energy needed to knock over ram 200 meters

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kdiver58
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energy needed to knock over ram 200 meters

Post by kdiver58 »

I am trying to frustrate myself even more .

As anyone published a number as to the energy to knock over a ram at 200 meters.

I want to find that number and work back for load a load for the 25 br/ xp-100

Thanks .. K
Last edited by kdiver58 on Sat Jun 11, 2016 11:32 pm, edited 1 time in total.
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energy needed to knock over ram 200 meters

Post by kdiver58 »

Now if I can just figure out a way to see the sights and somewhat see the Rams .. No luck so far ..
Last edited by kdiver58 on Sun Jun 12, 2016 12:32 pm, edited 2 times in total.
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Re: energy needed to knock over ram 200 yards

Post by AtomicDogg »

The theoretical minimum for Ram knockdown is a Terminal Momentum(TM) of 0.7; the closer to 1.0 the better. TM is calculated by multiplying the remaining velocity at 200m (FPS) x bullet weight (grains) divided by 225200 (constant). Ex. 140 Grain bullet w/ a muzzle velocity of 1758 FPS and a 200m velocity of 1459 FPS = 1459 x 140 / 225200 = TM of 0.91.

So, you will need the muzzle velocity and a ballistic program to give you the 200m velocity to perform the calculation. As a general rule of thumb, a 140 Grain bullet needs to start out at least at 1500 FPS, and assuming it sheds ~300 FPS @ 200m you will have a TM of 0.75 (minimum). The new Sierra v7 Ballistic Program performs the TM calculations. The final test is to test on 200m Rams, but remember, some ranges have harder Rams than others, so you might what to be above the minimum.
Last edited by AtomicDogg on Sat Jun 11, 2016 6:37 am, edited 5 times in total.
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Re: energy needed to knock over ram 200 yards

Post by jmoore »

I would imagine he's destined to make his debut at Lincolnton, if that's any help!

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Re: energy needed to knock over ram 200 yards

Post by AtomicDogg »

Great; we'll help get him sorted out !!! I'll bring my chronograph; but the true test is if the load will take a Ram.
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Re: energy needed to knock over ram 200 meters

Post by kdiver58 »

Robert .. You are .. DA MAN !!!!!!
Last edited by kdiver58 on Sat Jun 11, 2016 11:33 pm, edited 1 time in total.
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Re: energy needed to knock over ram 200 meters

Post by kdiver58 »

I have contacted Barnes and Sierra ..

After I gave them all of the particulars on my gun both suggest a smaller bullet for accuracy.

Lincolnton, GA shooting will all depend on the load I develop and if I can find creedmoor
position that will not make my arm go numb. I am paying for past sins and damage to my Neck.

Could someone please edit my post to read 200 meters ..
Last edited by kdiver58 on Sat Jun 11, 2016 11:33 pm, edited 1 time in total.
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Re: energy needed to knock over ram 200 yards

Post by Richard Pickering »

You posted that just to get my attention, didn't you. As Robert mentions, there is theory and there is ''real world''. A shortcut for this is to multiply Vt (velocity at the ram) by bullet weight. An example is bullet 168.9 gr x Vt 1000fps. Result----168900, which is exactly .75 pounds/ft., which is a fairly reliable minimum for the ram. So----now----if you want to have 1000fps at 200m----what MV do you need ? In your case lets select a bullet of 100gr. The formula says it needs to impact at 1689fps---or 1700fps to satisfy the .75 minimum. A good online program is http://www.jbmballistics.com . You can insert various mv for your selected bullet and show the result at 200m. Try about 2200fps mv and see where it leads. RP (ps-----JBM says a 100gr Hornady spire point .257 at mv 2200 will result in 1743fps at 200m.) RP
I have served as assistant match director, Southern Silhouette club, 1980s. Also, the Griffin Gun Club for Silhouette during the 1990s, to about 2005. For a short period I authored the ''Cast Bullet'' section of The IHMSA News. Joined IHMSA March 1979.
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Re: energy needed to knock over ram 200 yards

Post by ole95 »

Ran some numbers using Serria 120gr. 25 cal #1650 with a BC of .357 mv1800 which =1394 @ 200m which = .74
So I would think anything over 1800 with the 120 should work
I use 120 @1950 in a 7tcu
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Re: energy needed to knock over ram 200 yards

Post by AtomicDogg »

kdiver58 wrote:I have contacted Barnes and Sierra ..

After I gave them all of the particulars on my gun both suggest a smaller bullet for accuracy.

Lincolnton, GA shooting will all depend on the load I develop and if I can find creedmoor
position that will not make my arm go numb. I am paying for past sins and damage to my Neck.

Could someone please edit my post to read 200 meters ..
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