Thread: 7mm PRC Factory Hornady ammo issue

Just a bit of warning regarding Hornady factory 7mm PRC 180 eldm.

I had 5 rounds among 60 loaded really hot. Bolt was super hard to lift, bolt face and ejector mark on the case. Primer felt of the case on one and I can push a new primer with my finger back in.

The other 55 rounds were fine so it is clearly not the rifle.
All ammo shot was from same batch.

Running a quick search on google it seems it happened to others, bit dodgy

Do you run any suppressor on your gun?
How thorough are you with your cleaning, notably between chamber neck area and beginning of the rifling?
As a curiosity, take a measurement with a micrometer at the base of each of you fired cases, that might give you an indication of how much pressure was coming out of them. Just to see if you see an increase in the web diameter as your barrel got dirtier

Were they sporadic or all on a row?

Originally Posted by Friwi

Do you run any suppressor on your gun?
How thorough are you with your cleaning, notably between chamber neck area and beginning of the rifling?
As a curiosity, take a measurement with a micrometer at the base of each of you fired cases, that might give you an indication of how much pressure was coming out of them. Just to see if you see an increase in the web diameter as your barrel got dirtier

Yes I had a suppressor on. I’m pretty thorough with the cleaning. Will have a look at the web diameter thanks for the suggestion.

Issue was sporadic, didn’t happen in a row. I found some post on Rokslide and Reddit mentioning hot 7mm PRC Hornady factory load.

Did you give equal cooling time to the barrel between shots? I found when shooting two rounds in quick succession with hornady precision hunter in my 300wsm is fine, but a third shot while hot will cause stiff bolt lift and pressure signs like you have experienced. Let everything cool down and not an issue. Heat things up and back to pressure signs.

I thought it was ammo issues until I clicked as the cause.

Originally Posted by Kimber 7mm-08

Did you give equal cooling time to the barrel between shots? I found when shooting two rounds in quick succession with hornady precision hunter in my 300wsm is fine, but a third shot while hot will cause stiff bolt lift and pressure signs like you have experienced. Let everything cool down and not an issue. Heat things up and back to pressure signs.

I thought it was ammo issues until I clicked as the cause.

Not really good enough if thats the case is their a warning about rapid "rapid bolt gun" firing. Iv never struck pressure issues with a warm barrels all being fair and equal my loads arnt hot and i generally use temp stable powders my uneducated guess would be inconsistent brass

Originally Posted by Kimber 7mm-08

Did you give equal cooling time to the barrel between shots? I found when shooting two rounds in quick succession with hornady precision hunter in my 300wsm is fine, but a third shot while hot will cause stiff bolt lift and pressure signs like you have experienced. Let everything cool down and not an issue. Heat things up and back to pressure signs.

I thought it was ammo issues until I clicked as the cause.

Interesting I will pay more attention next time, I always touch barrel and can to check they not too warm before firing another shot

I have come to the conclusion its inconsistent brass, nothing to do with cleaning or heat etc. I have gone through the same thing with my 7mm PRC. Managed to weed out most of the bad brass now it seems, i started with 3x packets of factory ammo & pulled it all to get the brass originally, Then another 2 packets after having to biff some of the original brass.

I shot a bunch of 175 ELDX over 2225 yesterday doing seating depths, below book max charge & experienced the same thing as the first lot of development i did with RL26. Every now and then a stiff bolt lift & stamped/swiped brass, sometimes last shot on a string sometimes first, no particular pattern. Primers all look the same & was all shot across the chronograph & the "hot" loads went no faster than the others. Clearly cant be heat related as sometimes it would be the first shot that would do it after a 10 min cool down, id follow up with 2 more straight away to complete the group & they would be the same speed but no stamp/swipe.

I think all you can really do is either run really slow/soft loads, or if your trying to run it fast/up close to max just throw out the bad brass & eventually you will end up with stuff thats ok.

Originally Posted by 6.5 CRD

I have come to the conclusion its inconsistent brass, nothing to do with cleaning or heat etc. I have gone through the same thing with my 7mm PRC. Managed to weed out most of the bad brass now it seems, i started with 3x packets of factory ammo & pulled it all to get the brass originally, Then another 2 packets after having to biff some of the original brass.

I shot a bunch of 175 ELDX over 2225 yesterday doing seating depths, below book max charge & experienced the same thing as the first lot of development i did with RL26. Every now and then a stiff bolt lift & stamped/swiped brass, sometimes last shot on a string sometimes first, no particular pattern. Primers all look the same & was all shot across the chronograph & the "hot" loads went no faster than the others. Clearly cant be heat related as sometimes it would be the first shot that would do it after a 10 min cool down, id follow up with 2 more straight away to complete the group & they would be the same speed but no stamp/swipe.

I think all you can really do is either run really slow/soft loads, or if your trying to run it fast/up close to max just throw out the bad brass & eventually you will end up with stuff thats ok.

This seems to be a common problem with the Hornady brass.
I get the odd stamping with mine I haven't had an issue with blowing primers in factory yet.
I'm not doing too much load development till I get some decent brass.

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I have found its not actually bad brass once you have weeded out the dud ones. My first batch is on its 3rd firing now & its a reasonably warm load. Time will tell though.

Originally Posted by 6.5 CRD

I have found its not actually bad brass once you have weeded out the dud ones. My first batch is on its 3rd firing now & its a reasonably warm load. Time will tell though.

How do you find the bad ones? Just by isolating the heavy bolt lift brass or visually somehow?


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Originally Posted by Bill999

How do you find the bad ones? Just by isolating the heavy bolt lift brass or visually somehow?


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Shooting them. Heres a picture from yesterday showing what i mean. 3 shot group from left to right with the same below max powder charge, same seating depth, 2932fps average, ES of 7fps. I have been to 3008fps with another 1.5gr of powder & not seen pressure signs on some of my other hornady brass.

As you can see all the primers look roughly "the same amount of flat" for lack of a better term. As above MV showed the 2nd shot to be the same speed as the rest, yet bolt was hard to lift & as you can see the brass is done. Just deprimed them, Shot 1 & 3 the primers still snug, shot 2 which is showing all the "pressure" the primer pocket is gone, primer almost fell out.

That’s a bit concerning… from what I have been reading the issue is more prononce with the 180eldm than the 175 eldx.
All the primers of these 60 rounds I shot decapped really easily and looked pretty flat. I guess the 180eldm are loaded hotter than the 175eldx and it doesn’t help in case of bad brass.


Not to sure what to do from there. Should I pull the bullet of the factory 180eldm I have left or just keep shooting them. I prefer to start load development on fire formed brass but if first shit ruins them no much point

Throw out the brass thats showing pressure and start your load development with the brass thats still good after that first firing. If it survives the initial firing, it will be fine after that. Thats what i have experienced anyway.

Originally Posted by 6.5 CRD

Throw out the brass thats showing pressure and start your load development with the brass thats still good after that first firing. If it survives the initial firing, it will be fine after that. Thats what i have experienced anyway.

I have 55 fired case already. I might return the rest of the ammo, reload these few cases and wait for some ADG or Peterson brass.
I’m not really at ease playing with hot round. To get the bolt face stamped like that in the case and primer falling these rounds are not only slightly over pressure.

Anyone taking the risk make sure your chamber is really cleaned of any oil, bore cleaner and dry. You don’t really want to add anything to rounds that are already maxed out.