New Savage 12 LRP blowing primers

[sawgunner2001]

Got out to the range today with a new Savage 12 LRP in 6.5 Creedmoor. But it was raining its ass off outside so I didn't shoot much. Glad I packed up when I did, because this is what I saw when I was picking up my brass:



I did look at the first piece of brass fired and it appeared fine, and I didn't look again until I was done (you can see how many rounds I fired). These are factory Hornady 140gr Amax loads and a factory chambered and assembled Savage 12 LRP. Now, I'm sure the ammo got at least a little wet and transferred some of that moisture into the chamber. Is it possible that the wet ammo/chamber caused this obviously overpressure situation? If so, what is the best way to prevent this when I "must" shoot in the rain (I normally won't...unless I've spent bookoo bucks and am at a match). If it is unlikely that the wet ammo/chamber caused this, what did?

If it would help to answer my question, I used a comparator to measure the base to datum line and came up with this (in order from L to R):

Unfired cartridge: 3.533"
3.536"
3.544" (measured twice and confirmed)
3.539"
3.538"
3.539"
3.535"
3.535"

 

[Snoball]

I a piece of primer before that wedged between the bolt and chamber causing similar results before. Might be worth it to make sure there is nothing in the chamber or against the bolt head? Where they hard to exyract or chamber? I would be finding the number for Hornady just in case.

 

[wadebrown]

any water on the brass when chambered can cause high pressure problems.

 

[Mayhem52]

Your cartridge measurements are worrisome. I just opened a brand new box of Hornady 140gr 6.5CR A-Max because after reading your post alarms went off all over the place. The 6.5CR 140gr A-Max should measure close to 2.81", which is within .0005" of what I just measured. That's also what is printed on the loading info label. My hand loads are set between 2.82" and 2.83" and if you are shoving a 3" bullet into the chamber I'd be expecting more than blown primers.

That aside, water in the chamber also creates a fit issue. I shoot a Savage 6.5CR as well. Haven't had any problems with the Hornady 120 or 140 A-Max but for one time, and that time I had an oil wet chamber. I have blown primers out of some hand loads in new Hornady brass but every one of those were a little hot.

I suppose the old adage about "keep your powder dry" is still applicable

 

[Frank Green]

Oil or cleaning solvents in the chamber or water for that fact will cause chamber pressures to go up. For an instance when the gun is fired the brass case should bite and grip the walls of the chamber. If the chamber/ammo is wet at all, all the pressure and thrust will go towards the bolt. I've seen it more than once with oil or cleaning solvents in the chamber and there was hard bolt lift and pressure signs etc....

If it does it again with known good ammo and the gun/ammo isn't wet......

Have the barrel checked if possible as well (have the bore/groove size measured) if possible. Most guys cannot do this but what I'm getting at here is I've seen barrels with undersize bores/grooves and this will cause pressure to go up as well.

One of the guys in the shop has a older factory rifle (brand doesn't matter) was originally a 7mm-08 and was rechambered to .284win. Any ways he cannot run the same type of standard loads like other guys can. Has to have reduced loads. The bore of his barrel and groove sizes were really undersize. We made a new barrel for his rifle needless to say.

Later, Frank
Bartlein Barrels

 

[sawgunner2001]

Thanks for the comments, folks.

Mayhem, those measurements were taken from the base of the cartridge to the datum line of the shoulder and include the length of the comparator. The numbers are meaningless really, only meant to compare the headspace length of fired cartridges with new, unfired cartridge (in this instance). To calm your worries, the cartridges fit in the magazine with room to spare

The rain has stopped and I've finished taking my college exam for the day and I may head back to the range with some dry ammo and see what happens.

 

[Mayhem52]

Missed the comparator part I've had a few get pretty tight with a "wet" chamber, which is prolly what you experienced. Didn't blow the primers on those but the bolt was pretty tight after sending it. Let us know how things work out after the dry day shoot. Got 16" of snow last night here and at 20* I think the shooting day is over before it started.

 

[sawgunner2001]

It must have been the moisture. I went out to the range today and fired roughly 10 rounds. One or two had some slight ejector marks, but no other high pressure signs. Got the rifle zero'd at 100 yds and found that it is shooting roughly 3/4 MOA.

Another question, though. I fired the 10 rounds over a chronograph today and found the average velocity to be ~2875 fps. Although these are my first outings with a 6.5 Creedmoor, that seems pretty fast for factory loaded 140gr ammunition, even when fired from a 26" barrel, doesn't it? I checked through the reloading forum and found that this is faster than most (all?) of the handloaders are.

I fired my 223 over the chronograph to see what it said about that, and it was actually reading a little slower than I had previously recorded. So, I suspect that the 6.5CM might actually be even a little faster than 2875!

 

[wakajawaka]

Probably unrelated but I have a Savage LRP in .260.
It is not happy when approaching maximum book loads.
Never shot any factory ammo.

 

[sawgunner2001]

I went and dug a little deeper in the 6.5 Creedmoor reloading thread and found a few that are getting similar velocity which lowers my concern that something is amiss. Maybe I was blessed with a fast barrel.

Hopefully the planets line up and I can get to an extended range sometime in the next month or two and verify dope and double check that against my chrono.

 

[HodgdonExtreme]

A friends 12LRP in 6.5CM shoots the 140 factory ammo at 2730fps, as measured by Magnetospeed V2.

I don't believe wet ammo increases chamber pressure. If you disagree, please present your theory on the physics at play.

I do, however, believe wet/oily ammo/chamber lubricates the case, preventing the case from "grabbing", and allowing the case head to more easily flow rearwards into the bolt face.

 

[sawgunner2001]

And blowing primers, apparently. I don't have an answer as to why, though. Which sucks because one cannot always keep everything dry. I do know that I've shot other rifles in the rain without ill effect, so I don't know what's up with this one. Eventually, if no answers can be come up with, I'll end up trying to replicate the condition which caused the primers to blow on the first outing and see what happens. All scientific method like.

 

[gatorgrizz27]

It looks like even the cases that didn't pop the primers out are very cratered and I believe I see marks from the extractor on every case. I'd probably verify the headspacing and make sure your chamber is cut deep enough. I don't know if its possible that a burr or something kept the reamer from inserting fully or something else is going on, but its not right with factory ammo for sure. FWIW I shot some .223 test loads today that were at 26.7 gr with soft primers (26 gr max book load), and my primers started showing slight cratering, but not nearly as badly as that.

It wouldn't surprise me if Savage rifles have extremely tight chambers compared to others. This may allow the accuracy they are known for to be possible at their price points.

 

[HodgdonExtreme]

And blowing primers, apparently. I don't have an answer as to why, though. Which sucks because one cannot always keep everything dry. I do know that I've shot other rifles in the rain without ill effect, so I don't know what's up with this one. Eventually, if no answers can be come up with, I'll end up trying to replicate the condition which caused the primers to blow on the first outing and see what happens. All scientific method like.

When I work up load, I do so with a clean dry chamber and use squeaky clean brass. I do not tolerate any ejector marks whatsoever.

However, if I shoot in the rain, I completely ignore the ejector marks, which happens to 75%+ of the cases. Often, they won't even fit in the shell holder of the press after being shot wet. Just how it goes...

 

[Sherrick5]

An earlier poster mentioned about having a 12 LRP in .260 and not liking max book loads... I have a factory one as well except mine shoots like a dream with max loads and higher... running Varget with 123gr Lapuas and h4350 for 140 A-Maxs (got 5 lb of RL-17 yesterday going to see how it runs, from what I've heard it should do well/same).... I'm shooting 1-4 gr higher than max load in book (pushing and showing no pressure signs at all except for a slight cratering that happens with any round I shoot just because of it's firing pin I believe... I mean with the 123s I'm getting a mean 2920 with the Varget and with the 140s I'm getting around a 2850-75

 

[Makrexd45]

An earlier poster mentioned about having a 12 LRP in .260 and not liking max book loads... I have a factory one as well except mine shoots like a dream with max loads and higher... running Varget with 123gr Lapuas and h4350 for 140 A-Maxs (got 5 lb of RL-17 yesterday going to see how it runs, from what I've heard it should do well/same).... I'm shooting 1-4 gr higher than max load in book (pushing and showing no pressure signs at all except for a slight cratering that happens with any round I shoot just because of it's firing pin I believe... I mean with the 123s I'm getting a mean 2920 with the Varget and with the 140s I'm getting around a 2850-75

Yeah I have a 12 LRP in 6.5 CM. Every single shot factory/handload all have cratering. This is due to a larger firing pin hole. Just the way it is. As for the primer issue I know that Hornady had a run of soft brass at some point. I have some brass that was only fired once with a load that was not near max that have loose primer pockets, most of the brass I have doesn't have this issue but there is definitely some soft stuff out there. Id go over to 65creedmoor.com and as the guys on the forum over there lots of guys with a ton of info and experience with the Creedmoor. Hope this helps.

 

[Makrexd45]

May want to check if the chamber was cut correctly too. I have heard of some LRPs that have chambers that are not correct causing problems with closing the bolt, and opening the bolt with a non fired round in the chamber.

 

[sawgunner2001]

I've now fired 34 rounds through the rifle, including the 7 wet ones. Most of them have mild cratering on the primer, but I haven't experienced any more sticky bolt or blown any more primers.

 

[Greg Langelius *]

I don't believe wet ammo increases chamber pressure. If you disagree, please present your theory on the physics at play.

...and there are also folks who insist that the world is not round and that the moon landings were faked. Calling a known phenomenon a 'theory' only demonstrates a closed mind.

The physics involved are clear and straightforward. When water flashes to steam it expands by a factor of 1700:1, and this increases even more as the steam becomes superheated. When this is combined with an expanding/sealing brass cartridge case and case temps that rise to at least several hundred degrees, deliberately obtuse observations make about as much sense as writing 'there be dragons beyond here' on a map. Putting things mildly, this process vastly increases the probability of a pressure excursion.

More to the point, I and several others here have observed the consequences of keeping ammo in a cooler on a hot and humid day, and feeding rounds with condensation on them into a rifle. We blew lots of primers that day until we wised up and dried off the cartridges just prior to chambering them. No condensation/water/moisture, no blown primers.

My experience with Hornady loads (and especially their Superformance loads) is that they tend to develop higher velocities, which may be an indication of warmer loadings than other makers' ammunition, and could be supported by more pronounced cratering than is considered normal on dry days. Add this to wet cases, and the recipe for blown primers becomes much more of a probability than a possibility, and certainly more than a 'theory'.

The defense rests.

For the record, this phenomenon has already been discussed to this conclusion on here a number times. I suggest a new poster do more research on this site before they try glibly informing us that we must be in error. Frank Green (who represents Bartlein barrels here and can be reliably counted upon for informed reporting) had already provided a polite and reasonable explanation of causes and effects before you made your rather rash declaration to the contrary.

Greg

 

[HodgdonExtreme]

[MENTION=79378]greglangelius*[/MENTION]

I apologize if the "tone" of my post seemed glib or offensive in any way, I had zero intention of that.

I don't feel I was pontificating, but rather, fishing for someone to present a reasonable explanation for how a drop or two of water on the exterior of a cartridge case could increase internal chamber pressure by 10-20ksi.

You state this is a known phenomenon. Please link me to the test data.

Final thought for now: If chamber pressure is drastically increased, that means you'd expect to see a nice healthy increase in velocity also, right? Meaning you could chrono 10 dry rounds at, say, 2800, and then get an extra 50-150 by spritzing some moisture on the next 10 prior to firing??

 

[Greg Langelius *]

Please link me to the test data.

Do I LOOK like your personal researcher? You want to find something, don't come on like I have some sort of obligation to find it for you. I got nothin' to prove to you. Use the search feature.

If chamber pressure is drastically increased, that means you'd expect to see a nice healthy increase in velocity also, right? Meaning you could chrono 10 dry rounds at, say, 2800, and then get an extra 50-150 by spritzing some moisture on the next 10 prior to firing??

Stop and look at what you typed. It appears you are proposing a test that's deliberately intended to create a potentially dangerous condition, and/or insisting I provide links to data derived from such a test. That's completely off my page. I think you're frackin' crazy. From now on you are on my 'ignore list'.

Greg

 

[djskit]

Water does not compress...

 

[Txvarmint_hunter]

Hey Sawgunner
I have just purchased a Mod 12 LRP
In a 6.5 Creedmoore
Having the exact same problem factory Hornady 140gr A-Max and the first 6 rounds through it and 3 blown primers and the rest are cratered. First thought was bad ammo so I tried another box of 140s and some 120gr GMXs and same thing.
So I came to the conclusion that it is a heads spacing issue.
Just wondering if you have found any answers or talked to savage about the issue?

I plan on calling savage this week because I have another brand new 6.5 in a Mod 16 that barely groups 2.5" at 100yds after a good break-in so not real happy with savage right now.

 

[Bender]

[MENTION=79378]greglangelius*[/MENTION]

I apologize if the "tone" of my post seemed glib or offensive in any way, I had zero intention of that.

I don't feel I was pontificating, but rather, fishing for someone to present a reasonable explanation for how a drop or two of water on the exterior of a cartridge case could increase internal chamber pressure by 10-20ksi.

You state this is a known phenomenon. Please link me to the test data.

Final thought for now: If chamber pressure is drastically increased, that means you'd expect to see a nice healthy increase in velocity also, right? Meaning you could chrono 10 dry rounds at, say, 2800, and then get an extra 50-150 by spritzing some moisture on the next 10 prior to firing??

Your ignorance is showing......might want to tuck that back in.

 

[Frank Green]

Water does not compress...

Bingo!!!!!!!!!!!!!!

Later, Frank
Bartlein Barrels

 

[Greg Langelius *]

I blew primers on a factory Savage 10FP .260 in 2002, but we checked all our decimals and it turned out to be a marginally hot load combined with brass that got wet while shooting in a rain storm.

It was confirmed later in the week (the 1st Spirit of America Matches) when we put our ammo in a cooler then took it out and loaded it. The temps were high and humidity was very high, allowing condensation to form on the brass before chambering it, and we started blowing primers all over again.

When we figured out what was happening, we began wiping the rounds dry with a towel just before chambering and the issue disappeared.

Greg

 

[MDM]

My dad has a Savage LRP in 6.5 Creedmoor and it has intermittent pressure problems. Primer pockets will leak and he will get pierced primers with light charges. This has been going on since he bought it middle of last year. Turns out the freebore portion of the reamer just past case mouth, all the way up the lead of the lands, must have been worn out when the rifle was chambered. When using a hornady OAL gauge, the bullet makes contact with the bore in that it leaves marks all the way around the bullet, all the way to where the ogive actually comes in contact with the lands. For example, you can feel slight resistance at a length of 2.690 with a 140 amax. If push past this, the bullet will make it's final contact and come to a stop on the lands at a length of 2.845". You can't feel this tightness on the bullet when closing the bolt on a round that is loaded to 2.830, but it is there and I'm sure that's what's causing the problems. The bullet is being gripped by the bore ever so slightly from the case mouth, all the way to the ogive. I'm guessing the bore from the case mouth to the ogive is the same diameter as the bullet as the marks on the bullet clearly show this. I know someone with a lathe and Creedmoor reamer and we plan on taking 1 turn of the threads off the shank and reaming in .050 to clean up the suspect area. I'm certain this is gonna fix the issue.

I doubt this is a common issue, and as others have said, water can cause bad pressure spikes.

 

[sawgunner2001]

Hey Sawgunner
I have just purchased a Mod 12 LRP
In a 6.5 Creedmoore
Having the exact same problem factory Hornady 140gr A-Max and the first 6 rounds through it and 3 blown primers and the rest are cratered. First thought was bad ammo so I tried another box of 140s and some 120gr GMXs and same thing.
So I came to the conclusion that it is a heads spacing issue.
Just wondering if you have found any answers or talked to savage about the issue?

I plan on calling savage this week because I have another brand new 6.5 in a Mod 16 that barely groups 2.5" at 100yds after a good break-in so not real happy with savage right now.

I've since taken the rifle to the range once or twice and haven't seen any more popped/leaking primers, but I'm still getting ejector swipe on about half the fired cartridges. I haven't checked the depth of the throat yet, but that's the first thing I'm gonna check when I've got a free minute.

 

[Txvarmint_hunter]

Thanks for the replies.
Sounds like the LRPs have had some chamber length issues. I do not have the tools to measure the chamber on mine so I got in touch with Savage last week and they told me to send both rifles back no charge and they will have the gun shop go through them.

 

[sawgunner2001]

To follow up with this, I'm still getting the occasional popped primer (one in twenty maybe?) and intermittent ejector swipe (twelve out of twenty or so) with factory loaded Hornady 140gr Amax ammunition, even during dry conditions. Velocity is still ridiculously high at 2850fps confirmed with my 1000 meter dope being 8.1 mils, which is precisely what Shooter predicted it would be for my shooting conditions this morning.

So, apparently this isn't due solely to wet ammunition. I've checked the freebore and found it to be roughly .009", so I'm not jamming the bullets into the lands. I'm reading quite a bit about Hornady loading this ammo pretty hot which would explain this issue (amongst other recent complaints about accuracy). I've also read that Hornady is blaming Savage and saying that Savage rifles have tight bores causing these pressure spikes. Speaking of accuracy however, I kept a five shot group around 5" at 1000m today. No complaints in the speed or accuracy department, just the pressure one.

I'm off work this week and will get in touch with a 'smith and figure out the cost to have the bore slugged and find out what it's true ID really is so I can put that argument to bed, especially considering other high-end custom rifles have exhibited this same behavior with this ammunition. I'm extremely suspicious of the ammunition, but will eat crow if my bore measures much less than .256" bore and .264" groove.

 

[excaliber]

Also check to see if the boltface isn`t "dished". I have seen this problem with more than one Savage.

 

[sawgunner2001]

Also check to see if the boltface isn`t "dished". I have seen this problem with more than one Savage.

I hadn't thought of that, but I just checked and the bolt face is not "dished." Thanks for the suggestion, though.

 

[sawgunner2001]

Further follow up...

I never did get the bore slugged, but I did start handloading. 41.6gr of H4350 behind a 140gr A-max shoots ~2800fps (give or take 15-20fps chrono error given small sample size) with no pressure signs. I'm still loading to ~0.009" off the lands.

 

[Dezelrig]

I witnessed this same popped primers issue during a class this past may. Two shooters were both using the factory Hornady 6.5 ammo with 140 A-max. One guy was shooting a DT, the other was shooting an AIAX. They came to the conclusion that a carbon ring in the leade had formed quickly by firing 100-150 rounds of this particular ammo. I never confirmed if there was a carbon ring or not, as the 2 guys left the class, and I didn't see them again.

 

[Brux]

My dad has a Savage LRP in 6.5 Creedmoor and it has intermittent pressure problems. Primer pockets will leak and he will get pierced primers with light charges. This has been going on since he bought it middle of last year. Turns out the freebore portion of the reamer just past case mouth, all the way up the lead of the lands, must have been worn out when the rifle was chambered. When using a hornady OAL gauge, the bullet makes contact with the bore in that it leaves marks all the way around the bullet, all the way to where the ogive actually comes in contact with the lands. For example, you can feel slight resistance at a length of 2.690 with a 140 amax. If push past this, the bullet will make it's final contact and come to a stop on the lands at a length of 2.845". You can't feel this tightness on the bullet when closing the bolt on a round that is loaded to 2.830, but it is there and I'm sure that's what's causing the problems. The bullet is being gripped by the bore ever so slightly from the case mouth, all the way to the ogive. I'm guessing the bore from the case mouth to the ogive is the same diameter as the bullet as the marks on the bullet clearly show this. I know someone with a lathe and Creedmoor reamer and we plan on taking 1 turn of the threads off the shank and reaming in .050 to clean up the suspect area. I'm certain this is gonna fix the issue.

I doubt this is a common issue, and as others have said, water can cause bad pressure spikes.

I just got my son's back today for this exact same thing.I had to send it back to savage twice to get this problem fixed.I checked it this afternoon and now with a 140 Amax bullet,the OAL can be 2.830 if needed.Before it was fixed it was 2.740.It was causing very bad pressure problems.Now to see if it will shoot straight.

 

[cottonant]

If its another shallow throat issue with Savage LRPs this was recently discussed in this thread:

http://www.snipershide.com/shooting.../259855-savage-12-lrp-scratching-bullets.html

My brother in law's throat was so shallow it was scratching the bullets. He had a smith extend the throat about .120 and it not only corrected the scratching issue, the gun shoots really well now.