120mm Light Field Howitzer

Ive built a small air-powered Howitzer. Wasnt planning on going this far, but...I bought a 2' ball valve yesterday and built the rest from sch40 PVC scraps. I attached it to a hardstand to test fire, then addapted the stand to a crude balance trunion. Then put the whole thing on a small pullcart and added gunshields and paint. I think once I saw how cool it worked when it fired, I got carried away.LoL

Im getting nice shots in direct fire mode at 75-100ft distance and 50-60lbs pressure. Ammo is 3" nerf-type footballs with stab. Have yet to test indirect fire range as the carraige is just now complete.
No electronics. Fired by using "firing key" to yank back quickly on valve handle.Works great. Elevation is controlled by the rear handle. Azmuth is controlled by rotating the chassis. A 3rd wheel section is being added to the handle to aid this.

Still have yet to add insignia, sights (cosmetic) and handle-mounted storage tank(s). Now that I have a working prototype, I can now refine the design and streamline and improve lots of areas.

Wow thats nice! You know, at FuldaGap they had these smokebombs (nonflammable, not sure how they worked, looked like gatorade mix cans, cept they spewed out huge amounts of smoke) that you could throw, if anyone got caught in the smoke they were dead. Imagine loading this up with those and shelling the other team, if they got caught in the smoke same rule, they would be dead. That would be so cool...

EDIT: These http://www.kapowwe.com/mk3-smoke-bomb.html

This thing looks legit! Nice work man!

Thanks guys! I like the smoke idea.

I think I was reading that Fuldas rules dont allow PVC. That sux. Im sure its because some idiot might overpressure something or build some rickkety crap... But personally I dont think the PVC is dangerous at all if constructed correctly and kept under 100lbs psi.

Also, please dont get the idea that Im turning to some cannon cranker. LOL
This is just a concept proof that turned into a prototype. Im also building a couple of vehicles, but they are long way off.

I hope maybe we could use this (and some others) in future scenarios locally with or without vehicles. One team could defend the arty while it trys to get X number hits on a target (enemy hq building), the other team trys to kill/capture gun crews. ECt..

Being a FA guy, I am digging this. I am impressed.

I know Airdog would be down with some test runs. And if you ever needs some guys to aim that thing at the test it out, Dagger Unit is totally game. I'm sure there are alot of people out there who want to peg us with 80lbs of pressure anyways

Airdog is down for this for sure.

This is a work of art!

Ate you using an air tank with a compressor or just filling an airtank an getting a couple bursts out of it

Ya, this thing is legit for sure.. I just got to fire it for the first time today. It is a dream!!! I can not wait to get it 100% game ready and true, it is going to be a lot of fun! Speaking of which, Rhino, you have a PM!

this is amazing! how far does it shoot?

xyzpdq0121 wrote:Ya, this thing is legit for sure.. I just got to fire it for the first time today. It is a dream!!! I can not wait to get it 100% game ready and true, it is going to be a lot of fun! Speaking of which, Rhino, you have a PM!

No I dont

Rhino wrote:

xyzpdq0121 wrote:Ya, this thing is legit for sure.. I just got to fire it for the first time today. It is a dream!!! I can not wait to get it 100% game ready and true, it is going to be a lot of fun! Speaking of which, Rhino, you have a PM!

No I dont

You do now, the wife called and tied me up!!

just some kid wrote:this is amazing! how far does it shoot?

In the first measured performance tests today it did well. We never took it over 69 psi and had some great shots even though it was windy as hell.

With fin sabilized 120mm football rounds:
Indirect fire (high angle) max effective range is 200ft
Direct fire (anti-tank) max effective range is 150ft

We test fired several "experimental" AP (beehive, shotgun) rounds with about 100BBs per shot in several wadding/plug configs. mixed results. At times effective to 60ft with a 12ft cone at impact, but inconsistant resuts because of plug design.
Back to the drawing board! LoL

bbuba68 wrote:Ate you using an air tank with a compressor or just filling an airtank an getting a couple bursts out of it

Right now for test firing we're using a compressor.n the field We are going to try a bike floor pump by hand. Might be a workout for the "loader"...we'll see

have you tried to figure out a way with paintball CO2 canisters? I imagine that would be easier than a bike pump and more portable than a compressor

just some kid wrote:have you tried to figure out a way with paintball CO2 canisters? I imagine that would be easier than a bike pump and more portable than a compressor

You are not going to get many shots off with a CO2 can because 88 cubic inches of air is NOT that much... You would need a 88cuft alum SCUBA tank but you are looking for $100 for a banged up used one at best.

i know but how many shots do you plan on shooting per game? you just buy a few of those cans not the little ones and you can refill them at dicks. after you're done for the day just go refill them.

AK-Andrew wrote:

just some kid wrote:this is amazing! how far does it shoot?

In the first measured performance tests today it did well. We never took it over 69 psi and had some great shots even though it was windy as hell.

With fin sabilized 120mm football rounds:
Indirect fire (high angle) max effective range is 200ft
Direct fire (anti-tank) max effective range is 150ft

We test fired several "experimental" AP (beehive, shotgun) rounds with about 100BBs per shot in several wadding/plug configs. mixed results. At times effective to 60ft with a 12ft cone at impact, but inconsistant resuts because of plug design.
Back to the drawing board! LoL

try cutting off part of a water/soda bottle and using that, also cut slits in the side of it(top to 1/4 of bottom). think shot gun wad when you are cutting it.
hope it helps, and i'm looking foward to seeing this thing on the field

I can imagine that refilling your CO2 all the time would be pretty expensive. On the other hand, a manual pump or a compressor would be very cheap in terms of resources to power it. That way you can shoot more often without spending much. Maybe not the highest mobility or rate of fire, but still, you'll probably end up shooting more if it costs less.

Very nicely done AK-Andrew, excellent build. Do I see a former garden tiller as the chassis?

50-60 psi compressed air is what I run my tank's cannon off of as well (small compressor with pig tank, warning, you'll burn up little compressors every so often, they have low duty cycles and can't be run for long), except we're using the smaller 2" (52mm) Nerf mini vortex rounds instead. Yours should be easier to find afterwards, there has been some talk of giving the larger ones like yours a "blast radius" when fired indirectly at Fulda Gap 2011. Not official yet though.
Co2 really is not that expensive, the tank(s) are what typically set you back, but you'll have to regulate it some way since out of the bottle it is 870psi....PVC no likey.

Speaking of PVC, I happen to agree with you regarding its strength and durability. Sch 40 2" and/or 3" PVC actually has greater nominal operating pressure ratings than welded black iron gas pipe (220 psi for 2", vs. 150 for 2" gas pipe). Actual burst pressure is several times that (for factor of safety). Ferg at Fulda has seen problems in the past with home-built man-portable CO2 (overpressured) powered ones, where the guy carrying it can take a tumble and smash it against a rock/stump/whatever, resulting in a crack/burst/catastrophic failure. His insurance is his concern, and to be fair in the same boat I would be to. But there's no way you're going to fall on yours and smash it against something hard, and you're only using low pressure air. I'd field it and use that as my argument. But I digress.....

I've never had any real luck with a beehive/shotgun round either, even after all these years. They tend to be hit or miss and require a lot of effort on the front end to prep them. Typically better off with just AEG fire.

Nice field gun!

Fallout- Thanks so much for the tank info..invaluable! yep-Old seed spreader as carriage.LoL So youre going Soviets for Fulda 2011?

Yeah..I gotta stick to PVC for now-dont have the means to plump metals.
Im planning a couple of more quick Howitzers for a battery of 3. It would be great if we could use them at Fulda.
Still stalled on my tank build fooling with the engine wiring.

Really brainwracking today to try and come up with some kind of Anti-Personnel (HE) shell that can fire indirect and burst on target.

just some kid wrote:i know but how many shots do you plan on shooting per game? you just buy a few of those cans not the little ones and you can refill them at dicks. after you're done for the day just go refill them.

Well, when you run the math, you would get about 3-4 shots out of a 88 cubic in CO2 tank... Hardly worth the cost of a tank and the refills needed... I portable compressor might be an option but 1) you have to transport and power it in the field and 2) it is loud as hell. Scuba tanks are not the best option because 1) they are heavy as hell (I have carried MANY on my back long distances) and 2) they are not cheap either. On the plus side, you can fill then to 4000PSI at 80 Cubit FEET of volume for a standard tank. So you are going to get a good number of shots off of a tank. If this thing was in a tank, maybe a compressor or a SCUBA tank would be a better option, but I think that a bike pump or some other method is really worth testing out here. Just depends on how hard it is to get it to 60+ PSI.

I would like to see a version done with cheaper 2" vortex rockets to test the distance difference. The build cost would be cheaper since you are looking a 2" PVC and not 3". Your exit pressure will be better. Your projectile is lighter. You should see a marked improvement over the 3" but only testing would tell (and some physics calculations which I have not ran in years!).

I do not see why Fulda would not allow this... As Fallout said, it is not like you are going to drop it while it is under pressure and if you put some sort of blowout valve your are even safer! But I do think the Max operating pressure for 2" schedule 40 PVC is 166 PSI and 158 PSI for 3"... for conservative estimates and cheap PVC. So, at any rate, you are fine cranking that thing up to 100 PSI Andrew!!!

As for Shotgun round... We either need to make a blast round like this which can be fired using a sabot int a round like this:



I don't know, just thoughts!!!

for this airsoft stuff I would classify a 2" shell as an Anti-tank round, and a 3" shell as an artillery round.

Find me a local source for this 2" ammo, and Ill start building an AT gun TODAY. Ims thinkink PAK37, ya?

AK-Andrew wrote: for this airsoft stuff I would classify a 2" shell as an Anti-tank round, and a 3" shell as an artillery round.

Find me a local source for this 2" ammo, and Ill start building an AT gun TODAY. Ims thinkink PAK37, ya?

Fine leave it up to me to do all the hard work while you just build the damn thing... Jeeze!!! I can find them on the internets and have them two day shipped. Looks like they are about the same price you paid for the 3" though... Rumor has it Nerf stopped making them back in 2004 but who knows.