I made a patch trimming tool.

[MBTcustom]

I have a theory that the length of the patch is one of the factors that effects accuracy. It stands to reason, that if the patch length is anywhere in a .020 inch area, then the patch will act slightly different depending on how far up the ogive it goes.
So far, the best I can do is to mark the patch and try to wrap it as closely as possible to that mark, or if the boolit has a feature that I can pick out, I try to wrap to that feature.
The problem is that no matter how careful I am, I always get some fluctuation in patch length, also the patch is often uneven on the leading edge. It is very difficult to get the patch both lined up, and to a certain height on the boolit.
I started applying myself to find a solution to this problem. I figured that if I could wrap the patch <.050 inch past where I would like it to stop, then maybe I could find a way to trim it back to a certain spot.
This morning I fired up the lathe and built a tool to do just that. With this tool I can trim the patches on 100 boolits and expect no more than .005 inch difference in length over the entire batch.
I will use my straight wall boolit as an example. This one is loaded in the case and has been wrapped all the way to the tip of the boolit for demonstration perposes.
http://i1120.photobucket.com/albums/l481/goodsteel/IMG_1168-1.jpg
Here is the tool. It is made of steel with a razor blade glued to the face of it, a 5/16-18 adjustable stop, and an aluminum lock-ring.
http://i1120.photobucket.com/albums/l481/goodsteel/IMG_1166.jpg
http://i1120.photobucket.com/albums/l481/goodsteel/IMG_1163.jpg
http://i1120.photobucket.com/albums/l481/goodsteel/IMG_1167.jpg
In order to use the tool, first you load up your cartridges with boolits that have extra long patches. Then you insert the tip of the boolit into the tool and adjust the height of the patch with the threaded rod and lock it in place with the lock-nut.
http://i1120.photobucket.com/albums/l481/goodsteel/IMG_1170-1.jpg
Then you keep constant, light, pressure on the cartridge in order to keep it centered, then nudge the patch into the blade in order to begin the cut,
http://i1120.photobucket.com/albums/l481/goodsteel/IMG_1172.jpg
Then just finish the cut by twisting the cartridge a full 360 degrees, and pull out a perfect, clean-cut patch!
http://i1120.photobucket.com/albums/l481/goodsteel/IMG_1173.jpg
Works every time, and you can be sure that your patches will engage the rifling, fly, and shred more consistently than ever before.
Feel free to copy this design for your own use. Hope this helps[smilie=s:

[longbow]

Now there is an interesting idea!

I have pushout mould I made and find I have a little trouble with patching/seating depth. This would make it easy to pick a seating depth then trim patches back until they just touch the rifling. After I can record the length and patch accordingly. Last time I patched up a bunch then found I had to seat deeper than I wanted to get them to chamber.

Thanks for sharing. I believe I will give that a try!

Longbow

[montana_charlie]

A possibility worthy of consideration ...
CM

[MBTcustom]

This would make it easy to pick a seating depth then trim patches back until they just touch the rifling. After I can record the length and patch accordingly.
That is the whole idea! I hope it works for you.
What I plan to do is to take a chamber cast to the range with me, that way I can compare the trimmed patch to the casting and get a real good idea of how much the patch will be inserted into the rifling. Kind of like this picture.
http://i1120.photobucket.com/albums/l481/goodsteel/IMG_1178.jpg

[303Guy]

Good one! :2_high5:

[no34570]

Bloody good idea mate
Wish I had the skills to make them :( and the tools!

[dnepr]

yup the lathe is going to get fired up soon i see , great idea ,

[725]

Let us know how it works at the range.

[barrabruce]

Looks good to me!!
How about a tapered cut one!!!
So the patch don't end 10 thou think but in a tapered edge.
Just to be painful.

Barra

[nanuk]

GoodSteel: I stand by my comments in your other thread!

Good work!

No... Amazing thinking outside the box!

now... make another 50 and send them out to us!

[DrB]

+1 Nice.

[MBTcustom]

By the way, you dont have to load the cartridges to use the patch trimmer, It will work just fine for trimming your patches ahead of time. I just prefer to use that extra paper to keep the patch from moving around until I get the boolit seated then I can do whatever I want to with it.

[de Guers]

Superbe idée , goodsteel !

[MBTcustom]

Merci Beaucoup! Welcome to cast boolits!

[bbqncigars]

I'll take 'Fun With Lathes' for $300, Alek. ;-)
That's a danged good idea there. I'll have to see what I can come up with for materials to make one for the Sharps.

[barrabruce]

For the non lathe people and rough rural mob.

I made this for mine if I ever need it.(cos' I wrap perfect[smilie=s: )

http://castboolits.gunloads.com/picture.php?albumid=563&pictureid=4117

I do have a 5/16 ww tap thou.

Hunting around I found a bolt and a rusty old washer.

Tapped spent unredeemable case.

Cut of the head of the bolt and used my trust poor mans lathe to true and clean it up.
By chucking the bolt in a drill and bringing it to the grinder I put a slight angle on it then out with the file and flattened it pretty good while it was still spinning.

Cleaned up the washer enough so I could solder it on the Nose then super glued the blade to it.

Seems to work pretty well.

Althou the adjustment could be easier if I had the head on the sticky out end and a finer thread.

Micrometer maybe!!!![smilie=l:[smilie=l:

A smaller long necked 30 cal case for me would be better as I didn't have enough thread to go through the base end.

Hope it helps!!
Barra

[303Guy]

Great to see how one does it when one has to make do! :drinks:

[303Guy]

Say, goodsteel, May I suggest trimming a few castings in a lathe to get a patched bore-ride just to see how they perform? They've worked for me (preliminary test anyway) and if they work for you I would think there are a whole lot of folks out there who would like to know about it. (I don't need to mention the simple clamping collet).

[no34570]

For the non lathe people and rough rural mob.

I made this for mine if I ever need it.(cos' I wrap perfect[smilie=s: )

http://castboolits.gunloads.com/picture.php?albumid=563&pictureid=4117

I do have a 5/16 ww tap thou.

Hunting around I found a bolt and a rusty old washer.

Tapped spent unredeemable case.

Cut of the head of the bolt and used my trust poor mans lathe to true and clean it up.
By chucking the bolt in a drill and bringing it to the grinder I put a slight angle on it then out with the file and flattened it pretty good while it was still spinning.

Cleaned up the washer enough so I could solder it on the Nose then super glued the blade to it.

Seems to work pretty well.

Althou the adjustment could be easier if I had the head on the sticky out end and a finer thread.

Micrometer maybe!!!![smilie=l:[smilie=l:

A smaller long necked 30 cal case for me would be better as I didn't have enough thread to go through the base end.

Hope it helps!!
Barra
Bloody awesome mate :D
now that,I can make ;)

[rwsem]

Well, I've been thinking (dangerous). Since I just picked up a .450 Martini I better look into the art of paper-patching.
The cutter is neat, but of course I have no access to a lathe. What I do have in my tool box at home is a copper tube cutter. Seems to me that should do the trick, eh?
Ron

[JIMinPHX]

That's an interesting idea & a well reasoned concept. I think that you are on to something there.

One little offshoot of that idea that you might want to consider is making the tool out of a V-block & using a razor blade that has holes in it so that you can put a screw through one of the holes & use it for a pivot. With the V-block, one tool could work for all calibers. With the razor blade held on by a screw, it would be easy to change the blade when it gets dull.

...just some ideas.

Nice job. Nice pictures too.

[barrabruce]

Good thinking Jim I like that idea.

[303Guy]

What I do have in my tool box at home is a copper tube cutter. Seems to me that should do the trick,The blade would have to be razor sharp. A sliding blade might also be a requirement I should think.

I've picked up a boolit I patched a while back - it is a GC design and the patch ends flush with the base. I've found that that such patches work just fine. See where this is heading? Trim both ends of the batch!

[MBTcustom]

I'm not following you buddy. Don't you have to have at least some paper covering the corner of the boolit?
By the way, I got the best groups yet out of my .358 malcolm using this trick, coupled with 303guys roll crimp base design. It is just more consistant. By the way there are two holes at 12:00 from the square in this photo. Five shot group:
http://i1120.photobucket.com/albums/l481/goodsteel/IMG_1194.jpg
and my 100 yard group:
http://i1120.photobucket.com/albums/l481/goodsteel/IMG_1191.jpg
I pulled that bottom most boolit out of the group. I was shooting iron sights.

[303Guy]

Looking good! Very good!

I've only test tube fired these that I can remember. They work but they need a bit more to hold the patch down like wet wrapping. The dab of glue trick under the trailing corner works but I feel it makes the patch inconsistant in strength which may or may not affect patch disintegration at the muzzle. Those of my boolits that take the patch all the way to the target would prolly not be affected.

http://i388.photobucket.com/albums/oo327/303Guy/pictures.jpg

This is the recovered remnant from such a patch. It's the ring that sits over the small rebate I use to prevent base edge distortion from being swaged during entering the bore.

http://i388.photobucket.com/albums/oo327/303Guy/BSAMPATCH42GR.jpg

The rebate is visible here.

http://i388.photobucket.com/albums/oo327/303Guy/PIGGUN206gr.jpg