[Bounce12]

You're going to have to get some "depleted uranium" rounds for that thing!

[KrisFox]

I've been looking at really big guns and have brainstormed a few ideas.

A barrel nut that uses a cartridge rim as the wrench. IE nut is 8 sided and has a U shaped slot in each side for the rim to lock in.

Like the nut on this barrel.


Bullpup... This would help balance the rifle especially if I cut the barrel down from 7.5 feet to 5 feet.

If I go bullpup I could to a "shifter linkage" to move the bolt handle forward of the pistol grip for ease of operation.


I may also cut a slot in the rear of the mag (Like the S-12 mags) to keep the shells from bouncing back and forth from recoil and damaging the tips (very important If I spend the $300 *$100 round $200 stamp* and get some explosive fused shells)

Other Ideas are using the lath in the shop to make Plastic Sabots for tungsten darts, as well as sub caliber sabots to allow me to use 20mm, 14.5mm or even 50 bmg projos at blistering velocities.

I could get some DU from United Nuclear.

I could form the DU into darts or tips.

If I go cheap, I can buy DU in powder/flakes, mix it with lead and compress it into a very heavy frangable round. Sort of like a 30mm varmint grenade.

Or I could use the much cheaper Tungsten from
AAAOE

This post has been edited by KrisFox: 04 November 2009 - 10:08 AM

[dobravery]

I think Dinzag rents a TAT for that.

[Shandlanos]

If you can find a friendly dealer in your area, you might be able to save a lot on the explosive ammunition. My dealer made me a great offer if I ever get a 40mm launcher. He is willing to order in grenades, transferred to him tax-free, and allow me to fire them on his range for the cost of the ammunition. Just like renting out a post-sample MG, he is present whenever I am handling the NFA item, so no transfer occurs and no tax is due.

A similar arrangement could be great for you, unless you really just want to have explosive rounds on hand for whenever you need to blow up a car from a few miles away.

[BuffetDestroyer]

KrisFox, what kind of optics are you going to put on that thing?

I am jealous to the point that I will simply say that I disregard the gun as a simple novelty. But in reality, I really can't wait for video of you shooting that beast!

BTW, if I have any terrorists in tanks/armored vehicles up to no good in my area, I will be sure to call you!

[KrisFox]

Shandlanos, on 04 November 2009 - 12:37 PM, said:

If you can find a friendly dealer in your area, you might be able to save a lot on the explosive ammunition. My dealer made me a great offer if I ever get a 40mm launcher. He is willing to order in grenades, transferred to him tax-free, and allow me to fire them on his range for the cost of the ammunition. Just like renting out a post-sample MG, he is present whenever I am handling the NFA item, so no transfer occurs and no tax is due.

A similar arrangement could be great for you, unless you really just want to have explosive rounds on hand for whenever you need to blow up a car from a few miles away.

I hope to have a SOT, Demo letter, license to manufacture etc within a year or so. Tell then I'mm be tinkering with 30mm Training ammo and my own home loads.



I'm thinking my initial design might be this in 30x173mm?


A shell holder type single shot bolt action.

If I go that rout I should be able to keep weight to well under 100lbs.

[IndyArms]

How would you mount the barrel?? Could you keep it truly "free floated" without some SERIOUS "barrel droop" just from the sheer length and weight of it?? Or with that kind of mounting to the receiver, will that be non-existent?

Or... just say fuck it, and place a bipod lug on it someplace and call it a day?

[KrisFox]

BuffetDestroyer, on 04 November 2009 - 01:05 PM, said:

KrisFox, what kind of optics are you going to put on that thing?

I am jealous to the point that I will simply say that I disregard the gun as a simple novelty. But in reality, I really can't wait for video of you shooting that beast!

BTW, if I have any terrorists in tanks/armored vehicles up to no good in my area, I will be sure to call you!

The optics are going to depend on how much safe eye relief I can get. If I use a shock that compresses 6-8 inches under recoil I'm going to need a lot of eye relief.

If I have to float the barrel so the upper assembly recoils than I'm going to need as much as 16" of eye relief.

I would have to use a pistol scope in those cases.

I hope to tame it with a break similar to the JP Arms "Tank Break" or other really effective break and just put a Leupold MK4 8.5-25x50 on it as the round is effective out to 4000 m or roughly 2.5 miles when engaging armor.


As it stands this rifle would be 30% novelty, 30% conversation peace, 30% advertising and 10% entertainment.

I'm positive it would be a world record for largest shoulder fired rifle.

IndyArms, on 04 November 2009 - 06:52 PM, said:

How would you mount the barrel?? Could you keep it truly "free floated" without some SERIOUS "barrel droop" just from the sheer length and weight of it?? Or with that kind of mounting to the receiver, will that be non-existent?

Or... just say fuck it, and place a bipod lug on it someplace and call it a day?

The chamber end already has that handy rim. I plan on making an externally threaded receiver, then securing it with a barrel nut. Similar to how an AR barrel is secured to an upper receiver.

As far as "barrel droop" goes. This is a GAU-8 barrel. It normally spins at a high rate of speed as it fires. I'm sure any "barrel droop" will be minimal and I won't notice its effect on accuracy.

As for the bipod...

Think this but with 3 foot length of 2" steel pipe.


Most likely I'll say fuck it and place the bipod about 6" ahead of the balance point.



In all likely hood I'll build it first as a single shot like in the pic above.

Later It may become a true single feed bolt action with ejector and extractor.

After that I may add a magwell and 3 round mag.



With something like this a $200 stamp for each new receiver won't be a big deal.

One for the shell holder receiver and one for the bolt action single that I weld a magwell to and make into a repeater.

One day I may even make it a semi-auto... Or even a full auto...

[Cobra 76 two]

Heheheheheh!

[evildog69]

full auto???

[KrisFox]

evildog69, on 04 November 2009 - 09:06 PM, said:

full auto???

If your gonna dream dream big.

[voonman]

Now i feel outgunned

[bigcec1]

evildog69, on 04 November 2009 - 09:06 PM, said:

full auto???

They already made a full auto hehe this is where the barrel came from if im not mistaken

[sicktooth]

I'm fucking speechless...

[Diamondback]

Or, could you maybe attach the scope to the frame rather than the barrel so that the scope doesn't move on recoil? (I envision a bracket either alongside or around the barrel, and the barrel slides alongside or through it on its way back.)

[KrisFox]

Diamondback, on 05 November 2009 - 08:35 PM, said:

Or, could you maybe attach the scope to the frame rather than the barrel so that the scope doesn't move on recoil? (I envision a bracket either alongside or around the barrel, and the barrel slides alongside or through it on its way back.)

Problem with that is that any slop in the system between the frame and barrel will effect accuracy.

[Diamondback]

Good point--would it help to have the barrel mounted on rails to hold it in alignment? (I'm thinking 3, one each at 4, 8, 12 o'clock positions.)

[KrisFox]

Diamondback, on 07 November 2009 - 04:43 PM, said:

Good point--would it help to have the barrel mounted on rails to hold it in alignment? (I'm thinking 3, one each at 4, 8, 12 o'clock positions.)

I was thinking more like the barrel mounted to the top (Slide) and the FGC stock and grip all on the lower (frame) and they would fit like a CZ82 slide and frame and have a hydraulic damper build in.

[KrisFox]

Single shot 30x173 test fire!!!

Firing test of a single shot 30x173 in Alaska. Owner is planing to build it into a 30mm version of a 37mm Anti Tank Gun like this.

[Juggernaut]

Suppress it!!!!

[KrisFox]

Juggernaut, on 14 December 2009 - 11:18 PM, said:

Suppress it!!!!

Plan to. Already into this project for $1500 whats another $200 in stamps?

[Sly]

I'm pullin for ya Kris, But I take exception to The 50BMG is for pussies.

http://splodetv.com/.../armalite-angel

Till I see ya shoot it.........

[zakmatthews]

Shit, Kris. You pull this off and you will be worshipped.

[YARP]

Hey KrisFox did you say you were going to make this a bolt action? You probaly already thought of this, but why not go with a rotary breech?

[KrisFox]

YARP, on 15 December 2009 - 11:28 AM, said:

Hey KrisFox did you say you were going to make this a bolt action? You probaly already thought of this, but why not go with a rotary breech?

I'm going to go with a combination of a shell holder bolt, and an interrupted thread breach.



And combine the two with the rifle layed out something like this.

[KrisFox]

Well a couple weeks ago the barrel showed up at the shop.

Today I found where I can get the steel I want to use for the muzzle break assembly, receiver, bolt and stock/trigger assembly.

Mmmmm, metal.

They even have Titanium... Titanium tube for the bipod and maybe even the stock/trigger housing.

[protected static]

KrisFox, on 27 December 2009 - 02:04 PM, said:

Well a couple weeks ago the barrel showed up at the shop.

Today I found where I can get the steel I want to use for the muzzle break assembly, receiver, bolt and stock/trigger assembly.

Mmmmm, metal.

They even have Titanium... Titanium tube for the bipod and maybe even the stock/trigger housing.

+1 for onlinemetals.com. Very reasonable prices for small orders, good service.

[ReverendFranz]

Metals Depot is nice, as well, for Steel and Al

[KrisFox]

Using a JP style tank break.



Has the potential to neutralize the recoil.

70% of the recoil of a 20" 5.56 is gas. That's 55 grain bullet at 3200 fps.

Now the 30mm launches a 6500gn bullet at 3300 fps.

I'm assuming that the velocity of the gas and proportion of gas volume to projo weight is similar between the 20" 5.56 and the 90" 30x173mm.

IF that is the case then the JP break will redirect enough gas to nearly neutralize recoil.

The rub... To make the break work I need to use FULL POWER loads. O.O

I talked to someone who handloads a 338 Lapua with a JP break. He said that lower power loads recoil MORE and higher power LESS, bass ackwards from normal. When he pushes max pressure loads the rifle jumps slightly FORWARD OFF his shoulder.

Not only do I have to build a rifle action that can handle 30x173 I have a very narrow window between enough pressure to make the break work and enough pressure to blow up the gun.

[scoutjoe]

KrisFox, on 14 January 2010 - 06:56 AM, said:

Not only do I have to build a rifle action that can handle 30x173 I have a very narrow window between enough pressure to make the break work and enough pressure to blow up the gun.

So....what are we talking about pressure wise here? The logistics of this are mind boggling to me