2 Blown Primers....Replace Bolthead?

[keeki]

Ive also noticed this problem and Ive narrowed it down to RL-17. This powder is very heat sensitive and once my chamber heats up I start having pressure problems on what is normally a mild load. 53gr RL-17 over 100gr NBT in 25-06 is alliants max load and I have no pressure problems with it until my chamber heats up.
So I made up some loads from 53gr down to 50gr in .5gr increments and I never made it down to 50gr. I shot 3 shots at 53gr and all was fine, waited 5 minutes shot 3 at 52.5 and all good. The next round I didnt allow cooling time and started getting cratered primers on the 3rd shot at 52gr. Popped a primer at 51.5gr.

[keeki]

I also have another post on here about 75gr vmax bullets not staying together. Also done with RL-17. 57gr of 17 over 75gr vmax is a warm load but it does fine for 3 shots so I decided to load down a little. Done the same test on this load and by the 12th shot 56gr velocity was exceding the 57gr load. Matter of fact is that bullets started coming apart on me.
Let the barrel cool for an hour and done the same thing with basically the same results in reverse. Shot 3 shots at 56gr and all was great, 3rd shot at 56.5 the bullet came apart. Velocities off the chart.

[handirifle]

Keeki
I bet you have solved the delima.

[teebirdhyzer]

Ellobo, I charge each shell by hand, and trickle until I have exactly the same measurment each shell. I also re-zero after each charge weight. I have not measured the primer pockets, but that is also a possiblity. Handirifle, you bring up some very valid points that I cannot argue. I know pressure signs can exhibit themselves in other ways besides a sticky bolt (which I never had even a slight sign of) and flattened primers. Going back through the trash and pulling out some of the primers and cases, it seems that some of them may have been slightly flattened, but not pancaked at all, and although I don't see any ejector marks on the brass, there are some shiny spots that can be seen. I am also thinking that perhaps keeki is on to somethign with the lingering heat that builds up in the chamber with repeated firings adding to the pressure. i am also wondering if perhaps some of the bergers may have been seated out longer into the rifling, because the oal of them seems to vary quite a bit using my rcbs dies. The round that popped could have been seated closer to the lands than anticipated causing a pressure spike. This along with the fact that the load data I was using was not specifically detailed for the bergers, as Handirifle mentioned. Be it what it is.....I have chalked all of this up to a learning experience. Glad that it wasn't any more serious, and even though I thought I was being very careful, I will be even more so from now on. I'm not gonna lie, it was quite scary, especially the second time!

[gotcha]

handirifle, Keeki, Excellent input. T-bird, Good observation skills! Isn't it amazing what can be accomplished when we all put our heads together.......... ;) Always smart to carry a caliper to range when working up new loads. Measure cases just below web before & after firing to get indicator of any potential problems. Case head expansion will usually be your 1st indicator of high pressure. Works for me 8)

[handirifle]

Hey, glad to help. I'm not gonna even come close to acting like I have it all figured out, even after about 41yrs of reloading. By the way, the first rifle I started reloading for was my "J" series ;D that was born and reloaded for, as a 243, but took my first CA deer as a 308.

Gotta love them Savages, and this forum. We are all here to learn together.

Am also glad it was nothing more than popped primers. Once MANY years ago circa 1974) , I read of a guy mixing powders in pistol rounds, he even listed his loads and mix ratios. I thought, "that's a cool idea", so I tried it. I used my Ruger Blackhawk (1972 model) 357, and I gotta tell you, that bullet went hyperballistic. But I also have to tell you that was the GREATEST learning experience I have ever had from reloading. It took me over two hours to be able to get the cylinder to rotate again, because that case had so much thrust it jammed it beyond belief. I did have a smith check the gun over though, just to be sure. When I told him why, he just stared at me for a bit then laughed, and said, "I bet it takes a while before you do that again, huh?" Yup!

I cannot tell you how lucky I was, and how I will swear by the strength of those pistols. I do not ever want to even know how much pressure that was. One shot changed my cavalier attitude towards reloading FOREVER. If we live, hopefully we learn.

So far I am still here. ;D

[Eric in NC]

I will add that I have found the 243 to be very sensitive when you get close to max and I have seen similar bad/erratic behaviour. Going from "seemingly" ok to way over pressure with just minor changes. Measuring case heads will usually show you more accurately where you are than bolt lift and primer reading but 243 is one that I tend to stay on the mild side with.

[Murphy]

Have two Savages that I purchased new , they both had dark rings on the bolt face straight out of the box, most likely it is just the way they are polished. Would love to see a photo of that blown primer, then I could give a better opinion of what happened. Blew a rifle up once under mysterious circumstances. I blame very lite neck tension, think the bullet was forced into the lands before the powder had ignited properly, had fired about 20 rounds no problem then suddenly wammo! The bolt had to be belted open with a block of wood, had blood spots over my face, boltface was burned and the extractor blown off, the primer was never recovered and probably vaporised. :o

[teebirdhyzer]

My goodness. That sounds like a textbook example of "Murphy's Law"..... you've probably never heard that one huh?