Glock 35 .40 Kaboom

[rockymtnflash]

I just had my Glock 35 explode in a kaboom today. I had a stock barrel and had put about 1000 factory rounds through it this summer...so I decided to read up and start reloading.

I loaded once fired Winchester brass, Titegroup 4.4g, 180 grain jacketed Speer bullets, OAL 1.125", as many have suggested here.

The first ten rounds were great. I was happy with the grouping. Then KABOOM!!!

It blew the mag out, broke the mag catch, which exploded into my right hand, and knocked the gun out of my hands. My hands were really stinging, but all my digits were thankfully still attached and undamaged.

The case had a hole at the case head (where it is unsupported in the chamber?) and split the chamber. Luckily, I had just received a KKM match barrel and had not used it yet.

My first thought was that there may have been a double charge. So I went to weigh the remaining rounds I loaded. Most were within a grain total weight of each other. A couple were a couple grains less, and a few were over 4 grains heavier than the lightest loaded round.

So I weighed the empty deprimed cases waiting to be loaded. I found the same weight variances in the empty cases. I pulled the bullets in the heavier bullets and weighed the powder. They were all 4.3-4.4g. I deprimed the cases and found that the empty cases were heavier than others.

SO...I can't measure the loaded rounds to see if there is a double charge because if there is a lighter case with a double charge, it will weigh the same as a single charge in a heavy case, which makes me nervous of the heavier cases.

OR...was it the Glock and the new KKM barrel will fix this?

Any thoughts?

[mike cyrwus]

sorry to hear that; Id pull them all, or throw the remaining rounds away; but if you find one double charge then you found the culprit, and its a lot more reassuring to know you just screwed up, rather than think theres gremlins running around your reloading setup. -makes you a bit punchy when working up loads.

It split the chamber?

Im afraid its probably either a overcharge, or you had a squib before it, but since it was 10 shots into shooting, Id go with a double throw.

I never understood guys saying to weigh loaded pistol bullets, when a guy has a squib. An extra 4 grains can hide in a lot of places in a loaded cartridge, as you found out.

Are you using a dillon 550?

[wsimpso1]

Ever since I found out the standard Glock chambers, I have been expecting that we would all hear about about blown cases and ruined magazines. The Glock chambers are big and they have a bunch of the case unsupported, resulting in the Glock "guppy belly" on the fired cases. The story is that Federal was making 40 S&W cases with thin heads, and the story goes that they changed to a beefier case head to prevent blown cases. With time we have been expecting early Federals to get used up and go away. This was all written about in the reloading column in Front Sight recently. All the same, I expect that this is only part of your story.

Next is that autoloading pistols do tend to blow the magazine out the bottom when the case goes. This nasty surprise is usually attributed to double charges, firing a good round behind a squib, and too much chamber relief to improve feeding.

Now the broken barrel and blown magazine makes me suspect the double charge or the squib. While you did not find any more in your ammo, you might have only been interrupted once. I would tear down the rest of that batch...

Will the new barrel prevent recurrence? Maybe. Read the Front Sight relaoding column on the topic (I think that it was this year) and be an excellent reloader.

Billski

[rockymtnflash]

sorry to hear that; Id pull them all, or throw the remaining rounds away; but if you find one double charge then you found the culprit, and its a lot more reassuring to know you just screwed up, rather than think theres gremlins running around your reloading setup. -makes you a bit punchy when working up loads.

It split the chamber?

Im afraid its probably either a overcharge, or you had a squib before it, but since it was 10 shots into shooting, Id go with a double throw.

I never understood guys saying to weigh loaded pistol bullets, when a guy has a squib. An extra 4 grains can hide in a lot of places in a loaded cartridge, as you found out.

Are you using a dillon 550?

Sorry, I can't add to that statistic. I'm using a Lee Pro 1000 progressive press with Lee dies. By doing the math, only the heavier loaded rounds are suspect, but I can't reload my fingers so I'm tossing the batch. One of the many lessons learned, wacth every cases, and only load small batches.

Also for clarification, the chamber only had stress fractures on either side. It was not split apart. Thanks!

Edited June 30, 2006 by rockymtnflash

[Flexmoney]

Before you toss those rounds, check them for set-back.

Measure a round with your calipers, then put the nose of your bullet against the side of your bench. Press the back of the round with your thumb, squeezing the nose into the bench.

Measure again and see if you pushed the bullet further into the case or not (setback).

[Big Bore]

My 35 blew up on me last fall after only 300 rds. I thought it might be a double charge also. But after some investigation it would be impossible to double charge a 7.5 grain load of HS-6 under a 180 gr. Berry's and still have it go in the mag.

It was probable the 5th or 6th shot on a plate rack, no squib. The barrell was split down each side and the case head was gone and the case walls were still in the chamber. The extractor was put into orbit and my right hand felt like it had been hit with a hammer and I had some pretty good burns also.

The slide was OK so I dropped in a Storm Lake Barrel and have been good ever since. Probably the unsupported barrell and a suspect piece of brass.

[dillon]

If it was a squib, then there would either be a ring in the barrel where the projectile was lodged, or a primer only squib could leave a projectile stuck at the forcing cone in front of the chamber, in effect creating a 360 grain projectile. In either instance it is most likely that the pistol wouldn't have cycled,requiring the slide to be manually operated to chamber another cartridge.With the head of the case just perforated, and not completely detached, I doubt a double charge was the cause. More likely either a weakened piece of brass, or the bullet was pushed back further into the case when it chambered.

The book" The Glock in Competition" by Robin Taylor,Bobby Carver and Mark Passamanck has the most thorough eploration into Glock kabooms I have ever read. This chapter alone makes the book worth purchasing, in my opinion.

[HSMITH]

I am with Flex and Dillon on this, setback blew the case in your gun.

Take some of the loaded rounds from this batch and press them into your bathroom scale with at least 50 pounds of force on the bullet. Measure them and see how much shorter they get. If they get shorter by more than a couple thousandths you just discovered why your KB happened. It WILL happen with a fully supported barrel too, so you MUST eliminate the setback. Setback can only be eliminated in the sizing die, adding more crimp will only make the situation worse.

[Sean Gaines]

Before you toss those rounds, check them for set-back.

Measure a round with your calipers, then put the nose of your bullet against the side of your bench. Press the back of the round with your thumb, squeezing the nose into the bench.

Measure again and see if you pushed the bullet further into the case or not (setback).

that was my first thought because your load sounds ok. I would probably go to 1.135 on your oal. check your crimp. The farther the bullet is in the case the more pressure will develop. I guess your lucky that you didn't have any bodily harm,just your barrel was damaged and a few easily replaceable parts.

Other things you probably want to do:

get the Kkm barrel

inspect your brass before it goes to your loading press. Since the brass is the weakest link in the bullet. Also look for various headstamps, use Federal(not FC),winchester, RP, CBC

When inspecting brass look for imperfections, deep scratches in cases, peened looking brass(looks like someone took a punch and put a deep circular dent in the case)Dark stained brown looking color

anything that looks suspect or if you have to think about it when inspecting gets trashed.

As far as that batch of bullets I would trash them or take them apart and reuse them if you can

Sorry to hear about that good luck in the future

PK

[Gregg K]

Also be sure to drop check your load into your barrel to see if the projectile contacts the rifling. I have changed projectiles before and loaded them to the same length only to have them contact the rifling before seating in the chamber because the profile of the bullet was different. I don't know how much free bore you have in the Glock but you should always check for contact with the rifling since this can cause pressure to spike.

[TBF]

Rockymtnflash,

Glad to hear you are OK !

Good advice above , also check your brass for cases that may not be " once fired " .

I have had some problems with this when cases are just floor sweepings from the local range , sometimes multifired and abused brass gets mixed in.

Travis F.