Pressure signs
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Re: Pressure signs
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JPipes</div><div class="ubbcode-body">Ejector marks. </div></div>
Difficult to extract.
Effort to rechamber.
Loose primer pockets.
Brass growth above extractor groove.
Flattened primers (in *some* rifles... my 300WM flattens ALL primers)
Cratered primers (in *some* rifles... there are rifles that crater primers on normal loads.
Heavier than normal bolt lift (this shows up in my rifle before any other sign)
The key is to know YOUR rifle. Start low. Build up slow. Shoot a lot. Take LOTS of notes. Do your load development in HOT weather.
John
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JPipes</div><div class="ubbcode-body">Ejector marks. </div></div>
Difficult to extract.
Effort to rechamber.
Loose primer pockets.
Brass growth above extractor groove.
Flattened primers (in *some* rifles... my 300WM flattens ALL primers)
Cratered primers (in *some* rifles... there are rifles that crater primers on normal loads.
Heavier than normal bolt lift (this shows up in my rifle before any other sign)
The key is to know YOUR rifle. Start low. Build up slow. Shoot a lot. Take LOTS of notes. Do your load development in HOT weather.
John
Re: Pressure signs
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jrob300</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JPipes</div><div class="ubbcode-body">Ejector marks. </div></div>
Difficult to extract.
Effort to rechamber.
Loose primer pockets.
Brass growth above extractor groove.
Flattened primers (in *some* rifles... my 300WM flattens ALL primers)
Cratered primers (in *some* rifles... there are rifles that crater primers on normal loads.
Heavier than normal bolt lift (this shows up in my rifle before any other sign)
The key is to know YOUR rifle. Start low. Build up slow. Shoot a lot. Take LOTS of notes. Do your load development in HOT weather.
John
</div></div>
All very good info, wish I had had such advise when I started out.
I'll give you a hint, when the primer anvil is starting to protrude from the hole in your primer, its time to back off a grain or three.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jrob300</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JPipes</div><div class="ubbcode-body">Ejector marks. </div></div>
Difficult to extract.
Effort to rechamber.
Loose primer pockets.
Brass growth above extractor groove.
Flattened primers (in *some* rifles... my 300WM flattens ALL primers)
Cratered primers (in *some* rifles... there are rifles that crater primers on normal loads.
Heavier than normal bolt lift (this shows up in my rifle before any other sign)
The key is to know YOUR rifle. Start low. Build up slow. Shoot a lot. Take LOTS of notes. Do your load development in HOT weather.
John
</div></div>
All very good info, wish I had had such advise when I started out.
I'll give you a hint, when the primer anvil is starting to protrude from the hole in your primer, its time to back off a grain or three.
Re: Pressure signs
Ejector marks, flattened primers, blown primers, a difficult bolt lift, and I'm probably forgetting some others. Here are some links with pictures and more info:
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1658942
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1456442
Ejector marks, flattened primers, blown primers, a difficult bolt lift, and I'm probably forgetting some others. Here are some links with pictures and more info:
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1658942
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1456442
Re: Pressure signs
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: coldboremiracle</div><div class="ubbcode-body">I'll give you a hint, when the primer anvil is starting to protrude from the hole in your primer, its time to back off a grain or three.
</div></div>
Or my shooting partner, whom I affectionately refer to as "Mongo" shooting his 7STW loads, 160gr AB's at 3200+fps on a 90 degree day... "Hey, John! How come my bolt won't open?" Begins beating on it with a 2x4 block. Face palm.
"Uh... maybe we shouldn't shoot any more of those today...".
<span style="font-weight: bold">EDIT:</span> To be fair, this was an "aha" moment for him regarding velocity and pressure and he doesn't do stuff like this any more or I wouldn't shoot with him. A 911 call from E.B.E. is not what I call a fun day shooting.
John
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: coldboremiracle</div><div class="ubbcode-body">I'll give you a hint, when the primer anvil is starting to protrude from the hole in your primer, its time to back off a grain or three.
Or my shooting partner, whom I affectionately refer to as "Mongo" shooting his 7STW loads, 160gr AB's at 3200+fps on a 90 degree day... "Hey, John! How come my bolt won't open?" Begins beating on it with a 2x4 block. Face palm.
"Uh... maybe we shouldn't shoot any more of those today...".
<span style="font-weight: bold">EDIT:</span> To be fair, this was an "aha" moment for him regarding velocity and pressure and he doesn't do stuff like this any more or I wouldn't shoot with him. A 911 call from E.B.E. is not what I call a fun day shooting.
John
Re: Pressure signs
I've had rifles exhibit none of the "typical" signs of over pressure, but develop loose primer pockets. Best way for me is to mic the base of the case and compare it to a new one.
I've had rifles exhibit none of the "typical" signs of over pressure, but develop loose primer pockets. Best way for me is to mic the base of the case and compare it to a new one.
Re: Pressure signs
All good info for sure.
FYI, If you're using Lapua brass and you're getting loose primer pockets, you are most certainly WELLLL beyond over pressure. I know guys that won't even use Lapua brass for load developement. Their brass is tough and often won't show some of the typical signs.
All good info for sure.
FYI, If you're using Lapua brass and you're getting loose primer pockets, you are most certainly WELLLL beyond over pressure. I know guys that won't even use Lapua brass for load developement. Their brass is tough and often won't show some of the typical signs.
Re: Pressure signs
In addition to what everyone else has said, Sometimes I'll use a redding shell holder and see if the case will slide into the shellholder. If it doesn't, then you know you've gone too far and need to back down a grain or two.
In addition to what everyone else has said, Sometimes I'll use a redding shell holder and see if the case will slide into the shellholder. If it doesn't, then you know you've gone too far and need to back down a grain or two.
Re: Pressure signs
All of the above advise is good.
If you have a remington, dont be suprised to see cratered primer holes on factory loads... its a remington bolt thing.
Difficult bolt lift is a pretty common sign. If you get this back off or procede with caution.
Flattening of primers is also a common sign of over pressure.
If you can take to the base of your brass with a micrometer you are deffinately going about it the right way.
All of the above advise is good.
If you have a remington, dont be suprised to see cratered primer holes on factory loads... its a remington bolt thing.
Difficult bolt lift is a pretty common sign. If you get this back off or procede with caution.
Flattening of primers is also a common sign of over pressure.
If you can take to the base of your brass with a micrometer you are deffinately going about it the right way.
Re: Pressure signs
I addition to all the other tips, another quick way to check if the head is swollen is to slide the brass in backwards in a case length gauge. If it doesn't go in easily you have problems. You can compare the depth it enters the gauge with a new or resized case. Usually if the head is swollen it will barely enter the gauge.
I addition to all the other tips, another quick way to check if the head is swollen is to slide the brass in backwards in a case length gauge. If it doesn't go in easily you have problems. You can compare the depth it enters the gauge with a new or resized case. Usually if the head is swollen it will barely enter the gauge.
Re: Pressure signs
This guy has a fairly long list:
http://www.shootersforum.com/showthread.htm?t=58763
I don't think he has found that list empirically, but compiled it from reading.
I, OTOH, have done just about every over pressure sign again and again with no end in sight.
This guy has a fairly long list:
http://www.shootersforum.com/showthread.htm?t=58763
I don't think he has found that list empirically, but compiled it from reading.
I, OTOH, have done just about every over pressure sign again and again with no end in sight.
Re: Pressure signs
As has been said, don't expect to see them. Don't expect to see ALL of them. You may get one or two. In most cases by the time you do see them you are well over where you want to be.
Velocity is useful as a tell tale. There is no magic, if you are well beyond what others can safely get you have high pressures. Just watch out for the many guys reporting "safe" loads and excessive speeds. That just means they are pushing the limit. A little bit above manual figures is likely to be safe in most guns if you work up.
Load for accuracy
Then check your load at the maximum distance you shoot.
If your on target and accurate you have the right load.
As has been said, don't expect to see them. Don't expect to see ALL of them. You may get one or two. In most cases by the time you do see them you are well over where you want to be.
Velocity is useful as a tell tale. There is no magic, if you are well beyond what others can safely get you have high pressures. Just watch out for the many guys reporting "safe" loads and excessive speeds. That just means they are pushing the limit. A little bit above manual figures is likely to be safe in most guns if you work up.
Load for accuracy
Then check your load at the maximum distance you shoot.
If your on target and accurate you have the right load.
