45-70 paper patch issue

[bpshooter13]

My first attempt at paper patching 45-70 cast lead bullets and I met with a slight issue. Everything seemed to work great except I think I have the patch riding too high up on the bullet nose on the Lee 457-340 395 gr 2 cavity mold. This is my go to boolit in my Browning 1885 45-70 in black powder but now I'm experimenting with paper patching and using Unique as a powder charge.

The particulars;
Unique 11-15 grains...still doing charge workup.
WLR primer
.060 vegie wad on top of powder to separate from my filler.
Case filler to keep boolit from dropping deep into case when seating. I'm using steel cut oats, seems to work better than corn meal. I don't resize the cases as they are only shot in this high wall rifle, I just bell the case mouth, seat and minimal if any crimp is applied but if I don't use filler the boolit drops into the case out of sight.

Anhyway, my problem is the paper patch contacts the rifling when inserting and a small ring of paper is being cut when I close the breech. The next bullet won't chamber but If I press it in firmly with my fingers the paper ring sticks to the bullet tip and I can remove the bullet, pick off the ring, reinsert the next round and it seats fine.

I realize this is an obvious problem, the paper is too long. My question is how far up the boolit nose should the paper extend? Do I want it just below where the lands touch the boolit nose? This boolit contacts the rifling in my Browning well above the crimp groove on this bullet relatively far up on the curved radius of the nose. Should I run the paper patch just under the point where the bullet contacts the rifling or can I have it even lower, perhaps just protruding above the case.

Bullet shown in photo on the left, right bullet is Lyman 457-191 which I tried yet again to get my 45-70 to like but it does not. It's getting resized and repurposed as a 45 Colt bullet.




Thanks in advance for any help.

[Old Coot]

It sounds like you have the "Dreaded Paper Ring Syndrome" It is usually ascribed to too short brass. Or, don't trim to minimum case length. I think that your idea of shortening how far up the bullet you put the patch will solve this. If worse comes to worse you may have to get some 45/90 brass and trim it back to the maximum length that will chamber in your rifle.
A simple jig can be constructed to make it easier to put the patch the same distance down the bullet. Take a short piece of plywood (say 6"x9'' ) and glue a second piece of wood lengthwise down the board thick enough that the bullet nose can rest and rotate against it. Then mark a line with indelible parallel to the glued on board at the distance you want the patch to be on the bullet (if you want to use this jig for several different calibers or bullets use different colored inks). To use this thing is probably obvious, but I'll tell you anyway. For a right twist barrel , lay the board with the nose rest on your right in front of you. Place your wet patch along the appropriate line, bullet on top of the patch. Lay the tail of the patch over the bullet at the spot where you want the patch to be at the forward most edge, and just roll the patch on with your finger. Twist the tail and place bullet upright in a holder ( a 45cal ammo box would work good for you). Let dry and you know the rest. Brodie

[CJR]

bpshooter13,

I don't shoot 45/70 but PP other calibers. I know there is a popular theory going that states short cases cause paper rings. However, the NRA found that paper rings are caused by too large a PP OD being cut by the chamber's entrance diameter to the forcing cone. Believe what theory you like. But SAAMI lists the 45/70 chamber entrance diameter as 0.465"D, the groove diameter as 0.456"D and the bore diameter as 0.450"D. IF your rifle is a standard SAAMI cut chamber, which should be checked, then I would suspect your final PP diameter should be less than 0.465"D. If it were my gun I'd try a final PP diameter of groove diameter or 0.456"D. Good luck on your PP adventure!

Best regards,

CJR

[OverMax]

My first patched boolit exercise was with a cast of blunt nose design in another caliber. Never could get that boolit to meet my expectations. In short order I gave up trying and move onto a boolit design similar to what is pictured to the Right. Which seems for the moment capable of good accuracy which I know I can improve upon.
Just a thought. You might want to try feathering ever so little the forward edges of your patch material. Front to back. It may help. Then again it might not. Or try what was proposed by Old Coot. A technique which indeed has been tried by many patcher's.

[Good Cheer]

At top is my brother's hunting load that worked plum wunnerful in his Japanese 1885.

His Japanese 1885 was stolen so he got a latter day replacement and got the ring.

[montana_charlie]

bpshooter13,

I don't shoot 45/70 but PP other calibers. I know there is a popular theory going that states short cases cause paper rings. However, the NRA found that paper rings are caused by too large a PP OD being cut by the chamber's entrance diameter to the forcing cone.

Do you have a link to the source of that information?

IF your rifle is a standard SAAMI cut chamber, which should be checked, then I would suspect your final PP diameter should be less than 0.465"D. If it were my gun I'd try a final PP diameter of groove diameter or 0.456"D.

If bpshooter was asking for advice on a black powder loading, yours might be useful to him.
But, since he IS using smokeless powder, his bullet will not bump up quickly enough to obturate if it is less than groove diameter after patching.

Short cases DO cause paper rings when using patched fixed ammunition.

CM

[CJR]

Montana Charlie

As you requested, the NRA source for the "cut paper patch rings" is NRA's Cast Bullets Manual (available free at Castpics), p111, 1st column, bottom paragraph, which starts with "At one time..........." and continues to the top of the 2nd column.

In response to your 2nd statement. Groove diameter is best to start with. However. depending on what powder he's using, as well as Pb hardness, I would suspect a digressive powder (short fast pressure pulse) might work with a diameter less than groove diameter. Final testing would answer that question.

Best regards,

CJR

[montana_charlie]

Montana Charlie

As you requested, the NRA source for the "cut paper patch rings" is NRA's Cast Bullets Manual (available free at Castpics), p111, 1st column, bottom paragraph, which starts with "At one time..........." and continues to the top of the 2nd column.

Thanks for identifying the source so I could read it for myself.
Most of the shooters who were troubled by paper rings were also patching their bullets to bore diameter ... and firing them with black powder.
Obviously, that should not result in the kind of situation being discussed in the NRA handbook.

Since that 'answer' about patching thirty caliber bullets has .301" diameter bullets being patched up to .313", it might be conceivable that patches which were 12 thousandths thick would leave paper in the chamber. Without the teflon, there may have been enough paper wrapped on the bullets to wallpaper the entire barrel ... inside and out.
Also, it might be noted that the bullets were of a gascheck design, which probably indicates that muzzle velocities were pretty high, with smokeless powders as the propellants.

Those factors are all well and good for the genre, but that information (from 1979) has little to do with paper patching BPCR bullets with reasonable paper thicknesses in straight wall cases such as the 45/70.

Matching case length to chamber depth, in a effort to eliminate paper rings, came to be more common in late 2008 and early 2009 ... which is when case stretching tools began to appear for use by indvidual shooters. As cases grew longer paper rings diminished.

CM

[CJR]

Montana Charlie,

Are you saying that BP shooters "patch their soft CB to bore diameter" where the CB diameter is less than bore diameter? If so, then at BP ignition, the less-than-bore-diameter CB is rapidly expanded first to bore diameter and then to groove diameter as it starts moving?

Best regards,

CJR

[montana_charlie]

Montana Charlie,

Are you saying that BP shooters "patch their soft CB to bore diameter" where the CB diameter is less than bore diameter? If so, then at BP ignition, the less-than-bore-diameter CB is rapidly expanded first to bore diameter and then to groove diameter as it starts moving?

Sort of ...

They typically start with a .442" to .446" bullet, and patch it to .450" or .451".
The patched bullet is seated about 1/10th to 1/8th of an inch into the case mouth ... with most of the bullet lying up in the bore.
At ignition, the bullet expands to groove diameter, and that happens (probably) before it even starts to move.

If alloy hardness (or some other factor) delays reaching groove diameter, the selection of wads placed under the bullet become critical for preventing blowby until obturation is achieved.

Having the bullet so far out of the case means that only the extreme rear end is subject to 'damage' from the chamber transition step ... which is often a 45 degree angle in modern guns.
If the case is shorter than the chamber, there is a sizeable empty space being filled with expanding paper backed by lead, and some of that paper can be sheared off as the bullet moves forward.
Make the case match chamber depth and the 'void' caused by the 45 degree transition is almost microscopic ... unable to 'collect' enough paper to even notice.

There you have the 'short cases cause paper rings' issue ... and it's cure.

I should probably stop at this point.
The foregoing is primarily just how-things-fit within a given space. But, when put in motion, it all works in a certain way because of the propellant used.

In deference to the non-smoking nature of this forum section I will not press any further into the black arts.

CM

[303Guy]

At top is my brother's hunting load that worked plum wunnerful in his Japanese 1885.

His Japanese 1885 was stolen so he got a latter day replacement and got the ring.

Goodcheer, what is that bottom cartridge? It kinda resembles something one should have a rifle for in one's collection.

[OverMax]

Hope you don't mind my doing OP. Just refocusing with a bit of clarity added to your questions. So's to stay on point.

It appears to me you're not too sure about the (correct) process of measuring a patched cartridge to its chamber or bore. That subject matter is covered in the P/P sticky's. Its a straight forward procedure. But that procedure does have a step by step sequence to its process to do it right.

My question is how far up the boolit nose should the paper extend?

Should I run the paper patch just beyond the point where the bullet contacts the rifling? _or can I have it even lower, perhaps just protruding beyond the case?

A few questions the OP needs answer so we all have a better idea of how to help.

Brass length?
Boolit diameter prior too? And resized (down) to what diameter? (prior to its patching)
Cast boolits diameter w/ wrap?

[CJR]

Back on point. I recommend the following for a smokeless 45/70 PPCB load:
1. CB sized to 0.451"D to 0.452"D. If as-cast CB diameter is very large in diameter, then size the CB in steps so as not to remove the grease grooves from one-side of the CB.
2. Wet PP, let paper shrink for a day or two. Final size PPCB to rifle groove diameter of 0.456"D or slightly larger but less than the entrance diameter of the chamber's forcing cone of 0.465"D. In other words the final sized PPCB diameter should be 0.456" to about 0.460" to prevent the forcing cone entrance diameter from cutting the PP on round chambering.
3. Prepare test round to locate position of PP on CB. Seat a square-cut based jacketed bullet into an EMPTY , UNPRIMED CASE nose-first to a long OAL. Keep adjusting OAL , of this test round, until you can just chamber the round in YOUR rifle. This test round now shows you where the leading edge of the PP must be on your CB.
4. Select a max OAL for your PPCB round. Reload a round and cut the PP back to where your test round shows where the leading edge of the PP should be. Now when you chamber a live round, the PP will be against the chamber's forcing cone.
5. Do a pound-cast, etc. to verify YOUR chamber/barrel dimensions, i.e bore diameter, groove diameter, forcing cone entrance diameter.

Finally, enjoy the journey!

Best regards,

CJR