Goodbye 45 degree!

[RMulhern]

I just finished using a reamer to remove the 45 degree shoulder in my 45 2 7/8 Shiloh and it went smoothly! The key to this is having an 'extension' on a T handle long enough to clear the stock; this is especially so if the stock is of the LRE or the Sporter #1 that has a fairly high comb! The extension I had wasn't long enough but the extension I had was afixed with a sliding handle through a hole in the extension and it wasn't any problem using the shorter extension. I'll make me one soon in the shop I have access to. The extension needs to be somewhat thinner in OD than the shank of the reamer as this one just cleared the rear of the loading slot on the Shiloh! I cleaned the chamber good before starting using brake cleaner and then running a couple of patches through the chamber/bore. I then took a black magic marker and marked the bottom of the cartridge rim area and my instructions from Dave Kiffe at Pacific Tooling was when I cut down to the point whereby I just removed a slight bit of the black....GO NO FARTHER! At first, as expected, when first turning I could feel a bump, bump, bump, but this got smoother and smoother as I got down toward the finish point and the last couple of turns were smooth as silk!!

My thanks to Orville and Kurt for advice given!! Shooting comes next after the rains move out! Very Happy Laughing Very Happy

Gonna do the Sporter #1 next!!

[longranger]

Mr. Mulhern,

Is the purpose of changing the shoulder from 45 deg. to ? for paper patch bullets ? Once that is done can non P.P's(G.G's) be shot with accuracy ? I am interested in what you did.I would like my 40-70 SS be a dedicated P.P. rifle. Would I be better to have Shiloh do it ? or with reasonable mechanical skills achieve the same ?

[RMulhern]

Mr. Mulhern,

Is the purpose of changing the shoulder from 45 deg. to ? for paper patch bullets ? Once that is done can non P.P's(G.G's) be shot with accuracy ? I am interested in what you did.I would like my 40-70 SS be a dedicated P.P. rifle. Would I be better to have Shiloh do it ? or with reasonable mechanical skills achieve the same ?

longranger

From 45* to 7*! Yes....it's for PP bullets! If one is getting 'paper rings' either left in the mouth of the case or within the chamber/bore area....it's because the patch is getting torn off because the base of the bullet gets blown into the 45* area and when it enters the bore....it gets swaged down and tears off the patch where it's folded over the base! The operation makes a SMOOTHER TRANSITION area to alleviate the torn patch.

Shoot your rifle FIRST using brass that is the same length as your chamber and check the results therefrom! You may....not have to do this so give your rifle several sessions before making a decision! RMC (Rocky Mountain Cartridge, Cody, Wyoming) brass which is custom fitted more or less to your chamber (which can possibly solve the paper ring problem) is expensive and hopefully with this operation I will be able to use standard Starline brass without getting the paper rings which causes LEADING!!

Orville over on the Shiloh board and Lead Pot here have done this same thing to a couple of rifles with good results so I have gone the same way. There's no question as to whether or not Kirk Bryan could do the work but my thinking is that you'd probably have to have a reamer made for your caliber involved! Shooting cast GG bullets should not be a problem either! I don't shoot GG bullets any more!

[montana_charlie]

Once that is done can non P.P's(G.G's) be shot with accuracy ?

There is no reason to think that the modification will be detrimental to shooting grease grooved bullets. The factory chamber in Pedersoli Sharps rifles has a low angle transition step similar to the one Mr. Mulhern just created in his Shiloh.
They shoot GG bullets just fine...

Rick, can you post a picture of that reamer?

CM

[Lead pot]

It will shoot the GG just as good and better. It just has to be seated a little farther out.
With that 7° taper it will be just one groove and the lead or PP bullet will really be happy.
Rick, you will still see the folded under portion of the patch separate but it will just be at the very base of the bullet not at the case mouth.
I think the folded portion gets blown off when the bullet clears the muzzle not as the bullet starts it's way down the bore.

I'm starting to draw up a reamer now for the .50. This will be the last of my rifles that will get changed and it will have the same 5° to 2° 30' compound lead like the .40, .44 .45, have.

[Lead pot]

Made an error.
The .40/65 and .40/70 have a 4° / 2° 30' compound.

[RMulhern]

There is no reason to think that the modification will be detrimental to shooting grease grooved bullets. The factory chamber in Pedersoli Sharps rifles has a low angle transition step similar to the one Mr. Mulhern just created in his Shiloh.
They shoot GG bullets just fine...

Rick, can you post a picture of that reamer?

CM

Charlie

Don't have a schematic of the reamer! Now...if you want just a plain photo...I can do that tomorrow!

[missionary5155]

Good morning
Interesting that a "Custom" shop like Shiloh would still cut that lead at 45 degrees. I remember 35 years ago the debates about the lead angle in revolvers. You think people who cater to cast booñits shooters would completely wake up ... but I guess that just is not gonna happen until enough buyes demand the correct application of information.

[longranger]

It will shoot the GG just as good and better. It just has to be seated a little farther out.
With that 7° taper it will be just one groove and the lead or PP bullet will really be happy

LP,
Thank you, my chamber is so tight and short it will be a blessing to seat the bullet out.I have PJ Creedmoor mould in 40 cal 410gr. It is the right dia.@ .410 but it has to be seated very deep and tooled in if any fouling is present,shoots lights out.Snover as well has to be seated to the middle of the front driving band,shoots lights out, not so fouling senistive as the P.J. bullet.
I get paper rings consistently and I am convinced,tight tolences and 45 deg leade,RMC brass trimmed to 2.50" is what's causing paper rings and marginal accuracy.My bullet is pure lead @.395" wrapped 25% rag cotton onion skin(Mr Mulhern method) to .401dia. slight pressure to chamber,O.K. accuracy and paper rings.It just makes sense to change the leade and if I can seat greasers out some that's a big plus.
You guys are the best,
Thanks
Randy

[Don McDowell]

I think the change in lead is a good thing. However if you continue to crimp those loads the rings and leading won't stop. (yes even a taper crimp will cut the base off)

[Lead pot]

Before you guys start changing your chambers you better think about it some. You can ruin a perfectly good barrel. The 45° chamber end will work just fine as is.
I have in the past starting in 1955 or 6 shooting these fine rifles and never seen original Remingtons (except the later rolling blocks) or Sharps with a 45° chamber end except the 1878 Borchardt it had a 18° as near as I could measure it.
And all the .22 rifles have this long tapered lead that I have checked with a bore scope. There must be a reason for this.
The first three chamber casts are .44 BN.
The forth photo is of my .45/2.4 I changed from a .45°
The bottom photo is of the two .44-2-5/8 (.44-90BN) the left is the first with a 45° chamber end and the one along side of it is a chamber cut using a reamer I had made of a cast of a original 1877 Sharps to show you the difference between the two chambers.

[RMulhern]

Charlie

Don't have a schematic of the reamer! Now...if you want just a plain photo...I can do that tomorrow!

Charlie

Go to the Shiloh Board! Posted photos there!

[montana_charlie]

Kurt,
Thanks for posting those pictures. They should go far in explaining what the low angle transition modification is supposed to do.

Your program differs from Orville's in one notable way. You have the 'compound angle' where you have a low degree transition angle from point A to B (removing the 'step'), then a normal leade angle between B and C to raise the lands.

Orvile cuts a seven degree angle from A to C...totally eliminating the normal leade angle of between 1 and 3 degrees.
I have a feeling his mod will not handle GG bullets very well.



For modifying a modern chamber cut with a ~.480" neck OD, I like your plan best.

I went to the Shiloh site to see Rick's pictures and it looks like he followed your method.
But, it looks like he had an entire chamber reamer built...not one that just cuts in the throat area.
I would be afraid to use something like that when doing it 'by hand' for fear of enlarging a dimension that I don't want changed.

CM

[ole pizen slinger]

Kurt, Charlie, etc.
Explain something to me, please. My understanding is that the 45 degree angle at the case mouth is allowing lead, patch paper, etc to swell out into this area upon firing and then the bullet is swaged down again as it enters the bore. If the angle in front of the case mouth is altered to a shallower angle, is this not leaving more room for the bullet to swell out creating a larger 'band' on the bullet that must be swaged down when the bullet enters the bore. Is it that the bullet can stand being swaged down at a shollow angle much better than it can at the more abrupt angle?

As for Rick's reamer, it is a finish reamer and shouldn't enlarge the chamber dimensions much, if any. In looking at Rick's reamer and enlarging the photo, it appears that his reamer is going to make about a 15 degree cut from what Charlie shows as A to B and then about a 3 degree cut from B to C. According to Dave Kiffe, one puts layout bluing on the breech end of the chamber in the recess where the case rim seats, then runs the reamer in until it just marks the barrel where the rim of the case seats in the end of the barrel. I would think that if the reamer starts to cut into the original chamber and enlarge it, one would be able to feel the added drag as the flutes begin to cut into the chamber walls. If this begins to occur, stop the cut. It should work out that only the area in front of the case mouth gets altered. Also, in talking with Mr. Kiffe, he recommends about a 15degree angle just infront of the case mouth, said some folks have not been obtaining good results with an angle as shallow as 7 degrees.

Anyway, you guys hash over this stuff some more--I'm learning.

ole pizen slinger

PS Kurt, what angle is being cut into the chamber on the original from A to B (bottom right picture)? Looks to be much shallower than 15 degrees.

[Lead pot]

OPS.

That chamber was cut with a finish reamer I had made from a cast from an original 77 Sharps. I made one change and that was changing the original taper that was 3 1/2° to a 5 degree compound. 5° from the case neck wall to a 2-1/2° to the base of the lands. Just like the original except the change of the 3-1/2° I did not want that long 3/8" lead.
The 5° is .128" long not counting the 2.5°on the lands. and the chamber in this rifle was cut at the Shiloh when they build the rifle.
Your question on the taper getting swagged down in a longer cone.
Yes it does expand to the cone walls but it is about .004 and than gets pushed forward into the bore with a gentle push with no lead getting shaved off or paper getting cut.
Think about it like pushing a bullet through a funnel or a flat washer.
When you have a 45° at the end of a chamber and a gap between a case wall that is .011 deep that donut that gets formed at the end of the case mouth gets cut off instead of getting pushed forward and gently getting shaped into the bullet side wall.
This is very evident when you look at recovered bullets and checking the throat with a bore scope you will not see the lead or paper left behind plastered against that 45° chamber end wall no mater how short the case is.
My .40/65 and .40 2.5 have a 4° compound lead, and it is a great PP shooting rifle.

[montana_charlie]

checking the throat with a bore scope you will not see the lead or paper left behind plastered against that 45° chamber end wall no mater how short the case is.

That statement, and the physics which make it true, might explain the origin of the notion that you can shoot 'short ammo' in deep chambers.

If the original guns had the 'cone' transition, firing a 45/70 in a deeper chamber would mean the bullet would be 'gently' swaged down as it approached the rifling. There would be no 'cutting edge' sitting there to shave lead off and retain it in the end of the chamber.

The advent of modern 'standardized chamber specs' with the 45 degree step, pushed the effectiveness of that practice out the window.
But, you still see 'gun experts' writing articles where it is considered a useful option.

CM

[Lead pot]

CM.
When I say short brass I mean less than .010". The short brass causes havoc with lead bullets or PP in the modern chambers as you know.
Will it hurt in the chambers I use? I think it would in time if a guy would shoot it short consistently like using a .22 short in a long rifle chamber like I did when I was a 11 year old Kid. I was restricked to the .22 shorts and in time when I did get ahold of some long rifles they would not eject in my Winchester because the wash they formed in the chamber. But I once had some .45-70 rounds in my cartridge belt with .45-90's and used the .45-70 by mistake but the accuracy was still good in the 2.4 chamber.

[montana_charlie]

CM.
When I say short brass I mean less than .010". The short brass causes havoc with lead bullets or PP in the modern chambers as you know.

Yeah, I have not mixed up the two 'short things'.

Just speculating about the origin of that 'thing' which you hear newbies asking about from time to time...

CM

[semtav]

CM.
.
Will it hurt in the chambers I use? I think it would in time if a guy would shoot it short consistently like using a .22 short in a long rifle chamber like I did when I was a 11 year old Kid. I was restricked to the .22 shorts and in time when I did get ahold of some long rifles they would not eject in my Winchester because the wash they formed in the chamber. .

Do you suppose it was really erosion, or could it have been corrosion. Kinda hard to believe lead and powder would erode a barrel. Too bad somebody can't to a conclusive test on this and see which it really is. Not advocating one way or other, just not sure if the real cause has been confirmed.
thinking maybe if the gun was cleaned, the front part of the chamber might not have gotten that cleaning. Hard to believe a 22 short would have enough power to erode the chamber.

[Lead pot]

semtav.

Even as a Kid I cleaned my rifles after every use, that was stressed into me by an old friend that was in his 80's back in 1952 that was like a Father to me that sort of took me under his wing because I didn't have a Dad. Ol Spike got me into this mess I'm into now with these black powder guns

I think it is most likely erosion that caused the ring ahead of the case mouth. Back then the priming compound had glass mixed in it and other components that were corrosive I'm sure.