WesWorld

Really heavy shell for that bore- over twice standard, plus a relatively high MV. This could explain why you allocated higher than normal weight for a 105mm range gun. I believe firing platform with 360 traverse is a generation early, not certain. While there were AA platforms with outriggers, the wheel up, platform down, very widely split tail strongly resembles a smaller 122mm D-30, which was somewhat known for that.

Quoted

Originally posted by howard

1. Skoda designed something like this in 1937. It was rejected as too radical.

2. I merely assume Siam would dust it off and try.

3. Heavy shell is a long skinny shell with lots of explosive filler. I want a large grenade going downrange in a jungle gun when I fight a jungle war.

4. Ballistically I wind up with a high MV because the shell ogive is not efficient. Drag is going to cut range dramatically. On the other hand SMASH is outstanding. This shell will arrive with all the joy of a lightweight 6 inch dropping in to say hello..

H.

1. Rejected as too radical is a long way from an in service weapon, or something they planned on and were stopped by war or budget cuts, or political favoritism. Thats not exactly a good a precedent.

2. Hmm, arms company with excellent rep says ' this is a terrible idea', so country with limited budget says 'ooh, the experts say this won't work, lets pour money into developing it' ?

3. My impression from reading about superheavy US naval shells is there practical limits on shell length, as well is a penalty for the additional length in excessive shell battering of the bore...somebody else can chime in.

However, taking the shell weight from 41lbs to 100 lbs seems like one of those neat tricks you wonder why people don't do. You do see some guns issued with higher weight short range rounds, and you do have shell like the US superheavies, but you are no where near 250% of the baseline.

4. You are also confining all the KE necessary to propel the equivalent 150mm shell at 600m/s in the chamber of a 100mm weapon.

Just using tanksharp for a comparison baseline, the historical Canon de 105mm M1913 comes out as 1.65tonnes for gun+recoil system vs. an OTL 2.3tonnes weight in action . Your beast has 3.35 times the energy and comes out as 5.44tonnes for gun+recoil system alone.

Putting in the numbers for the 152mm gun-howitzer I get 5.74 tonnes for the gun+recoil vs. the weight in action of 7.13tonnes.

Quoted

Originally posted by howard


This is a proposed near future Skoda Siam gun.

Comments?

H.

A bit early, the Picture shows the mock up for the 105mm leFH 43 (model Krupp), there was also the Model Skoda on which many delive the 122mm D-30 got its inspiration.

Just noticed its only 100 kg heavier than the leFH 43 and has a 2000 m longer range

Now you made me curious, vz (Vzor) or model indicates that it entered service. Do you have any link?

The over-length projectile probably won't give you much more payload (ie, explosive), most of the additional projectile weight is going to be just more metal. Also, stabilizing the over-length projectile is going to be a problem, you may hit issues with inadequate driving bands or the shells tumbling. For a jungle war, I'd think lightweight guns that could be more easily moved would be more useful than heavy-weight guns that need good roads.

You're limited to a length of about 4-5 calibres before the shell isn't able to be stabilised by the barrel rifling. I'm pretty sure the only way to get that weight is by making the entire thing from lead. A larger calibre weapon with lower mv might be more useful in the enclosed jungle terrain - just need some airbursting shells...

Quoted

Actually at 7.2 grams per cubic mm a shell 100 mm x 900 mm with an ogive of 0.8, as solid iron would be about 47.5 kilograms. Using aluminum boosted PBX filler and a blast/frag steel case [thinner but heavier] you get around 44.8 kg with 10% filler by volume.

But 9:1 length ratio is getting on for fin stabilised dart territory. 4-5:1 is about the maximum possible. This comes to around 22-25kg.

Exactly: the shell's too long (probably) to stabilize by the means used in the 1930s. Tumbling is NOT what you want in a projectile.

The gun got a strong resemblence to the post-ww2 Bofors 105mm 4140 howtizer. Apart from firing a much heavier shell, with a lower muzzle velocity, from a lighter gun with shorter barrel. Same range however&
Google books
Cannot find any pictures of it however.

Quoted

Originally posted by Korpen
The gun got a strong resemblence to the post-ww2 Bofors 105mm 4140 howtizer. Apart from firing a much heavier shell, with a lower muzzle velocity, from a lighter gun with shorter barrel. Same range however&
Google books
Cannot find any pictures of it however.

Haubits 4140