Has anyone experienced blown primers with factory ammo?

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altak5

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I have purchased a used Savage weather warrior in 270 wsm, while working up loads for it I experienced high velocities at below Max charges including blown primers. I test fired a round of Nosler factory accubond 140grain, this went 250 fps faster than stated velocity and also blew the primer out.

I am assuming this is why the gun was sold, but don't want to make any accusations.
I have purchased a box of low end Federal 130's but haven't had time to test fire one yet.
 
yes, I bought a box of the Winchester "Fail Safe" loads for a 30-06 to try out before the components became available. 3 shots and 3 blown primers later I gave up on them. I contacted Winchester with the lot number and they requested I send the blown cases and un-fired remainder back to them. That was 15 or so years ago and Winchester has not yet got back to me.
 
Lots of factors here. Factory brass is normally undersize and fire forming will cause stretch. I think reading some where this is a cartridge prone to stretch and case head separation.

Take a factory round apart, see if there are any issues with the mystery powder load against suggested loads. May have been overcharged?????

Check headspace. Is Primer pierced or flattened. Try sizing brass down after fire forming to a slight pressure fit. Measure against a factory round and see how much variation in length to shoulder/neck junction is noted 10 thou is a lot. Upon firing if there is lots of room the primer pushes out first onto the bolt head and then the brass flows back. You get a very flat, sometimes pierced, some times stretched primer pocket with stout loads. If so, use the false shoulder method for resizing.

Check bore. Is all copper or carbon removed. Is the bore undersize or rough. tighter bore=more pressure.

Check neck clearance. Carbon build up in the neck can squeeze the bullet/brass combo and result in more pressure. Place a bullet into a fired case, if any resistance is noted then you have neck clearance issues.

Is the bullet jammed or jumped. May have a tight tolerance freebore and this will increase pressures.

Add all of this stew together and you get a pressure picture.

I have found that without a good cleaning over time the residue/copper build up will increase pressures and make sure the neck is clean in that barrel. Carbon build up there can cause issues. Factory barrels can be copper hounds. Second hand barrels cannot be trusted for being really clean. I suggest cleaning used barrels with JB prior to use. You will feel where there are tight spots due to fouling. Work on those areas.

Elky.....
 
blown primers sound more like a possible headspace issue .

savage rifles can have the headspace knocked out of adjustment by people just wanting to tinker , without realising what they are actually doing ..... they are also easy enough to put the headspace back into adjustment ....... assuming this is your issue , it could very easily be something else

pictures would be a necessary for the guys here to help properly.
 
I have not had a factory round in a factory rifle blow a primer although I have experienced factory ammo loaded too hot and extremely hard extraction... the factory occasionally does make a mistake.

Are you sure your used rifle's chamber hasn't been messed with?
 
Brother blew several primers out of factory Hornady 6.5 Creedmoor. I arrived to the range after this occurred but I'm guessing heat had a lot to do with it.
 
Damage to the bolt face. This happens when primers "leak" hot gasses during firing. The plasma cuts the bolt face
Barrel repositioned. Just an indicator of previous work, not necessarily a bad thing.
It is more than likely you have a barrel issue or two such as fouling build up, short throat and hot factory rounds [of which wsm cartridges have been known to suffer]
 
altak5 said:
I have purchased a used Savage weather warrior in 270 wsm, while working up loads for it I experienced high velocities at below Max charges including blown primers. I test fired a round of Nosler factory accubond 140grain, this went 250 fps faster than stated velocity and also blew the primer out.

I am assuming this is why the gun was sold, but don't want to make any accusations.
I have purchased a box of low end Federal 130's but haven't had time to test fire one yet.
Click to expand...

Did this rifle come from N-B by any chance ,I had a guy come to my shop last fall with the same rifle and was experiencing the same thing , he told me it did it with most factory ammo.
the bolt was stiff on opening and I suggested he load some with mild loads to try, he had to go less than minimum loads otherwise it would create to much pressure.
I told him to contact Savage and he sold the gun a very stupid mistake imo and I told him that to. there is obviously an issue with the barrel for creating high pressures like that.

Contact Savage and see what they have to say the barrel is obviously not to spec
 
Can't figure out how to upload a picture. Barrel looks normal to me, the bolt face did have a pretty good black ring, most of it I had already cleaned up.
The barrel has been cleaned well with both lead & copper solution.

The last hand load fired was a 130 ttsx; 60.5 grain RL-19, 3224fps. (Max being 65 grain, 3217fps)

I was thinking it might be a tight bore, the previous owner claims he only ever shot factory loads and never had a problem.
 
I bought it from a local guy here in Calgary last fall, but at the time I got the impression that he had taken it on trade, or maybe bought it for the scope, etc.
Did the one at your shop have a stainless barrel, and a silver paint design on the stock?
 
I have seen blown primers with WSMs in 270 and 300. Winchester and federal factory loads. I think we will see pressures reduced in the coming years. Blown primers are NOT caused by a headspace issue.
 
Leeper said:
Blown primers are NOT caused by a headspace issue.
Click to expand...




read about half way down the link provided below .

I mentioned headspace because it is easy for someone to knock a rifle using a barrel nut out of whack if it is being tinkered with , and it is easy to verify if it is or isn't with in spec .

http://www.shootingillustrated.com/articles/2012/2/16/problems-with-primers/

"When primers are truly blown, this is almost always a sign of high pressure, but it does not necessarily mean the ammo is to blame. Dave Emary, Hornady's chief ballistics scientist, says excessive headspace can cause primers to back out or even pop out completely. There can be other culprits, like a rifle chamber cut very tightly, a throat cut too short or a barrel with a tight bore. On rare occasions, the cartridge brass might not have been properly annealed. Temperature can also be an issue, and this was my suspicion.
 
altak5 said:
I bought it from a local guy here in Calgary last fall, but at the time I got the impression that he had taken it on trade, or maybe bought it for the scope, etc.
Did the one at your shop have a stainless barrel, and a silver paint design on the stock?
Click to expand...

It was black CM seems like savage might have issues with these unless all the ammo manufacturers are the culprit which I doubt, could be a tight bore but my guess as a barrel maker would be narrow grooves rather than the bore.

Definitely contact savage they have to be aware of this problem can't be the first time they here of this because it is the second one I hear of since October

Btw the one I seen did the same as your it had to be loaded way down
 
IMO, there is a distinction between "blown" primers which would be caused by very high pressure and would be accompanied by high MV's and loosened primer pockets, and "backed out" primers, which are typically the result of a poor brass-chamber fit (could be the brass, not the chamber) and/or low pressure with low MV's.

Again IMO, the notion that tight necks (lack of clearance) increase pressure is well documented, but that "tight bores" (smaller than spec bore diameter and/or larger than spec groove diameter) also increases pressure to a significant degree, is not.
 
burnt_servo said:
read about half way down the link provided below .

I mentioned headspace because it is easy for someone to knock a rifle using a barrel nut out of whack if it is being tinkered with , and it is easy to verify if it is or isn't with in spec .

http://www.shootingillustrated.com/articles/2012/2/16/problems-with-primers/

"When primers are truly blown, this is almost always a sign of high pressure, but it does not necessarily mean the ammo is to blame. Dave Emary, Hornady's chief ballistics scientist, says excessive headspace can cause primers to back out or even pop out completely. There can be other culprits, like a rifle chamber cut very tightly, a throat cut too short or a barrel with a tight bore. On rare occasions, the cartridge brass might not have been properly annealed. Temperature can also be an issue, and this was my suspicion.
Click to expand...

This above quote is referring to semi auto rifles out of time 'dropping' a primer.

Excessive headspace won't blow a primer pocket larger, it may cause a primer to back up, flatten and leak. What I call a blown primer is when the primer pocket has enlarged and won't hold a primer any longer.
 
By the time a primer can back out completely from excessive headspace, it is unlikely the firing pin could reach it to set it off. As Dennis pointed out, these are two entirely different occurences. A blown primer is the result of higher pressure than the brass can handle.
 
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