Reply With QuoteA couple of pits from blown primers will not cause a problem. Other than they look bad and your friends will question your loads.
Course if you keep putting pits in it and they become craters, now we have a problem.
You need to find out why.
Here is some background on the issue.... In the past few days, I have blown two primers and now have two different spots on my bolt head that are pitted. The first one happened while working up to find my max load for my .243 wiith RL 17 and Berger 105 VLD's. I had worked up to 41.5 grains and everything seemed fine pressure wise. The best looking group came from 41 grains, so I loaded up a bunch of different 3 shot groups at diffent seating depths to find the best one and fine tune. On the second round of the second group (which was actually seated to the same depth as the day before), I had a primer blow out and make a pit on my bolt, and scare the crap out of me! I immediately packed up and went back to the shop to pull the bullets and start again. I dropped back down to 38 grains and started working my way back up looking for pressure. At 39.5 grains (a full 2 grains below where I had tested a few days before) I blew another primer. Again, I packed up, pulled the bullets, and threw out the 50 pieces of win brass and the remaining win primers. I am going to leave the RL17 for my .270 and get some H4350 and start all over. My question is this....will the pits on my bolt face cause any issues? If so, I will just purchase a new head before beginning load development again. Also, will I need to re-headspace if I install a new bolt head? thanks guys!
A couple of pits from blown primers will not cause a problem. Other than they look bad and your friends will question your loads.
Course if you keep putting pits in it and they become craters, now we have a problem.
You need to find out why.
Have had the firing pin hole too large and the primer actually flows around it. A SAVAGE? Yes!!! The bolt heads are made by 4 different places by last count. Tolerances need to be tightened up. Have a Winchester 22 wildcat that will do it with one powder but nothing else.
Here's a pic of the bolt. THe pits from the two primer blowouts are at 10 and 4.
Also, that ring around the firing pin hole isn't really on any of my other bolts.
What primers are you using ?
Are you measuring case head expansion? If so, what are you getting for before and after case head diameters?
I've not used that powder in my 243, so I don't know how hot that load is, but something's not right. Where are you getting that load data from? The closest I can find on Alliant's website is a 100 gr speer and a max charge of 41.0 grs. I believe the Berger will build more pressure than the Speer as it would have a longer bearing surface.
How far off the lands are you seating your bullets? Or are you "jamming" them?
You've already thrown out all the fired brass?
?
Not trying to point fingers or anything, but we need more info to be more help.
I suspect the problem may have nothing to do with your brass or primers.
12F, McGowen 6.5x284 1-8" twist, Nightforce 12-42x BR<br />BVSS, McGowen barrel, 22-250 1-9" twist, Nikon 6-18x<br />16 FHLSS Weather Warrior, Sinarms 257 Roberts, Pentax 3-9<br />Stevens 200, 223 bone-factory-stock, Nikon 3-9x<br />Scratch-built BVSS, LW 243 1-8" twist, Viper 6.5-20x50 mil-dot
Have you cleaned your barrel yet? Signs of copper?
If these are standard Win primers, you need to change brands to something with a thicker cup.
Alliant's website does not list 105 VLD's in the reloading manual for the 243. Also does not list RL17 with the 105 AMax's, 90 or 95 gr bullets:
http://www.alliantpowder.com/reloaders/default.aspx
Win large rifle primers.
Not measuring brass for expansion. The brass is still in the trash bag in my shop. Yes the barrel was pretty clean on both of these occurences....less than 20 rounds since cleaning, and this barrel copper fouls very, very little. The load data I am using came mostly from other sources, as alliant does not list the Bergers with their RL17. I found alot of people on other sites using it with very good success, and used some of their loads as a guide to work up to.
The seating depth of the two blown primers were .035 off on the one at 41grains, and .20 off on the one at 39.5. I am definitely not blaming either the brass or the primers, just want to get rid of all the variables and start over with good, published data of a well known powder with good new components. If I was operating under too high of pressure, I don't want to use the brass as it may be compromised.
I will use win brass and primers the next go round, but will be using either imr or h 4350 by the book.
It sounds like you have the situation well in hand, doing the right thing.
Hi,
Did the firing pin pierce the primer cups?
His pictures show gas is escaping between the primer pocket and cup.
Are you hand priming? If so how easy are the primers going in to the pockets?
My guess it's just the signs of the times in regard to ammo components IMHO...meaning there is a lack of quality and quality control in many of the brass and primer brands these days not to mention all manufacturers are in the cost cutting mode like never before. I have had the same thing happen using 2 brands of primers on loads with no CHE. Many primers don't seem to fit the primer pockets the same way on lot to lot variations with new or used brass (multiple brands).
The pits, they won't hurt a thing other than annoy you and as someone else stated; draw some attention to your loads by others.
I agree with 250 Savage. It looks more like a primer problem. I had some CCI pistol primers that were almost 100% of them too large for the primer pocket 0ver 20 yrs ago. They made a cruching sound when seated and it took so much force the primer was flattened like it had been fired. Made them very sensative. The other scenario may be that those two cartidges had oversize primer pockets or flash holes or both.
El Lobo
teebirdhyzer
Contact the primer company, years ago I had a brick of Remington primers that were defective and were rupturing well below maximum loads. Remington gave me a new brick of primers and replaced the bolt on my 760 Gamemaster pump free of charge.
Note, there was a primer recall for that lot number.
Also Winchester no longer makes its own brass and buys the pellets for making cases from other vendors, you might want to contact Winchester also. Keep the defective cases/primers and both lot numbers for the cases and primers as evidence. With Remington all I had to do was call and then send in the primer box flap with the lot number on it and Remington picked up the bill and repairs.
T bird... I had a box of 1000 WLR primers I broke into 4 months ago. Within the first week, maybe the 100th round I had 2 primers blow a tiny hole out the edge of the primer. Both happened within 10 rounds of each other. I closed the box with the remainder of the unused primers and set them aside. I have been meaning to send a note to Winchester about it & you just reminded me of it.
A while back I had 2 Federal Premium Nosler BT .270 rounds blow primers. After a few emails back & forth to Federal, They sent me 2 new boxes of Fed. Prem. Nosler BT bullets FREE.
Drop them a line after you make sure everything on your end is OK. In my case, I ended up buying a new bolt from Savage for $145. It was starting to look real bad with the pitting & collecting soot. I believe if it's a minor claim, they may send you some freebies to replace the bad stuff & maybe a little something for your trouble(?)....
Good luck with your adventure.
'Scuse me while I whip this out...!
T bird, Blowing primers at 39.5 grs as well as 41.0 grs would point to problems w/ thickness or consistency of metalurgy on cup material. The ring on the B/F would be an indicator of gas leakage usually associated w/ too soft brass, over sized primer pocket or undersized primer cup. Can also be a sign of excessive pressure on good primers. Speer manual states case expansion should be .001" or less. A good "rule of thumb". Most of us have had holes like yours in primers at one time or another. Changing to a different primer would probably be the best 1st step unless the primer is seating way too easily. Also be sure primers are .002" to .003" below surface of cartridge base. Fired cases that otherwise show no signs of pressure can exceed .001" of case expansion. Some would argue that .0015" is a more realistic max. I'd just prefer to be on the safe side. Change one component at a time to isolate problem. Then you've "got the goods" on the faulty Mfg. ..... Good pic of B/F!... Pic of failed primer? Could be F/P protrusion though I'd think that unlikely. Good luck, keep us posted :)
thanks for all the help guys! I will try and get a pic of the brass and primers that failed. knew I would get a wealth of good opinions and tips on what happened. So, everyone still under the impression that the bolt will still be ok and functional and I can safely use it without without replacing the head?
Looks to me like the damage is more cosmetic that dangerous. But if it bothers you get a new bolt head just for your peace of mind.
El Lobo
What data are you using for your loads? Someone else wondered and it was never answered.
The blown primer may not be the primer, but may be over expanded primer pockets. This sounds like a serious over pressure issue, to me, and needs to be looked at.
What are your velocities at the blown primer load levels, and what are the published velocities for that load level and bullet? Keep in mind if there are no listed loads for that primer/bullet/powder/charge, you are venturing into uncharted territory and it could be dangerous.
Handirifle, he listed his loads in the initial post. The second blown primer was about 3 grains below the load of the first one. He stated he checked for pressure signs. I assume he knows what to look for. Using the same brass and primers, t he only question I would ask other than those that have been asked is how do you charge your cases with powder. There may be a possibility that a heavier charge may have been put in the cases in question. Highly unlikely. I still would point to a primer problem. When he measures the primer pockets of the blown cases that may tell another story. It seems all the facts arnt in yet but I still think it is a primer or pocket problem.
El Lobo
Yea I understand, but looking back, it was slowpoke that pointed out that he could find no load data in Alliants list for the Berger 105gr bullet, and with a Speer 100 was 41gr, which the OP had gone over. If anything, with a longer, heavier bullet, the top charge should have been somewhere around 39gr.Originally Posted by ellobo
I suspect, that due (again as slowpoke mentioned) the longer bearing surface of the Berger, the blown primer, is a sign of serious overpressue. Just because a certain powder charge is listed as a max, it does not mean EVERY rifle will allow that. Chambers are different, barrels are different, and the longer bearing surface would most certainly affect pressure.
That is one of the reasons Barnes has the grooves in their all copper bullets, because their longer bearing surfaces (plus the metal makeup of 100% copper instead of guilding metal) were causing pressure spikes using load data from similar weight bullets.
I have read of different bullets, other than listed ones, causing pressure spikes well above normal for that bullet/powder weight combo.
If he reused the same cases, the primer pockets may well have expanded, and you can blow a loose primer very easily from a case like that.
That was why I was asking specifically, what manual he got those particular loads from, or whether or not he was guesstimating.
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.
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.
Keeki
I bet you have solved the delima.
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!
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)
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