GTA
All Springer/NP/PCP Air Gun Discussion General => Air Gun Gate => Topic started by: dcmeyer on August 30, 2018, 05:54:20 PM
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What types of guns shoot them well.
I'm assuming they are for higher velocity, likely PCP rifles. I've read they don't work well in the "smooth twist" barrels and have also read about the sizing and getting stuck or not loading in some barrels.
So is there a minimum speed (fps) to get them to work properly since they are generally heavier for the caliber. From what I understand they are not accurate in some guns, but why? What is your experience, pro's, con's.
I obviously see one con being some are more than I pay for 9mm, but more concerned with performance.
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Diabolo (waisted) pellets only have a two tiny rings of lead in contact with the bore, and the back one (the skirt) is hollow with a thin edge designed to easily collapse to ease loading.... Bullets (slugs) generally have two or more much wider lead bands designed to engage the rifling, and some have a very long single band.... If these bullets are not sized small enough so that they can easily be pushed into the rifling, they can be difficult, if not impossible, to load.... The chamber for a bullet should have a long taper (called the leade) where the barrel diameter gradually decreases from the groove diameter (or a couple of thou larger) to the land diameter.... When I am making a chamber reamer, I use a taper of just 1 deg. per side.... This shallow taper helps in loading the bullet, and also eases the initial resistance as the bullet is fired and must be engraved by the rifling.... Even so, the chamber must be long enough that you are not trying to ram the forward full diameter portion of the bullet into the rifling, that can make it hard to load....
While diabolo pellets, with their "shuttlecock" shape, are mainly drag stabilized (and hence can work in a very slow twist, such as the FX Smooth Twist barrels)…. bullets require a much faster spin rate to be stable and avoid tumbling as they travel downrange.... The longer the bullet (in calibers), the faster the twist required (in calibers) to remain stable.... Some airgun barrels are not a fast enough twist rate to properly stabilize bullets....
Generally speaking, when Subsonic, bullets will stabilize better at lower muzzle velocities, so the idea of a minimum MV is really not an issue, but rather the opposite.... If the twist rate is marginal, a bullet might be stable at 800 fps but unstable at 1000 fps....
Bob
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For us our slugs will come down a lot next year. We ordered a new machine that will spit slugs out very fast in comparison to what we do now which is made one by one. Same slugs I make now with a few mods to them but price will be much closer to that of quality pellets.
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Has anyone try slug on a high power springer.
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i had good luck running rat sniper slugs in my .25 condor,
was pushing them about 920-930fps
but the condor had a LW barrel
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This video may be helpful.
https://youtu.be/Ur6iIcVhHmM
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This video may be helpful.
https://youtu.be/Ur6iIcVhHmM
Thanks, I've seen it, one of my favorite channels.
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Thanks, I've seen it ...
Posted on 8-29-18, just in case you are thinking of a previous episode.
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They're a lot like snails, but without shells. Penetration is guaranteed with any pellet, but you'll want to pay attention to shot placement, nothing is more dangerous than a wounded slug. ;-)
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That Video of Matt's is GREAT.... I highly recommend viewing it as many times as you need to fully absorb every little detail.... I have been harping about twist rates for pellets being too fast as the cause of spiralling downrange for quite a while.... It's nice to see that explained in such a clear manner....
Bob
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For us our slugs will come down a lot next year. We ordered a new machine that will spit slugs out very fast in comparison to what we do now which is made one by one. Same slugs I make now with a few mods to them but price will be much closer to that of quality pellets.
Very glad to hear, I believe you will be giving Pellet manufacturers a run for their money as the industry moves towards slugs for performance...
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That Video of Matt's is GREAT.... I highly recommend viewing it as many times as you need to fully absorb every little detail.... I have been harping about twist rates for pellets being too fast as the cause of spiralling downrange for quite a while.... It's nice to see that explained in such a clear manner....
Bob
Ditto on the video Matt has a way of translating complicated things into a simple to understand format...
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Are there BC numbers on any of these slugs/bullets on the market?
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Nick has BCs on most of his slugs....
Bob