Missing Rotating Band


#1

I have a few projectiles in the collection with missing rotating (driving) bands. I assume this is a result of the demilling process.

Anyway, anybody got any easy solutions to replace or mock up missing rotating bands?

There is/are one - maybe two (going to an auction here in about one hour) 90 mm rounds and one soon to be acquired 175 mm round. I have an o-ring on the one 90 mm projo to keep it from falling inside the case, but it does not work all that well.


#2

NUT

I have made a couple of rotating bands out of copper but there is no easy or cheap way of doing it. You need access to a lathe big enough to handle the projectile and a source of copper, either rounds or flats.

Unless the projectiles are one of a kind you are better off trying to find a complete one to start with.

Of course, it is fairly easy to make a faux band out of wood or epoxy or some such material, and painting it. Such a band can be made in two pieces and glued on. Turning them on a wood lathe is easy and takes only a couple of hours.

JMHO

Ray


#3

Well, for certain I can turn them on a lathe. :>)

I am a little concerned about using wood for the band and then putting the projo in a case (with the wood band). I suspect most any type of wood will have a difficult time with the stress of keeping the projo from falling into the case.

I will have to think outside of the box on the lathe aspect. Perhaps some type of high density plastic?

Any ideas to locate measured drawings of the bands - for various types of projos?


#4

Tried to copy/paste and then tried print, but a fine picture of a sectioned 90MM AP was protected in some way. Anyway, the OD of the band will be near the same as the OD of the case mouth. There a two or three grooves equadistant in the band. Guessing that’s what you’ve got. The HEAT round is a little different, but the band OD matches the case, regardless. Variations abound, so the need for perfection is diminished.

Same would apply to the 175MM.


#5

“Variations abound, so the need for perfection is diminished.”

That is kinda what I was thinking. I have a few rounds of different caliber. I will just try and get close to what they look like. Still will need to think of some type of material.

No promises for anything soon, but I will try and post photos, when I finish.


#6

Apparently if you can find a company that manufactures hydraulic hoses and is willing to do it, they have machinery that can press a turned copper ring into the groove.

It then has to be turned to the right profile. Obviously the piece of copper to make the ring from would be expensive, and they would then want to charge for the work.

Another possibility is turning the ring from steel and then somehow copper plating iut once it’s pressed into the groove.

I have thought about this before as there are alot of otherwise good condition projectiles around in the UK with no bands. The bands are usually removed for the value of the scrap copper.


#7

GUN

I think you are being a little too concerned about the strength of a rotating band made of wood. If you use a hard wood it should be more than strong enough to hold the weight of the projectile. Turn it on a lathe, making careful calculations of the inside diameter, saw it in two, and glue it on with a good epoxy adhesive. The seam should be invisible after it is finished.

Using any sort of metal will cost you more than the value of the projectile, IMHO. Unless you already have the material in your scrap bucket.

You should be able to find photographs of originals to determine the dimensions and shape of an original band. If it’s a US Army or Navy projectile, there are all sorts of documents that have photos and/or drawings.

Here’s a photo of a 3"/23 Shrapnel cartridge in my collection. It had been fired so I replaced the rotating band with one that I made from copper. The steps I took were a little complicated and I would not have done it except that I had the copper on hand, and it was a garage project done more for pleasure than trying to save a few bucks.

Ray


#8

I have seen one replacement band made from a section of PVC pipe. slit on one side so it could be spread enough to slip over the projectile to reach the rebated area for the band. A bit of shaping and copper paint and it looked pretty good. PVC can be shaped somewhat if heated so you may be able to adapt a piece that is a bit larger or smaller than you need.

You could wrap some rope or cord around to fill up some of the volume then apply Bondo body filler or other epoxy to build up the balance. While fresh it can be shaped pretty easily and worked with wood working tools. Several thin coats would be better than a single thick coat which may be more likely to sag.

Maybe you could turn an appropriately shaped mold on a lathe to be secured to the projectile where the band goes, well coated with release agent (paste wax probably would work). Then pour in your epoxy and let it harden and remove the mold. Injecting the epoxy under pressure would help fill out the mold, and it may be a good idea to drill small vent holes in the mold to allow the air to escape and the epoxy to flow in.


#9

[quote=“JohnS”]I have seen one replacement band made from a section of PVC pipe. slit on one side so it could be spread enough to slip over the projectile to reach the rebated area for the band. A bit of shaping and copper paint and it looked pretty good. PVC can be shaped somewhat if heated so you may be able to adapt a piece that is a bit larger or smaller than you need.

You could wrap some rope or cord around to fill up some of the volume then apply Bondo body filler or other epoxy to build up the balance. While fresh it can be shaped pretty easily and worked with wood working tools. Several thin coats would be better than a single thick coat which may be more likely to sag.

Maybe you could turn an appropriately shaped mold on a lathe to be secured to the projectile where the band goes, well coated with release agent (paste wax probably would work). Then pour in your epoxy and let it harden and remove the mold. Injecting the epoxy under pressure would help fill out the mold, and it may be a good idea to drill small vent holes in the mold to allow the air to escape and the epoxy to flow in.[/quote]

Now those are some excellent suggstions! Thank you!