Does anyone know the proper way to paper patch a dual diameter cast PP bullet?

[MHS4575]

Looking at the BACO website I see that the have a dual diameter PP mold that looks like it might fit my Loan Star chamber that has more free bore that my Shiloh rifles. Does anyone know how to cut a patch for these that wraps around the bullet twice? The 45 degree angle on my template would obviously leave a considerable gap at the base of the bullet. What is the common approach in patching this style of bullet?

[powderburner]

I dont see the big gap on mine. I just use the same patch as on my other bullets. It’s 8tho different from base to nose. And if you Just turn them a tiny bit while wrapping you wont see an edge varience or a large gap.

[Clarence]

2 Pi (6.28) times the larger diameter will make the patch too long for the smaller diameter, so 6.28 times the smaller diameter should get the patch fit the smaller diameter properly.

If your present template doesn't give you that dimension, make very minor adjustments as necessary and make a new template when you get length you want.

As Powderburner said, adjust the angle of the patch wrap until the end of the patch is even with the beginning.

Clarence

[mike herth]

Contact Doug Fleming at doug@westfork.net. His adjustable DD patch template works perfectly for my DD bullets.

On a related topic, just how perfectly and consistently must a patch embrace the bullet before accuracy is affected, particularly at long range? I have often wondered how much agony we should accept chasing perfection or utility of the patch to bullet. Lots of opinions, but I have seen no hard scientific data addressing this. I believe consistency is important, as in other loading and shooting factors, but how far must we go until it's "good enough"? I constantly question a flyer with: was it my load, my mechanics, or poor wind read? I suspect the latter two in my experience.

[Don McDowell]

I dont see the big gap on mine. I just use the same patch as on my other bullets. It’s 8tho different from base to nose. And if you Just turn them a tiny bit while wrapping you wont see an edge varience or a large gap.

Bingo

[bpcr shooter]

make your patch the size of the large dia, when you order the mold hav ethem put a patch line on it, if it doesn't have one. Keep that edge straight and all will be fine, at least it has the past 6yrs Ive been shooting them anyway. this method has worked in 45-70, 45-90, 45-100, 40-70, 40-82, 38-55, 44-100 and 44-70, I dont think youll have an issue.

If you feel you need it to be closer, wet wrap them and stretch the paper fit.


matt

[Drahopa7]

While we are on dual diameter... I have been thinking of getting a BACO 2 diameter Arnie Seitz bullet.
I have a Pedersolli 45-90 rolling block. My newbie question is, with a dual diameter, do I patch to groove or bore?

[Aviator]

Yes to both.

The forward end of the bullet is patched to bore diameter.
The aft end of the bullet is patched to groove diameter.
One piece of paper patches both.
The diameters must be chosen wisely to come out right for your rifle.

[desert deuce]

Yep, a bullet has a fore and aft, but, how does one determine port and starboard?

[Drahopa7]

Ah, that makes sense.
Cerasafe tells me groove is .4581. Bore is .4495. Think .450 -.006 wrap should give me a good ballpark.
.452 base and a .444 bore diameter. Assuming using BACO #9 onion paper.
Do I need to consider shrinkage of the lead due to a 1-30 mix, or am I over thinking a free meal.

[Drahopa7]

These are the (2) from BACO that make sense.
Any preference out there on flat bottom vs boat tail?

JIM452595E_7404.jpg

JIM452590ZEBT_9501 (1).jpg

[bpcr shooter]

dont go from groove dia, go from fired case dia. It "should" be close but not always. 8 of them I have, are a slight snug fit, and seat in .100. There is very little need for crimp then. With .002 paper I would add .007 for paper thickness. As for lead mix, I'd run 16+1.

[Kenny Wasserburger]

Ah, that makes sense.
Cerasafe tells me groove is .4581. Bore is .4495. Think .450 -.006 wrap should give me a good ballpark.
.452 base and a .444 bore diameter. Assuming using BACO #9 onion paper.
Do I need to consider shrinkage of the lead due to a 1-30 mix, or am I over thinking a free meal.

Forget the 30-1 for this bullet, nose will slump like crazy.

Forget the 9# paper also… too thick. Seth Cole 55W

As was mentioned you need to consider the brass wall thickness and the outside diameter of your fired case. Plus the amount of leade you have.

Consider how you will support the boat tail especially at a 30-1 alloy.

Wet patching is the way to go.

Another mould to consider.

IMG_0658.png

[Don McDowell]

Likely to have a reall problem getting those 1.6 in long bullets to stay stabile in an 18 twist barrel

[steveu834]

I have just started patching my DD bullets and I have one of the bpcr3d adjustable templates. It works well so far. One thing that I did notice is that with dry patches the above formulas work well for dry patches. With the SC55W when wet patching you will have to shorten the patch due to stretching.

FWIW,
Steve