Skout Had a chance to do some .22 cal EPOCH shot count testing today ...

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Motorhead

Motorhead

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Nov 1, 2018
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25" barrel ( TJ 3g ) shooting some H&N 25g slugs.
3K bottle fill ( 500cc )
Reg at 1700 psi
Average speed 960 fps for @51+ Ft lbs :oops: Pretty healthy !!
It made 82 shots before coming off reg.

Sadly w/o Lloyd Sykes efficiency calculator being on line any longer ... No idea where the efficiency number crunch :unsure:
If anyone can crunch the numbers ? ... Thank You in advance.
 
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broekzwans said:
When I’ve tested the EPOCH I found they were rather inefficient based on the way they can be tuned (only reg pressure). I don’t have numbers to compare readily available at the moment
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Of course, it is ineffective due to the small plenum, especially when you push more power and on larger calibers, let someone prove the opposite...
 
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Airfuture said:
Of course, it is ineffective due to the small plenum, especially when you push more power and on larger calibers, let someone prove the opposite...
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What size do you think the plenum is? Plenum size isn't everything, especially for smaller calibers, since the airway resistance in the barrel is relatively large compared to bigger calibers. Basically the larger your caliber and the larger the need for speed the bigger the plenum needs to be.

The relatively large air consumption is because there is not really a way to decrease the speed on a certain regulator pressure so your always using the highest air consumption. Higher reg pressures give lower air consumption but in the EPOCH that just means the velocity will increase. The impressive thing with the EPOCH though is that they use a large air passage for the valve so they can use very low regulated pressures to achieve relatively high energy.
 
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Here’s how to calculate efficiency.

Take psi of air used and convert that to bar by dividing by 14.5.

Multiply this number by the cubic inches of the airtube or tank. The conversion for cc to ci is 16.39cc per cubic inch.

This gives you the total air available in cubic inches.

Take total air available divided by the fpe. Then take your total number of shots divided by this number to get the efficiency in fpe per cubic inch. The higher the number...the more efficient the rifle is.

Mike
 
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mubhaur said:
There is also another formula in which the lower the resulting value the more is efficiency.

I will share that as I shall find it.

Yarrah, Harry from Australia advised that to me
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FPE per cubic inch of air (bigger number is more efficient)
and
bar-cc per FPE (smaller number is more efficient)
 
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Privateer said:
@ Mike
With Lloyds spreadsheet We get 1.53 air efficency in FPE per std ci of air
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Which sure seems more in line with previous rifles at similar output when Lloyds calc was up and running.
I mien 82 shots at 51+ fpe in .22 caliber on 1300 psi on a 500 cc tank I thought was pretty dang good ?

See if Mikes comes back to the thread so we may converse if something in data crunching is amiss with either calculation :unsure:
 
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Centercut said:
Is the spreadsheet a secret? ;)
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Right now I'm working on getting it back online with Lloyd's full support and also working to turn out an App you can download to a phone. All free in case anyone wonders about that!
The spreadsheet is online but I can't open it as anyone could edit stuff and I can't have that until I get further down the road.
 
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