New Savage 12 LRP popping primers with factory ammo

[SoCal326]

I picked up a savage 12 LRP in 6.5 Creedmoor and headed out to the range with my cleaning rod, rod guide, solvent and three boxes of Hornady 140 gr A-max to break the barrel in per the instructions on the Savage website.

I was a little hesitant about the idea of running a patch with two drops of oil down the barrel after cleaning--right before my next shot but I did it.

Anyways, I ran through the prescribed 50 rounds. Clean after each round for ten rounds. Clean after each three round groups for 5 groups. clean after each 5 shot groups for 5 groups.

During that process I had stiff bolts on about 15 of the rounds. I popped three primers and about 6 of the cases had indents from the ejector on the head--two them were pretty deep.

Is it normal to deal with pressure signs from factory ammo during the break in period? I stopped pushing oil down the barrel because I was worried that the oil was
bringing up the pressure. That seemed to help a bit, although I still popped one primer after I stopped using the oil. The last ten rounds seemed good. No pressure signs, no stiff bolt, no carbon blowing past the primer.

Was this just a normal part of breaking in a barrel?

http://img.tapatalk.com/d/14/02/27/y5y6y5a3.jpg
http://img.tapatalk.com/d/14/02/27/a6u4y8e9.jpghttp://img.tapatalk.com/d/14/02/27/7edezyme.jpg
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[jbjh]

I'm trying to recall what forum I read it on, but this was a problem for many shooters using the Superformance ammo.

[SoCal326]

I was gettings about 2850 fps out of the 26 inch barrel where the box states that I should be getting 2700 fps out of a 24 inch barrel. Not sure if that's excessive or not. Ill have to look around and see what others say.

[broncbob]

It looks like the primers are all flat, and some of them are cratered, plus the blown primers. You have pressure problems no doubt.

As to why, did you have any lube in the chamber? That ammo should run fine through your rifle.

[jonbearman]

I'm with broncbob,you more than likely got oil in the chamber and this will cause high pressure.You have to dry patch the chamber when you put anything that is similar to oil in the chamber.Clean the gun and dont put any oil in the bore unless you wont be shooting for awhile. But before you go out make sure that chamber is dry or the case upon ignition cant grip the chamber walls like it is supposed too. If the oil was present you will get wild pressure spikes.

[broncbob]

I have never shot factory ammo out of my 6.5 CM build, and I'm just getting started with load development, but you MV seams really high.

I know my friends 12 LRP is giving high 2700's with 41 ish grains of H4350 under a 140 Nosler custom competition bullet. This would explain your pressure problems.

Have you loaded a live round then ejected it? I'm wondering if your throat is stupid short and your jamming the lands really hard.

[emtrescue6]

I don't really think the little bit of oil you pushed down the barrel, especially if you used a action/rod guide is causing this...the pressure looks inconsistent...and many of those primers look really flat. FWIW, I woulda stopped shooting after the first primer blew out, yer just asking for trouble continuing to shoot with those pressure signs. My guess is it's a chamber issue (e.g. undersized)...

[82boy]

Starting out, if your experiencing pressure problems stop and do not go any further. Them rounds show pressure signs with the flat cratered primers. Many have ejector marks. and if your having a sticky bolt there is a pressure problem. Now when your blanking primers you are damaging the gun. I would first contact Hornady, and then Savage.

[ColColt]

I think Hornady needs to wake up and realize some of their ammo is just too hot. I had a similar problem with their SST 130 gr ammo in 270 Winchester. I sent them pics and even after they saw the flattened primer still refuse to acknowledge their ammo could be at fault. The box said the velocity was 3200 fps, that's at least 100-150 fps faster than Winchester's Power Point ammo with the same bullet weight. I get no primer flattening using my reloads of 58-60 gr of H4831 and a 130 gr bullet but their stuff is hot whether they choose to believe it or not.

This is what they told me about the flattened primer...blaming everything but their ammo.

"The case on the right, although the primer is flatter it is not filling the entire primer pocket and radius on the edge. Also the printing on the base of both cases shown clearly that the lettering is still ridged and the lettering is exhibiting sharp cut corners and has not been set back against the face of the bolt with any significant pressure."

http://i180.photobucket.com/albums/x220/ColColt/Jack%20OConnor%20Tribute/_DEF4599a_zps535950a9.jpg (http://s180.photobucket.com/user/ColColt/media/Jack%20OConnor%20Tribute/_DEF4599a_zps535950a9.jpg.html)

[SoCal326]

Thanks for the suggestions and ideas. Looking back on it I think emtrescue6 and 82boy are correct. I should have stopped shooting. I convinced myself that with a factory rifle and factory ammo, It couldn’t be that bad. Funny thing is if they were my reloads I would have stopped right away. I wont fall into the “but its factory and must be safe” trap again.

It looks like a few ideas came up about possible causes:

1. Three people mentioned that factory loads may have just been too hot for my rifle.

2. Another suggestion was that my chamber is too short and the bullet is being jammed too far into the lands.
I chambered a round then ejected it and didn’t see any markings from the lands. I also measured the OAL of 3 rounds. The Hornady reloading manual they should be at 2.800” and the three that I measured were 2.8135”, 2.8120”, and 2.8135”. That’s longer than the Hornady manual states but people go long all the time.

3. Oil in the barrel/chamber increased pressure or prevented good seal in chamber.
Emtrescue noted that the pressure signs were inconsistent. This inconsistency suggests that something was changing from shot to shot. I expect the rifle to be the same each time, and I also expect the ammo to be the same (within a tenth of a grain). The only variable that could have changed from round to round was how much oil/solvent I may have left in the chamber/barrel. I like to think that there was no solvent left in the barrel--but I can’t eliminate that possibility. The oil was suggested by Savage and I never added more than 2 drops.

The last thing that makes me think this could be the issue is that the last 10 rounds didn’t seem to be an issue. No stiff bolt and no ejector mark. The primers were a bit flat but no worse than I’ve seen from other factory ammo.
I’d really like to blame it on myself because that means that I can go out and shoot this weekend because nothing’s wrong with the rifle/ammo. I’ll take the advice offered though and let Hornady and Savage chime in first.

Thanks Fellas!!

[1.618]

2. Another suggestion was that my chamber is too short

I would also consider the possibility that your chamber is too LONG (or your shoulders have been set back too far in the case of reloads), giving excessive headspace.

What can happen then is:
1. the firing pin drives the cartridge forward, leaving a gap between the bolt face and the head of the cartridge
2. the powder ignites, raising pressure and causing the sides of the case to expand and grip against the sides of the chamber
3. the unsupported primer begins to "balloon" out the back of the case
4. then the rising pressure SLAMS the head of the case back against the bolt face, and
5. this somewhat flattens the primer, making it more "square" than radiused at the edges (if it doesn't blow the primer out).

See below:

http://i122.photobucket.com/albums/o254/bigedp51/HeadClearance_zpsf30a3af1.gif

I don't think it applies to you, but this can also happen if your pressures are too LOW, because the primer begins to balloon out BEFORE you get enough pressure to push the case back against the bolt face.

[shoalwater]

Get on the 6.5 Creedmoor forum, this is more than likely a Hornady issue as it appears they have switched from H4350, due to the shortage, to Hybrid 100 or something similar and it has made the factory ammo in some cases to hot and sub par on accuracy at distance. Most are seeing vertical stringing issues with the newer lots of the match 140 ammo. I roll my own so I haven't experienced this personally, but quite a few on the Creedmoor forum have.

[SoCal326]

Thanks shoalwater! I was all set to blame myself and it looks like there are quite a few people commenting on this same issue. When you mentioned that they were using a different powder I assumed they would have indicated it on the box of ammo, but no. Folks are saying that they changed powder without changing the label. I'm now leaning toward blaming this on an ammo issue.

http://forum.snipershide.com/showthread.php?t=236169