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[Tierraalta66]

Gents,

For CQB applications, what is the best bb weight for high ROF (25+) / low FPS (350-) aeg setups? Also, what is the best weight for this same type of setup for field use?

My unscientific thinking is heavier for CQB (due to short ranges), and lighter for field (longer ranges).

Note: I'm aware that using light bb's (.20 / .23) in the field may not allow close groupings - especially when it's windy.

Many thanks in advance,

T66

[BLiTz-R]

I'm not an expert on it, but I believe the general idea is opposite your claim.

For longer ranges, you need a heavier BB, it is less affected by wind that you get outside.

[PiMan]

I'm not an expert on it, but I believe the general idea is opposite your claim.

For longer ranges, you need a heavier BB, it is less affected by wind that you get outside.

It is indeed. lighter BBs "hurt less" at close ranges, so its out of courtesy, plus, who wants to spend that much on ammo when you can use the cheaper stuff anyways.

I suggest you look into R-Hops and heavier BBs for outdoors.

BTW, 25 RPS is not high anymore, it's average 

[Limey]

I'm restricted to 350 fps on all my local fields and I use .25 or sometimes .28g bbs but for CQB you can use .2g ammo

[gunfighters]

It is indeed. lighter BBs "hurt less" at close ranges, so its out of courtesy, plus, who wants to spend that much on ammo when you can use the cheaper stuff anyways.

outher way around.. they hurt less @ longer ranges as they loose engery faster
@ closer range they are moving faster and can do more damage.. if you have ever seen the ever present group of noobs  load .12s(cause they ran out of "good" bbs) @ the local CQB joint, you know what I mean.. all of a suden there a bunch of bleading players and every ones like WTF happened


.20s for CQB, if its real CQB... not outdoor ranges that happen to be covered with a roof(aka warehouse cqb)

[cptpackrat]

My current CA M4 is shooting 355fps at upwards of 32+ rps... For outdoor field games i use .25s and heavier... for indoor CQB i either stay with .25 or drop to a .23 if i have them... thats just my personal preference as i know where my gun shoots at different ranges

[PiMan]

outher way around.. they hurt less @ longer ranges as they loose engery faster

I know that, but don't they impart less energy because of the decreased mass?
Throwing a pebble or a rock, the pebble will sting, but not do nearly as much damage, no? I know you probably won't get blunt force trauma from BB...

And I did mean .20-.25, I don't consider .12 on my weight scale 

To surmise, the general consensus is .20-.25 for indoor, .25+ (.28-.32 preferred) for outdoor.

[gunfighters]

nope..
the muzzle engery is the same (more or less) so the rock vs pebble doesnt work out..
its all about watts, aka engery over time.. and the FPS makes the difrance as we are talking about how fast the engery is transfred
if i stand chest to chest(as in touching) with you, put my fist on your chest and push with all I can, I will shove you back, but it won't really hurt much.. now if I stand 2 feet away and punch you in the chest with the same about of force its going to hurt.. even tho the engery is the same, the punch delivers it in a shorter time span

lets look @ a point blank shot form a 1 J gun
 a .12 is flying(numbers rounded) 1290 cm/s and a .43 is 680 cm/s
lets say the engery is transfred over 1cm of inpact in to the skin
the .43 transfers 1 j in .00147 sec for an impact of 680.272 watts
the .12  transfers in    .00075 sec for an impact of 1333.333 watts
the lighter faster round does more damage do to the speed.. things flip flop down range as the light round losses engery quicker.
throw numbers out the windo, heres a real world look @ the efect
***opens note book***
"Annex 1
Demonstration of increased penetration form the same muzzle energy, caused by less mass and more speed.

Test platform CM030 @ 4", last crony 183-185 w/.2s
Test media- 2 sheets of Styrofoam
Ammo-Excel .25s and cheep .12s that have been rolling around in my trunk for years , (what do you want I haven’t owned a gun that takes .12s for years ;-)

First photo, the 2 sheets stacked showing the top of the 1st sheet, entrance holes clearly visible, you can see the pencil zip tied to the gun as a standoff to keep the distance the same for all shots.

Second photo, the bottom of the 1st sheet. The .12s broke threw in all 4 shots and are visible in 2 cases, kept going in 2 cases and were caught between the sheets.
The .25s did not break threw but did deform the back side of the foam in 3 cases, in one case it left no disturbance on the back side.

Top of the second sheet, 3 dents form the .12s can be seen. The .25s left no marks on the second sheet.


In an ideal would I would have put all the shots across a crony so were could be sure the energy levels were the same and the .12 do to the short barrel were getting more energy then the slower .25
But either way the results seem to be imperial data that in many cases, @ close range, lighter faster ammo has more penetration.
"

[PiMan]

What about at and outside the usual MED? Maybe testing at 10 and 20ft, maybe a broken MED at 5ft? While I have been shot at from <6 in. (thankfully on the mask). I don't thinks it's a very common occurrence...

But I must say, props man! very good test! and I stand corrected... at 4"

...Actually, I think I have some .12s, maybe I'll try it.

Also, I believe if you over-volume, you can get higher J at the same spring, and I know it happens w/ a P*, which I have seen at my CQC field, but I digress...

[gunfighters]

I gusee in my head.. if you are playing with a MED your arn't playing CQB!
"on field" faily supjetive results show about 300 fps to break the skin (some places are easer then outhers) say on the arm and draw blood. so once you have droped below that it dosent matter much form a safty perspective (asuming full face)

@ 20' you start to see a real difrance.(staying with the 1J example) do to the lighter bbs loose engery faster do to higher drag numbers do to faster fps.
@ 20' a .3 hits with 16% more engery then a .2 @ 70' its all most 50% more engery!!!

so ya... ouch.. and @ CQB ranges there is no performance gain on the hevery bbs, they just hurt people more, so nothing but .2s should be used!

[PiMan]

Oh wow! That is quite a bit, although I suppose 50% more mass equates to 50% energy at some point 

I do have to use .25s so that my MP9 doesn't over hop...

[Lord Merlin]

Oh wow! That is quite a bit, although I suppose 50% more mass equates to 50% energy at some point 

I do have to use .25s so that my MP9 doesn't over hop...

Don't suppose things you can not prove.
v = velocity, and m = mass of the object.
The formula for movement energy is 1/2m multiplied by the square of v. In other words: v*v*m/2. So if you reduce weight, the initial energy will be higher.
On the other hand, the formula used for flying drag is only using frontal area multiplied by v (and some constants, but it is way overkill to write them here).

And we all know, that the higher weight you have the more energy you will keep, as the fps is squared for the energy formula. (And since the only thing you can pay the drag work from is the initial fps you have).

[PiMan]

Don't suppose things you can not prove.

The ATP chart shows ~50%

It was more of a reaction to the amount of energy retained by higher mass ammunition at longer ranges...

@ 20' a .3 hits with 16% more engery then a .2 @ 70' its all most 50% more energy
 

[gunfighters]

the amount of energy stored by higher mass ammunition at range...

not in the least.. bolth rounds leave with the same amount of "stored" engery and @ point blank will hit with the same force...
that is kinda of the point of faster=more damage @ some muzzle engery
the chart shows ONE example.. that is far form a rule or pattern other speed and weight yeaild very diffrent reslts..

[PiMan]

not in the least.. bolth rounds leave with the same amount of "stored" engery and @ point blank will hit with the same force...
that is kinda of the point of faster=more damage @ some muzzle engery
the chart shows ONE example.. that is far form a rule or pattern other speed and weight yield very diffrent reslts..

I more meant something alonge the lines of retained  oops...

And again, I point out that my comment was not meant to be a "rule" more of a reaction to the data provided. I knew they "held on" to their energy longer, but I had no idea it was 50% more at 70'...