Reloading- What pressure signs do you stop at?

[gohring3006]

Ejector mark I take notice, I don't use primers as an indicator because of the nature of the process inside the chamber during firing.
Velocity is my next indicator. If I'm 100fps over I'll start monitoring one piece of brass to see how many firing I get before the primer pocket starts leaking. If I can get 6-8 firings, I'll probably roll with it. I'd like more, but if it's shooting tight with low numbers, I stick with it.

 

[akmtnhnt]

This^^. If you notice Hogdon and western powder put pressure numbers in their data. Most bullet companies do not. Hogdons data is also lower than Noslers on average. Why? Because they pressure test all their data. The Bullet companies test some but not all of their data.

Some bullet companies test none of their data.

 

[akmtnhnt]

I look at all the old wives tale signs spoken about before. Then I realized modern brass is so doggone good it covers a multitude of sins then I just go look at the muzzle velocity.

If it's too good to be true it's too much pressure for a new combo or an unknown combo. It's displacement and pressure behind a bullet weight burned in a length of tube, if you're doing more than can be explained for Barrel speed variation or elevation... it's to much pressure.

Someday I'm going to bite the bullet and figure out what it actually cost to set up a Piezo pressure sensing unit. We have portable dopplers for 650 bucks just got to be someone making a decent setup for the Everyman. For now I trust the muzzle velocity.

Here's another option.

Rifle Barrel Chamber Pressure Testing Hardware & Software | Pressure Trace

Measure ACTUAL rifle chamber pressure for each shot, barrel harmonics, rise time, time to muzzle exit and OBT barrel timing.

www.shootingsoftware.com

 

[comfisherman]

799 and 32 dollars per glued on setup. I'm actually not terribly shocked by that. Come to think of it, makes me wonder why there isn't way more adaptation by purveyors of wildcat rounds.... barring the pressure buzz kill obviously.

Very interesting.

 

[Dean2]

Here's another option.

Rifle Barrel Chamber Pressure Testing Hardware & Software | Pressure Trace

Measure ACTUAL rifle chamber pressure for each shot, barrel harmonics, rise time, time to muzzle exit and OBT barrel timing.

www.shootingsoftware.com

These actually work very well. Have seen them in action.

 

[DoneNOut]

Thank you for sharing! A lot of people are too prideful to share there mistakes, especially surrounded by the type A personalities on a forum like this. A lot of information information doesn't get shared because of lack of humility. These are things we need to see and think through...

Thanks again!
HW

You're welcome. I'm here to seek, gain, and share knowledge & experience. Even if it's ugly like this to be of some benefit to others. I really beat myself up hard about this. I get madder at no man but myself the most. Only consolation was being proud of myself for fabricating new ejectors, and a retaining pin from stuff around the armory. She is back in action and shooting great!

 

[akmtnhnt]

799 and 32 dollars per glued on setup. I'm actually not terribly shocked by that. Come to think of it, makes me wonder why there isn't way more adaptation by purveyors of wildcat rounds.... barring the pressure buzz kill obviously.

Very interesting.

I think because with hard data and pressure limits, the gains on a lot of stuff would be so minimal no one would bother.
With nothing but an eyeball you can claim no signs of pressure while running a lot hotter than a factory round, that if also ran at that pressure would be rather close in performance.

 

[crkckr]

Using primers to "read" pressure can be done but you have to know the firearm & primer brand well to do so. Without some experience it's little more than a crap shoot. It is best done in conjunction with a chrono!

As has been stated before, but cannot be overemphasized, if you are experiencing any abnormal bolt lift, you have far exceeded max pressure! I'm not sure backing off just one grain is enough!

If you're going to work in that max pressure realm a chronograph is a necessity. They don't cost that much and although often a total pain in the rear end, are worth their weight in gold when they work right! Playing around in the max load world can be dangerous to your firearms and your safety. Don't do it without all the tools you can afford!

Using the case as a pressure measuring tool can be as much of a crap shoot as using primers! So much depends on the case itself that even small changes can make a big difference, especially brand changes. Any measurements taken must be consistent as to placement. Records must be kept!

I suppose the absolute best way to do it is to use the p'electric sensors. Personally, I simply can't afford the equipment, not to mention I'd probably scare the snot out myself measuring some of my loads! Until I win the lotto, I'll have to stick with my chrono & my personal brand of voodoo!
Cheers,
crkckr

 

[General RE LEE]

Using primers to "read" pressure can be done but you have to know the firearm & primer brand well to do so. Without some experience it's little more than a crap shoot. It is best done in conjunction with a chrono!

As has been stated before, but cannot be overemphasized, if you are experiencing any abnormal bolt lift, you have far exceeded max pressure! I'm not sure backing off just one grain is enough!

If you're going to work in that max pressure realm a chronograph is a necessity. They don't cost that much and although often a total pain in the rear end, are worth their weight in gold when they work right! Playing around in the max load world can be dangerous to your firearms and your safety. Don't do it without all the tools you can afford!

Using the case as a pressure measuring tool can be as much of a crap shoot as using primers! So much depends on the case itself that even small changes can make a big difference, especially brand changes. Any measurements taken must be consistent as to placement. Records must be kept!

I suppose the absolute best way to do it is to use the p'electric sensors. Personally, I simply can't afford the equipment, not to mention I'd probably scare the snot out myself measuring some of my loads! Until I win the lotto, I'll have to stick with my chrono & my personal brand of voodoo!
Cheers,
crkckr

My virgin Alpha Munitions OCD SRP 308 brass had stiff bolt lift with rather benign loads. I am perplexed. Is it truly high pressure or because it's virgin brass.

 

[memtb]

I think because with hard data and pressure limits, the gains on a lot of stuff would be so minimal no one would bother.
With nothing but an eyeball you can claim no signs of pressure while running a lot hotter than a factory round, that if also ran at that pressure would be rather close in performance.

Now what fun would it be to actually use scientific means to determine the actual pressures your hand loads are producing!

"If you ain't standing on the edge….you're tak'n up too much room!" memtb

 

[Calvin45]

Now what fun would it be to actually use scientific means to determine the actual pressures your hand loads are producing!

"If you ain't standing on the edge….you're tak'n up too much room!" memtb

Correct!

I've honestly come to disregard most primer signs and bolt face marks because I've had rifles that left marks from merely chambering a round and not firing it, and certainly I've had factory ammo leave ejector swipes…and primers aren't so absolute either though a blown one is obvious.

If and when I'm pushing the envelope in uncharted territory with a particular combo for which there isn't data, some things I've come to value, in addition to paying attention to the chrono, are my "one finger bolt lift" rule….if I can't EASILY lift the bolt using one finger, too hot. Might not catch very slight stiffness if just ham fistedly caveman handling the bolt open haha. I do still look at primer and headstamp signs of course, look for head separation signs…

The other big signs to me at least in some cartridges are excessive stretch and expansion. I take before and after measurements of case length and diameter at the web. Now some brass is much softer than others and will move more. I'm fine acknowledging that I do in fact load tougher brass to higher pressure . HOORAY FOR PETERSON!

And of course there's the matter of primer pocket longevity. The other day I tried prepping some 257 wby brass for development that had already been used in load workup for a failed combo experiment. Couldn't remember which one was the piece that had obviously pressured out way too far…until I tried seating a primer in one of my resized cases and it just fell back out! Only twice fired, no way that should happen

 

[crkckr]

My virgin Alpha Munitions OCD SRP 308 brass had stiff bolt lift with rather benign loads. I am perplexed. Is it truly high pressure or because it's virgin brass

Did you size the brass before you loaded it?New brass should always be sized before loading. How is it to to chamber? Is it stiff to chamber? If none of the above, try resizing five pieces if brass and see if they chamber and extract ok without loading them. It could be the brass is just too long in the body, even if the OAL is good.
If that's ok, try reloading five or so rounds with the same load after FL resizing and see if the bolt lift is still stiff. If it is, the load/brass combo is just too hot.
Of course, before any of that that you should double check everything, load data, powder & bullet and has your scale been zeroed lately! Little things can sneak in and mess with you! I scared the pee out of myself once when I used data for a 210 gr bullet while loading a 250 gr bullet in my .338 Win Mag. Huge boom, set me back real good and when I opened the bolt & extracted the case, the primer fell out too! Ruin't that case and put the fear in me, let me tell you! The .338 ticks the bottom of my glasses every time I torch it off on the bench. I'm kind of surprised that one didn't put a big frown on my forehead! Good old Ruger 77, built like a tank!
Cheers,
crkckr

 

[Dean2]

Correct!

I've honestly come to disregard most primer signs and bolt face marks because I've had rifles that left marks from merely chambering a round and not firing it, and certainly I've had factory ammo leave ejector swipes…and primers aren't so absolute either though a blown one is obvious.

If and when I'm pushing the envelope in uncharted territory with a particular combo for which there isn't data, some things I've come to value, in addition to paying attention to the chrono, are my "one finger bolt lift" rule….if I can't EASILY lift the bolt using one finger, too hot. Might not catch very slight stiffness if just ham fistedly caveman handling the bolt open haha. I do still look at primer and headstamp signs of course, look for head separation signs…

The other big signs to me at least in some cartridges are excessive stretch and expansion. I take before and after measurements of case length and diameter at the web. Now some brass is much softer than others and will move more. I'm fine acknowledging that I do in fact load tougher brass to higher pressure . HOORAY FOR PETERSON!

And of course there's the matter of primer pocket longevity. The other day I tried prepping some 257 wby brass for development that had already been used in load workup for a failed combo experiment. Couldn't remember which one was the piece that had obviously pressured out way too far…until I tried seating a primer in one of my resized cases and it just fell back out! Only twice fired, no way that should happen

If you are expanding the primer pocket to the point the primer won't hold on ANY brass, you are WAY over the proper pressure. Weatherby factory loads are on the hot end, so are published Nosler loads, same brass in most cartridges as Norma make all of Weatherby's brass and a lot of Nosler's. Never had any problem getting 10 firings on 257 Weatherby brass if I stuck to the published max velocities. Yes, Lapua and Peterson will put up with over pressure loads longer, but you are still shooting too hot a load.

 

[Rosebud]

Correct!

I've honestly come to disregard most primer signs and bolt face marks because I've had rifles that left marks from merely chambering a round and not firing it, and certainly I've had factory ammo leave ejector swipes…and primers aren't so absolute either though a blown one is obvious.

If and when I'm pushing the envelope in uncharted territory with a particular combo for which there isn't data, some things I've come to value, in addition to paying attention to the chrono, are my "one finger bolt lift" rule….if I can't EASILY lift the bolt using one finger, too hot. Might not catch very slight stiffness if just ham fistedly caveman handling the bolt open haha. I do still look at primer and headstamp signs of course, look for head separation signs…

The other big signs to me at least in some cartridges are excessive stretch and expansion. I take before and after measurements of case length and diameter at the web. Now some brass is much softer than others and will move more. I'm fine acknowledging that I do in fact load tougher brass to higher pressure . HOORAY FOR PETERSON!

And of course there's the matter of primer pocket longevity. The other day I tried prepping some 257 wby brass for development that had already been used in load workup for a failed combo experiment. Couldn't remember which one was the piece that had obviously pressured out way too far…until I tried seating a primer in one of my resized cases and it just fell back out! Only twice fired, no way that should happen

Had that happen on loaded factory Barnes ammo after one firing. Was a 300 Rum. Called Barnes and asked about the problem! They said well someone overloaded it. Never told them who did it! Guy was unhappy with the way his rifle was shooting but had nothing but factory ammo. Had friend shoot it up, my shoulder couldn't take the punishment. He agreed with the crappy shooting part. Remington custom shop 700. Shot great after we got some useable brass.