Advice from experienced golf ball mortarmen requested

I have been shooting my .75 handgonne and really love it, but it's time to move from the 1500s to the ACW. I'm yearning for a steel golf ball mortar and have been considering the Trail Rock Arsenal one, looks really robust and well made, and the Cannon Fuse model that is adjustable for angle. I don't intend to sling balls into orbit, but would hope to lob them 100-200 yards. What are the minimum charges of 2F that you have used, do they safely perform with lower charges, and overall what do you think of the mortars themselves? Thanks!

This one cost me $125 unfired. The seller recommended 90 grains. I started with 30 and the result was like a scene from a Looney Tunes cartoon. I jumped up in 10 grain increments keeping the landing spot within the clearing I had so that I could retrieve them. I got about 300 feet for a guess possibly more, fixed elevation, mortar sitting more or less level with 70 grains. There is quite a bit of blow-by as there is a fair amount of clearance around the ball. Check eBay for used golf balls.

I was out today shooting my mortar. Mine is smaller than a golf ball mortar, but can also be fun and all the procedures are mostly the same. I visited the Trail Rock Ordnance and found it very interesting. Their products look very nice and the price of a finished golf ball steel mortar is very reasonable. You might luck into a great buy as Hawkeye2 found, but the waiting time would frustrate me. TRO says it is a 30% scale, mine is more like 20% to 25% scale. It can be seen in action at

https://www.muzzleloadingforum.com/threads/my-new-cannon-barrel-has-found-a-new-playmate.185720/

And

https://www.muzzleloadingforum.com/threads/firing-results-for-the-“pin-ball-machine”-mortar.185969/

TRO also says “It is bored and chambered to shoot golf balls, using 20 Grains of powder and achieving a range up to 300 yards.” That statement I would have a hard time believing as I use 25 grain of 3f powder to get 70 yards at 55 degrees from horizontal, keeps me in the clearing that is used. Mortar range seems to be much more dependent on amount of powder used than the angle of fire. 45 degrees will give most range with 55 or 35 degrees being the same in shorter distance traveled. And that is the fun in learning to fire a mortar round to land the distance you want. Using too little powder will not hurt and I use 3F as the barrel is very short. Hawkeye’s 70 grain load will probably give you close to that 200 yard range, but if you have a limit on space work up to it carefully. I would recommend 40 grain as a starting point. Also this Bullet Trajectory Program I highly recommend as you can see different results in angel vs velocity in distance and height. Gives a idea what is happening.

https://www.omnicalculator.com/phys...on?c=USD&v=a:0,v:90!ftps,angle:55!deg,h0:0!ft

Good Luck with you new ordnance piece, I think you will love it.

To deal with the 'blow by" due to the undersized golf ball/bore fit, I patched the golf ball with damp pillow ticking (moose milk.) It have a better seal and a louder POP. The wadding/patch dropped close by and I could reuse it a few times. I also tried a 1/2" section of dowel under the golf ball and that improved efficiency. Lots of fun.

ADK Bigfoot

Thanks, @Rich44, that 20gr load that I saw on their site puzzled me too and that's why I posted. I did email them but no reply yet. I see lots of 100+ loads on this site, but they seem excessive/unnecessary/borderline sketchy. BP is too costly and hard to come by to blast it away unnecessarily. I hope more people reply to my post, especially any who own and use the two I'm considering.

The Miner '49er said:

Thanks, @Rich44, that 20gr load that I saw on their site puzzled me too and that's why I posted. I did email them but no reply yet. I see lots of 100+ loads on this site, but they seem excessive/unnecessary/borderline sketchy. BP is too costly and hard to come by to blast it away unnecessarily. I hope more people reply to my post, especially any who own and use the two I'm considering.

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A 100 grain + load will make it jump around and look like a toy. May even flip over. And would also be hard on the wood bed.

ADK Bigfoot said:

To deal with the 'blow by" due to the undersized golf ball/bore fit, I patched the golf ball with damp pillow ticking (moose milk.) It have a better seal and a louder POP. The wadding/patch dropped close by and I could reuse it a few times. I also tried a 1/2" section of dowel under the golf ball and that improved efficiency. Lots of fun.

ADK Bigfoot

Click to expand...

ADK Bigfoot is right on the money using a patched ball. Too much velocity is given up with blow by and velocity is what gives you greater range. And yes the bang is a lot better. Might not be exactly how the originals were loaded but they were bigger and probably more forgiving. I actually use a loading block that is the same size as bore, so it is know how the fit will be beforehand. I am still on the honeymoon with my mortar, after awhile it will get some dust on it.

Models maybe dimensionally 1/3 scale but the total weight will most likely not be 1/3 of the original, but lighter. So if you are trying to get some distance with a mortar adding weight to the base would help, like in-letting brass or lead in the wood. As can be seen in this video the mortar does not move much, as it should be.

https://www.muzzleloadingforum.com/threads/big-mortar.186992/