Discussion: Airsoft ammo ballistics vs. aerodynamics vs. conditions

[Greylocks]

Stalker, you are mean. You make me want to write a volume about how bizarre airsoft ballistics are, and my brain hurts.
But I would discuss it over beer...

(PS, remember who'se brain you picked at long ago?)

[CDN_Stalker]

Originally Posted by Greylocks

Stalker, you are mean. You make me want to write a volume about how bizarre airsoft ballistics are, and my brain hurts.
But I would discuss it over beer...

(PS, remember who'se brain you picked at long ago?)

Of course I do, but I'm taking it farther. Should see the airflow drawings I drew up on paper last night, pretty cool. Gonna draw up bigger and better, then take pics and post here. Just a matter of time for me, seem to be lacking it a lot lately.

[The Saint]

Stalker, care to comment on barrel length? Over at Arnies, many are quite sceptical of deriving any real benefit from barrels over 363mm.

[CDN_Stalker]

Originally Posted by The Saint

Stalker, care to comment on barrel length? Over at Arnies, many are quite sceptical of deriving any real benefit from barrels over 363mm.

Interesting thing to bring up, I'm not really sure. Any chance you can outline their discussions for/against? All I can really see negative is the air pushing the BB becoming more turbulent behind the BB, possibly setting up the spin to be slightly more erratic, but considering there is a lot of "fact" about longer inner barrels being more accurate than short................ I really can't say the downsides of longer barrels vs. shorter.

[tunabreath]

Originally Posted by The Saint

Stalker, care to comment on barrel length? Over at Arnies, many are quite sceptical of deriving any real benefit from barrels over 363mm.

I am as well - the bullet has no memory of the barrel once it's down range. Although we have to keep in mind that they're mostly also limited to 328fps, and I expect a significant part of the "longer barrel advantage" plays out at (or in attaining) higher velocities (especially for gas guns).
I don't think there was much in the way of downsides, just that there was really a negligible benefit from going any longer than about P90 length, so beyond the aesthetic differences of a long gun, there was next to no actual performance boost (although it would naturally be more difficult to move around than a short barreled rifle, one big con). I think there was also mention that considering the speed that BBs travel through the barrel, the BB is in there long enough that changing the barrel orientation while the BB was being fired would have a more significant effect in longer barrels, causing inaccuracy in that the trajectory would be farther off of its original firing axis than it would be from a shorter barrel, contributed to by barrel/body flex, vibration, higher likelihood of imperfection, etc.

Stalker, I'm also interested in comparisons with real steel/rifled ballistics in addition to just the airsoft relevant stuff, so that we can put to rest the "why aren't airsoft guns rifled" bit once and for all, as well as potentially come up with a better BB (enlongated perhaps? I believe finned BBs tend to give poor results, aka corkscrew flight paths).

Veering ever further off course, I'm also interested in energy transfer characteristics. I had the idea that if we used projectiles more akin to real rifle boat-tail shaped rounds, which keep one end pointed forward, we could use more pliable materials there to absorb some impact. This could let us use heavier rounds at higher velocities (meaning enhanced range and hopefully accuracy, as well as brush cutting power and wind resistance) without causing any more pain or skin damage than what we use currently.

I'm toying with the idea of a teardrop shaped silicone projectile with a 4.5mm air rifle BB inside, maybe fired from a TK barrel (no hop up, obviously, and the silicone would probably engage the spiral grooves, acting like actual rifling rather than this air cushion theory that it's doing now).




@ Styrak below, yes it would be and yes you would have to, but I picked it because it's easy to get around the house in caulking form so I could attempt home experiments. I thought about using hot glue, but I don't think it's soft enough to see any real impact absorbption benefits.

**another edit, found these:
http://www.arniesairsoft.co.uk/forum...l=inner+barrel
http://www.arniesairsoft.co.uk/forum...pic=42475&st=0

[Styrak]

Wouldn't silicone be really sticky against the metal barrel? Unless you oiled them a lot?