Any of you guys reload 40MM chalk?

[mattnh]

I loaded a couple hundred chalk rounds for the upcoming GMB shoot in Eden,VT

Shooting M79 at burning cars @ 100-400yrds is a lot of fun…

 

[mattnh]

Few more pics from last year at GMB shoot

 

[ericthered]

Nope. Dont have a dd. But I am curious what your load is. You make your projectiles? What powder and how much are you using?
Just had a thought when I read you are shooting burning cars. Have you tried loading flour, or powdered coffee creamer in a shot? If it disperses properly on a burning target it should up the cool factor!

 

[Starvingboy]

Yep. I did for a while. I used chalk line chalk, tumbled in a rock tumbler to get it finer. Worked decent.

 

[mattnh]

Nope. Dont have a dd. But I am curious what your load is. You make your projectiles? What powder and how much are you using?
Just had a thought when I read you are shooting burning cars. Have you tried loading flour, or powdered coffee creamer in a shot? If it disperses properly on a burning target it should up the cool factor!

I just 3d print the ojives. I use surplus hulls, pushers, and pulled 38blanks. I put as much chalk as will fit in the ojive and superglue it on. Your idea likely has merit; however, rounds occasionally burst in the barrel, so that may not be 100% safe.

 

[Starvingboy]

I did a few round with some stuff called “ninja smoke”. It was a bit of work, but looked really cool when the smoke mix went off. I should do another batch…

 

[Kkontx]

Where do you get your surplus pushers from?

 

[mattnh]

Sorry, I haven't purchased any surplus pushers in a few years.
I'd ask over over on ar15 Armory/DD forum for best place to get them currently.

 

[Starvingboy]

Coffee creamer is on my “to try” list. I have a few ideas in the works, but I am waiting on parts for the printer…

 

[Kkontx]

Was able to find some pushers and ojives from KAK industries

 

[Slowmo]

Dumb question, but if you use a gas check, where does it go? Isn’t the part of the 40mm case where the .38 blank goes closed off on the end?

 

[mattnh]

there is no gas check for 40mm chalk

Diagram: http://www.masttechnology.com/M781.htm

 

[Slowmo]

there is no gas check for 40mm chalk

Diagram: http://www.masttechnology.com/M781.htm

What kind of 40mm rounds are these used with:

https://kakindustry.com/40mm-reloading-kit-reloading-die-brass-brass-checks/

I just thought it was interesting that the KAK stuff includes brass checks for all the .38 cases.

For the link you posted, where does the filler plug/wad go? Is it forced through that smaller hole (basically the flash hole if you think of the entire .38 blank as a primer)?

 

[mattnh]

The 40mm "38" blanks typically contain a burst disk inside it to allow for the powder to fully/properly burn.
The blank loading kit above are "nice" commercial burst disks.

Basically, the 38 blanks are either crimped closed and/or they contain a thin copper disk seated ontop of the powder.
Many people make burst disks themselves by punching out circles from a copper sheet.
Similar to these: https://reloadableshells.com/shop/standard-xd-burst-disks-016-10-pack/

Take a look at these blanks

M79/203 38 S&W launch cartridge. - CDVS

Shop Combat Disabled Veterans' Surplus for M79/203 38 S&W launch cartridge. - CDVS.

www.cdvs.us

 

[Starvingboy]

Hmmm, interesting. I’m not sure my original blanks would work, they have a heavy roll crimp that likely would get in the way.

Watch out for DIY burst disks. My initial attempt cost me a receiver…

 

[Dropsith]

The Form 1 M79 build is on the project table but there are a few other in front of it before it'll actually get built, if I'm being realistic. How long does the chalk hang around after the rounds are fired? Like does it dissipate with rain over a few weeks or is that area on the range permanently orange?

I'm a few hours south of that GMB shoot and have considered heading up for it one of these years. Is it worth the trip, Matt?

 

[mattnh]

Chalk washes away at first rain.

GMB is def worth the trip

 

[Slowmo]

Watch out for DIY burst disks. My initial attempt cost me a receiver…

Wow. I would have guessed that even if the .38 case failed, the 40mm case would protect the receiver.

 

[mattnh]

Wow. I would have guessed that even if the .38 case failed, the 40mm case would protect the receiver.

Yeah, I was surprised by this as well.
#Starvingboy - any details on exactly what led to the failure?

 

[Starvingboy]

The receiver was a 3D printed one. The burst disk… didn’t. Instead the blank was forced out the back of the shell. I can provide gory details, but the short version is things shattered. No injury, and I printed another receiver, and was back up and running a few hours later.