Recoil! 300 RUM vs 300 Win - Equal??

treillw

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Say you need 75 grains of powder to push a 215 Berger 2800 fps from a 300 win mag.

Say you need 85 grains of powder to push a 215 Berger 2800 fps from a 300 RUM.

The energy/pressure required to push the 215 berger down a .308 hole for the same barrel length at equal speeds needs to be the same for both guns - physics. Down range energy is the same. For every action, there is an equal and opposite reaction (recoil). Therefore the recoils needs to be the same.

So even though the RUM is burning more powder, it doesn't recoil any harder? Correct??

The only thing I can think that might change this is the RUM has more gasses escaping the barrel after the bullet exits, which might add to the recoil. But that doesn't really make sense. The extra gasses have nothing substantial to push against to make the rum recoil harder (it's pretty easy to push on air).

These are the things that keep me up at night.

Thoughts?
 

Geewhiz

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Every action has an equal and opposite reaction. I would think, everything else equal, if you are accelerating an equal weight projectile to the same velocities at the same rate, the recoil should be the same out of different rifles.

However there are a plethora of variables. Rifle weight, rate of powder burn (acceleration of projectile), twist rates, and on and on.

Your reasoning seams sound but i'm no physics major so who knows. 🤷‍♂️ lol
 
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treillw

treillw

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Further thought - the extra escaping gases with the rum might actually help to reduce recoil further, as they impart a greater force on the muzzle brake.
 
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treillw

treillw

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Every action has an equal and opposite reaction. I would think, everything else equal, if you are accelerating an equal weight projectile to the same velocities at the same rate, the recoil should be the same out of different rifles.

However there are a plethora of variables. Rifle weight, rate of powder burn (acceleration of projectile), twist rates, and on and on.

Your reasoning seams sound but i'm no physics major so who knows. 🤷‍♂️ lol
I'm talking everything as equal as possible.

Only differences would be cartridge and powder charge.
 

pyrotechnic

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In your example you have 10 more grains of material being ejected from the end of the RUM. It will generate more recoil.
 
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treillw

treillw

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I think the only nail in the coffin to this is to build the two rifles, drive up to proof, and put both rifles on their $xxxxxxx recoil testing machine.
 

pyrotechnic

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Its physics, whether it makes a noticeable difference to the shooter is probably up to alot of different things. Measurable, certainly.
 

Spoonman

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Why are you not getting more speed out of the rum than the winmag with the increased charge? Something doesn’t add up. The rum should push the same projectile a couple hundred fps faster which in turn would create more recoil.
 
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treillw

treillw

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Why are you not getting more speed out of the rum than the winmag with the increased charge? Something doesn’t add up. The rum should push the same projectile a couple hundred fps faster which in turn would create more recoil.
Look at a reloading manual, it should verify what I'm saying.

I surmise it's because there is more case capacity in the rum. You need more explosive to create the same pressure in that volume.
 
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treillw

treillw

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Why are you not getting more speed out of the rum than the winmag with the increased charge? Something doesn’t add up. The rum should push the same projectile a couple hundred fps faster which in turn would create more recoil.

Check out the data for the AA MAGPRO powder below (or others).

300-Winchester-Magnum (1).jpg300-Remington-Ultra-Magnum (1).jpg
 

PNWGATOR

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What are you trying to achieve?

No sense in loosing sleep vaulting over mouse turds.
 
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treillw

treillw

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What are you trying to achieve?

No sense in loosing sleep vaulting over mouse turds.
I'm trying to gain a better understanding of the recoil of a 300 RUM before I invest time and money in one.

I noticed the variation in powder charge while looking at reloading manuals. Also have had people tell me blindly that a rum will kick more because it has more powder, but I don't think that physics supports that necessarily if things are kept equal.
 

Spoonman

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treillw

treillw

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Look on the back of the ammo box of the two names cartridges in any brand and any weight projectile and you’ll see the difference in velocity. Not sure how this is so confusing?!?!
I don't get what you're saying.
 
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treillw

treillw

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I'm not shooting factory ammo, I can keep velocity equal, if desired.
 

Spoonman

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So I really don’t get why you want to keep the velocity the same ?!?! To get lower recoil? Use a brake or pick a different caliber if you are recoil sensitive. You will spend more to load a rum than the win and if there is a recoil difference it’s probably so minimal you wouldn’t notice.
 
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