60,000psi for the 6.5x55
 

Saami specifies 51,000 psi for the 6.5x55
the Swedish 96 mausers were tested to ~66,000 psi
Norma rates this mauser for 65,000 psi.
I have set my maximum loads for 60,000 psi
By using the barrel pressure calculation I can determine,
the velocity of each bullet I use at 60,000 psi. This seems to work fine.
Am I missing anything.

Are you using a strain gauge?

This is a question I have oftenwondered too. Especially in modern strong action why is the 6.5x55 so held back. My thought was it is a case strength issue. At 60000 psi it would blow the Creedmore out of the water. What kinds of velocity have you got with the bullets you use and your barrel length.

24" barrel
130gr ELD 2726fps @58.8k
139gr spbt 2574fps @59.5k
22" barrel
130gr ELD 2666fps @61.3k
139gr spbt 2574fps @61.4k

How are you arriving at those pressures in your rifle?

https://i.imgur.com/eaekeio.jpg

This is the program I use.

24"barrel; IMR-4350
Berger VLD 140gr - 2735fps
Sierra SPBT 142gr - 2835fps
Hornady SST 129gr - 2900fps
Don't know about pressure, primer looks OK. I know some people shoot 140gr bullets at 3000fps from 24" barrel with VV560 powder.

As you say no signs of hi press, your probably good to go , all but one are within the pressure test range of 66k, I would definitely stay away from the 3000fps/140gr.

I compared spreadsheet predictions with QL results for a 30-06 load I use.
I adjusted correction factor in the spreadsheet to match my chrony data and the resulting pressure was about 5500psi less then the Pmax calculated by quickload.
I would say while the spreadsheet gives approximate values, it does not take in account the burning characteristics of different powders and should not be used to determine maximal loads.

Exactly. Reloading manuals and online load data from Alliant, Hodgdon and Nosler use pressure tested loads in their rifles and would be more reliable.
Always start low and work up...

You use what ever your Happy with , and stick to the 51k as a max:sHa_sarcasticlol:

Start low and work up means work up until you notice signs of pressure in your specific rifle.
Back off 1 full grain of powder and that is the max load in your rifle. This is how I do it and every rifle is different.
I would never trust a spreadsheet listing max pressures when they can't even spell 30-06 lol...

At what temp and altitude is that chart set for? Even quick load needs to be adjusted for different temperatures. also need to be careful with loading to hot in February -20° and then shooting in the summer at +25° the pressure won’t be the same and brass life will suffer. I like to reserve 15% from max to account for external ballistic changes and record speeds every time I shoot to check for temp stability then plug that data into SterlokPro to get current target dope. Reserving 15% would put you at 51000psi if your using 60000psi as your max. just because you don't see pressure doesn't mean there isn’t pressure, speed is a pressure sign often ignored when one is only looking to see if the ejector and extractor are stamped on the brass or the primer is cratered or pancaked.

That's my spelling id t I know what it means. Are You Giving me rules for reloading, I have probably been reloading since before you were a gleam in your fathers eye.

Please reread the original post, as you probably have noticed no reloading manuals set the temp and atmospheric press required for their loads, so it's insignificant. By the way you must have pressure to get the bullet moving, How much pressure at what velocity is the purpose of the program. The ambient temp may make a little change but not significant. Also what the heck is this 15% reserve your talking about. By the way this is not a chart, but a photo of the program I use. Sorry your response was not very useful.

Oh boy, you sure are. And it doesn't sound like you are interested in listening to anyone else anyways...

Sounds like you have it all figured out best of luck.

WOW can't fix....!

Thanks Dubious :love0025:

I'm with you on the pressure subject. I've been running the 6.5 x55 SE in my modern actions for quite a while now at 60,000+ psi.


I check my pressures against choreographed velocities in Quickload and they are pretty close to what you are seeing. No issues at all. It' a great cartridge when it's fed properly.

Thanks for confirming my beliefs.

It doesn't account for a smaller or larger chamber, rate of twist, bearing area, freebore, or the various powder variations, so it is a very rough estimate at best. It it was accurate, there would be no disclaimers in the various manuals about working up loads while watching for pressure signs. The ammunition manufacturers and loading manual producers would not bother with pressure testing equipment.

Since when did reloading become an exact science ? It has alway been a thing about an "educated approximation". Any two rifle bores and chambers always vary a bit, as do atmospheric conditions, altitudes, etc. A large part of successful reloading is totally dependent on experience. If you don't have much experience, for sure, go by a manual. If you have sufficient experience, and have the equipment and reloading tools required, use them and reap the benefits. You won't need to worry about any pressure trace equipment or disclaimers like the ammo manufacturers do. And if you require a critique on your methods and results, just post it on a forum.

.

The point being. it is meaningless to quote pressure numbers based on a very rough calculation, that could easily be out 10-15% or more. Load what you like, based on the absence of pressure signs, but don't pretend to know what kind of pressure the load is producing, based on such a rough guess.

Lots of European outgits were clambering '96 actions in csrtridges like the 30'06 which is in the 60,000PSI range .
The big causation in manuals were about certain actions for cartridges like the 6.5x55, 45/70 and the 303 Brit., not the cartridge itself.
Cat

I certainly agree with the "not quoting pressure numbers" but I don't believe that pressures indicated by good software are easily anywhere near 10-15 % error..maybe 5% on the highest side...at least, I've never seen it. Not sure what you have verified.

Look what he posted, it doesn't even consider powder you can easily vary the velocity by 10% or more, at the same pressure, just by changing the powder.

OMG Elk ..you're a genius. I forgot they made more than two powders. Find another job.

Exactly. The numbers posted can't be taken seriously by anyone with a basic understanding of reloading.
Even reloading data from manuals that use pressure trace equipment needs to be used cautiously as you approach max loads listed...

That's a crock.
Go load the program, and check the results against existing reloading data, You'll find the results are very close regardless of powder, Your variations of 10% or more are purely out to lunch. I realize you have a lot of experience, but me thinks it is time you may want to go back to the books. Change of powder will change the velocity significantly, which in turn changes the pressure. But the velocity calculated against the bullet parameters, barrel length, will still calculate the pressure very close.