I watched the youtube videos on wax slugs and have made a few hundred. They are fun to shoot and easy to make. Head my warning, DO NOT make them if you dont know what you are doing, like me! This shotgun started out as a maverick 88 that i bought in 07, now its a pile of parts. I shot 50 rounds throught it today and number 50 blew up. Im a few weeks away from deploying and could have possibly lost my arm if I hadnt been very lucky. A $20 tacstar side saddle shell carrier saved me from possibly rupturing my artery or possibly losing my left arm. This is my one warning and i will remember this for the rest of my life. Please dont make my mistake!

Damn!

How were you making these wax slugs?

Ooops!

Dodged a bullet, but got hit by a crayon...

Wore out shotguns don't blow up in my experience... They may jam, misfire, or pattern poorly but blow up?

That had to be either a wickedly overloaded shell(or filled with unique or some other pistol powder) or the barrel was plugged solidly somehow and another round was fired.

Could there have been a squib round prior to your kaboom that lodged in the barrel? Were those handloads?

Very glad you didn't lose that hand/arm or an eye.

That KB looks pretty nasty and glad you're not more seriously injured.

For one thing the added wax would add weight to the projectile load, which will increase pressure if used with the same powder charge. If you didn't get the same load of pellets back in, and added some pellets that would add to that effect. I'm also wondering about creating a projectile with too large of a diameter... if the forcing cone is trying to squeeze down that large mass very much it would tend to spike the chamber pressure quite a bit. There's a reason why rifled slugs are "rifled" and it has nothing to do with imparting spin.

They aren't effective as defensive/anti personnel loads when used with birdshot, you still need to use an adequate pellet size to get reasonable penetration. With that being the case, you're better off with something like the flite control buckshot loads which give you a little bit of pattern. If you need a slug, just shoot a slug.

I was just looking up some past threads regarding #1 buckshot loads last night and found a couple that might be informative:
http://ar15.com/archive/topic.html?b=6&f=1&t=350475
http://www.ar15.com/archive/topic.html?b=6&f=1&t=209689

Best wished for a speedy recovery. Thanks for posting your story.

Did these rounds spend their entire life in a climate controlled environment? Ever leave any in your car?

Melted wax aint good for powder. Possibly you had a round fail to make it out of the barrel from the powder getting melted wax on it. Next shot = pressure buildup in the barrel = dead barrel.

Thinking the same thing. Look how all the damage radiates from the area by the front of the receiver. The receiver end of the magazine tube is flattened, indicating downward force right at that spot.

I'll stick to factory slugs.

Bore obstruction.

holy shit.

i'm glad you are unharmed. that's one big f'ing kaboom there.

No i didnt mess with the powder but i did take the wad out and replace it with a shorter one out of a different shell which sat in the shell further down. So my theory is that the added weight from the shorter wad and adding more bb's and wax. I dont remember actually seeing shot #49 on the paper and i dont remember how it sounded because i wear ear muffs and everyone else at the range was shooting. So its very likely the previous shell was stuck in the chamber. Also would me taking the wad out and the powder not being properly packed cause anything?

After looking at the remains im a believer in barrell shrouds, 4" of the barrell vaporized and luckily the shroud absorbed what would have shot up in my face. I shot this from my hip. Also looking at my northface fleece jacket the majority of damage i received was burn, my sleeve was melted.

Again this was 100% my fault. I dont question the integrity of maverick/mossberg but my next shotgun will be an 870 and i will never fire anything other than a factory load. Thank you everyone for your concerns. I guess its a good thing parents pray for they're kids because everything in the chain of events worked out in favor and i still have 10 fingers, 2 eyes and both my arms!

So let me gets this straight...

You took a cup that was larger and replaced the factory one, so in the end your wax slugs were heavier then the original shot in the birdshot? Was there a noticeable amount of recoil?

That will do it. I guess you are not a reloader because a reloader would know, the heavier the projectile the less powder it takes. So you significantly increased the weight of the projectile and kept the same amount of powder. Its also worth it to note that birdshot uses somewhat flimsy casings that are not meant for higher pressures.