GTA
General Discussion To Gateway To Airguns => The Shop => : howie1a April 16, 2008, 12:02:35 PM
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I just got a chrony and how much of a spread from low to high fps is considered the norm I think we are looking for a mimnum spread so the pellets don't either drop or raise because of fps changes what kind of the spread we are looking for? howie1a
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Usually consider anything at or under 2% to be very good over 10 shots; probably won't see that low a variation with a springer or PCP. Can think of 5% as "good" and anything over 10% as being too large.
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howie, I don;t think you'll notice much if any difference in elevation high or low if the spread is within 20-25 fps. If its pretty wide say 50-60 fps you are gonna probably see a difference. The farther you are shooting the more noticable it will become. I doubt their have been clinical enough studies on variations of velocity//changes in poi to give a real technical answer so this is just an ( I'm not sure educated) guess. It's hard to measure these things because shot to shot hold consistency will have a greater effect than a few fps changes in velocity. I've chronied match grade rimfire ammo and some of the premium stuff had variations of 65-70 fps. Surprised me too.Pellets we shoot lose energy fast so outside of 30 yds it gets dicey.Naturally the closer the spread the more consistent the power is from shot to shot. Won't necesarily translate into better accuracy though..But if the ammo is accurate in your gun and its really pretty consistent in your gun it stands to reason that you should get good accuracy all other things being equal. If what your spittin out is avg. 15-20 fps spread you won't notice it unless your shootin a target gun.One less thing....
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Iyeild to ribbonstone.
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Percentages might be better. 30fps is OK for an 800fps airgun (which is less than 4%) but wouldn't be so great for a 450fps 0ne. Really need top-notch pellets, and taking time to visually sort out the "odd" ones pays off.
Mimor variations probably pass unoticed at short range....but the longer the range, the more effect it has. On the other hand, have had some wonderfully uniform pellets that shot with very low vel. variations, but still wouldn't group worth sour-snail-snot....they were uniform, and the barrel uniformly didn't like them one bit.
Start with accuracy; it's really all that counts. IF crunching numbers was a sure way to small groups, we'd all stop shootin paper and just take vel. readings.
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well with the way my guns consistency seems to be improving with every shot, by the time the spring finialy gives up the ghost and breaks, it will be giving 0 fps deviation he he he
sorry
fin
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I would have to agree with the 5% . Half that would be great . IMO. kirby