10mm blowing primers - factory Hornady ammo

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steveNChunter

New member
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:
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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.
 
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.

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

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!
 
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.
 
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
 
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.
 
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?
 
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.
 
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.

 
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.
 
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.
 
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.
 
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.
 
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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
 
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