Serbu Firearms, Inc., Tampa, Florida

TCPilot · Guru Joined: 14 May 2005 Posts: 105 Location: PRK

Over at Calguns the guys are armchair-quarterbacking a .50 Kaboom where the shooter badly injured his hands/wrist. Here's the link with pics:

.50 Cal Kaboom - Calguns

There seems to be some debate as to what the hammer was being used for, but either way, it's a reminder to not shoot a gun that isn't functioning 100% correctly.

/TCP
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markserbu

The jury's still out on this until we hear from the shooter. No doubt at this point there are a lot of people out there hoping it was a hangfire....

TCPilot · Guru Joined: 14 May 2005 Posts: 105 Location: PRK

It also seems, based on the pix, that he was working up some loads. So, hammer, handloads, no comment from the shooter yet.....we have no way of knowing what really happened.

It does make me nervous about owning a .50BMG rifle (you know...in 2 weeks...when I get my Serbu). I think I'll verify on every shot that the bolt is fully closed!

/TCP
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50 Shooter · Posted: Mon Jan 11, 2010 6:09 pm Post subject:

Mark,
I was talking to Ben/Mr. Kubota and from looking at the photos we were thinking it's operator error. The guy was working up loads for 50 DTC and from the pic of the ammo the cases look kinda long. We were thinking that if they weren't prepped right and he was trying to jam them into the chamber... Plus the safety was off which probably didn't help either while he was prying on the bolt to get it to shut.

If you look at the pics of the bolt you can see that it was partially locked up as you can see the shear on the bolt when it let go. So if he was man handling it and Murphy stepped in you get a tragic accident. Hopefully this will serve as a lesson to other 50 shooters, don't force ammo, if it doesn't fit set it aside and inspect it later.

markserbu · Posted: Mon Jan 11, 2010 7:38 pm Post subject:

I'd bet on hangfire before I'd bet on manhandling a round into the chamber being the culprit. Pounding on a bolt handle should never cause a round to go off unless there is firing pin protrusion. There didn't appear to be any high primers in the picture, so I think we can rule that out. At a glance, there appears to have only been 20 to 30 percent lockup when the round went off. No way the hammer could reach the firing pin in that condition. Anyway, this is all academic until we hear from the shooter.

markserbu · Posted: Mon Jan 11, 2010 10:19 pm Post subject:

Speaking of hangfire, I guess I need to chime in for the next guy who decides to make a copy of a copy of a derivation of one of my designs. Or for anyone who makes an AR-15 based (or hammer-fired) bolt-action .50 BMG, for that matter. When I designed the BFG-50 I was fortunate enough to have someone connected with FCSA supply me with the military drawing which specified the energy required to reliably set off .50 bmg primers. With that data I was able to figure out the windup required to get enough energy out of an AR-15 hammer spring to reliably touch off .50 BMG rounds. The BFG-50 hammer winds up around 20-degrees more than a standard AR-15 hammer, and that imparts a LOT more energy to the firing pin. I don't know enough about the chemistry of primers to know if a hangfire can be called a gun problem or an ammunition problem, but one thing is for sure; if a round goes off that eliminates the chances of it becoming a hangfire!

markserbu · Posted: Tue Jan 12, 2010 12:49 pm Post subject:

Just read the shooter's dad's post on Calguns. Well I guess it wasn't a hangfire. Regardless of whether the accident was due to an ammunition problem or a gun problem, this part spells bad news for Bohica: "If you notice the hole on the side of the I believe chamber is a vent, that's where he received a good amount of schrapnel that broke his hand." I don't know if that was an intentional vent hole or if it was a mounting hole, but it obviously became a schrapnel spewing hole and caused a lot of damage that otherwise wouldn't have been caused had it not been there. This will be ugly. All my personal opinion, of course.

50 Shooter · Posted: Tue Jan 12, 2010 3:28 pm Post subject:

His dad posted and said he was holding the rifle with his left hand at the front of the receiver. When it detonated the left hand caught the shrapnel from the vent hole in the receiver.

If you saw the pics of the bolt you could tell it was partially locked up when it went off. You could see some shearing of the lugs when they were forced out by the detonation.

I don't know what type of trigger he was using but it could've been a combination of things like, high primer, firing pin sticking out, light trigger and how hard he hit the bolt to close it. If all of these things were in play then it could've resulted in what happened. Any thoughts on this Mark?

In the end it doesn't matter, the shooter will never forget what happened to him. Hopefully it won't keep him from ever shooting again.

markserbu · Posted: Tue Jan 12, 2010 4:53 pm Post subject:

I've pretty much posted all my thoughts except for the actual reason for the bang. It's fairly obvious that there was a firing pin hit...you can see that on the head of the jammed cartridge. I doubt a stuck firing pin would do that. I don't want to speculate beyond that.

Hawaii five-0 · Posted: Sun Jan 17, 2010 7:55 pm Post subject:

I have had more than one gun fire out of batterey as a result of a broken firing pin.If the break happens at an angle,then the pieces of pin can rotate so the two longest areas come into contact,the firing pin then has just"grown".If the pin has "grown"long enough,it will detonate the primer when the bolt is pushed forward,or during the camming of bolt lock up.There are soooo many possibilities.....
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