40-70 paper patch reamer

Discussions of powders, bullets and loading information.

Moderators: Kirk, Lucinda

beltfed
Posts: 1962
Joined: Sun Jun 03, 2007 10:07 am
Location: Central Wi

Re: 40-70 paper patch reamer

Post by beltfed »

Bruce,
I was using my tube mike to measure them. Checked brass from several different boxes of 50.
I had got my 405 Hornady brass a number of years ago.
Perhaps they changed their drawing process and more
recently the brass necks come out thicker ????
Arnie
Perentie
Posts: 417
Joined: Mon Jul 21, 2014 9:22 am
Location: Queensland, Australia.

Re: 40-70 paper patch reamer

Post by Perentie »

bruce m wrote: Tue Jun 11, 2019 4:30 am my Hornady brass is 0.0115 to 0.0125 inches thick at the neck
the non turned ones can have up to 0.0005 variation from side to side.
they are batched by weight, and the heavier ones are about 0.0005 average thicker than the light ones.

a thing to be aware of when thinning rims is to remove brass from the front, not the rear of the rims, or you might have protruding primers.

if you go for a chamber that will need groove diameter bullets - read dual diameter paper patched bullets - I can lend you a throating reamer that is 7 degrees, and will remove what you call the case stop and I call the 45 degree transition.
do this and you will never get a paper ring again.

if I were to have a reamer made specifically for pp now I would put this angle at 4 degrees.

bruce.
Yes I think I will go for broke and order a specific reamer.
PM sent.
Perentie
Posts: 417
Joined: Mon Jul 21, 2014 9:22 am
Location: Queensland, Australia.

Re: 40-70 paper patch reamer

Post by Perentie »

BFD wrote: Sun Jun 09, 2019 5:53 am Buy your brass first, then reamer to fit.
Yup. Brass arrived.
Now the reamer print from Dave for Hornady brass gives the Rim at .546 and base at .4615
Cartridges of the world for .405 Win gives the rim at .543 and base at .461
My measurement of a few cases gives the rim at .537 and base at .4555

The rim does not matter so much but why would I get a reamer that cut the base so much bigger than the case measurement.
Have Hornady changed their dimensions lately?
So should I order this reamer for full length .405 brass with a rim at .538 and a base of .456 and the neck .200 long at .425 diameter.
A reamer is more likely to cut bigger anyway (or should I say the operator)and I hate the look of fired brass that comes from an oversize chamber with that swollen look in front of the base.
bruce m
Posts: 3350
Joined: Tue Aug 04, 2009 5:25 am
Location: australia

Re: 40-70 paper patch reamer

Post by bruce m »

that is why you get your brass first.
it is interesting to go on the saami website and look at max/min spec of cases and chambers.
bruce.
ventum est amicus meus
77 sharps
Posts: 330
Joined: Thu Nov 11, 2010 9:45 pm
Location: N. CA

Re: 40-70 paper patch reamer

Post by 77 sharps »

Talk to PTG about altering the reamer dimensions to fit your brass. They will make it how ever you specify. When I had my reamer ground, I only had a sheet from Hornady giving the dimensions. After I got my brass I emailed PTG and had them reduce the neck.002”.
bruce m
Posts: 3350
Joined: Tue Aug 04, 2009 5:25 am
Location: australia

Re: 40-70 paper patch reamer

Post by bruce m »

what he said.
ventum est amicus meus
Post Reply