10mm blowing primers - factory Hornady ammo

[steveNChunter]

I've got a Glock 40mos with a Lone Wolf 10mm replacement barrel. I put the first rounds through the Lone Wolf barrel today.

The plan was to shoot some factory Hornady Custom 180 gr XTP's to test function before moving up to some Underwood 220 gr hardcast ammo that I want to try out on some hogs later this spring.

I shot 16 rounds (a mag full +1) of the Hornady ammo and then picked up my brass. I found three rounds that had some really disturbing pressure signs for what is supposed to be a mild factory loading for 10mm. Needless to say I didn't try any of the Underwood ammo for fear of a ka-boom if the fault lies with the barrel.

So I'm trying to figure out if it's the ammo, or the barrel. My first thought is that it's the ammo because it only did it with three rounds, but the Lone Wolf barrel makes me a little suspicious because it locks up in the slide MUCH tighter than the factory barrel. Not sure if that could cause a pressure spike in the gun before it tilts down far enough to unlock and let the slide come back. But it does feed and function fine so I don't know. Check out the pics of the suspect rounds. All three had serious bulges but I just took a pic of the bulge on one: https://scontent-lga3-1.xx.fbcdn.net/v/t1.0-9/17103821_1471641399535913_6297468825012502758_n.jpg?oh=ad365b917ecce29558afaadfde1ffb03&oe=59689E89

https://scontent-lga3-1.xx.fbcdn.net/v/t1.0-9/17103765_1471641636202556_1154496216279837156_n.jpg?oh=4abdc2ed524d8b48e72387efb8a037a1&oe=596944B9

https://scontent-lga3-1.xx.fbcdn.net/v/t1.0-9/17098484_1471641732869213_6311336897508424033_n.jpg?oh=aa3dbd826fd4725eed22f724ae9a1c29&oe=592C8493

[ShootistPRS]

My first phone call would be to Hornady. Give them the lot number and see what they say. I can think of nothing a barrel could do to cause blown primers unless it has a very short chamber and that would cause chambering problems.

[Aguila Blanca]

Or a long chamber with excessive headspace ...

[steveNChunter]

Here's the Lone Wolf barrel next to the factory barrel with loaded rounds sitting in the chambers. They look about the same to me with the exception of the diameter of the Lone Wolf chamber being noticeably tighter. That shouldn't have an effect on chamber pressure though because there's still a little wiggle room.

https://scontent-lga3-1.xx.fbcdn.net/v/t1.0-9/17155875_1471739869526066_134706137067065068_n.jpg?oh=4dba4af0782875f52e7ef9a723f9cebf&oe=596B3B37

[jmr40]

Fire a few rounds through the factory barrel. A load that is maxed out in one barrel could well be over pressure in another.

[steveNChunter]

Those were the last rounds I had of the Hornady ammo. I shot it first because it was cheaper. The Underwood 220 gr hardcast is what I want to shoot now, since I will be hunting with it. That's why I wanted to try to determine whether the barrel or the ammo was the cause. Because if it's something to do with the barrel, I know the Underwood ammo is supposed to be a much stouter load than the Hornady. I'd rather not blow up the gun if I can help it.

[bamaranger]

Since the suspect ammo is gone.....it really doesn't matter. I'd call Hornady with the lot number, and I'd call Lone Wolf and see what they might have to say re their tube.

The high pressure episode I had with my G20 was pretty apparent from the start.....recoil, blast and flash were noticably hotter than my regular reloads. MY cases didn't look anywhere near as bad as yours!

As you noted, the Hornady ammo is known for being a bit timid. I'm going to risk a guess and suspect the LW barrel. The G40 is a new item, and though LW has been making 10mm Glock barrels for a long time, that length is new to them. The "tighter lock up" sounds suspicious too. Could well be a manufactuer glitch on a newer product.

Myself, I'd be tempted to shoot a FEW of the Underwood for group from the factory barrel. Yes, accuracy could be unacceptable, and Glock frowns on lead from their hex rifling, but...... If I were satisfied with the accuracy. I'd clean the snot out of the factory tube, call the Underwoods my hunting ammo, and shoot it VERY sparingly, cleaning heavily afterwards. Then I'd shoot jacketed ammo for GP and practice with the factory tube the rest of the time. And I'd take the Underwood tube back for a refund, and put the money towards ammo or components!

[steveNChunter]

They have been making this barrel since before the G40 came out. It is supposed to fit the G20 and stick out about an inch and a half, or match the factory length of the G40. It's also very interesting to me that, other than these three cases, all the others look perfectly normal. No bulging whatsoever, no primers pushing out, nothing. I would think if it were the barrel all the spent cases would show pressure signs. I'll contact both Hornady and Lone Wolf.

[Shimpy]

A too tight bore could cause higher pressures. I'd slug the bbl.

[steveNChunter]

I've measured the grooves and lands at the muzzle, and they are the same. I've also measured every possible exterior dimension of both barrels and they are the same everywhere. I put the same fired case in each chamber and measured how much was sticking out the back. Same. Starting to lean more towards three rounds getting overcharged at the Hornady factory

[steveNChunter]

Well I did something that some might call stupid, and maybe it was, but it turned out okay.

I put on a face shield and gloves, loaded up a mag full of the Underwood 220 grain hardcast and let 'er rip.

No blown primers, no bulges, no pressure signs whatsoever.

Hornady has got some splainin' to do...

For anyone who wants to know, the Hornady ammo in question is item # 9126, Custom 180 gr XTP. Lot # 3142627. If you've got any of this lot #, I strongly advise against shooting it.

We'll see what Hornady says.

[DaleA]

Well, ummm, thanks I guess.

I'd be very reluctant to ask somebody to do this because of the potential problems and I hesitate to thank you for checking it out because it might encourage somebody else to do something they maybe shouldn't do.

Still, I think you figured things out on your own. Congratulations and I really mean that.

I'm surprised you got the bulge on the case even with the Lone Wolf barrel. I reload and I've always thought if I got a Glock I'd be smart to get a Lone Wolf barrel.

I assume (and we know what that means) that you attribute the bulged case you got from an over pressure round that even the Lone Wolf barrel could not prevent and the bulge would have been worse with the standard Glock barrel?

In short, what I am asking, is even after this situation do you still like/recommend the Lone Wolf barrel?

[steveNChunter]

If I wasn't pretty confident it was the ammo by this point, I wouldn't have done it, and I admit it wasn't the safest bet. And I certainly wouldn't ask or recommend anyone else do this if they find themselves in my dilemma. The chances I may take with my safety are not what I would ask of others. That being said...

To answer you question, I think the Lone Wolf barrel is exactly in spec with what they designed it to be. And yes I would recommend them. I do attribute the bulge and blown primer to three waayyy overpressure rounds out of that box of ammo. I believe this is 100% Hornady's fault, not Lone Wolf.

If you look at my pic of the barrels with loaded rounds sitting in the chambers, you see that the LW barrel doesn't really have much more chamber support around 6-o-clock than the factory barrel. The feed ramp is still blended into the chamber albeit to a slightly lesser degree. This might cause the Glock barrel to allow for a case rupture a little quicker but when you get to that point in pressure, you're playing with fire no matter what brand barrel is in there.

The main difference in these barrels IMO (besides the obvious - conventional vs polygonal rifling) is the diameter of the chamber. The LW is noticeably tighter chambered. This will help the reloader get more firings out of their brass, but isn't really safer IMO. As long as the case doesn't expand to the point of rupture it isn't going to make much difference. And if your brass is bulging like mine did, you aren't gonna want to reuse that brass anyway.

[Dan-O]

I concur that it's an overcharge issue. Factory ammo can get goofed up too.

Not a fan of Lonewolf 10mm barrels anymore. The one on the left was purchased in 2012, the one on right is from 2008 or 2009. And you are correct they have been making G40 length barrels forever. I recently went with a 6" Stormlake for my Lonewolf longslide.

I'd call hornady. Chances are they'll mail you some free stuff for your troubles.

http://i726.photobucket.com/albums/ww266/yeahitsthatbig/33B207E2-D868-4C38-A414-8D5385A8DA27-15338-000010B97D0829F6.jpg (http://s726.photobucket.com/user/yeahitsthatbig/media/33B207E2-D868-4C38-A414-8D5385A8DA27-15338-000010B97D0829F6.jpg.html)

[steveNChunter]

Regarding the feed ramp vs chamber support issue, they can't please everybody.

You have the crowd that wants absolute reliability with any bullet profile even if the gun is dirty, and the crowd that wants the brass from a hot loaded round to come out the exact same dimensions it went in. You can't have both at the same time.

The hot Underwood ammo I just fired through my LW barrel doesn't have a bulge on it at all, so I think as long as you are keeping pressures in check and the brass is good and thick like 10mm brass should be, you will be fine with the amount of chamber support the newer LW barrels have. They are still tighter than factory Glock.

Not saying LW makes the best Glock barrels, but best for the money? Maybe. I haven't personally tried them all.

[DaleA]

Thank you for posting all this information.

For a long time I have seriously considered getting a Glock 20 or 40.

I really appreciate your first hand experiences.

Thanks and Good Luck.

[disseminator]

Sounds like that Hornady ammo was extra spicy for sure.

I have shot in the thousands of 10mm handloads from my Glock 20 with the factory barrel and two different Lone Wolf barrels and they are all 100%

I have some pretty hot hand loads, all within spec though, and they have all worked Bigly in the mighty G20.

[WmCC]

Howdy. Here's another possibility: With three problematic rounds out of sixteen (XTP's) and no problems with the 220's you might consider the possibility of bullet setback. The 220's are no doubt well crimped. The semiauto XTP's do not have a cannelure and are taper crimped. The three over pressure rounds may have received a marginal/light crimp or were cycled through the pistol more than once prior to being fired. Setback would be my guess as I have found that most "current" factory 10mm rounds are loaded conservatively.

[steveNChunter]

Bill, that is certainly a possibility, thanks. Either way I wouldn't want any more ammo from that lot # going through my gun.

I am a reloader but I'm new to the 10mm game. The Hornady ammo was thrown in with the gun when I bought it at my LGS. I'll reload some practice ammo when I get some brass accumulated but I bought a few boxes of the Underwood stuff to use for hunting. I'd rather have fresh brass for the hotter loads in a chamber that's not 100% supported

[steveNChunter]

I emailed Hornady three days ago and no response yet, I'm starting to think maybe they don't care.

[WmCC]

Steve, You are doing a good job of thinking through the possible issues.
As to Hornady's lack of a timely response, you might want to give them a call and ask for technical assistance, (have the lot number handy). I made a call to them in 1969, and Mr. Joyce Hornady,( the founder & Steve's Dad), answered the phone and shot the bull with me for half an hour. You never know! Good luck to you and be safe.

[bamaranger]

Wmcc, setback, that is a very good idea, well done.

[rodfac]

You might consider the possibility of bullet setback. Yep...I've had setback problems with Hornady's XTP's in .45 ACP, Nearly every round, if cycled 2-3 times will setback. My cure was to re-apply a good taper crimp. Rod

[steveNChunter]

Finally got a reply from Hornady. They gave me a number to call, so I did and talked to one of their representatives who said he would share my experience and pics with a ballistician and get back to me. But the lot number had no other documented reports of any issues. He said he was sorry about the ring cut into my slide from the blown primers but they couldn't do anything about it because since there was no ammo left to shoot it could not be determined for sure what happened. At this point all they can do is make an educated guess based on the pictures.

...But I get a free hat for my trouble :rolleyes:

[steveNChunter]

Hornady's reply after I told them exactly what happened and showed them the pictures of the bulges and the blown primers. Here is their response:




"Thank you for the photos. The mark by the base of the case is called the "Glock bulge", caused by a partially unsupported chamber. Glock does this so that they have extremely reliable function. Sometimes this can cause some pressure signs.

Thank you and have a great day."

I guess blown primers is considered part of the "Glock bulge" now??? :mad:

I know what a Glock bulge looks like, this is much more than that. And I discussed that with the guy on the phone, obviously to no avail. I use a lot of Hornady's products (mostly bullets for reloading) and will continue to do so, but this really leaves a bad taste in my mouth with them. I know there's nothing they can do about it now that I've shot all of the ammo. But an acknowledgement that there could be a problem would be nice. For them to expect me to believe that this is normal is a bit of a slap in the face.

[jrothWA]

at my home range. Another member fired and left them, they are "mag-tech" 9mm brass. the most noticeable was the "rectangular" extrusion into the fire pin
passage. that would not allow the case to slide into the case holder for depriming.

Most semi's do not support completely the case during firing. So another factor most be addressed.

Good luck.

[Bongo Boy]

The photo posted by OP appears to be what I'd consider a fairly normal Glocked case in my experience with G20 and G29 only. I didn't see a photo of a post-mortem primer pocket, but that might be more informative. Is OP saying all 3 rounds blew the primers out of the cases?

I've had quite a good number of blown out primer pockets and blown primers with my own handloads, none of which have been beyond published maximums--at least to the best of my memory. All brass in those cases was Starline, which appeared to flow like butter.

I wouldn't have much reason to suspect a barrel--and as far as lock-up--chamber pressure is chamber pressure, and it's basically zero long before anything is unlocked AFAIK. You can certainly fire any auto pistol without allowing it to unlock at all--that doesn't do anything to change peak chamber pressure to the best of my understanding.

In any case, I'd agree that any ammo-firearm combination where the case is severely damaged isn't a good combination, and any combination where the case is allowed to deform to the extent the primers fall out is probably a poor, and potentially unsafe, combination.

I've thought for some time 10mm might be better off using small pistol primers and heftier brass.

I've never checked for setback--that would be worthwhile looking at.

[stagpanther]

I have a glock 20 which I have been using several 10mm barrels on for years--and of all the different barrels the lone wolf one seems to be the all-around best performer in terms of adapting to most off-the-shelf ammo as well as my reloads--which do sometimes explore the "outer limits" of full power loads.

10 mm is a tricky round that is immensely powerful for the small space you're jamming the powder and bullet into--in fact I think it really should be referred to as a magnum--but that's just my whimsical opinion. It might be possible that there is something wrong with the barrel--but what I have found is that if you remove the barrel prior to use and perform the "kerchunk" test you might be surprised at how much variation there is between ammo and case dimensions. Holding the barrel vertically, drop the rounds in and they should drop to the proper headspace clearance without any resistance--and also fall out when the barrel is inverted. My personal guess is that your issue is most likely cartridge related--and with the 10mm I could see how abnormal pressures--or chambering--could happen easily with only very slight variations in the cartridge dimensions. 4 to 6 inches isn't much length for a complete burn--my barrels can get fouled pretty easily depending on the powder used.

It can be hard--but listen for a difference in the report of the ignition. I once had a cartridge go off--sounded close to normal to me, and then the next round kept getting jammed. I re-racked it hard thinking that it was a feed issue--it was only after a couple of tries that it dawned on me to check the bore and sure enough a squib had lodged right in front of the case mouth datum--lucky for me it wasn't further in.

Your underwood loads are probably closer in pressure to what a "true" full power 10 mm is, while the Hornady--I'm guessing--is a more moderate load somewhere between a 40 sw and full power 10mm--but hornady is also skilled at often getting better performance with less pressure in their factory ammo I've noticed.

As usual--just my guesses;).

[SansSouci]

Were I to find a Delta Elite, I cannot say I wouldn't buy it. But I've never been a fan of the 10MM. It generates a whole lot of pressure for marginal gain.

Besides, the .45 ACP has established a track record that'll never be whipped.