Evaluating Pressure - What Do You Look For?

[Bill2905]

When evaluating new bullets and/or powders and determining max loads, I look for primer flattening and primer flow. I also assess relative ease of extraction on fired cases. I was wondering if there are any other indicators I should be considering that some of you more experienced reloaders are looking it.

Thanks

[Robinhood]

Swipe marks on the base. Primer flow or cratering is not always a pressure issue.

[Ted_Feasel]

Another is measuring the diameter of the web area. Make sure your baseline is new brass. I can't remember of the top what over pressured is considered... maybe it was .004? If someone remembers please correct that if I'm wrong

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[celltech]

Ejector swipes and hard bolt lifts mostly...all my hotter loads flatten the primers to some extent and my .223 craters them as well. I use my chrono to know when I am, in theory, getting up there.....so I try to avoid ever maxing out these days.

[Ted_Feasel]

I know on my 308 bolt rifle , I found 3 loads that were all perfect in relationship to eachother so I went with the middle one figuring that gives me a happy medium of brass life and power

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[charlie b]

Chronograph compared to book loads and usually flattened primers. Primer condition is not that accurate, but, I rarely shoot near max book loads.

FWIW, many years ago I had a Rem 788 in 7mm-08. All factory ammo came out of that rifle with flattened primers. So, I was not surprised when my 'mid-range' handloads showed the same flattened primers.

[Bill2905]

Swipe marks on the base. Primer flow or cratering is not always a pressure issue.

After reading this, I educated myself on the appearance and cause of swipe marks. I checked the 6BR brass and sure enough, found these marks on the last and heaviest loading. I also recall these were harder to extract. I found satisfactory velocities well below these so will stay away from this end of the loading range.

Thanks for the info.

[Robinhood]

Another is measuring the diameter of the web area. Make sure your baseline is new brass. I can't remember of the top what over pressured is considered... maybe it was .004? If someone remembers please correct that if I'm wrong

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If the brass expands .004 the chamber was likely the culprit

[Fuj']

Swipe marks on the base. Primer flow or cratering is not always a pressure issue.

Robin is correct in my book. I will use WLR primers for general testing.
They will flatten early on, where my BR2's do not. This Cat I'm working
on now has an indicator of hard bolt lift, coupled with head stamp swipe.
BR2's still have a decent definable round edge, and no cratering. The WLR's
on the other hand are flat with sharp edge.

[tric3imagery]

Spilt barrel, powder burns on my face, missing hurt fingers, eye problems, unconcious. Last indicators.

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[Robinhood]

Spilt barrel, powder burns on my face, missing hurt fingers, eye problems, unconcious. Last indicators.

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Ouch!

[Ted_Feasel]

If the brass expands .004 the chamber was likely the culpritThat may be but I do remember reading about measuring at the web but I don't remember what the specs were but it was directly related to pressure. Heck its been a long time ago it may have been handgun loads

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[hamiltonkiler]

I like to stick hot mil spec loads in a .223 chamber [emoji23][emoji23][emoji23][emoji23]

Usually cratered primers.


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[bigedp51]

That may be but I do remember reading about measuring at the web but I don't remember what the specs were but it was directly related to pressure. Heck its been a long time ago it may have been handgun loads

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When you read the information below from the Hodgdon's remember the base expanshion can vary with brass hardness and thickness in the base of the case.

SIMPLE TRICK FOR MONITORING PRESSURE OF YOUR RIFLE RELOADS

http://www.hodgdonreloading.com/reloading-education/tips-and-tricks/simple-trick-monitoring-pressure-your-rifle-reloads

"One of the first rules of handloading is to always follow the approved reload data. The cautious reloader gradually works up to approved maximum loads to ensure his particular gun does not show pressure signs. Generally this is visual observation of the fired shell case head and primer. There is another slick way to check for pressure signs if you are interested.

Using a blade micrometer that measures in ten thousandths (.0001"), new, unfired cases can be gauged before and after firing to determine reasonably accurate maximum loads. Micrometers measuring in thousandths (.001") are insufficiently accurate to perform these measurements, and should not be used. Previously fired cases cannot be used accurately due to various levels of brass hardening. Measurement is taken just ahead of the extractor groove on the case head and must be taken at the same place on the case before and after firing. By placing a small mark on the case head – entering the cartridge in the chamber with mark at 12 o’clock – a consistently accurate measurement can be taken with each firing.

Lower pressure rounds, like the .30-30 Winchester, usually yield maximum pressures at .0003"-.0004" expansion. Modern cartridges, like the .223 Remington, will show maximum pressure at .0004"-.0005", while .308 Winchester, .270 Winchester, etc., typically yield .0005"-.0006" expansion at max pressure. Magnums, like the .300 Winchester Magnum, show maximums at .0006”-.0007” expansion, and should be measured on the belt.

In conjunction with these measurements, case head signs of pressure should be monitored as well. These signs include very flat primers, slightly cratered primers, ejector marks on the case head, and stiff extraction. All these case head signs indicate high pressure, and loads should be reduced until these signs disappear.

As always, start with the beginning load listed, and cautiously work up to the maximum shown for that set of components, using the methods listed herein."

[Ted_Feasel]

When you read the information below from the Hodgdon's remember the base expanshion can vary with brass hardness and thickness in the base of the case.

SIMPLE TRICK FOR MONITORING PRESSURE OF YOUR RIFLE RELOADS

http://www.hodgdonreloading.com/reloading-education/tips-and-tricks/simple-trick-monitoring-pressure-your-rifle-reloads

"One of the first rules of handloading is to always follow the approved reload data. The cautious reloader gradually works up to approved maximum loads to ensure his particular gun does not show pressure signs. Generally this is visual observation of the fired shell case head and primer. There is another slick way to check for pressure signs if you are interested.

Using a blade micrometer that measures in ten thousandths (.0001"), new, unfired cases can be gauged before and after firing to determine reasonably accurate maximum loads. Micrometers measuring in thousandths (.001") are insufficiently accurate to perform these measurements, and should not be used. Previously fired cases cannot be used accurately due to various levels of brass hardening. Measurement is taken just ahead of the extractor groove on the case head and must be taken at the same place on the case before and after firing. By placing a small mark on the case head – entering the cartridge in the chamber with mark at 12 o’clock – a consistently accurate measurement can be taken with each firing.

Lower pressure rounds, like the .30-30 Winchester, usually yield maximum pressures at .0003"-.0004" expansion. Modern cartridges, like the .223 Remington, will show maximum pressure at .0004"-.0005", while .308 Winchester, .270 Winchester, etc., typically yield .0005"-.0006" expansion at max pressure. Magnums, like the .300 Winchester Magnum, show maximums at .0006”-.0007” expansion, and should be measured on the belt.

In conjunction with these measurements, case head signs of pressure should be monitored as well. These signs include very flat primers, slightly cratered primers, ejector marks on the case head, and stiff extraction. All these case head signs indicate high pressure, and loads should be reduced until these signs disappear.

As always, start with the beginning load listed, and cautiously work up to the maximum shown for that set of components, using the methods listed herein."I think that 2nd method you described is what I was getting at i just couldn't remember the numbers because I already have my pet loads so I just have not had to think about it in a few years

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[yobuck]

I pay very little attention to the brass when i work up a load for my high capacity case guns.
Bolt lift is a different matter, and first sign of a heavy bolt lift is the stop /backup sign.
I frankly see little need for max performance loads with the smaller cartridges, and it could be argued with any cartridge.
Thats what the elevation knob is for.
That said there isnt much point in owning a 300 Ultra Mag if your gonna settle for 300 Win Mag performance.
Most guys spend far more on beer than they do brass, thats a one and done deal, and theres no whining over it either.

[Ted_Feasel]

I pay very little attention to the brass when i work up a load for my high capacity case guns.
Bolt lift is a different matter, and first sign of a heavy bolt lift is the stop /backup sign.
I frankly see little need for max performance loads with the smaller cartridges, and it could be argued with any cartridge.
Thats what the elevation knob is for.
That said there isnt much point in owning a 300 Ultra Mag if your gonna settle for 300 Win Mag performance.
Most guys spend far more on beer than they do brass, thats a one and done deal, and theres no whining over it either.I definitely agree that you should not go hot.. it really shortens brass life. On my 308 bolt guns I use starline match small primer, anneal at every 3rd reload and I am consistently getting 10 and 11 out of them, some more and ill get a very very tiny percentage that will slit out at the neck or something but even that rarely happens since I went to annealing at 3rd, 6th etc instead of after 3rd, 6th etc.. the imi match for my ar10 has to be annealed on the 2nd reload(I kind of assume that because its much harder)

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[Fuj']

I have a favorite RRA gasser in 5.56 that tells me pressure by where
the brass ends up on the ground. Behind me is weak. Directly to the
right is the most accurate. In front of me is War material.:cool:

[Ted_Feasel]

I have a favorite RRA gasser in 5.56 that tells me pressure by where
the brass ends up on the ground. Behind me is weak. Directly to the
right is the most accurate. In front of me is War material.:cool:If brass comes out to the front, it is over gassed, if it comes out to the rear, it is under gassed, the ideal ejection is roughly the 3:30 to 4 o'clock position. You can be over gassed and still be not to hard on the brass. Your lock and dwell timing is what will determine that. I would take a look at rim, extaction marks, carbon covered brass.. those would all give to information to know if you need to slow down unlock time. Adjustable gas blocks don't really slow down lock time. Gas system length and buffer weight are best ways to control that

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[yobuck]

I have a favorite RRA gasser in 5.56 that tells me pressure by where
the brass ends up on the ground. Behind me is weak. Directly to the
right is the most accurate. In front of me is War material.:cool:
Well since ive never owned a single semi auto firearm i dont have that luxury Fuj.
Therefore i just go by feel and the decible level of the ear noise. lol