Paper thickness not adding up

[walkswithsticks]

I have read the forum for months now on this subject of BP PP and have read Matthews book "The Paper Jacket". I think that I have a grasp on the basics, but I am having some trouble putting them into practice. I am still quite a ways from my first shot!!!

Before I order a sizer, I am trying to determine what size I actually need.

My 38/55 boolits drop out of my Lee 250 gr mold at 379 to .380. I bought some 25% cotton Vellum that measures .004. I wet it until it changed from bright white to a dull light grey. Using a hard surface to hand roll on, the patches actually went on well. I twisted the tails and let them dry overnight.

Today, the feel dry. They measure .392 to .394. I had also wrapped a few that had been through a .379 sizer die with lube in the grooves. Same deminsions.

Is it normal to gain an extra .004 to .006?
If so, can someone explain why, or should I just accept it?
My barrel measures .373/.379. If I size to .363 and patch back up that would give me .375 to .377. Is that where I need to be?

Thanks,
Bill

[Lead pot]

If you get the proper diameter PP bullet mould no sizer is needed.

[Red River Rick]

This is not cast in stone, but you should be patching your bullet to "BORE" diameter if your wanting to shoot BP, and not "GROOVE" diameter.

That paper seems a bit thick (0.004") for patching, with two wraps that'll add 0.016" to the diameter. Most PP shooters use paper around 0.0017" - 0.002" thick. Thereby increasing the diameter by around 0.007" - 0.008".

RRR

[walkswithsticks]

Can I get my feet wet with what I have, or do I spend the money for a high dollar mold?

My 38/55 mold drops boolits at .379 to .380. Can I use a $22.89 Lyman .360 sizer to get the boolit diameter down knowing that my patch will bring it back to bore diameter, +/- .001?

How much does the thickness of the patch matter as long as the patched boolit fits the bore?

If .004 is too thick for good results, can anyone suggest a source of .002 paper? I know that I have read it in the forums, but I cannot find the answer today.

Can someone explain why you only patch to bore?


Thanks,
Bill

[Don McDowell]

Lee doesn't make a paper patch bullet mould. You'll need to go thru someplace like Buffalo Arms ,Brooks moulds , Old West moulds, Paul Jones, etc to get a paper patch bullet mould.
You need to know what the bore diameter of your barrel is then take off about .006, for the diameter of the bare slug, then you can get 9lb onionskin paper or heavy tracing paper from the local office supply to start your patching.

[powderburnerr]

traceing paper at wally world , drafting vellum from office max are a couple ways to go the traceing paper will be close to 2 tho. the drafting vellum will be around three, it is SIMPLEST to go under bore size with soft lead,but there are lots of ways to do it,

[405]

Like others have posted- you are trying to paper patch a bullet that was intended to be lubed and shot without a paper patch. I'd just lube and shoot the .379 bullet you have in the .379 groove diameter bore you have and see how it works.

For PP you'd be much better off getting a smooth sided bullet or mold that drops a bullet of soft alloy at about .366-7". Add two wraps of .0017" cotton paper and you end up with a patched bullet of about .373-4". Such paper used to be available at BACo. Dunno now?

[405]

For the best chance of success with your 38-55, this BACo swaged bullet wrapped with the thinnest cotton paper they have (.002 I think) may be worth trying.
http://www.buffaloarms.com/Detail.aspx?PROD=161909&CAT=3871