Trimming tails for = pressure

[charger 1]

Heres something I'm struggling with. Its basic I know but still I'm not up to speed. OK dont have a cupped base mold,only flat, so no tail tuck for this boy. Hey thats fine I read where lots of folk are getting away just great with trimminig the tail. Would/could someone please explain in high detail,perhaps even pictures how this is done so as he gets exactly the same volume of paper in the chamber with powder each and every trigger pull. Hey we all know if case capacity varies for whatever reason,then pressure varies ,then out goes the accuracy. Sometimes I wonder if for consistancy sake a fella shouldnt just leave tail on. To me heres the weak link. You cut all patches equal, put them all on boolit same way, powder charge case all same, then we just cut tails by eye thusly varying the amount left and shape from tail to tail. I'm actually thinking of getting a 5/16 ball nose end mill,chucking each boolit and cupping the base... Thoughts

[pdawg_shooter]

I clip my tails close to the bullet, lube, and then give them a final sizing to the diameter I want. This compresses and flattens the tail as well as sealing it. Any load for a jacketed bullet will be safe with a patched bullet of equal weight because the paper engraves the rifling so much easier than jacketed bullet. The patched bullet also has much less friction drag in the bore. Since pressure equals velocity, decreasing volume 10% increases pressure and velocity around 2.5 %. It would take a huge decrease in capacity to move pressure into the the danger area. Sorry I cant leave pictures, no digital camera. I tend to spend my extra funds (and some not so extra) on things that go bang. If there is any way I can help you with patching e-mail me, pdawg.shooter@gmail.com and I will try to help. I have been patching since the early 70s and I expect I have made every mistake there is to make. Maybe I can save you some grief!

[bcp477]

Excuse me, but I believe that you are thinking too much. There is no way, by whatever means, that you will ever get "exactly the same volume of paper in the chamber" with each and every shot. Paper patching simply does not lend itself to that kind of absolute exactitude. Yes, you can get close - by making sure that all of your patches are of the same size, before wrapping. As to the bases, without cupped bullets, all you can do is either twist tails or fold over the paper. Regardless, you will never get two patches to be exactly alike - never. Besides, I doubt that it matters anyway - since the paper patch only serves as a sabot - and is shed as soon as the bullet leaves the barrel. I understand your point about volume vs. pressure, but I think that you are taking hair splitting to a new level. Sorry, just my opinion.

[charger 1]

well ok

[Kenny Wasserburger]

Why not just shorten the patch width? have only a slight amount fold over the base and then no tail to twist-Cut?

Seems to work well for me, however I shoot my PP loads with Black Powder.



The lunger
Kenny Wasserburger

[405]

Kinda with the others here- the amount of volume difference would be insignificant so pressure variation would be likewise. The only theory, that some hold about tails, that seems to bear on accuracy is that odd tails can get rammed into the base at ignition and cause in-flight bullet problems. For flat-based bullets I've found that paper wrapped just short of forming a tail works well. Surely the case volume difference among rounds/bullets patched this way would be small indeed.

Pic showing FB bullet patched this way. (no tail)

[Kurachan]

Here are the remains of patches that weren’t twisted tails. Just formed over the base pretty much as in 405’s picture. This barrel has 4 grooves of nearly equal width to the lands. Various stuff gets found in the first 10 feet from the muzzle. Usually little rectangles or a “tail” from the part of the patch covering the base. In the picture a rectangle has a small cut from the crimp used or did the boolit bump up in the case before it moved? There is also a sliver off one of the box board wads. The very bottom piece of trash still has the four parts of the inner wrap attached. The paper confetti found in front of the firing position always gets smart comments from the J word users… After their eyes clear from the smoke!

[montana_charlie]

Interesting picture, Kurachan.
Isn't it fun trying to 'analyse' those paper shreds?

Your residue closely resembles what I found after my first P/P shooting session a few days ago...

It seems reasonable to me to assume the 'base fold' should exit (pretty much) intact since it is just sandwiched between the bullet and the wad...with no rifling contact.

I reckon the rifling-cut 'strips' extending forward to the front edge of the patch just get ripped away from the base fold when the paper hits the air.
So, I suppose, a certain lack of uniformity in the 'tags' on that base fold is to be expected.

I found a good number of those 'strips' around my bench, and they were just the right length to support the rip-off assumption above.

Those strips wanted to assume a spiral shape, which makes sense when you consider how they were formed.
Most were quite flat (from end to end) but a smaller amount had some 'accordian' creases across their width.
I am thinking the 'flat' strips came from the loads with .450" bullets. I suspect my .452" bullets created the crinkled ones because they didn't pass through the leade as smoothly as the others.

I also saw 'rectangles' such as yours, but I have no theory on how they were formed...
CM

[docone31]

I use smokeless with patching.
Hokay, I have cut the tails, not cut the tails. When I final size, the tails get reshaped to the base of the boolitt. When I have loaded uncut tails, they went in intact.
I have noticed no negative effect, either pressure signs, or accuracy. This was on 40.4gns of Surplus 4895, with 180gn .314 patched .303 British.
I started a thread on that, that ended up with some pretty usefull information.

[Lead pot]

Those long thin strips you see are from the patch cut from the end of a case to short for the chamber.

[montana_charlie]

Those long thin strips you see are from the patch cut from the end of a case to short for the chamber.

To whom is your comment directed...me, or Kurachan?
CM

[Lead pot]

To Kurachan looking at the picture CM

[Kurachan]

The strips in the picture of the range trash are from the section circled in this shot. The rectangles are from segments of the wraps themselves. In this rifle it seems that one groove and one land form a rectangle and that the paper gets cut against the side of the land that resists the bullet.

[montana_charlie]

Good use of an image to explain your point, Kurachan.
My 'strips' are single-wides. One from a groove, one from a land, one from a groove, etc.
But then, my patch may be thinner than it should be...
CM