Springers and Pellet Weight

[Bill_in_TR]

Maybe because I've been a serious shooter of all manner of projectile-launching implements for over sixty years, it just seems to me common sense that regardless of power-plant or weapon type, projectile weight should relate to power-level.

I've been there for those same sixty years. Yes projectile weight does relate to energy level. But in the formula the velocity value is squared where as mass is just a linear factor. The mathematical relationship is pretty straight forward. Changes in velocity will have a greater effect.

 

[AirNGasman]

"Changes in velocity will have a greater effect." If you mean on energy, correct!

However that's a moot point on powerful (enough) airguns or bows, where heavy projectiles absorb enough more of the power-plants' energy that they produce more muzzle energy with heavy projectiles than light projectiles... those heavy projectiles' energy advantage increasing with every yard downrange. Pretty simple Physics really; once you understand it.

 

[Guest]

I have found in my rifles that if I shoot a very light pellet of XX grains and you will get some awesome velocity. You will probably break the sound barrier in a powerful rifle, and place a pellet somewhere downrange, you won't have accuracy. When that light pellet breaks the sounds barrier, the sonic wave causes havoc with its flight path. If you take that same rifle and shoot a much heavier pellet the reduction in velocity will translate into better accuracy, which is what allows the hunter to hit his target in the desired place for a clean kill., I hunt with a variety of pellet types in different airguns that range in power from about 600 fps to some much more powerful pushing pellets over 1200 fps. And I have found that when I am shooting a pellet at top speeds, I get better accuracy with heavy, round-nosed pellets Heavier pellets also retain there velocity downrange longer than a light one. Just the laws of physics. 



I shoot nothing except Springer's. Don't own a .177 but this is true of any caliber I suspect.

Ditto

 

[Guest]

Yo! I finally bought these due to your amazing marketing.

My hw shoots these very well actually. Pretty good on pests too

 

[Bill_in_TR]

"Changes in velocity will have a greater effect." If you mean on energy, correct!

However that's a moot point on powerful (enough) airguns or bows, where heavy projectiles absorb enough more of the power-plants' energy that they produce more muzzle energy with heavy projectiles than light projectiles... those heavy projectiles' energy advantage increasing with every yard downrange. Pretty simple Physics really; once you understand it.

Thank you for calling into to question my knowledge and understanding of physics when you know nothing about me or my education.

Yes the efficiency of the power plant will come into play. But even with that consideration what you said about heavy projectiles is not an all encompassing fact. You can get too heavy and/or too light for a particular power plant. There is a range of optimum efficiency where any power plant works best. Within that range the energy formula is a pretty accurate analysis. What my original question pertained to was what people have found to be optimum pellet weights for different calibers and power levels.

It's all pretty simple once you have the complete picture.

 

[12_ft_lb_rules]

"Changes in velocity will have a greater effect." If you mean on energy, correct!

However that's a moot point on powerful (enough) airguns or bows, where heavy projectiles absorb enough more of the power-plants' energy that they produce more muzzle energy with heavy projectiles than light projectiles... those heavy projectiles' energy advantage increasing with every yard downrange. Pretty simple Physics really; once you understand it.

Thank you for calling into to question my knowledge and understanding of physics when you know nothing about me or my education.

Yes the efficiency of the power plant will come into play. But even with that consideration what you said about heavy projectiles is not an all encompassing fact. You can get too heavy and/or too light for a particular power plant. There is a range of optimum efficiency where any power plant works best. Within that range the energy formula is a pretty accurate analysis. What my original question pertained to was what people have found to be optimum pellet weights for different calibers and power levels.

It's all pretty simple once you have the complete picture.

He does not need to know your background as it seems he feels himself superior to all. He “corrected” a post I made as if ranges and events do not exist if he does not know about them.

 

[AirNGasman]

"He does not need to know your background as it seems he feels himself superior to all. He “corrected” a post I made as if ranges and events do not exist if he does not know about them." 

Sorry if I hurt your feelings, Fellas; but I neither called into question Bill's understanding of Physics, nor "corrected" 12's post ("as if ranges and events do not exist if he doesn't know about them").

Fact is, I told Bill he is correct! Only then did I point out how his statement, "Changes in velocity will have a greater effect" is untrue if he's talking about muzzle energy. 

And in my post about sub-15 yard air pistol competitions, I qualified my post with "to my knowledge". Apparently that qualification either fell on deaf ears or is purposely being ignored; and I might have been mistaken in assuming most folks would recognize I realize that someone, somewhere probably shoots some such competition. My bad.

So... reckon "he feels himself superior to all" might be a slight over-reaction?  Because I definitely don't feel I'm superior to all.

 

[Bill_in_TR]

Fact is, I told Bill he is correct! Only then did I point out how his statement, "Changes in velocity will have a greater effect" is untrue if he's talking about muzzle energy

I'm sorry by my statement is specifically true about muzzle energy. Changes in velocity have a greater effect than changes in the pellet weight. The math doesn't lie. The velocity is squared the mass is linear. Now if there are factors that make a particular pellet exit faster or slower than it relatively should because of fit or friction or the efficiency of the gun then that would make for a possible unexpected change in velocity.

The relationship between velocity and mass and their relative effect on the muzzle energy doesn't change however. Velocity is still squared, mass is not. That's a mathematical fact.

 

[AirNGasman]

And it's a fact of Physics that powerful airguns and bows produce more energy with heavy projectiles moving slower despite that mathematical fact. So we're both right. 

Right?

 

[Bill_in_TR]

And it's a fact of Physics that powerful airguns and bows produce more energy with heavy projectiles moving slower despite that mathematical fact. So we're both right. 

Right? 

Not true at all. The energy formula is definitely PART OF the "physics" of projectiles. And not all examples of heavy projectiles produce higher energy just because of their weight. The efficiency of the power plant is of course an issue as are other factors. But if the velocity changes in a normal relationship to the increase in weight then you won't see the muzzle energy increase you are talking about.

I shoot longbows quite a bit. The advantage of the heavier arrow is the effect of the momentum on penetration. But according to my chronograph results the relationship between velocity, mass and energy is the same. But the momentum vs energy effect on penetration is a whole 'nother argument and not for an airgun forum.

 

[Mossonarock]

Let's say this another way (or at least I'll try): A heavy pellet will dwell for a longer time before it starts to move down the barrel. However, if the piston slams against the end of the compression chamber before the pellet starts to really move, not as much energy will be transferred to the pellet as an optimum weight pellet will. That's why, as others have said before in this thread, there's a point after which a heavier pellet actually will actually deliver less energy than an optimum weight pellet for the power plant and gun architecture. The same is true with pellets that are too light for a certain powerplant because the pellets will start moving an may even completely leave the barrel before the piston have fully moved forward. Now, hard tin(lead-free) pellets may be light but because of their hardness they can actually dwell longer in the breech than an equal weight soft lead pellet will. So, the lead-free/tin pellet may actually have more muzzle energy than the equal weight soft lead pellet. How muddy is the water now?

My first hand experience: My Diana 35 which is a vintage .177 10m match gun can't push a lead-free pellet out the barrel because the pellets are too hard for the relatively weak powerplant to push the pellet. But the gun does fine with heavier lead pellets only because they are softer. In this case, pellet hardness makes all the difference and weight is less of an issue.

The OP's original question is a very good one for discussion. You can only get so much heavier with pellet weight before performance drops off. Also, pellet hardness plays a part too.

So yeah, there's the potential of balancing pellet weight and hardness to achieve flat trajectory and maximum fpe all while not destroying the gun's powerplant. Now wouldn't that be an interesting spec for pellet manufacturer's to begin including: Mohs hardness or such like?

 

[Guest]

My Diana 430L loves 10.34 Air Arms pellets. The shot cycle feels docile compared to shooting 8.4's. On the other hand my Remington break barrel eats up 8.4's. I say go with what's the most accurate within a reasonable weight range for your power plant.

Oh, both of mine shoot 11.5ft/lbs. The Diana shooting within .3ft/lbs between the two weights.