The Rifle:

The Damage:

The Pain:

From the thread over at calguns:

I didn’t take pictures of the shooter out of respect for their privacy.. but his hands/arms were injured pretty badly. He was obviously in tremendous pain as he and his buddies waited quite a while for paramedics. Are paramedics/EMTs supposed to take their sweet time when walking onsite?

Anyhow.. I was told that the shooter(s) often times used a hammer to close the bolt. Feel sorry for the pain and damage the shooter had to endure.. but that’s the potential consequence of improper reloading and firearm use. (Source)

Judging by the pictures, there appears to be no damage forward of the chamber. It is probably an “out of battery discharge” meaning that the round somehow discharged before it was fully chambered.  There appears to be some sort of damage 1/2 way down the buffer tube, but I assume that it is probably from the buffer spring or weight when the Kaboom happened.

As some of you know, I am not a huge fan of putting a .50 in the AR platform.  I am not saying it can’t handle the recoil and doesn’t work flawlessly for lots of people.  I just personally am not comfortable using a platform which was developed for a significantly lower powered round with such a beast.

The rifle is from BOHICA ARMS

Glock owners can rest easy tonight that the story wasn’t about one of us.  Maybe we need some AR platform .50 pictures like THESE :P

Hat Tip: Ry’s Blog



cmblake6 January 14, 2010 at 09:41 pm

Damn! Just…DAMN!!!! I’ve fired a Bohica, and it wasn’t a bad weapon. As with anything, there can be mistakes in shooter operation. This really looks like that was the cause.


Admin (Mike) January 14, 2010 at 09:49 pm

It seems like more often then not these kabooms are caused by people not reloading to the proper specifications. In the thread at calguns there is a picture of some .50 rounds with numbers written on them, so that makes me think he was testing out some new loads. Hitting the bolt with a hammer definitely doesn’t scream “safe operation” either :P


Rick A January 19, 2010 at 05:03 pm

This was most likely a partial out of battery discharge. If it was a case head separation the bolt ends up stuck in battery unless the lugs shear off. With this design the rifle will not fire unless the bolt is nearly fully engaged and has been tested to be able to safely withstand that partial lockup scenario. My guess is that the hammer might have struck the firing pin with only the initial camming surfaces of the bolt engaged. There is a lot of safety margin built into these uppers, but it’d probably be a good practice to put the rifle on safe before sending the bolt forward. Excessively loose tolerances or improper assembly of the FCG could potentially render it unsafe. It’s been thoroughly tested that a stuck firing pin is likely not the cause as has been investigated in incidents with another brand upper. It was found that a primed case could not be set off by a stuck firing pin in exhaustive tests (reportedly).

Despite best guesses nobody knows exactly what happened and hopefully it is something that will be found and resolved for the sake of existing and future owners.


Dan C April 1, 2010 at 08:16 pm

Darwin was taking a nap that day.


KC June 12, 2010 at 05:29 pm

one of the crappiest designs in the world!!…what idiot would trust any shitty 50bmg ar upper? give me a vulcan 50 BMG anyday over these cracker jack prizes


DG June 17, 2013 at 07:39 pm
Michael Z. Williamson April 19, 2011 at 06:31 am

KC: People have been shooting .50 BMG atop AR lowers for a couple of decades now.

As as been commented, using a mallet to set the bolt indicates either a headspace problem or an ammo problem.

This is a user error, not a design error.


Jaco February 13, 2014 at 06:49 pm

To answer your question, YES paramedics are supposed to take their time walking up to a scene. Many reasons for this, Surveying the scene to see what you have, scanning for any threats, Trying not to make the patient think you are in a panic, and avoiding injury to yourself running up to a scene.


M Jackson January 27, 2015 at 01:20 pm

Just to let the author of this article know; There is no buffer spring or buffer of any type on a bolt action 50 Bohica or any other bolt action 50. Also mentioning the AR lower is opinion only because looking closely at the pictures shows that the lower had nothing to do with the malfunction and held up to the misfire as well as any previous shooting that was done. Thank you for the pictures though!! Not that I am happy that someone was injured but it does refresh the mind into a vigilant state as to safety!


Dr Charly November 3, 2015 at 11:14 am

I have used a 50BMG upper on an aluminum lower about 30 times, and I have used a rubber mallet to open the bolt, it get stuck when you don’t grease the round, never to close the bolt, cause you are dealing with a live round. It shoots flawlessly.


Ben September 8, 2016 at 04:49 pm

I bought one of these rifles slightly used. I had read a lot about how they were on an AR lower. Well not really because there is no buffer or spring or tube and the bolt slides back into the stock where a buffer would be. Also the trigger group has a much larger hammer and spring to pound the huge firing pin into the huge thick primer. The lower has reinforced sides and no mag well. Even though the upper and lower are pinned just like an AR, the upper on the Bohica .50 BMG has a free floated barrel with all the forearm and bipod attached to the upper. If the bipod is on the table and the shoulder against the stock I don’t think much recoil goes to the pistol grip.

The photo of KABOOM accurately shows the out of battery condition since the bolt face is undamaged and the bolt handle is sheared off from rapid rearward motion and impact. Also the bolt may be bent, but I suspect it broke through the other side of the lower near the shooters face. The rifle as shown is very heavy. Mine is 22.5 lbs. empty with a scope mounted. With the 24-inch barrel it is 49 inches overall and the 30-inch is 55 inches overall. Most of the weight is on the bipod at near center of mass.


Ben September 8, 2016 at 04:52 pm

Yes, the very first photo shows where the firing pin may have come out through the stock. This hole is about where the adjustable cheek piece is on my rifle.


tomm hornn February 17, 2017 at 08:58 pm

who wants to know where HESSE lives?



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