As I am relatively new to reloading and thankfully have not made a mistake yet. I would like to know what are all the possible signs of overpressure. This way I can be better informed when I look at my fired cases.

Hoping for lots of input

Bud

Replies shouldn't be to many as there are few signs.

First, if you load more grains than a reputable loading manual recommends as a maximum charge, you are in dangerous territory.

Watch for a bolt that's hard to lift.

Watch for a case that extracts hard.

Examine the primer:

Look for a powder burn around the seam that indicates a gas leak.

A flat primer is a good sign of too much pressure.

Load a light load, a load that you know is safe. Fire it. Keep that fired case at hand when you shoot your hand loads. Compare the safe case to your fired cases.

Use a chronograph. Chronograph your start loads and all loads above that. If the chorny shows velocity much higher than a reputable manual, beware. Velocity comes from pressure and too much velocity comes from too much pressure.

Finally, if you can get your hands on and older Speer manuel, there is an excellent article on loading and pressue aby Jack O'Connor that manuel. It's old, but with plenty of good advice on loading your own.

If all fails, check your shorts. What happens back there is a good indication of excess pressure.

Never load when you are tired, distracted or ticked off at the old lady.

Safety first, second and always.

If you have a chrony, it will give you good service with regards to a "operating maximum".
As you increase your powder charge, you should get a fairly constant increase in velocity. When you see the increase in velocity start to tail-off or flatten out, then you have reached a operating max even tho it might not be max according to the book and by exceeding it you will only be burning more powder and losing barrel life for little if any gain in velocity. Also, fire a commerical round(s) and mike them acrosst the web. You don't want your reloads to exceed that measurement when fired.
That doesn't apply to some cartridges like the 7x57 and 45-70 as they are loaded quite mild in deference to some of the old, old rifles in those calibres still in use.

Bud, any good reloading manual will have a chapter on "how to" reload, safe practices, as well as some information on cases, primers and outward appearances of "normal". Study the pictures of cases and primers, -learn to read the signs of pressure.

Stay in the low to medieum velocity range set in the manual, and you will be safe. After you become more familiar with handloading you may strive for more performance safely.

bolt in the forehead?

if you're primers dont look like rounded edge primers, then it's too hot

jeffe

Clark
WOW!!!!!!!!!
Did you do all of those gun/caliber combinations yourself or did you have help?
Definitely looks like they made major.
Guy

Clark
A roller locker CZ52?
What kind of overload?
Guy

I hear they make good dog whistles like that ya just gotta get the hole the right size for the proper pitch

A lot of commonly used pressure signs are ambiguous. For instance, flattened primers can mean high or low chamber pressures. They can also mean a loose primer pocket.

Bolt lift used to be a good indicator, but they don't make guns like they used to. With modern machining methods, the parts of rifle actions are very concentric, and even if high pressure makes the brass flow, it tends not to flow into such a shape that it is hard to lift the bolt. You may lift the bolt very easily after a dangerously high pressure load.

Some people swear by case head expansion.

Most any pressure sign (including the very scary brass flow into the ejector recess) can be caused by soft case heads. If you use good brass, you're less likely to have any soft case heads.

Clark's pictures are probably not ambiguous.

If you are near the maximum load, and if your chronograph tells you you're at the reloading manual's maximum vleocity for that combination of components, you are most probably at the maximum pressure. If you go ahead and use the manual's maximum load and exceed the published velocity, you are probably at an excessive pressure.

There are strain-gage devices on the market ($200 to $800) that allow a hobby reloader to measure chamber pressure directly.

Then there's real piezoelectric pressure guns the ammunition manufacturers use. If you have to ask how much they cost, you and I have something in common.

H. C.

[ 06-13-2003, 04:41: Message edited by: HenryC470 ]

Heres a command sense sign I often notice first, if a load kicks harder then other known loads, its trying to tell you something!

Please try to avoid having signs of overpressure to look for. By the time you have signs of overpressure (with the exception of a small amount of miked expansion at the web?), you are already working with a dangerous load that might seriously injure you.

I noticed that no one has mentioned brass extrusion yet. With REALLY high pressure, the brass will start flowing into various recesses on the bolt, ex:, the ejector slot on some bolts, or the ejector plunger on the Remingtons. When you turn the bolt you will scrape off the extrusions, leaving a shiny spot on the case the shape of the plunger or the ejector slot. This observation should be accompanied by copious shivering, followed by a judicious decision to carefully use only factory ammunition in the future.

As Clint Eastwood's Dirty Harry character observed, "A man's got to know his limitations."

Handloading is a rigorous test of continuous, thoroughgoing caution. Every time, you have to follow the instructions in the reloading manual, even unto not loading ammunition that is perfect in every respect save a bullet that is seated out too far. You have to inspect the cases, even unto the doughnut at the bottom of the inside of the neck and the stretch mark above the web.

Yes, there are many of us who think we can't afford factory ammunition (really? how much are your eyes worth?) or we want better quality, or factory ammunition is not made for our firearm, and we buy surplus powder with no data available, and only a vague promise that it burns "just like H4831," and as cautiously as we would walk on a rope bridge over a crocodile pit, we put together starting loads and inspect every case and the bore every time we fire. With each load and firearm, we gradually gain some confidence but remain vigilant.

Yes, I walk the rope too. I load 80-grain fast twist .22-250s with surplus powder. I load for my pre-factory .338-.378 Wby. "wildcat," with surplus powder. The issue has never come up, but no way would I put factory ammunition in it before checking the dimensions of my chamber and the factory chamber. I load for my .510-.505 Gibbs with 700 gr. M2 ball with surplus powder, but in the beginning, because of caution, I put in so little slow-burning powder that it hangfired, which is not uncommon with large cases and loads that do not almost completely fill the case. We also tripped the trigger with a string from a distance for the first few loads, with a folded furniture blanket wrapped around the receiver to catch the pieces if they filed for divorce under pressure.

Everybody thinks that rifles are safe and grenades are not (not next to your face,anyway), but I wait for somebody to tell me that many rifle rounds have MORE powder in them than a grenade. There are times when I think about how much safer factory .223's out of a Ruger No. 1 might be, than my various bolts and funny cartridges. I'm having too much fun to be ready to stop, though.

Reloading accidents are extraordinarily rare. But every now and then we hear of the incorrigible gray-matter-challenged fellow who persisted in spite of many warnings to stop, and then his rifle blows up. Yes, we were smart enough to know that he was more likely than most of us to come to grief, but a moment of incaution could do us all in. Make sure Harry Callahan will not have a dry, pithy statement, to make about you.

I own at least a half-dozen reloading manuals. If you already have loads for your specific cartridge, there is scarcely a better manual from which to learn caution without getting your fingers burned than the A-Square manual.

WOW, talk about an eye opener.
Clark, I hope no one was hurt with the destruction you posted, it is almost enough to make someone reconsider.

I start 5 to 10% below listed maximum, I use a chrony and have not yet seen any funky fps or case damage but after this pile of information, you can bet I will excercise even more caution. Thanks for all this quick feedback.

Bud

Based on what I have read here, I don't know how I have lived so long!!! All this sez a lot for the gun builders who make allowances for us reloaders, thats for sure...

The average reloader can get away with using the standard old warnings

1. sticky bolts, but you have to know the feel
2. cratered primers, not mentioned
3. flash marks on the case head
4. ejector marks on the case head (square shaped) is a good indicator..not mentioned.
4. And last but not least spewing gas and little curly ques of smoke comming out of little black spots on your rosy red cheeks..

Without the use of safistacated equipment this is the only way to go...It works for intelligent reloaders just fine, it's the dumb ones it doesn't work for, that extra grain of powder, as opposed to one less grain to be safe...

This sort of problem results in stuck bolts and a little gas spewing...Blowups are caused by leaving Bullseye in the hopper when you thought it was 4831, using powder that will double load...Use a slow burning powder that near fills a case and you can never go wrong except when it is the wrong powder....

Common since is the salvation or reloading.

Good lord Mr Ford!

Just a little injecture, Clarks pictures are not what I would consider signs of pressure. Most of those appear to go beyond watching for the usual signs IMHO.

Get a good manual and stick to it. They tell us to do that for good reasons. Then learn to read primers and watch for hard bolt lift. And when you do Im guessing that youll probably find that a good manual suggest some excellent starting points and maximums.

I have done incremental work up overloads to see what gives thousands of times.

The third picture above is from yesterday:

Alliant max load: 357 mag, 8 gr Power Pistol, 158 gr JSP,1.575", 5.6" barrel, 1306 fps, 33,800 psi.

I shot in a Tokarev that I reamed from 9x19 to 9x23mm, 12 gr Power Pistol, 158 gr XTP JHP, 1.36", Starline 9mm super comp brass, wspm, blew hole in case and bent magazine.

What have I learned from overloading that is useful?
1) Beware of CZ52 pistols, they are very weak [The Sierra load book is in error on this and I have told them. They say they just printed what THEY read].
2) Most guns have lots of safety margin.
3) Bullets that are pinched make a bigger change in pressure than faster powders, more powder, heavier bullets, shorter seating, magnum primers, or small bores.

When I work up until something gives, it is possible that the increase in powder did not cause pressure directly, but instead the extra powder caused the bullet to get pinched. If I repeat the experiment with careful attention to bullet pinch sometimes I can go much higher before something gives.

I have never been hurt.

[ 06-13-2003, 08:35: Message edited by: Clark ]

Clark you crack me up. Do you have any more recent adventures beyond the tight necked cases that the primers fell out of?? Wern't you working on a small ring Mauser in 45acp? It would be interesting to spend a day at the range with you, no flame intended.

I ignored the pressure warnings listed above, looking for just 50 more fps. I now have a new cylinder in my Ruger Blackhawk.

Also remember that loads in mil brass needs to be reduced 15% to start.

Clark would you have any idea how much pressure your overloads are generateing??

I'm just starting into gun building and have been reading about proofing the barrel and action.

What I've read from the British proof standard is one round of 30% over pressure, and if that's not availible, then a standard load with 110% bullet weight.

Any thoughts on this?

One more bit of advice... don't buy one brand of reloading manual and treat it as gospel. Buy several, compare the info that they show for a given combination, start with the mildest of what you see and work carefully upward watching for the signs that folk have mentioned here. The results that one manufacturer gets in their gun at their range might not be exactly what you will experience in your gun at your range. This fact bit me in the butt once. I ended up with some 40S&W loads that were mid-velocity according to the manual I was using but were obviously way hot when I got to the range. I'm talking flat primer/high recoil/violent cycling/ejector marks in the brass hot. Needless to say one or two of those convinced me to pull bullets and buy more reference material. It was then that I recognized the wide variation possible between sources.

Ruger#1

Another problem I have not seen mentioned, yet:

As a general rule, the closer you can get the ogive of the bullet to the lands of the rifling, the more accurate the load will be. This causes people (me, for instance) to try to mic out the distance and cut it to a hair.

Too close, and you can get overpressure signs, even if you're using a light load.

kk

Bud,Note the temps. "when working up" a load too.I spent a winter "working up" a accurate load to shoot in my m-14,for summer matches.Had a tackdriving load Well one hot ass day,after the ammo was allmost too hot to touch from baking in my truck tool box all day before I got to the range,the first shot tore the rim off and left the case in the chamber,but that wasn't enough for me to pack it up,I knocked out the case with my cleaning rod,and tryed another,That one spit the primer through my beard and past my ear,packed up and went home after that.I saved the rest of that batch of winter practice,with no problems,or ,pressure signs.Good luck,Clay

http://talk.shooters.com/room_48/8525.cfm

This thread is extremely long so you may want to skim. Pay particular attention to OKShooter and Ken Howell as they are the experts.

It's been awhile since I read the thread myself but to sum it up from deep memory they advocate paying attention to the various manuals as their load data comes from extensive research with the sophisticated equipment mentioned previously. They speak of "not going to the wall" and being content to never "push beyond the warning track" to use a few baseball analogies.

Err to caution and if in doubt back off a grain.

Good luck.

Reed

Again thanks to all, I will maintain a constant watch on every case I reload before and after firing, keep my changes small and always within recommended limits. I had heard about the temperature change and was told to keep my loads in a cooler (not on ice) with a small cold pack on those crazy hot days.
SDS who publishes the A-Square manual so I can find a copy

Try www.midwayusa.com for the A-Square manual, it`s called "Any Shot You Want" and was handled by them the last I knew.
It is an excellent reference.

Clark,
I see some clues of ported automatics and thats a whole different ball game, I doubt that your experiments apply to most rifle shooters, but are of great importance to any pistol reloader.

Ray,
You are right.
I don't know as much or have anything new to say about rifles, yet.

I have overloaded the .223, .243, 257 RAI, 7.62x54R, 8x57mm, 45acp, 45Colt, and 45/70 in long guns.

When I overload, I get a sticky bolt and the brass does not last long before the primer pocket is too big. Rimmed cases are stronger.

When I back off to save brass, and allow for hot chambers, hot days, and my own loading tolerances, I wind up back at 10% above the max book load.

In semi auto pistols, I can sometimes double the max charge with safety margins. I am not clear why, but fast powder, 35 kpsi max rated pressures, I don't re use the brass, and forced extraction may have something to do with it.

[ 07-06-2003, 00:57: Message edited by: Clark ]

Pressure signs as mentioned above tell you when you have gone too far. The difficult thing to find is the right pressure, where you get all the performance the cartridge was designed for, while not going overboard. I believe you can usually determine that, in standard pressure rifle cartridges, by using a hand priming tool and noting how many reloads you get from a case before primer seating becomes noticeably easier. If the primers go in easier after one or two reloadings, I think the load is beyond design pressure. If you can get five or so reloads without primer pocket expansion, you are probably in the ball park. If you can get much more than that, you are probably under design pressure. What we are talking about here is actually case head expansion, and I find it a lot easier to determine by hand priming than measuring with a micrometer.

I have never seen this published by any loading authority, but it has seemed to be right for me with standard cartridges -- .243Win/.270Win/.308/30-06, etc., -- over the years.