Too much windage?

[Soot Sucker]

I have been shooting my golf ball mortar. It measures aprox 4 1/4" dia. at the muzzle. is aprox 8" long. Weighs 19 lbs.

Now I worked up my charges 20, 30, 40, 50, 55, 60  and up etc. up to a full powder chamber of 80 grns of FFFG

I know 80 grns is alot but the problem I have is I can't get this thing (mortar) to launch a golf ball a full 200 yds where I have a target set up. The farhest a golf ball has shot is aprox 160 yrds.

I suspect there is too much windage. The best I can measure shows that there is aprox 1/16 th (maybe 3/32 nds the most) of an inch windage around the ball when it is seated in the mortar. is this too much?...if not what gives? I am sure the powder is good. Its about 5 yrs old, but is stored in a dry place in its original containers (Goex).

I remember "Double D" stating he can launch a golf ball 200 yrds on 2 45 acp carts, full of FFFG. I fill my powder chamber to the top with 80 grns (aprox 4 and 1/2  45acp cartridges!) and lucky to get  150-160 yrds.

Help.

Soot
P.S. Mortar is set a 60 deg angle

[Cat Whisperer]

With my mortars in golf-ball caliber I'm getting the 100-200 yard range.  Bore is 1.70 inches in diameter with 2 caliber length.

But, that's shooting at about 45 degree elevation.  

From what I remember from the Comanche County Cannon Cocker College (Field Artillary OCS) the max range for the howitzers was obtained at 37 degrees elevation - the dividing point between high angle and low angle.  That's for pointed bullets.  Most all CW howizters are set at 45 degrees elevation.  I don't know for a sphere if that's max range.

My mortars are made from 4140 steel and because they're very much overbuilt I don't hesitate to use FFFg with it's short barrel.  Shooting two golf balls - one will always go further.  It's been my experience that a heavier bullet will cause better ignition and longer range.

[Cat Whisperer]

Let me just add, (don't ask how I know and don't do this at home) that at 85 degrees elevation a mortar that normally shoots a 7.5 lb 4.5" slug out to 350 yeads only goes about 20 yards.  Time of flight is reduced as well from 12 to about 8 seconds.

[Evil Dog]

The golf ball mortars will also fire a 1 pound "cannon ball" fishing weight, they are just under 1.700" diameter when cast from wheel weight.  The mold is real reasonable too, $36.00 plus shipping.  http://www.hiltsmolds.com/CannonBallSinkerMolds.htm

[Cat Whisperer]

When you start throwing lead, work up your loads carefully.  You will have MUCH more pressure and much better burning of powder, hence go to slower powder (at least at first) and work up.

[jsa0100]

Hi !
I think you are using to little powder :
I am using 1/2 film can of ff to shot to ball out of sight.
I am also using skin around the ball just like i would
if i shoot a lead ball.

also, take a look at this :

http://www.cannon-mania.com/mortars.htm