emmagator
Well-Known Member
Ok im am very new to reloading. I hear guys talking about seeing signs of pressure etc... What are the signs that a bullet is loaded to "hot?"
Newbie: signs of pressure
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WRG
Well-Known Member
It will depend on the type of firearm you are working with. For bolt guns, a sticky bolt or a tight extraction from the chamber is a clear sign of over pressure. Some feel a flatten primer but I tend to look for the sticky bolt and tight extraction before I deem the load too hot. This is why it is so important that you work your load up by starting low and work up slow. I have a few loads that I use that the primers are flatten but QL tells me they should be well within a safe pressure limit. But you certainly want to be cautious once you start to see those primers becoming noticably more flatten. As long as you think safety first you should be alright. If it don't feel right by all means stop and go over all your data. A chronograph is your best tool when doing load developement.
Be Safe
Be Safe
J E Custom
Well-Known Member
Heavy bolt lift, bright spots on the case head , flattened primers,Blown primers, split cases,
pierced primers. crater around firing pin indentation on primer, ETC.
If you look at a new unfired loaded case and one of the fired cases it is normal to see a little flatting of the primer , But normally the first signs of approaching pressure loads is the flattening of the
primer. From there it only gets worse
Factory loads are normally below maximum pressure so a fired factory case compared to one
of your reloads can be used as a comparison.
J E CUSTOM
emmagator
Well-Known Member
Is this exactly as described, the primer flattens out? What causes this, case pushing backward?
emmagator
Well-Known Member
delete
Flattened primers by themselves are not conclusive. Some primers are softer than others and flatten easier at same pressure.
More or less a cumulation of ALL of the signs.
BH
More or less a cumulation of ALL of the signs.
BH
elkaholic
Well-Known Member
If you have an accurate micrometer (one that will measure .0001') You can compare the diameter at the web of your case to a known (factory?) safe load and observe when that measurement exceeds the check measurement. Often, you can load a little hotter than factory, but this is a good indicator. Once you get some experience reading the cases in "your own rifle" most of the tips that the guys have already mentioned will make sense. Flattened primers are one of the best indicators but every rifle leaves a different look and can be misleading. That is why it is important to know what a safe load looks like in "YOUR" rifle.......Rich
Trickymissfit
Well-Known Member
I think the first place to watch is the primer. It'll flaten and the crater around the firing pin indentation. Also watch for a bright ring to form on the case wall O.D. about a quarter inch above the base of the case. When that ring expands about .0005" to .00075", it's time to back the load off at least a half grain if not a whole grain of powder.
gary
boomtube
Well-Known Member
"What are the signs that a bullet is loaded to "hot?"
When it flies too fast. You DO understand that a we reload cartridges, not "bullets"!
Primers are the least useful "sign" of pressure. We can get very flat primers with moderate loads if we set case shoulders back to far with the FL die. Cratered primers are much more often a result of a loose fitted firing pin than excess pressure. If the case is properly sized and the firing pin hole is tight we can blow an action apart and leave the primer looking perfectly normal.
It takes more skill with a blade micrometer to read expanded case heads than most of us have. And the "pressure ring" just ahead of the web is more a result of a slightly loose case-to-chamber fit than excessive pressure.
Leaving the best exessive pressure signs are tight bolt lift, sticky extraction and any head indents showing ejector marks from the brass flowing into the bolt face holes and cuts. Even primer pockets that loosen after a few cycles are an indication your "safe" load is too hot. Case brass flows like putty under too much pressure so if you see ANY of those signs, even slightly, you are WAY too hot! How much to back off in grains is highly variable. Small cases are much more sensitive to over charges than large cases so you get to be the judge of how much to back down, no one can tell you that without a lot more information than just "it's too hot."
One thing you should KNOW for sure is that a book max load may too hot for safety in YOUR RIFLE! Those who spout that book loads are "lawyered up" for safety don't know what they're talking about. Starting low and gradually working up while observing for meaningfull pressure signs is the only intelligent way to find a good shooting and safe load in YOUR rifle!
When it flies too fast. You DO understand that a we reload cartridges, not "bullets"!
Primers are the least useful "sign" of pressure. We can get very flat primers with moderate loads if we set case shoulders back to far with the FL die. Cratered primers are much more often a result of a loose fitted firing pin than excess pressure. If the case is properly sized and the firing pin hole is tight we can blow an action apart and leave the primer looking perfectly normal.
It takes more skill with a blade micrometer to read expanded case heads than most of us have. And the "pressure ring" just ahead of the web is more a result of a slightly loose case-to-chamber fit than excessive pressure.
Leaving the best exessive pressure signs are tight bolt lift, sticky extraction and any head indents showing ejector marks from the brass flowing into the bolt face holes and cuts. Even primer pockets that loosen after a few cycles are an indication your "safe" load is too hot. Case brass flows like putty under too much pressure so if you see ANY of those signs, even slightly, you are WAY too hot! How much to back off in grains is highly variable. Small cases are much more sensitive to over charges than large cases so you get to be the judge of how much to back down, no one can tell you that without a lot more information than just "it's too hot."
One thing you should KNOW for sure is that a book max load may too hot for safety in YOUR RIFLE! Those who spout that book loads are "lawyered up" for safety don't know what they're talking about. Starting low and gradually working up while observing for meaningfull pressure signs is the only intelligent way to find a good shooting and safe load in YOUR rifle!
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The change in the maximum diameter of the case will give an indication of pressure.
Yes, the case expands to fit the chamber but the case will shrink back due to memory in the brass(a little like a spring-otherwise the case would always be sticky after firing).
The higher the pressure the less memory the metal in the case has. Therefore the change in diameter can be used to gauge how much pressure the load has compared to know hot and normal loads in YOUR gun.
My normal loads in say my Kimber 270wsm may expand the maximum diameter of the case by .0035"
Hot loads may be .0055".
Factory stuff is around .005".
Pressure signs like extractor marks show up also somewhere around a diameter change of .005" to .0055". Case life goes down at this point also.
Yes, the case expands to fit the chamber but the case will shrink back due to memory in the brass(a little like a spring-otherwise the case would always be sticky after firing).
The higher the pressure the less memory the metal in the case has. Therefore the change in diameter can be used to gauge how much pressure the load has compared to know hot and normal loads in YOUR gun.
My normal loads in say my Kimber 270wsm may expand the maximum diameter of the case by .0035"
Hot loads may be .0055".
Factory stuff is around .005".
Pressure signs like extractor marks show up also somewhere around a diameter change of .005" to .0055". Case life goes down at this point also.
4xforfun
Well-Known Member
Watch lots of Wylie Coyote vs the Road Runner. I have seen signs of hot loads on that program.
