6.5 Creedmoor Blown Primer.... Stiller Action, Factory ammo.

S

swhiteh3

Sergeant
Full Member
Minuteman
Aug 19, 2013
267
67
North of Charlotte, NC
#1
I finally got a chance to get out my new build today - a 6.5 Creedmoor build based on a new Stiller SPECTRE action. It has a Brux 24" barrel and is mounted in an AICS. The only ammo I'm using right now is Hornaday 140gr A-Max factory ammo.

In the first 20 rounds, I got a blown primer. Just to make sure I'm calling it the right thing, the primer was completely blown out of the case (I never found it), and the case jammed in the bore. The bolt failed to pull the brass out of the breach, so I used a piece of drill rod to knock it out, which happened fairly easily.

I'm not sure if it was imagination, but the round seemed "hotter" than the other shots. Before I even knew something was wrong, I noted to myself that I must not have loaded the bipod correctly or something, because the bipod hopped and moved more than any other shot I took today. (It was an indoor range, with a smooth tile floor, so loading the bipod at all today was nearly impossible. I was just trying to get a rough zero on the gun before some range time this weekend).

Just wondering if this was a common occurrence with this ammo, or if it might point to some other issue with some part of my set-up. After a gunsmith took a quick glimpse at everything, he seemed unconcerned so I put it back together, and the next few shots happened without drama.

Thoughts?

-Scott Whitehead
 
#4
Scott, we've shot a lot of rounds of the 140-grain Hornady stuff in lots of different rifles over the past three years. We had a batch two years ago that was a bit inconsistent but never encountered anything hot as you described. Every ammo MFG will occasionally have something less than perfect. Sucks when it happens to you though, ya know? If the other cases don't show pressure signs, I'd not worry about it too much at this point. Make note of the lot number though for future reference.

Best regards,

Mark
 
#5
I have a brand new GAP that had the exact same thing happen but just one time in the first few rounds. No idea why, bought 400 rounds in one lot and have shot about 300 of it with no other issues. Rifle is fine and shoots amazing so not to worried about it. Could have been overcharged but also could have just been a bad primer pocket in the brass.
 
#6
There could have been some metal in the barrel that restricted the bullet.. If this was the first time you fired it, could have been some copper fouling. It takes a bit to break in a new barrel and goofy crap happens if you do not swab the barrel after each shot for the first 30 rounds.
 
#7
RHunter said:
There could have been some metal in the barrel that restricted the bullet.. If this was the first time you fired it, could have been some copper fouling. It takes a bit to break in a new barrel and goofy crap happens if you do not swab the barrel after each shot for the first 30 rounds.
Click to expand...


LOL, sounds like you spend more time with a cleaning rod than actually shooting that new rifle :) . I've never done that and have never had a issue
 
#8
RHunter said:
There could have been some metal in the barrel that restricted the bullet.. If this was the first time you fired it, could have been some copper fouling. It takes a bit to break in a new barrel and goofy crap happens if you do not swab the barrel after each shot for the first 30 rounds.
Click to expand...

Ahhh...no.
 
#9
LOL, sounds like you spend more time with a cleaning rod than actually shooting that new rifle . I've never done that and have never had a issue
Click to expand...

From Kreiger Barrels Inc.:

With any premium barrel that has been finish lapped -- such as your Krieger Barrel --, the lay or direction of the finish is in the direction of the bullet travel, so fouling is minimal compared to a barrel with internal tooling marks. This is true of any properly finish-lapped barrel regardless of how it is rifled. If it is not finish-lapped, there will be reamer marks left in the bore that are directly across the direction of the bullet travel. This occurs even in a button-rifled barrel as the button cannot completely iron out these reamer marks.

Because the lay of the finish is in the direction of the bullet travel, very little is done to the bore during break-in, but the throat is another story. When your barrel is chambered, by necessity there are reamer marks left in the throat that are across the lands, i.e. across the direction of the bullet travel. In a new barrel they are very distinct; much like the teeth on a very fine file. When the bullet is forced into the throat, copper dust is removed from the jacket material and released into the gas which at this temperature and pressure is actually a plasma. The copper dust is vaporized in this plasma and is carried down the barrel. As the gas expands and cools, the copper comes out of suspension and is deposited in the bore. This makes it appear as if the source of the fouling is the bore when it is actually for the most part the new throat. If this copper is allowed to stay in the bore, and subsequent bullets and deposits are fired over it, copper which adheres well to itself, will build up quickly and may be difficult to remove later. So when we break in a barrel, our goal is to get the throat “polished” without allowing copper to build up in the bore. This is the reasoning for the "fire-one-shot-and-clean" procedure.
Click to expand...

The original OP asked for a possible reason why, sorry I offered a possible reason. I should have left the opinions to be posted by the know-it-alls in the room. My Bad.
 
#10
Whether of not it was broken in would not have caused a over pressure round as the OP described. Krieger is talking about tiny reamer marks left over from cutting the chamber not any big bore obstruction.

So rather than derail this thread further lets just move on
 
#11
RHunter said:
The original OP asked for a possible reason why, sorry I offered a possible reason. I should have left the opinions to be posted by the know-it-alls in the room. My Bad.
Click to expand...


Everyone is entitled to their opinions, but on a premium cut rile bbl. I've never found the need to break in a BBL. Now to help the op out with my opinion, there are three things that I would do to help determine the cause. 1. Check the brass for any pressure signs. 2. Get the case in question and pop a new primer in it(that will determine if the brass had a loose pocket). 3. last thing which I really doubt, check the chamber for any oil,grease, or any type of build up. Anything in the chamber will not let the case expand and result to over pressure





From Brux website

Making a Cut Rifled Barrel



To make a cut rifled barrel you have to start off with the proper ingredients: The best steel available, skill, and experience. Since there are really only two main suppliers of barrel quality steel, the skill and experience is what really makes a barrel maker stand out.



First, we start out with either 4150 chrome-moly or 416R stainless steel double stress relieved bar stock. The bar stock starts out at 1-9/32” in diameter and 20-24 feet long so we cut it to length.



Step two is to rough contour the outside of the barrel blank in a lathe.



Thirdly, the blank gets mounted into a Barnes gun drill. The cutter bit has holes through which oil or coolant is injected under pressure to allow the evacuation of chips formed during the cutting process. This is called “oil-through” or “coolant-through”. Without this, you wouldn’t want to even attempt drilling a hole 30” long and under ¼” in diameter. The combination of a 3600rpm and good flushing allows us to drill a beautifully straight and centered hole .005” under “land” diameter at a rate of 1” per minute.



Clean the barrel.



Next the blank is sent back to the lathe to machine the finished contour of the outside.



Clean the barrel.



Now, the blank is sent on to the Pratt & Whitney reamer in which an “oil through” reaming tool is used to cut away the extra .005” left in the drilling process. The reamer makes an extremely accurate bore size and after it is finished the bore will have a better surface finish and will be at the proper “land” diameter.



Clean the barrel.



In the sixth step we hand lap each barrel to remove any slight tool marks that may have been left by the reamer and inspect every one with a bore scope. If the barrel doesn’t meet our standards for surface finish and tolerance it doesn’t get any further.



Clean the barrel.



The barrels then go onto the rifling machine which is responsible for cutting the all so familiar grooves in the bore. A Caliber/land configuration specific rifling head is used to progressively shave away small amounts of steel to form the rifling grooves. This is accomplished by simultaneously pulling the rifling head through the reamed blank as the blank is spun at a controlled rate. After each cut, the blank is rotated 90 degrees (for a four land configuration) and after one full rotation (360 degrees) the rifling head is slightly raised to shave off the next bit of material. This process is repeated until we reach groove diameter.



Clean the barrel.



Lastly, the barrel is hand lapped again to ensure an ultra-smooth bore and inspected with the bore scope.



The barrel is cleaned one last time, wrapped, packed, and shipped to your door.
 
#12
swhiteh3 said:
I finally got a chance to get out my new build today - a 6.5 Creedmoor build based on a new Stiller SPECTRE action. It has a Brux 24" barrel and is mounted in an AICS. The only ammo I'm using right now is Hornaday 140gr A-Max factory ammo.

In the first 20 rounds, I got a blown primer. Just to make sure I'm calling it the right thing, the primer was completely blown out of the case (I never found it), and the case jammed in the bore. The bolt failed to pull the brass out of the breach, so I used a piece of drill rod to knock it out, which happened fairly easily.

I'm not sure if it was imagination, but the round seemed "hotter" than the other shots. Before I even knew something was wrong, I noted to myself that I must not have loaded the bipod correctly or something, because the bipod hopped and moved more than any other shot I took today. (It was an indoor range, with a smooth tile floor, so loading the bipod at all today was nearly impossible. I was just trying to get a rough zero on the gun before some range time this weekend).

Just wondering if this was a common occurrence with this ammo, or if it might point to some other issue with some part of my set-up. After a gunsmith took a quick glimpse at everything, he seemed unconcerned so I put it back together, and the next few shots happened without drama.

Thoughts?

-Scott Whitehead
Click to expand...

Scott contact Hornady and let them know the problem. Can happen with any ammo. I have shot thousands of factory 140s and never had any trouble. Usually it's the Superformance loads that have problems as some rifles like them and some don't.
 
#13
Anything in the chamber will not let the case expand and result to over pressure
Click to expand...

I don't remember saying anything about the chamber, I believe my comments were directed at the bore.

If you don't think fouling, which includes a buildup of metal from bullet jackets, will not increase the pressure, you are on crack.

I have had a piece of a jacket get cut off from a bullet due to a burr on a gas port hole and get lodged between the rifling and the next round caused one HELL of a pressure build up when the next round was fired. Thank god it was in a semi auto and past the gas port or I could have lost half my face. When the whole mess was cleaned out there was a bullet and a piece of a jacket from the previous round. So now when I break in a new barrel I clean it between shots and have had ZERO issues. Last thing I am going to do is trust a manufacturer when human error is human error regardless of their claims.

Is this an exercise in who is "most right" for the sake of being right or was this supposed to be a group of opinions of what could have caused the OP's problem based on the experience of different members? Many many people have experienced issues when breaking in a new barrel.

OK, here is one for you all to dog pile on, if you want fuel for a chest pounding "I'm right" session, the wrong diameter of bullet was loaded by Hornady and it turned out to be made of solid steel.

There, that should keep you all busy trying to discredit my opinion for awhile and satisfy your need to be right.

Unbelievable.................
 
#14
RHunter said:
I don't remember saying anything about the chamber, I believe my comments were directed at the bore.

If you don't think fouling, which includes a buildup of metal from bullet jackets, will not increase the pressure, you are on crack.

I have had a piece of a jacket get cut off from a bullet due to a burr on a gas port hole and get lodged between the rifling and the next round caused one HELL of a pressure build up when the next round was fired. Thank god it was in a semi auto and past the gas port or I could have lost half my face. When the whole mess was cleaned out there was a bullet and a piece of a jacket from the previous round. So now when I break in a new barrel I clean it between shots and have had ZERO issues. Last thing I am going to do is trust a manufacturer when human error is human error regardless of their claims.

Is this an exercise in who is "most right" for the sake of being right or was this supposed to be a group of opinions of what could have caused the OP's problem based on the experience of different members? Many many people have experienced issues when breaking in a new barrel.

OK, here is one for you all to dog pile on, if you want fuel for a chest pounding "I'm right" session, the wrong diameter of bullet was loaded by Hornady and it turned out to be made of solid steel.

There, that should keep you all busy trying to discredit my opinion for awhile and satisfy your need to be right.

Unbelievable.................
Click to expand...

He had one round that acted funny and fired several after the problem round with no issues. Did you read his post? Are you suggesting the barrel fouling/obstruction went away on its own?

I am having a hard time making the connection you are trying to make
 
#17
I had a similar experience a few yeas back with an old rifle and a box of Hornady TAP, I took pictures and sent them to Hornady, they apologized, asked for my remaining 5 boxes and shipped me 7 boxes of another lot. I was pleased with the outcome, they were quick to take care of the problem. Mine were not 6.5cm.

I have noticed that Hornady's ammo can be a little more sensitive than I prefer, but they definitely stand behind their stuff.
 
#18
My take on hornady brass, IMHO. To me it seems that the factory ammo brass lasts longer then the component brass. While i haven't sent as many factory cm rds down range as rob01 has, i have fired several thousands of rds of reloads. The factory ammo brass seems to keep primer pockets longer, up to 12 firings on one batch. Load was 140@2830 fps, definitely not softball loads. I can usually get 6-10 firings on my cm brass, not lapua quality, but not as bad as some people make the hornady out to be. My bet is a hot rd, almost sounds superformance like. I can tell u hornady will say they have never had any issues/complaints with the 140 amax factory ammo. Thats what they told me about a bad lot of bullets last year, no complaints ever. Even though several all people with same lot # called and complained before me.
 
#19
He had one round that acted funny and fired several after the problem round with no issues. Did you read his post? Are you suggesting the barrel fouling/obstruction went away on its own?
Click to expand...

Certainly. A round can scrape away fouling left over by a previous round or previous rounds.

A lot of guys that shoot cast bullets in handguns will shoot a jacketed round to clean out some of the lead fouling between magazines. Same applies here. You get an excess buildup of copper inside the barrel at a particular point in the barrel or along the barrel the bullet from a next fired round can scrape it off. But in the process of doing so, you are going to get a pressure buildup that can blow primers and cause excessive case expansion from the increased pressure caused by the increased resistance.

Until new barrels get "polished" from a few hundred rounds, their rough surface and open pores in the metal are magnets for fouling. Sometimes that fouling gets to be excessive from buildup and gets in the way of a bullet exiting the bore easily and causes a pressure spike a few thousand PSI more and that is often enough to blow a primer out. That increased pressure is also often enough to help the bullet currently traveling down the barrel scrape off excessive fouling.

In my opinion, that is more likely what happened than Hornady screwing up and loading extra powder in a case. Most cases are filled to damn near 100% of capacity anyway and a quality gun can handle a little hotter of a load... but a fouled barrel can cause a much higher pressure spike than a slightly hotter round.

Another scenario that can cause a massive increase is pressure is if the bullet was seated deeper by a bad feed. This increases the initial pressure and can cause the primer to be blown out.

It is easy to blame the manufacturer but 99% of what they get blamed for is not a problem with the ammo, it is the shooting condition. That is not to say their was a problem with the ammo, but their controlled manufacturing process really makes errors few and far between. The liability is such that they have to take every step fiscally possible to make sure that ammo is right going out the door.
 
#20
dtibbals said:
I have a brand new GAP that had the exact same thing happen but just one time in the first few rounds. No idea why, bought 400 rounds in one lot and have shot about 300 of it with no other issues. Rifle is fine and shoots amazing so not to worried about it. Could have been overcharged but also could have just been a bad primer pocket in the brass.
Click to expand...

Some time ago I had a similar experience while breaking in my Surgeon Scalpel 6.5 CM using Hornady Match 140 AMAX ammo. I believe out of the first two of four rounds fired, I blew two primers. I started a thread about it which kind of turned into a debate on the quality of the Hornady Match 6.5 CM ammo (which I continue to use with good results). Anyway, I've had no such issues since initial break in.

When I blew those primers during break in, I was cleaning the bore after each shot. I've concluded that I probably did not dry the chamber completely after cleaning which can cause increased pressure.
 
#21
Thanks for all the opinions guys. I appreciate it.

I wasn't clear in my original post, but the round from this "hot" shot fired as expected. POI was approximately correct (hard to determine at such a short range).

Some of the other brass from that box show a little cratering, but it's not bad at all.

I've contacted Hornaday, and they have asked for some information that I don't have handy, so I'll have to send them that information tonight. Since it's a new gun, and I know that every company makes a mistake every once in a while (if it is even their mistake), I'm not expecting miracles from them, but I appreciate companies that at least try to make things like this right. Since there was no damage to the gun or me, I'm really just looking for reassurance that the rest of the batch is usable, or a replacement for it if they want to inspect it.
 
#22
I understood you just fine, I wouldn't lose any sleep over it. Every once in a while, you get a bad round. I once bought some brand new Lapua brass and on a few, I could push the primer with my thumb. I just trashed the few and moved on. Sometimes, it's not really worth it to mess with. But at the end of the day, you the customer should be happy and thats all that matters
 
#25
I've had a bunch of primers come out of my factory 6.5 CM (hornady 140g A-max and 129g Superperformance). I only notice when I pick up the brass. I didn't feel any high-recoil shots. I have a JP gas gun (semi-auto). I chalk it up to loose primer pockets or something. Some of the rims deformed during extraction. Just a little bend where the extractor clawed it. Gas pressure tuned to just cycle. Full length gas system so I don't think the case is still expanded when extraction begins. Anyway I think the hornady brass is a little soft.
 
#26
As an update to this.... I've shot about another 150 rounds of this lot of ammo with no other major issues. I can't see I've been thrilled with the short-range accuracy (100-200 yds), but I'm hoping that will improve with barrel break-in. Hornady was good about getting back to me, but I didn't have the time to replace the ammo - I had other shooting planned with that ammo and I didn't want to risk not having replacement ammo in time.

Scott
 
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