Ross Mk III Repro Nose Caps

cantom said:
I know him and I know that if it was $50 we'd be up to our knees in them.

Another problem is, with Rosses there are so many different variants and models...one style cap won't do it.
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I remember it quite clearly because I thought he was crazy for balking at $50 or even $80 each. That's a bargain.
 
I have a friend who owns a CNC shop. I asked him a year ago to make some up.

He said it can't be done in a one stage process. The outside is easy, but its the inside that is the problem. The tricky part is the 90 degree angle in the inside of the nose cap. The CNC bit would make that curved. Also, the square cut/slot around the bayonet lug to allow the bayonet to slide onto it. He said would take some small and specialized tools, and would be a multi stage process. This is why his shop can't do it - basically its lacking the tools required to finish up the internals and the bayonet lug slot.

I'm sure it can be done, but this is most likely what is keeping the price high.
 
stoggie said:
I have a friend who owns a CNC shop. I asked him a year ago to make some up.

He said it can't be done in a one stage process. The outside is easy, but its the inside that is the problem. The tricky part is the 90 degree angle in the inside of the nose cap. The CNC bit would make that curved. Also, the square cut/slot around the bayonet lug to allow the bayonet to slide onto it. He said would take some small and specialized tools, and would be a multi stage process. This is why his shop can't do it - basically its lacking the tools required to finish up the internals and the bayonet lug slot.

I'm sure it can be done, but this is most likely what is keeping the price high.
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That's interesting. Very hard to machine eh?

I was examining a disassembled bolt sleeve off of a Mk III 1910 a week ago. Man, how they machined those internal threads for the bolt...some very sophisticated machining.
 
My friend says its the hard angles in tight places. It can be done, but not with his machines. I don't think CNC machines will be able to machine those hard angles, as the bits my friend uses create rounded corners - it could be the bits - don't know.

What is keeping the cost high is most likely the labour. Every stage adds time, which adds cost. Also, setup time should be considered. Thats why ordering 100 is more than ordering 1000.

I asked him how they make receivers and such, and he says he has no idea how they did it back then. But if you read about the manufacturing process of making receivers was a multi stage process (possibly well over 10), not a one stage process. I'm sure even today its a multistage process.
 
Yep - that's how they do the 90* angle on the inside.

Here's a thought. What about leaving that 90* spot unfinished... just rounded? It could be done by hand with a good file relatively quickly. They do the rest, we just make the sharp corners?

So, to reiterate, the two 90 degree angles inside the nose cap could be left rounded, and the slots in the bayo lug could be too if they increase cost.

EBruder or anyone - could you ask how much that would lower the cost?
 
I thought about that too, chances are if you're going to put on a repro band, you are probably streching the wood, so a little sand paper wouldn't hurt to get it to fit. It still would look ok from the outside.

The things that set me back is the remaining work: the bayo lug slots, drilling the hole for the stacking swivel, the making and installing the stacking swivel, and finally drilling and tapping the hole for the screw. Finally cleaning/polishing and blueing. All little things really, but add up considerably. Plus if it doesn't look quite right, noone will buy it. If a guy had a jig and the tools he could bang these steps off really quick, but thats where the labour comes into play. As a hobby labour is free, but I would hate to take a week off to make 100 of these. I also don't own the correct tools right now. Thats where I hit my dead end.

If there are enough folks out there who are seriously interested in doing the finishing work themselves, I could re-visit this with my friend. I can't promise a $20 band, but you don't know till you ask. He has the tools and know how, and his time costs me a bottle of booze (within reason of course).
 
It'd be worth to see. I am ok with doing finishing work, just don't think I'm up to a whole piece yet. Small steps are after all, usually easier to do in a home shop, and considering the kinds of people doing the refurbishing, I think they'd be ok with it.
 
I talked to my buddy, and he said he can take another crack at it. He needs a MkIII band to use as a prototype. I sold all the spares I had. Does anyone want to lend me one?
 
Another thing to consider, is if you used a small finishing end-mill, the radii on the inside wouldn't be a problem if you just put a matching radius on the forend wood. However, the smaller the cutter the more trouble you would have holding parallel dimensions over the length of the inside. Grinding a broach would be the way to finish internal form to original configuration. The bayonet lug involves another setup. The part could be sold semi-finished, but doubt that not drilling the stacking swivel hole and tapping and countersinking the cross-screw hole, would save much money, given that the original thread is a #1 BA thread that is not easily obtainable at your corner fastener store.
 
None yet. Sept has been a b!#$% of a month for me, and my buddy is too busy to deal with it this week. Hopefully next week or the week after worst case. I will post my progress.

Another thing on my plate is to locate the front screw. If I can find a suitable replacement, then we will know which thread type to tap it with. I hope to take care of this tomorrow.
 
I got the screw that's in it from Canadian tire... I just brought the nose cap into the screw section and tried until I found one... I didn't change the threads or force it... I just ground the head down to be flush...

I'd be interested in seeing a repro screw that has the proper head dimensions.

EB
 
stoggie said:
None yet. Sept has been a b!#$% of a month for me, and my buddy is too busy to deal with it this week. Hopefully next week or the week after worst case. I will post my progress.

Another thing on my plate is to locate the front screw. If I can find a suitable replacement, then we will know which thread type to tap it with. I hope to take care of this tomorrow.
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Stoggie- The very good news is, since much of the Ross Rifle parts were made in the USA, the threads are American standard threads. Makes things a mite easier.
 
I have finally passed off the nose cap to my friend this week (was hunting last week). He will get it to one of his guys to take measurements and create a blueprint with measurements. This is the first step. The second step is to create the CNC program and figure out what can and can't be done.

My friend's shop is quite busy, but he hopes to squeeze this in when his guys are sitting idle.

I hope to have some info in the next month or so.

Cheers
 
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