Your story could probably be repeated by others on this site (I hate to admit this but I been there a couple of times...). Seems that at one point in our reloading life we just have to get as much velocity as possible. I believe that your rifle told you that enough is enough, before things really let go. Did you get a 0.210" black circle burned into the face of your bolt around the firing pin hole? That is a permanent reminder that we went too far.
Sometimes a person has to give his head a shake and ask what it is that he really wants. Accuracy should be the most important objective but getting accuracy and the full velocity potential of the case is also nice. Hot-rodding that accuracy limit is always a tantalizing notion - "if the book says 3000 is max and I am getting 3150, then I'm getting free performance!" That might be a fact but brass can only hold so much, and we will probably pay the price when our cases only last one or two loadings.
Your story also indicates that some other "reliable" pressure signs can't be counted on - such as increased pressure required to lift the bolt and circle marks on the case-head from the ejector plunger hole. If a person feels the need for more velocity then we should bite the bullet and go to a different cartridge.
Your little error was an all too common one, welcome to the club. Blown primers happen. That is one level of boo-boo. There is another level where people get hurt and that is what we really have to stay away from.
Brian, I've always gone by the statements put in the reloading manuals that accuracy is more important then blockbusting energy, although I've always thought, sure'd be nice to have another 100fps, but then came to my senses and thought, deer won't give a rats ass if he's getting hit by a 150gr bullet going 2600 or 2500fps, dead either way, and as Ian mentioned, case life is shot in the ass and what about that time I had my bolt stick after dispatching a deer for someone because I ignored an occasional flat primer from my 708 Savage(Tight chamber/throat)that incident could have cost me a deer had another deer been coming my way, I've since sold said rifle to bro-in-law, he shot like 6 deer with that rifle, and when he gave me some brass to reload I notice some flat primers, so I went down another grain, according to the last chrono I ran the rifle through, that load should run about 2500fps, 140gr Sierra. Still killing deer with it at 100+yds. Let's be careful out there. [img]images/icons/wink.gif[/img] Jay.
What a temptation, been there too. I still have never had a blown primer though, knock on wood.
Like Ian indicated, the pressure signs "very often" don't mean squat, most my tests have revealed they usually start showing at quite high pressure, around 70-75k psi.
Without pressure testing equipment, you never know how much to reduce the load by to get back down to reasonable pressure, as psi can ramp up slowly or real fast and you just never know. Velocity is your best indicator, and throttling back by 50-75 fps usually does the trick quite well.
I've went to bigger cartridges for the added velocity at lower psi now.
Glad it was just a "pop" for you this time, when my M14 blew up on me it freaked me out pretty damn bad. Don't load the wrong powder, mislable powder cans, barrow powder, or set more than one can by your powder dispensor or you could be in bad shape too.
My big mistake was barrowing a can of H380 my brother had poured a faster unknown powder into... not lableing it either. From now on, I remove the seal on a can of powder I load with.... nobody else. [img]images/icons/wink.gif[/img]
first, thanks for the concern. everything is fine, minus one case that wont hold a primer, and a slight ring on the you-know-what (good call Ian). obviously that wasnt my intention. normally when working a new head, i'll keep bumping up until i detect over-pressure sign, then know what the top end is. i wont even use that load, thats just so i know what my powder range is. although going by books is the safe way, it seems any more the newer the book, the lower the loads are. my guess is lawsuits. grab a book from years ago and see what it says about your current load. i agree, accuracy is top priority, but sometimes i get that by going above published weight. i know in my .357, i'm over 2 full grains on max for the current nosler book, however, its shooting tighter groups than anything the book has. no pressure signs exist, and the side note is, its actually half a grain less than max load in my uncles book- where i got the load from- but its dated 1970 something.
again, i agree with everything you guys said, i was just testing the range i could work in, and failed to get the signs i was looking for, thus paying the price. sometimes i can get a little more accuracy out of it, sometimes not, but thats just something i do when starting on a new load. first time i've blown a primer though, and although i'd just assume keep it to myself, too many on here were saying they wanted to start reloading. i wanted to throw this out to show you have to watch yourself, and having a few years experience under your belt means nothing. the fact a few of you threw in some small stories just proves my point, and helps the cause of helping others seeking advice. thats what this place is all about, right?
gotta go, its time to reload some more. dont worry, i'm backing it off. in fact, what'd i do with that book?...
If it were easy, I wouldn't be doing it.
just got back frome the range, where i had a small incident. normally around a bunch of experienced handloaders i wouldnt say anything because, one, they proabably already know, and two, the same reason you dont go around talking about your misses- but i've seen a lot of guys on here say they want to start reloading so i thought i'd post this. we all make mistakes, and hopefully someone learns from mine instead of doing it on their own.
i've been working on some new deer hunting loads for my 270. i was already at the max load listed for the nosler book i have, but from the past knew nosler keeps their loads low, for safety reasons, and most of my working loads already are either their max, or above it. no pressure signs existed, so i started stepping half a grain at a time to see how high i could accurately get for a for few extra fps. after shooting loads, i checked cases, and although noticed each load flattened primers a little bit more, no signs of cratering showed and cases never stuck in the chamber. i should have known once the primers hit a certain flatness- a hint i decided to ignore on the quest for speed- that i hit my limit, but since everything else looked ok, threw a couple more kernels in the next batch. the last load i did was too much. the first two rounds shot fine, but the third had that distinct 'pop' sound and a tit bit of smoke coming from the action. sure enough, the primer blew out. i got the hint THAT time. the first two cases still looked fine, but handled the extreme pressure well i guess. needless to say i'll be tearing the remaining 7 rounds apart tonite, and my working load will be reduced at least a full grain less.
reloading can be fun and rewarding, but for the new shooters starting out, be careful when you hit max load levels, and pay attention to cases. theres a reason the guys on here say reduce whatever load they give you and work up to it. remember, safety never takes a holiday.
other than that, hammer down.
If it were easy, I wouldn't be doing it.
Glad your OK
Just a personal note (IMHO) The reduction in book loads is more from improvments in pressure measurment (IE: crystal transducers vs copper crusher slug), than it is from lawyer proofing.
Also, a lot of the older manuals used only "pressure signs" NOT instrumentation of any kind, and had to be backed down a lot once they started using instrumented barrels.
Not even going to mention that powders have been re-formulated, the lot # to lot # variations etc.