primers flattening with no other signs of pressure?

[19 Badger]

While trying to save my good primers during the supply shortage I switched to to using up my cheaper primers just to keep shooting. In 25 years I have never had a hang fire in a rifle until a month ago, had 2 actually in a weekend. What primer was I using? Winchester WLMR.

 

[rammac]

Nothing unsafe or dangerous about having a little lube on the case for diagnostic purposes. I do it on some AI chamberings during fireforming. It is nothing new. It will give you a very good idea of your bolt face to shoulder dimension (at the chosen datum) with a single moderate pressure firing. If the OP would do that test then he would have a baseline as to where to set the die assuming the lubed case is at maximum length for his chamber minus springback. If the OP is sure that this rifle does not have headspace exceeding SAAMI specs it is a reasonable and easy test with much info to glean.

There is a big difference between using lubricant on a case that is filled with a reduced load for fireforming and lubricating a case that is loaded with a full load.

The reason a lubed case will give a good indication of the condition of the bolt face is because the case head is being pushed in to the bolt with far more pressure.

Read my post more carefully, I said that it's safer and has less potential for damaging the rifle, that's a fact. You can look at the bolt face and see if there are finish problems and you can actually measure dimensions to see if it is out of spec, you don't need to stress the bolt/lugs/receiver to find those issues. Simply reducing the shoulder bump IS safer and less of a risk, that's an undeniable fact. And since there is an easy way to test the theory why not do it the easier and safer way?

Your assuming that the increased bolt pressure of a reduced load is comparable to the increased bolt pressure of a full load, that's not even reasonable logic. I agree that rifle wont explode (assuming that rifle is in good condition) the first time you use a lubricated case but it certainly does stress everything much more than the designer's specifications (using a full power load, not a light load). Like all metal, hard impacts create stresses and those stresses accumulate over time. Eventually those stresses will fracture the metal. When a rifle experiences stresses that are above their design parameters it simply accelerates the time to failure. When that failure occurs I can't guess but it will be sooner than when it would have happened if you never overstressed the metal. I just don't recommend doing things that hasten the failure of firearms.

 

[MagnumManiac]

Winchester primer cups can be soft at times.
I have a similar issue in my 25-06.
I have measured the actual headspace of this rifle, it is .002" above minimum SAAMI spec.
However, it flattens ALL primers even on start loads. I bump the shoulder for .001" headspace every time I size cases.
This thing will shoot less than a 1/4" in certain conditions, but never more than 3/8" at 100.
So I don't tamper with it.
Still has me perplexed why it flattens primers though.

Cheers.

 

[rammac]

I just loaded a federal primer into the same exact piece of brass that I just annealed, resized and it was much more firm to seat so i don't believe primer pocket issue AND it has much less flattening after being fired. Please see the picture. What does this mean exactly? Can I not use the other primers as those are what I did the load work up with and actually found a very accurate node .3moa.

Why would you assume that the primer pocket isn't an issue when you use a different primer, it would suggest just the opposite to me. Which Federal primers did you use? Primer cups can have slightly different hardness and diameter. Maybe the Federal primers are just slightly larger in diameter or maybe they are harder material. Most primer cups are made from cartridge brass but how they were shaped, quenched, and sized during manufacturing will change their hardness. Depending the difference between priming compounds you could have reduced the primer's energy which reduced the cartridge's pressure. Who knows?

Like several people have said, I don't expect that you are pushing the rifle beyond the safe range and if it were my rifle I'd probably change my shoulder bump a little, test for groups, and then continue on with life.

 

[Bigeclipse]

Why would you assume that the primer pocket isn't an issue when you use a different primer, it would suggest just the opposite to me. Which Federal primers did you use? Primer cups can have slightly different hardness and diameter. Maybe the Federal primers are just slightly larger in diameter or maybe they are harder material. Most primer cups are made from cartridge brass but how they were shaped, quenched, and sized during manufacturing will change their hardness. Depending the difference between priming compounds you could have reduced the primer's energy which reduced the cartridge's pressure. Who knows?

Like several people have said, I don't expect that you are pushing the rifle beyond the safe range and if it were my rifle I'd probably change my shoulder bump a little, test for groups, and then continue on with life. This was an 10 year old box of Winchester primers. I will be buying some new ones to see if the newer ones have the same effect as the old ones

Did you not read my comments above? I have already changed my shoulder bump and still got the slightly flattened primers. I have now tested with federal primers and cci primers and both are harder to seat and don't flatten when being fired so it must be a Winchester primer issue and not the primer pockets of the brass. Also, this is only the second firing on brand new Lapua brass so I highly doubt they would have loose pockets.

 

[Rardoin]

There is a big difference between using lubricant on a case that is filled with a reduced load for fireforming and lubricating a case that is loaded with a full load.

The reason a lubed case will give a good indication of the condition of the bolt face is because the case head is being pushed in to the bolt with far more pressure.

Read my post more carefully, I said that it's safer and has less potential for damaging the rifle, that's a fact. You can look at the bolt face and see if there are finish problems and you can actually measure dimensions to see if it is out of spec, you don't need to stress the bolt/lugs/receiver to find those issues. Simply reducing the shoulder bump IS safer and less of a risk, that's an undeniable fact. And since there is an easy way to test the theory why not do it the easier and safer way?

Your assuming that the increased bolt pressure of a reduced load is comparable to the increased bolt pressure of a full load, that's not even reasonable logic. I agree that rifle wont explode (assuming that rifle is in good condition) the first time you use a lubricated case but it certainly does stress everything much more than the designer's specifications (using a full power load, not a light load). Like all metal, hard impacts create stresses and those stresses accumulate over time. Eventually those stresses will fracture the metal. When a rifle experiences stresses that are above their design parameters it simply accelerates the time to failure. When that failure occurs I can't guess but it will be sooner than when it would have happened if you never overstressed the metal. I just don't recommend doing things that hasten the failure of firearms.

OK.

 

[epags]

Did you not read my comments above? I have already changed my shoulder bump and still got the slightly flattened primers. I have now tested with federal primers and cci primers and both are harder to seat and don't flatten when being fired so it must be a Winchester primer issue and not the primer pockets of the brass. Also, this is only the second firing on brand new Lapua brass so I highly doubt they would have loose pockets.

After all is said and done more is said than done. You have identified the issue. You can continue to use the WLR Primers ( and I would), use the new Primers and tinker with the formula and send me those no good WLRPs. LOL.

 

[Bigeclipse]

After all is said and done more is said than done. You have identified the issue. You can continue to use the WLR Primers ( and I would), use the new Primers and tinker with the formula and send me those no good WLRPs. LOL.

Yes I did not to mean for that to sound so rude. I really appreciate everyone's help here and I do believe I have identified the issue.

 

[Big Turnips]

Winchester primer cups can be soft at times.
I have a similar issue in my 25-06.
I have measured the actual headspace of this rifle, it is .002" above minimum SAAMI spec.
However, it flattens ALL primers even on start loads. I bump the shoulder for .001" headspace every time I size cases.
This thing will shoot less than a 1/4" in certain conditions, but never more than 3/8" at 100.
So I don't tamper with it.
Still has me perplexed why it flattens primers though.

Cheers.

I had a 25-06 and I used the old 61/2 X 120 Winchester primers, they worked for me. Accuracy was identical to what you experienced. The primers, now that this subject is brought up, I remember, did flatten at times with no other signs of pressure. My loads were warm but not book maximum. At the time, I thought it was my resizing that caused this. I may have been wrong.

 

[baggy270]

I haven't been real impressed with Winchester rifle primers. Sold what I had on Gunbroker. Lol. Like mentioned before, they look like they are seated deep, I had a hard time getting them to go in for enough on Hornady 6.5 brass. I like them seated anywhere from .004"-.007" below is what I shoot for. A little less shoulder bump maybe too.

I returned 900 Winchester primers that blew torch marks on my bolt face. They kept rupturing at the edge and flame cutting my bolt. Nothing but CCI now.

 

[Flatbow]

I may have missed it somewhere but what riffle is it?
I have a Kimber mth assent that does the same thing with any amo. Factory and my hand loads.
I ffinally just ignored the primer flattening a d continued on with load development paying attention to other signs. I now have a great load.
still has flat primers (CCI BR 4) though.

 

[Bigeclipse]

I may have missed it somewhere but what riffle is it?
I have a Kimber mth assent that does the same thing with any amo. Factory and my hand loads.
I ffinally just ignored the primer flattening a d continued on with load development paying attention to other signs. I now have a great load.
still has flat primers (CCI BR 4) though.

Savage with a aftermarket barrel.