Homemade Single Shot Slam Fire Breech Loading Firearm "Upper Only Project"

[Longwalkhome]

One of Bronsons Death Wish movies had the pipe shotgun too.

Not much new under the sun nowdays.

 

[TTSX]

But how was extraction/ejection? I'm impressed you made it work at all and didn't shoot yourself in the eye

 

[arakboss]

But how was extraction/ejection? I'm impressed you made it work at all and didn't shoot yourself in the eye

The rounds extracted fine. I shot some steel and brass case rounds with upper mounted on a standard lower with generic ambi charging handle and with the Bear Creek side charging lower. The hardest part is making sure the bcg is fully into battery as I did not have a buffer tube on either lower. I also shot the 350 Legend upper in the same config and it had substantially more muzzle flip (10.5" barrel) with factory rounds.

 

[No_Regerts]

Holy Smokes Eric, does your brain ever rest?……

I think it’s his hands that are the problem.

 

[arakboss]

I am upgrading the upper only firearm's firing pin activator. With the previous activator, I was able to fire one round but the other couple of rounds I tried would not fire. The primers were not getting hit hard enough. These photos show the upgraded activator. I will powder coat it black to smooth out the edges of the threads. I will be testing this out in the next few weeks.

 

[arakboss]

I am upgrading the upper only firearm's firing pin activator. With the previous activator, I was able to fire one round but the other couple of rounds I tried would not fire. The primers were not getting hit hard enough. These photos show the upgraded activator. I will powder coat it black to smooth out the edges of the threads. I will be testing this out in the next few weeks.

View attachment 1228989


View attachment 1228990

The new firing pin activator worked splendidly. Next trip to the woods I am going to test the accuracy range of this upper only firearm.

 

[Stomper]

Holy Smokes Eric, does your brain ever rest?……

He’s an accountant…. so do the math on that!

 

[Stomper]

I think it’s his hands that are the problem.

That’s what his HS prom date’s dad said…

 

[arakboss]

I fired three rounds of 223 reloads I picked up from another member, out of this upper only firearm project. All rounds went bang and landed in a 8 inch group, shot from 15ft away. That makes for less than great MOA performance but it proves the concept, that somebody can make an operational firearm with an upper only and a 3/4×8 inch carriage bolt.

Next step is to see if I can legally add a stock to the carriage bolt and increase accuracy.

For legal purposes I will considered the upper receiver the firearm. I have no plans to sell it so I will not be serializing it.

 

[bradsteen]

That's some great outside-of-the-box thinking, can't wait to see what the stock-attached version looks like!

How do you plan to add the stock? I'm guessing you'll probably want some kind of retention device to keep the handle / firing mechanism captive, since it looks like you're still relying on the charging handle for extraction. I'm wondering if you could somehow attach the charging handle to the firing mechanism so that when you pull back after firing it extracts the round for you?

 

[arakboss]

That's some great outside-of-the-box thinking, can't wait to see what the stock-attached version looks like!

How do you plan to add the stock? I'm guessing you'll probably want some kind of retention device to keep the handle / firing mechanism captive, since it looks like you're still relying on the charging handle for extraction. I'm wondering if you could somehow attach the charging handle to the firing mechanism so that when you pull back after firing it extracts the round for you?

Sounds like a great idea but probably above my pay grade.

I will likely run a longer bolt through a stock and call it good. Having the firing mechanism separate from the upper is the safety. I will only connect the two parts when I am ready to fire it. It takes a pretty good whack to set off the primers but I don't want to get too cavalier.

It's definitely not designed for speed. But I can reload it faster than I can reload my black powder inline muzzle loader.