Author Topic: FPE  (Read 4827 times)

Truckr6969

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FPE
« on: February 02, 2016, 11:00:48 AM »
How do I calculate the Fpe when I tune the mrod


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nielsenammo

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Re: FPE
« Reply #1 on: February 02, 2016, 11:09:41 AM »
http://nielsenspecialtyammo.com/pages/fpe-calculator

I have one on my site.  You can put in 6 different velocities and/or weights and get a side by side comparison.  You can bookmark it to get quick access to the page.
  • La Verne, CA
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Truckr6969

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Re: FPE
« Reply #2 on: February 02, 2016, 11:14:05 AM »
Thx Nick... Gonna have an order for you soon
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Monkeydad1969

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Re: FPE
« Reply #3 on: February 02, 2016, 11:53:31 AM »
Nice fpe calculator, Nick.  Hey just ordered a .177 barrel for my Escape.  Going to try those .178's out first.  I'll be making a order later this month.

Joe
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nielsenammo

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Re: FPE
« Reply #4 on: February 02, 2016, 11:59:03 AM »
Get the barrel twist rate if you can.  Probably fast being a .177
  • La Verne, CA
Cast Bullets and Custom Swaged Pellets for Air Guns
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Whome1525

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Re: FPE
« Reply #5 on: February 02, 2016, 03:33:31 PM »
Perk.....................................someone say .177 slugs?

Monkeydad1969

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Re: FPE
« Reply #6 on: February 02, 2016, 03:42:17 PM »
Perk.....................................someone say .177 slugs?

IDK...maybe... :o
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Joe the P-Dawg Slayer!!!!!

nielsenammo

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Re: FPE
« Reply #7 on: February 02, 2016, 03:55:28 PM »
.177 die on order.  It actually takes 2 dies to make the slugs you see guys shooting.  I have the first die which makes the slug the correct weight, I am waiting on the second which forms it into the bullet shape.  Joe has some made in the first die, probably good for a springer but the second die will be better for PCP.
  • La Verne, CA
Cast Bullets and Custom Swaged Pellets for Air Guns
Sized for your rifle
http://nielsenspecialtyammo.com
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Monkeydad1969

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Re: FPE
« Reply #8 on: February 02, 2016, 03:58:13 PM »
.177 die on order.  It actually takes 2 dies to make the slugs you see guys shooting.  I have the first die which makes the slug the correct weight, I am waiting on the second which forms it into the bullet shape.  Joe has some made in the first die, probably good for a springer but the second die will be better for PCP.

The ones you sent me work just fine in my pcp's.
  • Aurora, Colorado
Joe the P-Dawg Slayer!!!!!

match

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Re: FPE
« Reply #9 on: February 02, 2016, 08:40:00 PM »
How do I calculate the Fpe when I tune the mrod

w = pellet weight in grains
v = velocity in fps
451250 = 950^2 / 2
f = fpe in ft-lbs

f = w * v^2 / 451250
.40 Badger (arrived!)
.25 Gen I MRod w/WAR valve/SSG & MM custom t-port @ 0.17 (Cothran valve on deck)
.22 1322 upgraded to 2289
.17 Webley Hurricane
.17 Daisy 853
.17 late '60's Crosman Powermaster 760 in the original box

Monkeydad1969

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Re: FPE
« Reply #10 on: February 02, 2016, 08:52:06 PM »
Or use a fpe calculator.  Sorry Match.  :'(
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Joe the P-Dawg Slayer!!!!!

match

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Re: FPE
« Reply #11 on: February 02, 2016, 09:03:30 PM »
I don't do javascript - look at the code... very complex for so little.
.40 Badger (arrived!)
.25 Gen I MRod w/WAR valve/SSG & MM custom t-port @ 0.17 (Cothran valve on deck)
.22 1322 upgraded to 2289
.17 Webley Hurricane
.17 Daisy 853
.17 late '60's Crosman Powermaster 760 in the original box

Monkeydad1969

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Re: FPE
« Reply #12 on: February 02, 2016, 09:04:23 PM »
Now you're speaking Chinese to me... ;D
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Joe the P-Dawg Slayer!!!!!

Matt15

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Re: FPE
« Reply #13 on: February 03, 2016, 05:46:37 AM »
I use a regular calculator and do

Pellet velocity^2 X pellet weight / 450400 

So say I have a gun that shoots a 7.9 gr pellet at 700 fps

 700^2 X 7.9 / 450400 = 8.6 FPE  8)

nielsenammo

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Re: FPE
« Reply #14 on: February 03, 2016, 06:03:08 AM »
The on the my site is cool because you can do side by side comparison at a glance.  Put in a couple of pellet weights and their velocity and compare to each other.
  • La Verne, CA
Cast Bullets and Custom Swaged Pellets for Air Guns
Sized for your rifle
http://nielsenspecialtyammo.com
nielsenspecialtyammo@yahoo.com