Paper Patch Reamer

[Keith]

Not sure where to ask this but will try here.
I am relining a Hepburn that was chambered in 40-1 7/8ths that I understand is 40-50 SS.
I want to make this a straight PP cartridge and was wondering where to scource a PP chamber reamer for that cartridge.
Thanks

Keith

[Nobade]

Dave Manson. http://www.mansonreamers.com/ He made me a beautiful 45-70 dedicated PP reamer, and knows what they need to look like to work properly. I plan on having him do a 40-50 Bottleneck for me sometime in the near future as well, he's a great guy and knows his stuff.

Now, whether the US allows him to send those to you, I don't know. With so much shooting equipment having export controls on it now things have gotten very difficult. But hopefully chamber reamers don't fall into that category.

-Nobade

[Gunlaker]

Reamers should be no problem. I get them from Manson sometimes and I'm in Canada. Chris.

[BrentD]

It isn't so much where you get your reamer, it is which reamer you get - a hunting rifle/ plinking reamer, or a target reamer. People talk about "paper patch chambers" as if there a concensus as to what that means. There isn't. Most of the discussion on the net directs people to reamers that are, at best, hunting rifle reamers, not target rifle reamers. If you want the latter, be sure you know what you are doing.

[Keith]

Thanks, I just sent him an email asking.
Keith

[Gunlaker]

Keith you might be best off talking it over in some detail with Brent, Kurt (Leadpot), or Dan Theodore, before picking a design. I know a lot of people who think that paper patch chamber needs a long freebore. Some of those people have been gunsmithing for years. But they haven't been shooting paper patched bullets.

I have a couple of rifles chambered with Dan's reamers and am very happy with them. I'm also getting one done with Brent's chamber design. That one looks very interesting to me.

Chris.

[montana_charlie]

People talk about "paper patch chambers" as if there a concensus as to what that means. There isn't.
I don't have one, but I define a 'paper patch chamber' as one which will only accept a bore diameter bullet.
What is your definition?

CM

[Keith]

The liner is .400 bore.
The paper I have is 2thou thick, I cant get thinner over here.
I was looking at the BACO Jim 392425 so 392 with 2 wraps gives me just on .400.
I was going to use .303 Br as the parent brass and as I understand the chamber should leave the ID of the neck at .400 to handseat the patched boolit with a short shallow taper to the bore size.
So twice the neck thickness of the brass plus a bit for clearance gives the neck size of the reamer.
Does this sound right?
Keith

[Nobade]

Yep. My chamber gives .001" clearance on Starline 45-70 cases when they are sized to accept a hand seated .450" boolit. No need to resize the cases, they spring back enough to not need it. No step at the end of the chamber, just a smooth transition about 5 deg./side into the bore. Chamber is the same length as the brass so there isn't any room for the bullet to expand into before it is sealing the bore. (you do have to watch your trim length) Very simple chamber design, works beautifully. And no, you absolutely do not want any freebore!

I don't see how a hunting and a target chamber would be any different. I can load ammo with no lube, wipe between shots, and get amazing accuracy or I can load with a grease cookie and get very good hunting accuracy and easy repeat shots. Just depends on what I want it to do.

-Nobade

[BrentD]

I don't have one, but I define a 'paper patch chamber' as one which will only accept a bore diameter bullet.
What is your definition?

CM

that is necessary, but not, in my opinion, sufficient.

The factor that is being missed is minimal distortion of the bullet (and patch). Pushing the bullet into a wide funnel throat where it bumps up to over groove diameter, that then has to reswage the bullet back down to get it into the lands and grooves, is self defeating. Think minimal lead deformation.

[BrentD]

NoBlade,
Hunting chambers have to deal with fouling on the second and third and even fourth or fifth shot, if necessary. And sometimes it is necessary, no matter how careful and good we think we are. That means that subsequent bullets have to chamber, even with fouling. Also, bullets will almost certainly be loaded much more deeply seated in the case. Groove diameter is NOT a bad hunting diameter, but regardless of bullet diameter, it has to fit over fouling. Some internet experts claim that undersized bullets (e.g., .447-.448" in a .450 land-diameter bore) will do that, and indeed they can. But not with the best accuracy. The chamber that is popularly touted as THE Paper Patch chamber is not at all a bad choice in a hunting rifle, but it ain't a target chamber. Not today, not tomorrow. Sure some will push it that way, but it is far from optimal and the folks that are consistently shooting paper patches at the top of the score boards (as opposed to winning a class with 3 shooters at the bottom of the classifications) are using chambers much different that what is being sold on the net.

The philosophical goal of bpcr, if you can do it, is a chamber that removes the absolute minimum amount of barrel metal and, in that way, mimics, to the highest degree possible, the long-range muzzleloading experience. In fact, if you could, you would want to mimic the long range muzzleloading-slug gun - the absolute pinnacle of cast and black shooting. But because we are competing with various time constraints and some other restrictions, we compromise, but not one iota more than necessary.

[M-Tecs]

Anyone have the current contact info for Dan Theodore? Most of the www.bpcr.net (http://www.bpcr.net) links don't work anymore.

[Red River Rick]

M-Tecs:

Dan Theodore posts regularly on the Shiloh forum, under DanTDesigns. You can try contacting him thru there.

RRR

[montana_charlie]

I don't have one, but I define a 'paper patch chamber' as one which will only accept a bore diameter bullet.
What is your definition?that is necessary, but not, in my opinion, sufficient.
So, we agree on the chamber, but you have definite ideas about the shape of the 'throat'.
I have no argument with that.

If you have a bore-diameter bullet sitting in a brass tube waiting to be fired ... and if it can slide forward seamlessly into a steel tube of the same diameter, that will create the least amount of 'change' in the original shape.

Although it may require meeting an impossible 'tolerance', a 90 degree mouth butted up against a 90 degree chamber end would provide the most 'seamless' transition.

CM

[BrentD]

Don't forget the ends of the lands. Comprise must be made, but should be minimized.

[montana_charlie]

Don't forget the ends of the lands. Comprise must be made, but should be minimized.
If the diameter of the circle formed by tops of the lands is 'bore diameter' and the interior of the case is 'bore diameter', the tops of the lands lie on the same plane as the inner wall of the cartridge case.

The end of a land is not exposed to the passing bullet because it is 'hidden' by brass.

As the bullet leaves the case, it must expand into the grooves ... not be engraved by the lands.

In a butted tube to butted tube transition, no part of the patch+bullet can expand to greater than groove diameter ... where it will stay until it exits the muzzle.

CM

[BrentD]

Yup, that is more or less the best approach. It is one step away from breach seating.

[Lead pot]

So, we agree on the chamber, but you have definite ideas about the shape of the 'throat'.
I have no argument with that.

If you have a bore-diameter bullet sitting in a brass tube waiting to be fired ... and if it can slide forward seamlessly into a steel tube of the same diameter, that will create the least amount of 'change' in the original shape.

Although it may require meeting an impossible 'tolerance', a 90 degree mouth butted up against a 90 degree chamber end would provide the most 'seamless' transition.

CM

I had a friend that had this same thought having a 90 degree chamber end and he had a reamer made and opened a .45-70 Hepburn to a 90. He ran into a problem with the case length tight to the chamber end getting rolled up and ended up with a terrible lead problem. I shortened the cases enough so they did not get pulled past the transition and fought paper and lead rings worse then the 45 degree did. He ended up throating the neck with a funnel lead and this stopped all his problems.

[montana_charlie]

I shortened the cases enough so they did not get pulled past the transition
I wonder if the case lengthening would have been prevented if he was thumb-seating bullets in unsized necks.

With thirty matched cases (that I use only for load development) I have fired 1056 shots.

None of those cases have ever lengthened after I initially stretched them to actual chamber length.

CM

[Lead pot]

Charlie I don't know what his loading procedure were, but I do know that I have never seen a crimp on his loads.
In my rifles that still have a 45 degree transition I can see the case mouth with a slight taper in when the case is right at the chamber end and I have a snug finger seated bullet. I think a compressed load of powder will pull the neck slightly and it will spring back after it was fired to a degree. I keep my cases .005" short of the transition in a 45 degree chamber end. My gentle long lead throats I don't have a problem if the case is on the short side with bullet bases getting deformed. But my chambers are cut to match the brass case wall thickness I use and they are a tight chamber wall at .475 for the .45's

[semtav]

It would be interesting to see some good side by side pictures of various chambers to compare. Something like in the program Tom Myers puts out. The mulititude of ways one can arrive at the same destination always intrigues me.

[Harry Eales]

Gentlemen,
Sadly Dan Theodore died in a house fire in his home earlier this year. He lived alone and although the emergency services arrived quickly after the fire was reported they were too late to save him. I have no knowledge of the cause of the fire that took him from us.
RIP Dan.
Harry.

[Lumpy grits]

It was an electrical fire, and Dan was killed from smoke inhalation.
LG