Bore Diameter relative to Recoil in SAME WEIGHT bullets

[98s1lightning]

If you take Surface Area of bullet
Multiply
π • radius squared (can't write it on my keyboard)

Then apply Force
Use a constant of whatever it may be to launch said bullet to 2800fps is it something like 50,000psi (I could be way off here I'm attempting to communicate)

Will bullets of SAME WEIGHT recoil more in larger diameter caliber if rifles weighed the same and applied force was the same? (or maybe this is where I don't understand it may take different amounts of force since surface area is different?)

I don't know how to word it exactly, but I think a 100gr 22cal, and 100gr 30 cal at same speeds will recoil differently if rifles weigh the same.

At the risk of sounding like a dummy, I've wondered about this. There's some incredibly smart people on here that will set me straight!

 

[98s1lightning]

There's a lot more friction-to-rifling on a long 22 bullet then a short 30

So that's a factor

 

[jebel]

Recoil energy is a function of the weight of the rifle on the one hand (full weight includes everything attached to it) versus the weight of what you're forcing down the barrel (weight of bullet plus weight of powder) and how fast you're pushing it (velocity).

The caliber of the bore doesn't come into it directly. Though as mentioned above, like weight bullets will be longer in a smaller caliber, requiring more pressure to get it to the same velocity.

Not sure if this gets to what you were asking.

 

[ARlife4me]

Seems like once engraving starts the force isn't as much? I'll state this, having 2 guns with 2 different bores 458 and 30cal creating the same muzzle energy, the 458 (45-70) has less recoil felt or not than my 300wm.

 

[doug2080]

I would think it may pertain more to the amount of powder in said cartridges maybe? Say for instance a120-125 grain bullet out of a 25-06 your max powder charge is gonna be around 50 grains depending on the powder. Same grain bullet in say a 300 RUM is gonna be closer to 110 grains max load. The more powder the bigger the boom?

 

[Gary in MD]

No where in the equation for calculating recoil will you find "bore diameter"

 

[eshell]

Is that a feature or a bug?

 

[FEENIX]

Recoil energy is a function of the weight of the rifle on the one hand (full weight includes everything attached to it) versus the weight of what you're forcing down the barrel (weight of bullet plus weight of powder) and how fast you're pushing it (velocity).

The caliber of the bore doesn't come into it directly. Though as mentioned above, like weight bullets will be longer in a smaller caliber, requiring more pressure to get it to the same velocity.

Not sure if this gets to what you were asking.

No where in the equation for calculating recoil will you find "bore diameter"

This! @98s1lightning, you are complicating things unnecessarily if you have all the attributes; there are plenty of (felt) recoil calculators out there, such as:

https://shooterscalculator.com/recoil-calculator.php

 

[Hand Skills]

He's onto something though, because one thing a bigger bore provides is larger EXPANSION RATIO

Meaning a faster powder can be used..

Same quantity of a faster powder will give more pressure

More pressure = more velocity


More velocity = more recoil

 

[Hugger-4641]

He's onto something though, because one thing a bigger bore provides is larger EXPANSION RATIO

Meaning a faster powder can be used..

Same quantity of a faster powder will give more pressure

More pressure = more velocity


More velocity = more recoil

Except that he specified equal bullet weight and equal velocity. If everything else is equal, there would be no difference in actual recoil of the two calibers, but that is actually impossible. If different powders or different charge weights of the same powder are used to get equal velocity, then the difference in mass of the powder charges will result in different recoil. As mentioned already, a smaller bullet is going to create more friction, so it will be impossible to use the same weight of the same powder and get equal velocity.

 

[98s1lightning]

My thought on the bore diameter/surface area of the back of the bullet

If you apply 50,000psi to a 22cal surface area versus a 30cal area

The 30 gets more energy because its 50,000 times the larger surface area is a bigger number.

Just another way to say it

Yes I'm confused!


Thanks for replies its interesting to hear what you guys think

 

[98s1lightning]

One person said a bigger bore has larger expansion ratio (I never heard of that one)

I know a bigger bore can burn more powder in a shorter length due to volume

That could make the recoil impulse shorter because the powder burn curve is quick

But then again a centerfire 22 must have some of the fastest burn curves because if not they would spit big fireballs out barrel and get low velocity w small bore/volume barrels.

 

[FEENIX]

Except that he specified equal bullet weight and equal velocity. If everything else is equal, there would be no difference in actual recoil of the two calibers, but that is actually impossible. If different powders or different charge weights of the same powder are used to get equal velocity, then the difference in mass of the powder charges will result in different recoil. As mentioned already, a smaller bullet is going to create more friction, so it will be impossible to use the same weight of the same powder and get equal velocity.

Exactly! As noted in #8, if the OP knows the attributes, he can use the recoil calculator to determine the yield result. Powder charge weight can make a difference even in recoil, as per the example below - 220 Swift 60 using 30.1g IMR 4064 vs. 37.8g RL-19, keeping bullet weight, velocity, and firearm weight the same:

 

[98s1lightning]

Wow Thanks Feenix, Hugger

Interesting stuff fer sure!

I had no idea a powder change would effect recoil like that