Designing A Rifle From Scratch(ish)

[Sturgeon]

I woke up one day and decided "why not design an entirely new rifle from scratch, and live blog it?" So here we are.

About ten minutes in and we've got the beginnings of a receiver extrusion made from 7075 T6 aluminum:

 

 

Currently I think the rifle will be in 5.56mm. It will not use STANAG magazines. @Ulric plz halp design new mag?

[Oedipus Wreckx-n-Effect]

5.56mm is too small for most north American game. 

 

I don't see a stripper clip guide in that drawing. 

 

What type of wood will you go with? 

 

I think if you put a forward mounted optic on it and kept throwing bolt and ejection path free that would work best.

 

Tell me, will the design be compatible with our previously existing saddle mounted rifle scabbards?

[Sturgeon]

Another 20 minutes of progress and some stuff has changed already:

 

 

BCG model is more of a placeholder right now:

 

 

This is all very seat-of-my-pants design. I have a general idea of what I am going for, but I'm basically winging the execution of it.

[Toxn]

Is making a rifle on the cards as well?

 

Because that would be very cool.

[Sturgeon]

5 minutes ago, Toxn said:

Is making a rifle on the cards as well?

 

Because that would be very cool.

 

Come again?

[Ulric]

2 hours ago, Sturgeon said:

I woke up one day and decided "why not design an entirely new rifle from scratch, and live blog it?" So here we are.

About ten minutes in and we've got the beginnings of a receiver extrusion made from 7075 T6 aluminum:

 

 

Currently I think the rifle will be in 5.56mm. It will not use STANAG magazines. @Ulric plz halp design new mag?

 

I might have something lying around.

[Toxn]

1 hour ago, Sturgeon said:

 

Come again?

Well you're designing one.

So next steps and all that.

[Sturgeon]

Putting these together while they are just simple shapes, so that I can optimize them before they get too complicated. Looking pretty good so far.

 

[Sturgeon]

Optimized geometry:

 

 

From the last step to this one reduced receiver mass by 0.12 lbs and BCG mass by 0.28 lbs, which I think really illustrates how important it is to optimize your weapon's geometry. I could have gone on from the last step and started adding details and such, but then my rifle would have ended up some 0.40 pounds heavier than it needed to be!

[Meplat]

Too complex, use existing structural rolls/channels.

 

Stoner had a good idea with the AR-16.  Use as many simple bits as possible.  Make it so you can whack parts for it out of scrap metal, if needed.

 

Determine your desired receiver width, and work from there so that the bolt carrier will be the sole critical component.  Then make that carrier (and the whole piece) so it will use as many AR (or AK) parts as possible.

[Meplat]

To add- Tubular reciever.  One for 5.56/5.45/7.62M43, one for 7,62/7,92/7,62X63.

Your bolt carrier is the sole critical component. Look at a Sterling bolt. Designed to be self clearing. Incorporate a cut for "bolt hold open".

You have two diameters of tube, with two matching diameters of bolt carrier, and three bolt faces.  Use the Johnson bolt, and the AR-16/18 gas system.

For the lower use the second gen AR-18 FCS (M-16 bitsa), and if you want to be "innovative" use a molded lower. It's taking NO stress, and merely serves to hold the magazine and FCS in alignment. For added grins you could incorporate a dovetailed section to the lower, to allow swapping magwells, for the people who think they my want to have one lower and a million uppers.( Maybe one in 6,5X55, using Swedish BAR mags, interchanging with U.S. BAR mags when sanity prevails).

 

The trick is in incorporating a "datum" line in the upper. This is your core reference. All measurements come from this.

Make this the point at which your barrel/chamber/barrel extension pins to (pins, so you can market it's "interchangeability")

 

[Sturgeon]

More progress. We're still in the "layout" stage, so the major dimensions of parts are subject to change. Looking good, though, still:

 

[Oedipus Wreckx-n-Effect]

3 hours ago, Sturgeon said:

More progress. We're still in the "layout" stage, so the major dimensions of parts are subject to change. Looking good, though, still:

 

 You're missing the tubular magazine. This is gonna be a thuddy thuddy right?

[Meplat]

Not wanting to scotch  any other's work, but I've seen a ton of offerings.

 

Which is why I now fix forklifts for a living.  let that sink in.

[Sturgeon]

3 minutes ago, Meplat said:

Not wanting to scotch  any other's work, but I've seen a ton of offerings.

 

Which is why I now fix forklifts for a living.  let that sink in.

 

It's just a project.

[Meplat]

Yeah, Been there. Best of luck.

 

Really. Sincerely.

 

[Oedipus Wreckx-n-Effect]

15 hours ago, Sturgeon said:

 

It's just a project.

Did you start with a sketch or jump right into stiffwerks??

[Sturgeon]

4 minutes ago, Oedipus Wreckx-n-Effect said:

Did you start with a sketch or jump right into stiffwerks??

 

Started in SW.

[Oedipus Wreckx-n-Effect]

Nice. I'm excited to see where this goes, despite my idiotic jokes and rambling. 

[Sturgeon]

BoIt work today:

 

 

[Sturgeon]

Bolt is looking good:

 

[Sturgeon]

BCG is mostly together now:

 

 

Overtravel is currently clocking at 2.33 inches. It'll be less by the time I'm done, but not a lot less.

[Oedipus Wreckx-n-Effect]

I'd you make it look like a high point PCC you win the day. 

[Sturgeon]

Enough progress for tonight, I think.

 

 

Current final estimated weight is less than 7lbs stripped/unloaded.

[Sturgeon]

Considering calling it the "Phantom". It's my fourth rifle design, see.