Diameter for .45s

[BD]

Hi All,
What diameter boolit would be suitable to pp to .453 ? Would pure lead be usable at 40,000 psi if paper patched?

I'm asking as I have an itch to try it in the .450B in an AR platform.

BD

[pdawg_shooter]

Slug your bore and size your bullet to BORE diameter +.001/.0015. Any mould you are using now will work by sizing it down. IMHE, pure lead with 2% tin added for fill out will give good accuracy up to around 2200/2250fps.

[BD]

Thanks!

[pdawg_shooter]

Your sure welcome. Glad you are getting into paper patching. I started in the 70s and have been hooked ever since. ALL my rifle loads 30cal and bigger get patched. If I can help in any way my e-mail is pdawg.shooter@gmail.com. Dont hesitate to ask!

[docone31]

You will find Pdawg a pretty good ally in paper patching.
If I had any experience in the larger calibers I would offer. I only patch .30, and .303.
I am hooked.

[yondering]

Slug your bore and size your bullet to BORE diameter +.001/.0015.

Why?
pdawg_shooter, I've seen you (and others) suggest this before, but don't understand why it would be necessary. Is just a hold-over from black powder paper patching?

I wrap them as-cast, and size down to throat diameter. I haven't found the need for an extra sizing step before wrapping.

[pdawg_shooter]

I have had loose patches when sizing too much after wrapping. If you size the bullet before patching then the final run through the finish die just smooths and removes excess lube. I seldom reduce the finished bullet over .001/.002 in the finish die. A loose patch destroys accuracy, IMHO.

[yondering]

OK, that makes sense. I've run into loose patches with smooth sided bullets, but not grease groove bullets. I do agree that loose patches hurt accuracy.

I also believe though, that you need to size the paper down more than just a couple thousandths to get a good hard patch. This would happen with my patches even if the bullet was sized to bore diameter, because my printer paper patches add ~.016" to the bullet diameter, but if you're using thin paper...

Paper is compressible, and if the bullet is too small to compress the paper hard in the sizer or the bore, accuracy will suffer. Of course a softer bullet will bump up, but I prefer to have the bullet fit right before firing, and not rely on bump-up to fit properly. This is for smokeless of course.

[Zeek]

. . . Paper is compressible . . . .
Yes. The best idea, when patching an undersize PPCBoo core is to put on TWICE the thickness of paper that you need for the desired after-sizing diameter and then remove half of that added diameter by the final sizing.

WHY: Good paper like we use looses around half of its added thickness before it becomes "harder than lead alloy." So, if you want to have a nice hard PPatch, start with an under-diameter CBoo, add twice what you need and size half of that away (i.e., size it to the desired final diameter).

HOW: So, a 2X patch of 16# paper will add 0.10 and you size off 0.005. So, if you want your finished PPCBoo to be 0.309", then, with this paper, you must first size it down to 0.304", patch it up to 0.314 (2x patch of 16#) then size it to 0.309", which will eliminate half the the added paper's thickness, so eliminates ALL of the patche's trapped air, leaving you a dead-hard PPatch to take the torque load.

A 2x patch of 20# paper will add 0.012", so, if your final desired as-sized diameter is 0.309, you size your CBoo core down to 0.303", patch it up to 0.315", then size to 0.309", thereby removing all of the air trapped inside the paper.

Go from what you have to what you want, via this simple plan-it-AHEAD-of-time process, and it will all come out right, every time ~~~> the CBoo core does not need to obturate to crush the PPatch to hardness before the PPatch can take the rifling's torque-up. The PPatch is already hard and the CBoo core is already at full diameter (core diameter plus added diameter of hard paper = desired final diameter = groove diameter or groove diameter plus 0.001" or 0.002" {if your throating design will tolerate the extra diameter}).
Zeek

[yondering]

Good explanation Zeek.

I was wondering why a number of people recommend sizing to bore diameter; my thought has been (if you size at all before wrapping) to size based on the requirements of the paper, as you said. I think bore diameter has nothing to do with it, for smokeless, but maybe it's just a convenient number for some folks to remember?

I've found that cast bullets with a hard paper patch sized just over groove diameter will give good accuracy with anything from very light gallery loads up to full power 55-60 Kpsi modern rifle loads, since no bump-up is required from the bullet.

[pdawg_shooter]

I size to bore diameter +.001-.0015 to give room for the paper. Two wraps of 16# paper will add .010 to the bullet diameter. If I dont size first, the bullet is to big for the throats of my rifles.