asking. Basically, with a new rifle should it be putting well defined notches in pellets skirts thus increasing the accuracy, or is there something special you need to do to get the notches into the skirts?
Im confusing myself now, but lets see if anyone knows what Im talking about.
Thank you,
Jman
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The ridges in the barrels are called rifling. Yes, they do cause the projectile to spin, thereby creating a gyroscopic effect which stabilizes the round. You should not have to do anything with the rifle other than to clean it well prior to your first outing and to tighten all of the screws and mount the scope.
pv
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k thanks. The ups statement says the gun should be here Thursday, but its in Maryland now so it may come tomorrow:). Im guessing the estimated arrival date of Thursday is correct though:(,that extra day goes by really slow!haha, hopefully tomorrow and Thursday I can focus in school!
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also, the deeper the notches in the pellet skirt after fired, the better rifling you have in your barrel correct?
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Maryland? You could have sent that to me in Virginia!! Just kidding, bro. Just get the grease off of it and from inside the barrel and you'll be fine IMHFO.
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Im in VA too! haha
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Don't confuse swaged pellets with marks from barrel rifling, though. Some pellets are manufactured with "pleated" skirts (eg, Gamo Hunters) vs. smooth (eg. JSB Exacts). A properly seated pellet should form enough of a seal that the pressure of a springer air rifle will actually balloon or expand the skirt from the underside to make it conform to the rifling.
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ok, thanks. Please explain what a pleated skirt is, Ive never heard of it before
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(http://www.accuratereloading.com/pellets.jpg)
(https://www.pyramydair.com/images/zoomed/RWS-2315039_zm2.jpg)
take a close look. The swaged pellet have vertical serrations in their skirts, hence my reference to "pleated" skirts.
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oh, thats cool. What purpose does the pleating serve if any?
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As far as the depth of the rifling, you need just enough to spin the round. If there is too much, there is additional friction and velocity will suffer. If they are too shallow, the pellet will pass through without spinning, and the rifling will just shave the skirt off the round and the round will likely tumble or be very unstable at the least. The difference between the two is only a couple of thousandths of an inch. Thats why its best to not clean the barrel too often and when you do, only use the trimmer string- there's no need for brushes, or rigid cleaning rods.
pv
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JmAN
Here's a link to some good info....straight from the Big Kahuna's site. ;D
http://www.charliedatuna.com/airgun_docs/Pellet%20Testing%20in%20Spring%20Airguns.doc (http://www.charliedatuna.com/airgun_docs/Pellet%20Testing%20in%20Spring%20Airguns.doc)
Try pushing the different pellets thru slowly....examine before/after dropping out of the barrel.
By doing that I can see which pellet types get groovy and how much. As well as inconsistencies in markings.
The crown comes into play heavily when it blasts and spins out the end - on it's way to the POI. Before I polished the crown on my Storm, I found it was digging into the pellet and causing accuracy problems. The polishing took care of it.