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Sleeper Breech Question


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#1 Skeetz

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Posted 10 August 2017 - 01:17 PM

Would putting a sleeper breech in a blaster with the ar's intact still improve range? I would like to put one in my EAT a 5 kg to get a bit more range.


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#2 blitz

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Posted 10 August 2017 - 03:06 PM

A sleeper breech needs to disable the air restrictor to achieve the full effects of a sealed barrel. So, no, it would not improve range.


With an Elite Alpha Trooper, the stock plunger tube and just a 5kg spring is great for HvZ and low-end superstock. For brass breeches and velocity past ~120 FPS, they need a far higher springload and a larger plunger tube. 


Edited by blitz, 10 August 2017 - 03:07 PM.

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#3 Skeetz

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Posted 16 August 2017 - 04:22 PM

Just to be clear, ar in means absolutely no range increase with a breech, or less increase than if the EAT had no ar?


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#4 Silly

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Posted 16 August 2017 - 05:42 PM

Less increase then if you completely removed the ar.
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#5 Bubba Longshot

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Posted 17 August 2017 - 10:52 AM

I'm assuming that you are planning to build a full sealed sleeper breech, correct? In that case, the AR must be removed. If it's intact, you'll actually see a range decrease. That's because a fully sealed breech system needs to utilize the whole plunger tube volume.
Anyways, a 5kg spring in an EAT is not enough to properly propel a dart from a brass breech system; you'd need to upgrade to 9kg<.

So don't put a sleeper breech in your EAT unless you're ok with upgrading the mainspring, or want a range decrease.
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#6 Eightdotno

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Posted 17 August 2017 - 12:24 PM

Would putting a sleeper breech in a blaster with the ar's intact still improve range? I would like to put one in my EAT a 5 kg to get a bit more range.

From most of the sleeper breechs I've seen, you have to drill out the dart post and ar for the breech to function smoothly, if you left the dart post and ar in it, you may encounter some jamming.

Edited by Eightdotno, 17 August 2017 - 12:25 PM.

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#7 Dino

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Posted 17 August 2017 - 09:25 PM

I'm assuming that you are planning to build a full sealed sleeper breech, correct? In that case, the AR must be removed. If it's intact, you'll actually see a range decrease. That's because a fully sealed breech system needs to utilize the whole plunger tube volume.
Anyways, a 5kg spring in an EAT is not enough to properly propel a dart from a brass breech system; you'd need to upgrade to 9kg<.

So don't put a sleeper breech in your EAT unless you're ok with upgrading the mainspring, or want a range decrease.

 

When building a sleeper you have to keep in mind the PT size and use the correct amount of brass; just under 10CM, unlike a Longshot where you can have > 1 foot of brass as the barrel, here's a vid comparing different springs with a sleeper breech. so you can use 4+ kg.

 

 

Would putting a sleeper breech in a blaster with the ar's intact still improve range? I would like to put one in my EAT a 5 kg to get a bit more range.

 

you can't have a sleeper with the a/r intact but you can build a lazy breech, look up Paige Rowntree on Facebook and ask him. here's his guide: https://www.facebook...546241822228022.


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#8 blitz

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Posted 18 August 2017 - 08:37 AM

 

When building a sleeper you have to keep in mind the PT size and use the correct amount of brass; just under 10CM, unlike a Longshot where you can have > 1 foot of brass as the barrel, here's a vid comparing different springs with a sleeper breech. so you can use 4+ kg.

 

 

 

you can't have a sleeper with the a/r intact but you can build a lazy breech, look up Paige Rowntree on Facebook and ask him. here's his guide: https://www.facebook...546241822228022.

 

From the few exPT EAT's that I have seen, the nature of the design (those weird priming bars) really limit the spring that a blaster can use. Not saying you can't get 110-120 fps, just that you can't get much more than that.

 

Besides, if one does brass a 5kg standard elite piston, you're going to use what, an inch or two of brass for minimal gains? Can't say I would recommend. 
 

Lazy breeches are lame and I imagine that the brass would wear down the plastic (thus having a terrible seal) the more one uses it. Not a fan. 


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#9 Skeetz

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Posted 20 September 2017 - 06:34 PM

Apologies. I was under the impression that a sleeper breech was simply placing 17/32 brass in the stock breech and nothing more. Would this give any performance increase by increasing the dart seal, or no? example http://nerfhaven.com...showtopic=22027


Edited by Skeetz, 20 September 2017 - 06:39 PM.

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#10 blitz

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Posted 21 September 2017 - 04:45 PM

Apologies. I was under the impression that a sleeper breech was simply placing 17/32 brass in the stock breech and nothing more. Would this give any performance increase by increasing the dart seal, or no? example http://nerfhaven.com...showtopic=22027

 

That's not the breech commonly known as a "sleeper." The link you have is a half-breech with 17/32. It should have a tighter fit around a dart and increase velocity. I would be somewhat concerned about feeding issues however. 

Sleeper breeches are basically 17/32" barreled angel breeches that utilize the whole original bolt (9/16" pipe shaped to fit and then glued in).


Edited by blitz, 21 September 2017 - 04:46 PM.

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