Scope/Rings and Ammo help .300 Win Mag Kimber 8400

[Joe.G]

Hi,
I just picked up a 2012 Kimber 8400 Ducks unlimited edition in .300 Win Mag new in he box UN-fired. I am thinking about putting on a 4x16x44 Sig Whiskey 4 scope with Sig Alpha 6 rings or Tally Rings. I am unsure on height? Med or High ?

Thinking about 2 Piece Warne Base.

I am open to other options, Honestly I have no real plans at teh moment for the rifle but would like to take it on a out west hunt at some point and just want to have it out fitted and ready to go. Thanks

Ammo selection I know it is what the rifle likes but I am looking at 180 to 200 Gr Barnes or Hornady ELDX.

https://www.federalpremium.com/rifle...11-P300WP.html

https://www.hornady.com/ammunition/r...sion-hunter#!/

https://www.sigsauer.com/whiskey4-sc...adj-black.html

[44 AMP]

In general, the scope needs to be high enough to allow easy working of the bolt handle, and line up with how YOU mount the rifle. Stocks are made to fit MOST people well enough, but aren't perfect for some of us. Your specific comb height, cheek weld and physical build need to be matched with the scope height so you don't have to "hunt" to get clear field of view.

A scope that's a little too high can be used, and while not perfect, is better than one that is too low FOR YOU.

The rifle will show which brand of ammo /bullet weight is likes best (if any) when you begin shooting it.

You might consider asking the scope maker, or ring maker which right height the recommend for that scope and that rifle. before you buy the rings.

Or you can just buy both sets, test both, and use the one that works best for you, and sell/trade the other, or keep it for use on a different rifle.

[Paul B.]

I pretty much agree with what 44AMP said. I used medium rings on all my .300 Win. Mags and never had a problem. Probably the size of the front bell of the scope may be the determining factor of which set of rings will work for you.
aul B.

[Joe.G]

4x16 or a 3x12 which would be the better way to go scope wise? I have a 3x12x44 on aother rifle and I am not sure I would ever shoot further than that scope goes, I run 3x9 on most of my stuff.

[ligonierbill]

Since you'll be shooting at big game, that top magnification will mainly be used shooting groups at the range. In the field, you probably will set what you are comfortable with and leave it. For me, that's 6X, but that's me.

Barnes bullets (and other copper monos) still generate some controversy, but I have almost always found them very accurate. Never put one in meat, though. My 300 mag is of the H&H variety, but the 178 Hornady ELD-X does very well in that rifle. I'm still testing their 200 and 212 bullets. You should test your own; it's part of the fun!

But, if you're going hunting, go with tried and true. It's terminal performance that counts.

[tangolima]

Such hard kicking round on such light rifle, I probably will get steel rings with higher screw torque and rosin dust on the tube. Everything I can do to keep the scope stay put.

Muzzle brake or recoil pad won't help. They are for the shooter's shoulder, not the scope.

-TL

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[44 AMP]

Muzzle brake or recoil pad won't help. They are for the shooter's shoulder, not the scope.

The pad, yes, but a muzzle brake will also reduce the recoil to the scope, not just the shooter's shoulder.

[tangolima]

Originally Posted by 44 AMP

The pad, yes, but a muzzle brake will also reduce the recoil to the scope, not just the shooter's shoulder.

The recoil effect on the scope happens when the bullet is accelerating in the bore.

-TL

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[Nathan]

I don’t know that rifle, but typically rings that are medium height in standard rings are the right height. Additionally, I would try Hornady Precision Hunter ammo before I worried about anything else.

[Joe.G]

Nathan the 200 ELD X is in their Precision Hunter line.

[44 AMP]

The recoil effect on the scope happens when the bullet is accelerating in the bore.

Thats when it begins, yes, but a proper brake reduces the overall amount of recoil in total, so I think it does count. HOW MUCH? it depends on several factors.

[tangolima]

Originally Posted by 44 AMP

Thats when it begins, yes, but a proper brake reduces the overall amount of recoil in total, so I think it does count. HOW MUCH? it depends on several factors.

Let's plug in some numbers.

200gr bullet weight. 3000fps MV. 9lb rifle. 1lb scope. 64kpsi chamber pressure.

Muzzle brake requires exiting gas, which comes way after peak chamber pressure, so it has little or no effect on peak recoil force.

(0.308/)^2*pi*64,000=4768 lbf

It is the force exerted on the rifle + scope assembly. The force on the scope is less following weight ratio.

4768*1/10=477 lbf

It is accelerating the scope backward to catch up with the rifle. Without enough friction from the rings, the scope slides forward in the rings, which is all I have seen.

After the bullet exits muzzle, the rifle decelerates to a stop within a short distance. With bare shoulder, it requires say 1/4".

Bullet muzzle energy 3975 ft-lbf. Recoil energy of rifle + scope

3975*200/7000/10=11.4 ft-lbf

Forward force on scope

11.4/0.25/10=4.5 lbf << 477 lbf

Pad or muzzle brake changes that somewhat, but it is nothing compared to when the bullet is accelerating in the bore.

-TL

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[44 AMP]

I'm not going to argue with your numbers, but your explanation leaves me confused in places and I'm not sure if its something being left out, or just my understanding of the way you phrased it.

It is accelerating the scope backward to catch up with the rifle. Without enough friction from the rings, the scope slides forward in the rings, which is all I have seen.

This, in particular. The scope does not slide forward. It appears to have done so, after the fact, like a revolver bullet "jumping crimp". This is inertia at work.

And this,

After the bullet exits muzzle, the rifle decelerates to a stop within a short distance. With bare shoulder, it requires say 1/4".

After the bullet exits muzzle, the rifle decelerates because force is no longer being applied. Where does the 1/4" or so come from??

[tangolima]

Originally Posted by 44 AMP

I'm not going to argue with your numbers, but your explanation leaves me confused in places and I'm not sure if its something being left out, or just my understanding of the way you phrased it.







This, in particular. The scope does not slide forward. It appears to have done so, after the fact, like a revolver bullet "jumping crimp". This is inertia at work.



And this,





After the bullet exits muzzle, the rifle decelerates because force is no longer being applied. Where does the 1/4" or so come from??

I should have said the scope slides forward of it original mounted position, similar to bullet jumping crimp in revolver. All the scope slippings I have seen are in this direction, never the other way.

Rifle stops because the shooter's shoulder pushes forward. The energy needs distance to dissipate. Work done = force * distance travel. 1/4" is just an estimate for bare shoulder. It comprises compressed clothing and flesh, body arch backwards etc. I know 1/4" is short for .300 wm, but the actual figure should be similar order of magnitude. Recoil pad lengthens this distance. Brake actually shortens it.

-TL

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[44 AMP]

Rifle stops because the shooter's shoulder pushes forward.

The rifle stops because it cannot physically move back as it is against the shooters shoulder and the energy is transferred to the shooter who has a mass of 10x-20x the mass of the rifle.

perhaps I am unconsciously pushing forward with my shoulder, but I am deliberately pulling the rifle back against my shoulder with my arms, to form one "solid" unit to absorb the recoil energy.

Calculating the velocity the recoiling rifle would reach based only on the weight of the rifle does not take into account the fact that the rifle is not unrestrained and is limited in movement, by being tight to the shoulder. The entire combined mass of the rifle and the shooter is what is being moved by the recoil energy, in sequence, over time, and other than as part of the rifle mass, the scope is just along for the ride.

[tangolima]

Originally Posted by 44 AMP

The rifle stops because it cannot physically move back as it is against the shooters shoulder and the energy is transferred to the shooter who has a mass of 10x-20x the mass of the rifle.



perhaps I am unconsciously pushing forward with my shoulder, but I am deliberately pulling the rifle back against my shoulder with my arms, to form one "solid" unit to absorb the recoil energy.



Calculating the velocity the recoiling rifle would reach based only on the weight of the rifle does not take into account the fact that the rifle is not unrestrained and is limited in movement, by being tight to the shoulder. The entire combined mass of the rifle and the shooter is what is being moved by the recoil energy, in sequence, over time, and other than as part of the rifle mass, the scope is just along for the ride.

Shooter's body can't possibly move exactly with the rifle, and hence be part of the rifle, unless there is nothing compressible between the rifle butt and your bone. The force transferred to the shooter's shoulder is the aftermath of the compression at much reduced magnitude. That's how recoil pad works.

-TL

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[44 AMP]

The shooter and the rifle are a combination of rigid and "squishy" parts, so force doesn't transmit as simply as it does through a solid steel forging.

[tangolima]

Right. Let's not linger much on this part of mechanics. The point is the backward force on the scope is the critical recoil force, and muzzle brake or recoil pad won't help much.

-TL

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[44 AMP]

muzzle brake or recoil pad won't help much.

True, but not much is not none, and that was my main point.

[tangolima]

Originally Posted by 44 AMP

True, but not much is not none, and that was my main point.

4.5lbf at the most vs 477lbf. Less than 1%.

-TL

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