I am asking this question to get better understanding of internal ballistics, and to educate myself . I have no problem understanding what a undersized pellet can do, but what is the real deal if the pellet is bigger than you need? Except for that they will be harder to load, does it really matters?
What happens when a pellet or slug is oversized?
- Thread starter tor47
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The potential that the barrel may get constipated to a point that it would need help relieving it.
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Pellets/slugs, relatively low pressure compared to 17Kpsi in a .22LR, blow by are odd internal ballistics.
Theoreticall a slug only needs 0.0005-0.001" engagement from rifling. Our LW barrels have about 0.004" deeper grooves. That's a lot of blow by. Lost pressure/efficiency.
I just tried .217" JSB Knockouts mic at .216-.2165" in my LW Condor. No preload and 2300psi got me 1030fps w/ a .188" top hat. I've sent 32 grain .true Griffin .217" at 1070 but they're fine at lower speeds.
Swaged is good for mass production or by hand. But cast with driving bands reduces friction. And again, if anyone thinks that cast slugs stink, well, everyone's barrel is different but;
https://www.pyramydair.com/blog/2012/03/lasso-2012/
When you know how to cast right and hand lap. These 420257's from his build proved 1/8" moa consistently all day long.
I'm actually suprised the pellets/slugs that fall back out of some barrels shoot as well as they do.
Other airguns I have need a 5.53/5.54 pellet or groups open up.
I'm wishing SAAMI type specs would be initiated but until then? Test test test.
Theoreticall a slug only needs 0.0005-0.001" engagement from rifling. Our LW barrels have about 0.004" deeper grooves. That's a lot of blow by. Lost pressure/efficiency.
I just tried .217" JSB Knockouts mic at .216-.2165" in my LW Condor. No preload and 2300psi got me 1030fps w/ a .188" top hat. I've sent 32 grain .true Griffin .217" at 1070 but they're fine at lower speeds.
Swaged is good for mass production or by hand. But cast with driving bands reduces friction. And again, if anyone thinks that cast slugs stink, well, everyone's barrel is different but;
https://www.pyramydair.com/blog/2012/03/lasso-2012/
When you know how to cast right and hand lap. These 420257's from his build proved 1/8" moa consistently all day long.
I'm actually suprised the pellets/slugs that fall back out of some barrels shoot as well as they do.
Other airguns I have need a 5.53/5.54 pellet or groups open up.
I'm wishing SAAMI type specs would be initiated but until then? Test test test.
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Edit: Yup. Cast 420257 slugs. 1/8" moa consistently.
You can ask anyone that was there.
Ask BB himself.
EDIT: or many other folks who are well known.
https://www.airgunguild.com/airgun-ammo/new-224-cal-from-arsenal/
Granted John was Military & over seas private security. Has shot in all altitudes, weather, winds.
If you doubt it give him a call. He might let you borrow one & see.
+1 (918) 801-6155
I'll tell him you can be trusted. Ask Cyclops Joe if you doubt me. He knows all about it.
I'd love for everyone to hear the entire true story
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