Sherman Wildcats pressure limits?

[Ckgworks]

I tagged on to this because I actually wanted to learn....... if it's over pressure, please show us the "proof in the numbers, the easy way to figure it out" because if you don't, you've only done this in this thread..... .

 

[MagnumManiac]

Proof is in the numbers.

Pretty easy to figure it out.

What numbers would those be?

I have pressure tested my 25-06 running 57.5gr of RE25 under a 115gr Partition @ 3226fps, which I have been told is way over max pressure.
WRONG! The pressure generated in MY rifle is 58,982psi AVERAGE for 20 shots.
So, again, I ask you HOW do you know the Shermans are running over max pressure?
Velocity is NOT absolute in regard to pressure.

Cheers.

 

[adam32]

So, again, I ask you HOW do you know the Shermans are running over max pressure?
Velocity is NOT absolute in regard to pressure.

Cheers.

Actually velocity is a good indicator...when you're running a case with the same or less capacity of a comparable case 100-200fps faster...pressure is the driving force.

Again, there's no magic pixie dust happening...

 

[bigngreen]

Actually velocity is a good indicator...when you're running a case with the same or less capacity of a comparable case 100-200fps faster...pressure is the driving force.

Again, there's no magic pixie dust happening...

Pressure is the driving force BUT there are components to pressure there is more to it than just peak pressure.
Look at powders, you can run them all to the same pressures but you see dramatic velocity differences, if it was just peak pressure that did this all powders at the same pressure would result in the same speed. We all know this is not how it works hence the using different powders to maximize each case capacity and design.
Many times design changes allow a different powder to be used or it's used more efficiently which puts the same pressure but changes the duration or time under the curve.
The same pressure for a longer duration equals more velocity seemingly for free, you get a better burn in 10-12 inches of barrel vs powder making it to the end of the barrel before burning gives you more velocity at the same pressure.

There is far more at work than just peak pressure!!

 

[KMG]

Pressure is the driving force BUT there are components to pressure there is more to it than just peak pressure.
Look at powders, you can run them all to the same pressures but you see dramatic velocity differences, if it was just peak pressure that did this all powders at the same pressure would result in the same speed. We all know this is not how it works hence the using different powders to maximize each case capacity and design.
Many times design changes allow a different powder to be used or it's used more efficiently which puts the same pressure but changes the duration or time under the curve.
The same pressure for a longer duration equals more velocity seemingly for free, you get a better burn in 10-12 inches of barrel vs powder making it to the end of the barrel before burning gives you more velocity at the same pressure.

There is far more at work than just peak pressure!!

"There is far more at work than just peak pressure"!! How true! How is the pressure achieved & then ultimately utilized is the key to max velocity. We are lucky that we have such a myriad of reloading data available to us today at our fingertips, thanks to the internet. Enough information if taken just at face value can be dangerous. If pressure is just pressure why are powders classified in burn rate categories & primers according to their brisance, why would case fill percentages of the powders matter, rifle throating, case construction, neck tension, jumping vs jamming, or seating depth matter other than for finding accuracy. And I'm sure I'm missing some too, but these factors matter as they all come into play in the pressure equation which intern equals your max velocity.

 

[adam32]

Pressure is the driving force BUT there are components to pressure there is more to it than just peak pressure.
Look at powders, you can run them all to the same pressures but you see dramatic velocity differences, if it was just peak pressure that did this all powders at the same pressure would result in the same speed. We all know this is not how it works hence the using different powders to maximize each case capacity and design.
Many times design changes allow a different powder to be used or it's used more efficiently which puts the same pressure but changes the duration or time under the curve.
The same pressure for a longer duration equals more velocity seemingly for free, you get a better burn in 10-12 inches of barrel vs powder making it to the end of the barrel before burning gives you more velocity at the same pressure.

There is far more at work than just peak pressure!!

That's apples vs oranges...

I'm saying take the 6.5 SAUM compared to the 6.5 SS...one is smaller than the other, correct? But yet all things (except pressure) being equal which one is "faster"?

One will be over SAAMI of the parent case...I'm not saying it's not safe. I'm just pointing out the obvious.

I'm just one that doesn't buy into all the hype. No worries, it doesn't concern me what other people want to shoot...as long as it isn't a Creedmoor!

 

[stirner]

Refer to my post on the first page. I don't know what, numerically, my pressures are. Furthermore, I don't care. What I do care about is which load combination will give me the most accuracy, first, at the highest velocity, second; all without showing signs of pressure. It's as simple as that.

 

[bigngreen]

That's apples vs oranges...

I'm saying take the 6.5 SAUM compared to the 6.5 SS...one is smaller than the other, correct? But yet all things (except pressure) being equal which one is "faster"?

One will be over SAAMI of the parent case...I'm not saying it's not safe. I'm just pointing out the obvious.

I'm just one that doesn't buy into all the hype. No worries, it doesn't concern me what other people want to shoot...as long as it isn't a Creedmoor!

The saum and SS are the same capacity, the SS is shorter but blown out to regain the lost capacity but it completely changes the character of the case, the recoils is even different.

 

[MagnumManiac]

Actually velocity is a good indicator...when you're running a case with the same or less capacity of a comparable case 100-200fps faster...pressure is the driving force.

Again, there's no magic pixie dust happening...

If your THEORY was correct, the 300WSM could not possibly drive a 150gr bullet FASTER than a 300WM can. The WM is 10-12% LARGER in capacity than the WSM, BUT it pushes lighter bullets faster.
It's ALL got to do with CASE SHAPE, not MAXIMUM PRESSURE.

Sorry, but without ACTUAL PRESSURE FIGURES, you, or anyone else can not compare 2 cartridges and poo-poo one because you THINK it's not possible.

Cheers.

 

[TG-5150]

If your THEORY was correct, the 300WSM could not possibly drive a 150gr bullet FASTER than a 300WM can. The WM is 10-12% LARGER in capacity than the WSM, BUT it pushes lighter bullets faster.
It's ALL got to do with CASE SHAPE, not MAXIMUM PRESSURE.

Sorry, but without ACTUAL PRESSURE FIGURES, you, or anyone else can not compare 2 cartridges and poo-poo one because you THINK it's not possible.

Cheers.

Stop yelling. Some of us get it.

 

[Heavyiron]

Refer to my post on the first page. I don't know what, numerically, my pressures are. Furthermore, I don't care. What I do care about is which load combination will give me the most accuracy, first, at the highest velocity, second; all without showing signs of pressure. It's as simple as that.

That is the way i see it too. I got flogged for saying the same thing on another forum.
When weatherby had his actions made up to his specs, he put his guns limit at 150,000 psi. Soon the major manufacturers followed. The brass is the weak component with the primer being the first, thing to show pressure. When a case body starts swelling and showing case high pressures, example 0005 expansion, that is where i draw the line. Notice that i said 0005, not 005 for clarification. Ken waters explained this to me probably 40 years ago and i'm still alive with no blown up action.
Certain old guns need respect that were made around the turn of the 20th century, and need to be loaded very lightly. Probably maybe earlier but any gun made after 1950 has the steel to stand up to modern loads.
I think most guns will blow a primer before turning loose. Estimates of pressure i have heard people with pressure guns say that a primer will blow around 80 to 90 thousand psi. The sherman is safe just like the ackley, no need to worry. Just my opinion though, beware

 

[Heavyiron]

Btw i do not own a pressure gun and never will. There is a forum that i go on that gang up and flog anyone that mentions wildcats. They are so radical that they even challenge companies that sell bullets about their data, not being correct.

 

[adam32]

If your THEORY was correct, the 300WSM could not possibly drive a 150gr bullet FASTER than a 300WM can. The WM is 10-12% LARGER in capacity than the WSM, BUT it pushes lighter bullets faster.
It's ALL got to do with CASE SHAPE, not MAXIMUM PRESSURE.

Sorry, but without ACTUAL PRESSURE FIGURES, you, or anyone else can not compare 2 cartridges and poo-poo one because you THINK it's not possible.

Cheers.

Check the pressure of the WSM that's pushing a bullet faster than a Win Mag and get back to me.

I've never said case shape doesn't play a role, but it's not as beneficial as capacity and pressure for creating velocity.

 

[MagnumManiac]

Check the pressure of the WSM that's pushing a bullet faster than a Win Mag and get back to me.

I've never said case shape doesn't play a role, but it's not as beneficial as capacity and pressure for creating velocity.

Really??
The WSM runs 7,000psi more than the WM, BUT with heavy bullets it cannot match the velocity of the larger WM case............please explain why this is?

The WSM pushes lighter bullets faster for one reason.........case shape provides a more efficient burn in START PRESSURE with light bullets that it cannot do with heavies due to case capacity being lost due to how much bullet protrudes into the case.

Cheers.