40-70 paper patch reamer

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Perentie
Posts: 417
Joined: Mon Jul 21, 2014 9:22 am
Location: Queensland, Australia.

40-70 paper patch reamer

Post by Perentie »

I have had a 40-70 SS reamer and a 40 cal green mountain barrel for about 8 years. Time to do something with them.
I want it to be paper patch. Did Dan ever do a reamer print for this cartridge?
Can anyone put me onto a print.
I thought instead of buying another reamer I could stone a couple of thou off the neck of the one I have.
It has a long throat but I could just grind the throat bit off and leave the 45 degree mouth.
I will use .405 Win brass.
Any thoughts?
BFD
Posts: 2789
Joined: Mon Jan 21, 2008 7:36 pm

Re: 40-70 paper patch reamer

Post by BFD »

Buy your brass first, then reamer to fit.
beltfed
Posts: 1962
Joined: Sun Jun 03, 2007 10:07 am
Location: Central Wi

Re: 40-70 paper patch reamer

Post by beltfed »

I hope your GM barrel is a 14 twist.
Coltsmoke
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Joined: Sun Jul 04, 2010 8:55 am
Location: GA.

Re: 40-70 paper patch reamer

Post by Coltsmoke »

Why a 14 twist? Just wondering? Educate me please.
Normal isn't coming back, but Jesus is.
Perentie
Posts: 417
Joined: Mon Jul 21, 2014 9:22 am
Location: Queensland, Australia.

Re: 40-70 paper patch reamer

Post by Perentie »

beltfed wrote: Sun Jun 09, 2019 7:35 am I hope your GM barrel is a 14 twist.
No its a 16
Actually last night I was thinking I should just buy a new reamer for PP and see if I could sell this one .
Looked at PTG ,s site and they list a whole stack of different 40-70 reamers. One is a 40-70 Hornady. I emailed them to see if its made for the Hornady 405 Winchester brass but both emails I sent bounced back. It seems as if their email address on the website does not work any more.
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 »

In 2014 I had them grind one for bore diameter bullets. I had them email all their drawings for .40-70 SS and picked one for the Hornady brass but made changes to the neck from a GG chamber to a PP chamber. It says 40-70 Hornady SS, PAPER PATCH FIN, PTG 5/14. I don’t know if they have a drawing for my reamer in their records. I had CPA build me a silhouette rife and last year Shiloh delivered my hunting rifle chambered with that reamer. I’ve never had any of the problems others have told me about getting the rifle to shoot well but get a supply of brass before you cut your chamber.
Mike
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.
Yes I just bought 100 cases @ $2 each :shock:
They are not here yet but I understand they are .020 thick against the usual .012. If I use this reamer I may not need to stone much off for bore size PP.
Perentie
Posts: 417
Joined: Mon Jul 21, 2014 9:22 am
Location: Queensland, Australia.

Re: 40-70 paper patch reamer

Post by Perentie »

77 sharps wrote: Sun Jun 09, 2019 5:03 pm In 2014 I had them grind one for bore diameter bullets. I had them email all their drawings for .40-70 SS and picked one for the Hornady brass but made changes to the neck from a GG chamber to a PP chamber. It says 40-70 Hornady SS, PAPER PATCH FIN, PTG 5/14. I don’t know if they have a drawing for my reamer in their records. I had CPA build me a silhouette rife and last year Shiloh delivered my hunting rifle chambered with that reamer. I’ve never had any of the problems others have told me about getting the rifle to shoot well but get a supply of brass before you cut your chamber.
Mike
Thanks for that. I cant email so will splash on a phone call tomorrow.
More reading tells me to use dies for 405 Winchester. I was going to get Lyman 40-70 SS but if the reamer has the larger base web diameter to suit the 405 then maybe I do need the 405 dies.
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 »

I full length size with standard RCBS .40-70 FL sizing die for the first loading. After that I just touch the case mouth with a bushing die if I need the bullet snugger. A .405 die probably won’t reduce the case mouth enough. .411 VS .408/.400”. Almost.010 too big. My chamber reamer is cut for the Hornady cases.
Perentie
Posts: 417
Joined: Mon Jul 21, 2014 9:22 am
Location: Queensland, Australia.

Re: 40-70 paper patch reamer

Post by Perentie »

I cant find RCBS over here , only Lyman.
Looking at my reamer again, and measuring with a caliper I get .432 at the case mouth case stop. just past the case stop its .408 so just takes the rifling out going to 400. With STD brass at say .015 x2 = 30, So 30 off the .432 is about the .400. Hornady brass being thicker would make it tighter but I probably cant cut a chamber that tight anyway. This reamer might do for PP OK
What do you think.?
My 45-70 PP Dan T reamer is tapered straight from the mouth OD. No case stop so it has this little gap at the mouth the bullet can bump into.
Here is a pic of the 40-70 Reamer I have.

Imagereamer 40-70 by [url=https://www.flickr.com/photos/141809689@N05/
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 »

When you get your brass, cut it to 2.5” and measure the thickness. My 405 brass has .012” neck thickness. But check yours to see where you are. Yes that reamer will work for paper patch,especially if you use a dual diameter bullet that patches snug in the case and bore. A standard chamber will shoot very well with bore diameter bullets. Where you are likely to have a problem with that reamer is with the rim dimensions. The 405 has a different rim than a 40-70 and may require thinning the rim thickness and reducing the rim diameter. I chose the 40-70 Hornady reamer to insure that I would not have to do a lot of case alterations.
Perentie
Posts: 417
Joined: Mon Jul 21, 2014 9:22 am
Location: Queensland, Australia.

Re: 40-70 paper patch reamer

Post by Perentie »

My brass should be here this week. I will wait until I can measure it as you say.
My calculations are a bit out then as I read that the Hornady brass was over .020 thick.
I can cut the rim recess with the lathe tool if I need to and polish out the base a bit.
I am pulling the barrel from my 45-90 Roller for this conversion. Its a No1 with the sliding bar extractor. I dont want to mess with the extractor in case I want to go back again so am ordering one from Distant Thunder to make fit.
Thanks for your help. I will ring PTG today.
beltfed
Posts: 1962
Joined: Sun Jun 03, 2007 10:07 am
Location: Central Wi

Re: 40-70 paper patch reamer

Post by beltfed »

Parentie
I can tell you by actual measurement today that , contrary to hear say,
my Actual NECK THICKNESS measurements on 405 Hornady brass I have been using for my 40-72 rifle
read 0.010 plus minus 0.0095 to 0.0105"

beltfed/arnie
bruce m
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Joined: Tue Aug 04, 2009 5:25 am
Location: australia

Re: 40-70 paper patch reamer

Post by bruce m »

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.
ventum est amicus meus
bruce m
Posts: 3350
Joined: Tue Aug 04, 2009 5:25 am
Location: australia

Re: 40-70 paper patch reamer

Post by bruce m »

arnie,
you seem to get about the same variation in thickness as me, but your average is thinner.
bruce.
ventum est amicus meus
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