Thread: Wilcats and Pressure

Originally Posted by L.R

Spanners you really are talking shit. My 375 Lunatic is at 67,000psi and makes a 400gr projectile go 3035fps. Kiwi Greg's 375 DCM is at ???? Pressure and makes a 425gr projectile go 3080fps.

Kiwi Greg's is at a higher pressure and therefore makes more pressure. End of story.

If its safe of not will depend on what Barnard have designed the action to take. Why don't you call them and ask if they are happy with the pressure Kiwi Greg is putting on his action insted of speculating all this shit.

22-250 and 223 WSSM run the same pressure and get different speeds for the same weight proj, as does 270 and 270 WSM

Fact of the matter is, you;re not even shooting the same chamber/case - so thats a pretty bold statement to make

Regardless of if KG is at a higher pressure or not, can you explain why 67000 was the chosen as the final number? - genuine interest not a dig - because I keep hearing 'overloading' and want to know how we get to a line in the sand that anything over and above is 'overloaded' - This is whats this is all about; Wildcats in general without industry standard data
Was it a accurate load and left at that?
Is it max that the brass will take?
Is it max that the chambering will take?
Is it max the action will take?

might seem like a dumb question but why dont they make/experiment with thicker brass to withstand more pressure for something custom?

Originally Posted by ARdave

might seem like a dumb question but why dont they make/experiment with thicker brass to withstand more pressure for something custom?

I Spose they could, but got to have a weak point so brass is probably the best thing to let go...

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yea true bro. probably been experimented with already, but trying titanium 'brass' or double thickness brass surely would squeeze you a few more psi in youd think a? like if cost wasnt an issue. i supose its better for the brass to crack thank your face hahaha

Originally Posted by Spanners

22-250 and 223 WSSM run the same pressure and get different speeds for the same weight proj, as does 270 and 270 WSM

Fact of the matter is, you;re not even shooting the same chamber/case - so thats a pretty bold statement to make

Regardless of if KG is at a higher pressure or not, can you explain why 67000 was the chosen as the final number? - genuine interest not a dig - because I keep hearing 'overloading' and want to know how we get to a line in the sand that anything over and above is 'overloaded' - This is whats this is all about; Wildcats in general without industry standard data
Was it a accurate load and left at that?
Is it max that the brass will take?
Is it max that the chambering will take?
Is it max the action will take?

Don't know the answers to your questions, but using your example of two different cases in the same calibre, 375 Lunatic vs 375 Terminator (I really was scratching my head as to was this thread was about...:rolleyes: ), one has stated velocity and pressure to achieve said velocity, using the same action and barrel but a different case design. If the other would post comparable data with regards to what pressure was being run then we wouldn't all be wasting time here with what ifs... If it so happens that the pressures are much the same with the higher velocity being quoted then well done to the designers of case X...

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Originally Posted by Spanners

22-250 and 223 WSSM run the same pressure and get different speeds for the same weight proj, as does 270 and 270 WSM

Fact of the matter is, you;re not even shooting the same chamber/case - so thats a pretty bold statement to make

Regardless of if KG is at a higher pressure or not, can you explain why 67000 was the chosen as the final number? - genuine interest not a dig - because I keep hearing 'overloading' and want to know how we get to a line in the sand that anything over and above is 'overloaded' - This is whats this is all about; Wildcats in general without industry standard data
Was it a accurate load and left at that?
Is it max that the brass will take?
Is it max that the chambering will take?
Is it max the action will take?

I'm enjoying the read so far and well done for keeping it professional (no name calling etc...)

If you look at older loads say the 45/70 or similar that run at much lower pressures it would be a combination of spanners list of Q's above that lead to the pressure being specked so low (SAAMI or whatever standard was used) to protect the user in all situations, based on the cartridge and rifle that it was likely to be used in. The old Henry rifles with their brass actions wouldn't handle any more than a given pressure (the action would fail), so the calibre was made around the limitations of the rifle.

I guess what Spanners is asking is that if we make a new wildcat, then fit the rifle around that wildcat...how far can we go?


Keep up the debate...


kj

That's exactly it Kimjon.
And especially so for new cases as opposed to others that are necked up/down eyc

The 375 cheytac is no new round. And in NZ we are by no means the first to improve it. So there is already data with regards to velocitys for the cheytac case.

Originally Posted by L.R

The 375 cheytac is no new round. And in NZ we are by no means the first to improve it. So there is already plenty of data with regards to acceptable velocitys for the cheytac case.

Correct - however the DCM is not the same chambering is it not?

Any reply to the 67k questions?

OK seeing as my last post was to long winded.... let me have another go...

The suggestion is that good brass because it is stronger does not show the signs of pressure in a strong action.

If the failure of brass is the problem that we are trying to avoid, then what does it matter what the pressure is as long as there are no pressure signs?

If the action isn't strong enough, we should be seeing pressure signs in the brass before failure?

So 50K or 70K or even 90K is irrelevent if there is no pressure signs in the brass?

There is not a lot between no signs and failure on some of the hard brass. Personally I would like a large safety margin back from the point of failure to protect my eyes, face, life if anything is to ever go wrong. If you are at the limit all it takes is a slight overcharge or high temp to cause failure. It seems a lot of people forget what is at stake if it all goes wrong.

Originally Posted by L.R

There is not a lot between no signs and failure on some of the hard brass. Personally I would like a large safety margin back from the point of failure to protect my eyes, face, life if anything is to ever go wrong. If you are at the limit all it takes is a slight overcharge or high temp to cause failure. It seems a lot of people forget what is at stake if it all goes wrong.

So what was the 'limit' in your gun?

It was not taken to the "limit" as it would risk my action, brass and the person shooting it.

Originally Posted by L.R

It was not taken to the "limit" as it would risk my action, brass and the person shooting it.

Thats the whole point of this thread, what is the limit with something that doesnt have a standard, and what signs exhibited etc to draw to that conclusion?
A line was obviously drawn, how, what, and why was it drawn there and not further up?

OK so what the limit.... in your gun

Do you not follow the tried and accepted practice of loading up incrementally until the first signs of pressure and then backing off a subjective safe amount?