o-ring detent for BBMG

Building or modifying BB, Airsoft, and Pellet type of guns. Show off your custom designs, find tips and other discussion. Target practice only!
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JDP12
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Fri Dec 24, 2010 12:40 am

well I'll be using .177 BBs, and was thinking of using a rubber washer with .125" hole. I think that should be sufficient, if not I can step it up.

I plan on housing in a coupling of some sort so I can adjust it if necessary, but I want quite a high pop-off pressure.
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jackssmirkingrevenge
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Fri Dec 24, 2010 12:42 am

JDP12 wrote:I plan on housing in a coupling of some sort so I can adjust it if necessary
In that case you should be fine, how thick is the gasket material you have?
hectmarr wrote:You have to make many weapons, because this field is long and short life
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JDP12
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Fri Dec 24, 2010 12:45 am

Have a couple thicknesses, I believe I have 1/16" and 1/8" available. Haven't decided which one to go with yet though.

Thinking 1/8", whats your opinion?
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jackssmirkingrevenge
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Fri Dec 24, 2010 1:33 am

I would go with the 1/16", you're holding the BB in a smaller area meaning there's less chance of two BBs getting stuck in the seal.

This is a problem with detent mechanisms in that a BB could be left stationary in the barrel and be struck by the next shot, at best giving you inconsistent performance and at worst ruining your barrel.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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JDP12
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Fri Dec 24, 2010 10:59 am

Hm....interesting, didn't even think of that. Crap. Well my barrel is brass sleeved in steel, so i don't know if barrel deformation will happen.. since the OD of the brass matches the ID of the steel almost perfectly.

We'll have to see what happens.

Would you put the detent after about an inch or two of barrel? seems like the logical place to put it, that way the BB's go into it straight
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jackssmirkingrevenge
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Fri Dec 24, 2010 12:11 pm

mech xmas

cokc
\bakks

yes,
hectmarr wrote:You have to make many weapons, because this field is long and short life
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JDP12
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Fri Dec 24, 2010 1:01 pm

Alright then......
"Some say his pet elephant is pink, and that he has no understanding of "PG rated forum". All we know is, he's called JSR. "
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JDP12
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Wed Dec 29, 2010 7:30 pm

Sorry to double post...but I have the detent all glued up and curing... so if I can get the actual gun workin tomorrow I should have some test results up tomorrow
"Some say his pet elephant is pink, and that he has no understanding of "PG rated forum". All we know is, he's called JSR. "
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Gaderelguitarist
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Wed Dec 29, 2010 8:10 pm

mech xmas

cokc
\bakks

yes,
Looks like someone had a little Xmas celebration...

Is there any blow-by in your barrel with the bbs? Having an inch or two of barrel material before the detent that is tight fitting with your ammo would cause some kind of jamming double feed thing.
so many muchness
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JDP12
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Wed Dec 29, 2010 8:17 pm

yea, there's some blowby in the barrel.
"Some say his pet elephant is pink, and that he has no understanding of "PG rated forum". All we know is, he's called JSR. "
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