New to paper patching

[craig61a]

I've been reading on the subject of paper patching, and while I have been reloading for years, both cast and metallic, I haven't done paper patching yet.

What has prompted me to consider this is that I have a Gahendra that I'm considering patching for. Magtech 24 ga. formed brass that was fireformed has a case mouth dimension of approximately .473". I would like to use .457 Lee boolits as the bore slugs right around that dimension. I made a patch from printer paper and applied it to the boolit, and the diameter comes to .475".

So the question I have is would it be safe to push that boolit down the bore. I have read all the stories about how the barrels split when fired with British ammo, and sizing boolits appropriately is prudent.

The arrangement I described above is convenient as it allows the boolit to fit in the fired case mouth without having to resize the neck of the case. But the boolit would also be quite oversized, about .018". Is the paper jacket going to have the same effect as if I were to push a lead solid of that diameter down the bore? Would patching a smaller boolit to say a few thousands over groove be the right thing to do?

[craig61a]

Well I just came across some info that recommends the boolit be patched to either bore diameter or groove diameter. So I guess I'll have to size the cases anyways...

[country gent]

You need to keep that in mind as there is roughly .010 diffrence in dia or bore riding and groove dia bullets so the sizing die needs to set up for one or the other, its hard to do both with one die. Look at meacham tool and his bushing dies. Then not only a cheapbushing change to use either or but neck tension can easily be adjusted with diffrent bushings. The if your bore is .450 and .002 paper is used that adds .008 to dia for the needed.450 dia. Paper thickness X 4 added to bullet dia = finished bullet dia. It will also depend on how you wrap the bullets wet or dry. Wet patches tend to strecth more thinning the pap[er and lengthing mean a shorter length patch may be needed to maintain no overlap of the edges. Gut a strip of your paper 3/4"-1" wide and put 3 to 4 wraps around you bullet, keep wrap tight and snug. with an exacto knife or razor put a nick thru paper to bullet about half the thickness, when unwrapped 2 nicks are close to the length of the patch you will need. Put the angled end on less .015-.030 and rubber cement this to a piece of thin sheet metal the width yo need for the patch and cut glose to paper on each end then finish with a fine file. You now have the template for cutting your patches.

[craig61a]

Yeah I looked at Meacham - thanks for the info. I'm not sure which die body will work for 577-450. The necks blow out to .473" and the OD is .502", so in order to get to say .458" my OD would have to be .487". I might have to give them a call.

[Lumpy grits]

Most folks patch to bore dia.
LG

[semtav]

So is the Bore dia .457 or the Groove dia?

[montana_charlie]

So is the Bore dia .457 or the Groove dia?

Bore - .457" ... fired case mouth - .473" ... bullet patched with printer paper - .475".

Sounds to me like he just needs thinner paper ...

[BRUCE MOULDS]

if that rifle is like a standard martini, it is designed to shoot groove diameter bullets and shoot dirty.
this means plenty of clearance so that a cartridge can be chambered in a fouled barrel.
a bullet patched to a neat bore diameter fit will not suit this rifle, as with say a sharps.
the original bullet was cupped based and had 2 beeswax wads to help seal the gas in until the bullet obturated enough.
a bullet that will finger seat into a fired case is the correct diameter, but the nose might have to be addressed to fit the throat.
a bullet patched to about 0.473 would be the way to go, but a bigger bullet with thinner paper would be better.
prior to the 577/450, long range matches in Britain were out to and exceeding 1000 yards, but the martini bullet became unstable between 900 and 1000 yards, causing the "queens prize " range to be reduced to 900.

keep safe,
bruce.

[Skipper]

Bore - .457" ... fired case mouth - .473" ... bullet patched with printer paper - .475".

Sounds to me like he just needs thinner paper ...

http://www.draftingsuppliesdew.com/s...ng-paper-rolls

[fouronesix]

Well I just came across some info that recommends the boolit be patched to either bore diameter or groove diameter. So I guess I'll have to size the cases anyways...

It's not an either-or kind of thing. Historically and for practicality, most paper patch bullets were closer to bore diameter or even a little smaller than bore diameter. More recently and re: competitive shooters, many are shooting paper patch diameters ranging between bore diameter and up to about .002-3" larger than bore diameter. Obturation of softer alloy needed for sealing and full groove engagement.

[montana_charlie]

It's not an either-orHistorically and for practicality, most paper patch bullets were closer to bore diameter or even a little smaller than bore diameter.

Those rifles had chambers which could not accept a bullet larger than bore diameter.
Today's chambers will take groove diameter bullets, and bullets patched up to groove diameter.

They shoot every bit as reliably as those bore diameter bullets in the antique chambers.

[fouronesix]

Those rifles had chambers which could not accept a bullet larger than bore diameter.
Today's chambers will take groove diameter bullets, and bullets patched up to groove diameter.

They shoot every bit as reliably as those bore diameter bullets in the antique chambers.

Hmmm is all that a fact, given old originals had very large throats and chambers that tended also to be somewhat variable- not to mention bore and groove diameters all over the place. Todays rifles are also chambered in very different ways- depending on the manufacturer, current trends and the whims of the individual shooter- many having custom reamers made for their individual pet bullet design or idea. Now I know why I haven't visited these sections of the forum in a long time.

[montana_charlie]

Hmmm is all that a fact, given old originals had very large throats and chambers

Do you know who Orville Loomer is?

[Red River Rick]

Do you know who Orville Loomer is?

I was thinking the same thing.................

RRR

[montana_charlie]

Waddayathink Rick?
Do you suppose fouronesix went off to learn something from Orville?