Guns vs. Howitzers

I raised a question as to "Why is an 8-inch a Howitzer but a 175mm is a Gun?"

This interesting dialogue resulted from that question.

Bill Taggart (66-67) Howitzer vs. Gun - I had a question that I have been meaning to ask and thought our friend Johnnie Pearson (68-69) would be a good resource. Our 8-inch Artillery were Howitzers but the 175mm was called a gun. It dawned on me recently that I never really understood why that was the case.
Johnnie Pearson (68-69)

I believe the difference is due to barrel length.  So the 105, 155, and 8-inch are (short barreled) howitzers, and the 175 is a (long barreled) gun.

I then opened the question to our entire group and following are the replies I received.
Paul Griffith (67-68) Bill, The difference is In rifling. The 175 had a rifled barrel and the 8” like the 105 and 155 were howitzers which are smooth bored. Rifling causes the projectile to spin as it leaves the tube and travel further, thus greater range. I hope this helps.
Dan O’Brien (69-70) The difference between the GUN and the HOWITZER is the Trajectory of the round.  One might go high and come down and the other might go straight to the target. The howitzer took the shortest path to the target.  The 175 gun may have fired farther but it had an arch in its travel pattern.  If the 175 ever fired at the same angle as the 8 inch, it would destroy the trunnion/ pistons that bring it back into battery.  How many of us have seen damage to the plate in the well as a result of a high angle and charge 3 load on a 175.
Dan O’Brien (69-70)

Hi Bill,

This clip from  Wikipedia further explains the difference of howitzer vs. gun and also one and the same.

Gun-howitzer (also referred to as gun howitzer) is a type of artillery weapon that is intended to fulfill both the role of ordinary cannon or field gun, and that of a howitzer. It is thus able to convey both direct and indirect fire.

To be able to serve as a howitzer, gun-howitzers are typically built to achieve up to 60—70° of elevation. For effective direct fire, the gun-howitzers typically employ a fairly long barrel, usually not shorter than 30 calibers. Its ammunition also has a high muzzle velocity and often large caliber (often 120 mm and larger).

Dan O’Brien (69-70)

A good link going back a hundred years where it all started.

Neal Schwartz (68-69)

And in reference to Gun Vs Howitzer I found this which is the simplest definition of the difference.  When we fired 175mm Guns we sometimes fired them as howitzers, angles (elevations) greater than 45 degrees (800 mils).  I remember a particular situation, I think it was “C” Btry at Bastogne, where we fired them almost straight up to attack the back side of a high hill.  We didn’t have any mortars or mortar crews around to defend the area.

All 8-inch and 175’s had rifling.

Rich Webekind (66-67)

My understanding of the difference is that a howitzer fired a shell that had a higher arch to it as opposed to the flatter path taken by the shell fired by a gun. 

Mark Hommel (69-70) The howitzer has spiral grooves inside the barrel that makes the projectile spin as is travels. A gun doesn't have grooves and the projectile doesn't spin. The howitzer is more accurate. Well, that is what I was told while I was there on the firebase. I assumed it was true.
Stan Markham (70-71) The wikipedia article on field guns has a definition of gun and howitzer that parallels my recollection of what we were taught at Ft Sill:

"the term has been applied to long-range artillery pieces that fire at a relatively low angle, as opposed to howitzers which can fire at higher angles."

In short, the difference is the "usual" angle of fire - low vs. high - intended for the piece. Mortars would have a higher angle than howitzers.

Rex Hon (66-67) As I remember from OCS class before WW1 or WW2 the artillery was not internationally standardized. The word howitzer is of Czech origin for a large bore diameter, short barrel, gunpowder weapon used in the middle 1400’s. 

However, throughout the years, the word howitzer could mean any kind of artillery.  At some time in modern history a mathematical standard was developed by various military organizations. As I remember a howitzer became a gun when the bore diameter was multiplied by 27 times and the barrel length exceeded the computed amount. I think this is correct.

Rex Hon (66-67) To Dave Stieghan (Not 1/83rd)

The men of the 1st Bn. 83rd Artillery need an answer to an old question.  We have been discussing when a howitzer should be called a gun.  Example—the M 107 SP —175mm gun vs. the M110 SP — 8” howitzer. You, being the Historian of the Army,  probably have the answer.

I think I remember from OCS class a howitzer is called a gun when the diameter of the bore of the barrel is multiplied by 27 times and this amount is longer than the length of the barrel.

However we need an expert’s opinion.  You are the only person I know that knows everything about the Army.


Dave Stieghan  The 175mm was a gun and the 8” was a howitzer. It has to do with the caliber/length of the tube. The gun shoots flat and the howitzer fires at a higher angle.
Barney Downey (70-71) I don’t think there is a definitive answer to why the 175mm Gun wasn’t referenced as a Howitzer but the Barrel was definitely rifled, I cleaned the bore on ours enough to note that my fist would be a depth measurement of that rifling. All modern artillery pieces had rifling, except mortar tubes and M-79 grenade launchers were smooth bore.

Just found this info, where the gun barrel of the M107 (175mm), had a separate military designation of “M113 gun barrel” and some other info I thought may be of interest.

Chuck (Smoke) Mattson (70-71) Having been an Artilleryman for 24 1/2 years I can safely say at the time I was in (1954 to 1979) all US Artillery that I personally Loaded Fired and cleaned had Lands and grooves (i.e.) rifling. This includes the 75mm pack Howitzer, 105mm Howitzer, 4.2mm Mortar, 155mm Howitzer, 8 inch Howitzer, and the 175mm Gun.

The Difference is Trajectory and too a lesser degree muzzle velocity. I think Stieghan was closet to the debate. Oh by the way, a soft copper rotating band engages the rifling and causes the spin of the Projo. Hope this helps.

Bob Billiards (67-68)
131 Divisional Locating Battery of the Royal Australian Artillery)
I missed your question originally but we were taught a Howitzer had a barrel elevation above 45 degrees, so the WWI 18 pounder was a gun and the WWII 25 pounder is a howitzer. The Australian army I believe have all Howitzers with the British Hamel gun and a British/US 155mm. Both of these have long barrels.
John Zagami (69-70) I agree with Chuck I tested every artillery weapon the Army had at Arty board Ft Sill 68. There’s Lines & Grooves in the tubes. A plastic ring is 5-6” from the bottom of the Projo, this will sit in the tube & make a thump sound once the Projo is loaded in the tube.

The 175 has the same trajectory as a M-14. I also agree with Neal, at FB Bastogne we fired directly at a hill that was firing at our position. I can’t remember if anything happened to the gun. All artillery weapons are indirect weapons meaning that they don’t see their targets 95% of the time. Tanks are a direct fire weapon meaning they see they target 95% of the time. Of course the situation can change at anytime. Back to the question about the difference between them, it is the Trajectory.

Dan O’Brien (69-70) All the tubes had lands and grooves which is why we had a plastic band on each Projo. That brass ring spun on the grooves as it left the tube on the 8 and 175.
Carl Bormet (68-69) During the Vietnam era, the reason the M107 175mm was called a gun verses the M110 8" was called a Howitzer is as follows:

#1 it was not because of Trajectory.

The 175mm barrel and the 8 inch tube fit on the same chassis. Variable Recoil control on each were about the same depending on elevation of the barrel on firing. Lower charges (Zone 1 & 2) could be fired at the highest trajectory (over 60 degrees) on the 175 without damage to the gun if needed and it was done quite often when trying to hit something on the far side of a hill. Especially during H & I firings.

Zone 3 could be fired at maximum trajectory if you wanted to take out a high flying target (it could land anywhere in approx. 5 mile area because it almost left the atmosphere) but it would do a lot of damage to the traversing carriage after a few rounds.

The 1/83rd "C" battery fired zone 1 and 2 rounds at almost the highest elevation at FSB Boyd and Bastogne. We had to get air clearance before doing it. It also could be fired at a flat trajectory and at close range but watch out for the 5 inch base plate on the round because it was coming whizzing back at you when it exploded. Firing zone 3 powder charges almost always required air clearance and firing was often held up because of that reason.

#2 it was not because of rifling of the barrel.

The 105 and 155 and the 175 and the 8 inch barrels were all rifled for improved accuracy and distance. A non-rotating round could be like a Knuckle Ball at distance.

#3 the 175mm gun was a gun because the rifled part of the barrel (Approx. 350 inches) of the gun was way longer than the formula of 27 times the diameter of the round (7.172 in.) = 193.65 inches. 350 inches is greater than 193.65 = gun. The 8 inch 27 times 8 inches = 216 inches rifled part of barrel = Approx 137 inches. 137 inches is less than 216 inches = Howitzer.

I, Sgt Russell (Rusty) Gray and Sgt Kenneth Knebler assigned to 1/83 spent 6 months in Fort Sill Oklahoma, along with 27 others, training and learning all the in and outs of all the artillery pieces used in Nam in order to go to Nam. That way we could step right into Chief of Section positions and pass on the details of firing accurately and maintaining any artillery piece we were assigned. They may be able to verify this if needed.

Why do I remember all this useless trivia after 50 years? it was burned into my brain by the special NCO's who spent more than 1 tour in Nam on those same pieces. I guess now I can forget it at my age.

I hope this helps explain it all.
Neal Schwartz (68-69) I found this article interesting, it even addressed the Gun/Howitzer issue we discussed recently.

The Weapons

There were two main types of field artillery – guns and howitzers.

Guns were closer to the canons of earlier warfare. Their long near-horizontal barrels fired rounds at a high velocity on a relatively flat trajectory. They shot directly at enemy positions and formations that lay within sight.

Howitzers were mortar-style weapons. They were identified by their steeper upward angled shorter barrels. Their rounds were not fired at such a high velocity. Instead, they were propelled in an arcing curve landing among the enemy from above. In that way, they could fire indirectly, getting around cover which was particularly important as it enabled rounds to be fired into enemy trenches.

Here's the link to the whole article


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