Paper Patch..HELP!!!

[bobv]

After shooting Benchrest and long range for about 15 years, I've decided to concentrate on shooting my Pedersoli 1874 in 45-70 with lead ..of course. I already cast 340g 405g and 500gr bullets and now I'm thinking of going the PP route. From what I understand ( which is not much!!) when you shoot with BP you patch and size a bullets that rides on the lands and when you use smokless , you size to ride in the grooves...right??? I'm sure there is more to it then just that but I want to start in the right direction as far as bullets go. I will be watching this section closely
Bob

[Don McDowell]

For paper pathing that rifle you'll likely want to start with a .440-.442 bullet ,450-500 grs weight,patched up to 450-.451.No crimp
For grease groove .459 - .460 diameter,500-535 gr weight.Again no crimp.
Powder charge of 65-70 grs weight of 2 f blackpowder.

[pdawg_shooter]

For smokeless cast or size your bullets to bore diameter +.001/.0015. wrap to grove diameter + .001/.003 or as large as will fit the throat. Dont worry, the paper will compress. Let dry, lube, load and enjoy!

[yeahbub]

Welcome, BobV.

The size-to-bore or size-to-groove question has more to do with the action/throat of the rifle in question and the duty of the ammo than whether the propellant is BP or smokeless. When shooting the Sharps/Remington/Winchester single shots, the only way to get max power with BP is to fill the case and seat the boolit way out, hence, the boolit will have to be small enough to get up into the bore where it will be seated with thumb pressure, so a bore dia. boolit with minor friction when seating becomes necessary. These rifles are generally throated fairly short, so reaching the rifling with ammo loaded long is not a problem. PP or bare cast in a lever or bolt action have to survive being cycled through the action, hence are tightly seated deeper in the case at an OAL appropriate for that action and for which the rifles are throated, hence, a boolit at groove dia +.001 or so. This won't cover all scenarios, but it's the basic story. My 2 cents.

[303Guy]

Now it all makes sense!

By the way, the paper patch is not all that fragile. (But it sure is a thing of beauty when you've wrapped them all up yourself!:wink:) I use a technique that causs the paper to bond to itself so it's difficult to take off once dry.

[montana_charlie]

Each of us 'learns things' in a variety of ways. Some of that is 'book learning', and some comes from experience. We also learn by associating information gleaned from several sources and blending it into 'a new revelation' that was not previously apparent. The revelation may be correct or incorrect according to the accuracy of the supporting information...and/or the logic skills of the learner.

My 'learning' about paper patching has given me a different point of view about the 'why of things' than has been expressed by yeahbub.
To wit...

The size-to-bore or size-to-groove question has more to do with the action/throat of the rifle in question and the duty of the ammo than whether the propellant is BP or smokeless.
Actually, the type of propellant is more important than you say, but I'll return to that later.

When shooting the Sharps/Remington/Winchester single shots, the only way to get max power with BP is to fill the case and seat the boolit way out, hence, the boolit will have to be small enough to get up into the bore where it will be seated with thumb pressure, so a bore dia. boolit with minor friction when seating becomes necessary.
'Maximum power', in a magazine-fed rifle can be clearly defined. The cartridge length is clearly established by the feed mechanism, and that length limitation translates directly into the maximum amount of powder that can be used.
However, 'max power' in a single shot rifle is merely subjective.
If the maximum powder charge in a 45/70 cartridge is insufficient for a given purpose, the chamber is simply deepened to accept the next longer normal cartridge length.

These rifles are generally throated fairly short, so reaching the rifling with ammo loaded long is not a problem. PP or bare cast in a lever or bolt action have to survive being cycled through the action, hence are tightly seated deeper in the case at an OAL appropriate for that action and for which the rifles are throated, hence, a boolit at groove dia +.001 or so. This won't cover all scenarios, but it's the basic story.
Perhaps you misspoke when saying that single shot rifles are short throated. Actually, there has been quite a lot of variation in throat length in the classic single shots.
Magazine rifles, especially the lever actions, are more typically chambered with short, or non-existant, throats.

But, returning to the question of patched diameter as it relates to bullet seating...
A 45/70 case with the bullet seated "way out" may have only 2/10 of an inch held in the neck. A 45/90 case loaded to the same overall length will have 5/10 of an inch of the bullet within the neck.
The amount of powder in both cartridges is equal, and there is no ballistic difference between them.
The 45/70 might be running at 'max power'...for a 45/70...but that is subjective only to the case length. The 45/90 cartridge would have the same 'power', but (subjectively speaking) would only be running at 'three quarter power'.
This description could apply to paper patched bullets...or grease grooved bullets. But, we'll stay with the paper patched variety.

The difference lies in the position of the bullet as relating to the rifle's bore.
The 45/70 bullet will need to lie well up inside the rifling...which hold's it fully concentric with the bore. This assures good alignment at launch. The primary reason for using patched to bore bullets is to achieve this launch alignment.
The ability to load a larger powder charge is a nice by product of working to achieve the main goal.

Obviously, a bullet lying in the lands like that MUST be of a diameter that allows it to fit within the bore diameter. That also means it has a lot of room around it (in the grooves) for propellant gases to blow by. For this bullet to perform satisfactorily (and, I said I would return to this) it must be propelled by black powder.
Why? Because smokeless powder will not cause the bullet to obturate quickly enough to seal the gases behind the bullet.

If you wish to shoot paper patched bullets with smokeless powder, you must patch to groove diameter...making bump-up unnecessary for obturation of the bore.

Yeahbub, your two cents and my two cents don't add up to a nickle's worth, but at least we have both contributed to this two-bit discussion.

CM

[Don McDowell]

No you don't have to patch to groove with smokeless powders. It sometimes helps but isn't always necessary, and bullets will bump up whether fired with smokeless or black.

[montana_charlie]

If you wish to shoot paper patched bullets with smokeless powder, you must patch to groove diameter...making bump-up unnecessary for obturation of the bore.No you don't have to patch to groove with smokeless powders.
So you say, but then you always disagree with me.
Does that mean I'm always wrong...or that you are always disagreeable?
CM

[303Guy]

... it must be propelled by black powder.
Why? Because smokeless powder will not cause the bullet to obturate quickly enough to seal the gases behind the bullet.After all the debate about smokless and BP we have the definative answer! Well, it makes a lot of sense to me anyway!

Just a question to you 45-70/45-90 shooters, is there any reason why you could not be using a two-diameter boolit? That way, slower pressure rising smokeless powders could be used, no? Just asking out of interest.

[Don McDowell]

It means just exactly what it said. No you don't have to always patch to groove with smokeless,just as you don't always have to patch under groove with black. Go grab yourself a handful of experience and find out.

303 you don't need a two diameter bullet. I have a .400 dia. 350 gr bullet, that patched to .408 and used in the 4065 with either black or smokeless displays about the same accuracy, and the same .408 diameter in the .411 diameter barrel of my .405 actually shoots better than when taken on up to .411 diameter, and thats with smokeless powder.

[yeahbub]

Happy New Year, MC! And everyone else.

You're quite right about experience adding to the number of arcane details that an individual will find necessary to get the thing to work. From my discussions with the BPCR silhouette and schuetzen folks, your reply shows more and better detail than I could provide in the time I had. My usual habit is to go the other direction and wind up drowning in details which leaves my co-workers wandering away in bewilderment. The only details I might expound on is that classic lever action calibers generally have no cylindrical portion of the bullet exposed forward of the case mouth with factory ammo, so just the angled entry into the rifling is sufficient to serve, even though no formal throat is present. This is true for the usual run of cartridges intended for lever action use. Others, like the BLR are chambered for .308 Win and have the appropriate chamber/throat combo for that and similar cartridges.

The only other point is the matter of obturation differences between BP and smokeless. There's no question that BP produces a more sudden acceleration even though it contains less total energy than smokeless, but smokeless will give good obturation also. One example is the obturation of .22 rimfire bullet heels up to full groove dia even with pressures low enough to safely use in the thin rimfire case. The ones I've recovered over the years are in a condition where the heel has essentially become an indistinguishable part of the bearing surface of the bullet. From what I read, this full obturation is necessary for accuracy with heel bullet designs. Another is the use of .308 dia. 150gr SP jacketeds intended for the .30-30 loaded in the 7.62x39 with published charges of AA 2015. These jacketeds would obturate to the full .310 dia for some 3/16" from the base forward and show clear drag marks from forming to the bottoms of the grooves. Thin jackets and soft cores used in these make this possible at acceptable pressures - other designs intended for .30-06, etc. are too stoutly built. Had they been fired with full charges of BP, I believe the portion showing full obturation would have extended farther forward.

One other detail that relates to shooting bore dia boolits in the single-shot BPCRs is the fairly common chambers which would not allow the use of a groove dia boolit. This was a neat way to keep the brass from expanding beyond it's elastic limit and having to be sized all the way down from a groove dia chamber to be small enough for a bore dia boolit using a tong tool when out on the prairie. No doubt the shooters were happier when the brass sprang back enough to grip the next boolit and the sizing step could be skipped for a few firings. As you mention, BP will take care of the obturation getting the boolit up to full dia along it's bearing length.

I've been playing with a Mosin 91/30 with a .317 groove dia, but it seems to do fairly well with .314 dia PP 311291s with a BHN of 10-11 and a middling charge of 4198. With a .314, it has .0015 "window" in each groove, but it must be obturating before the paper is burned away to get such consistent results and no leading. Recovered bits don't show any evidence of charring. The jury is still out on this one, but the PP performance is definitely there. Hmmm, do I make an offer or let it go. . .

Well, there's another penny or so. . . . .

[HPT]

It means just exactly what it said. No you don't have to always patch to groove with smokeless,just as you don't always have to patch under groove with black. Go grab yourself a handful of experience and find out.

303 you don't need a two diameter bullet. I have a .400 dia. 350 gr bullet, that patched to .408 and used in the 4065 with either black or smokeless displays about the same accuracy, and the same .408 diameter in the .411 diameter barrel of my .405 actually shoots better than when taken on up to .411 diameter, and thats with smokeless powder.

I wonder if there are 3 things that effect obturation:

Powder charge
Weight of bullet
Bullet Hardness

Case in point 4 bullets (30:1 alloy) in 2 guns firing blackpowder @ 1200 FPS:

.44 cal Muzzleloader
360 gr .421 p-patched in .420 bore/.428 groove barrel - 2.5" 10-shot group @ 100
377 gr .428 p-patched in .420 bore/.428 groove barrel - 2.5" 10-shot group @ 100

.38-55 Levergun
250gr .377 GG in .373 bore/.379 groove barrel - tumbling sideways @ 30
250gr .380 GG in .373 bore/.379 groove barrel - 2.5" 10-shot group @ 100

The only reasonable (to me) answer is the tumbling bullet was too light to obturate - even with blackpowder. I think to obturate you would to have a bullet that has a minimum weight, minimum powder charge and minimum soft alloy.

You can likely improve obturation by changing any one.

[Don McDowell]

Pressure . low pressure a bullet won't obturate much.
Tumbling bullet was to small to start with so while it likely filled the lands somewhere along the way, the amount it had to shorten up to fill those lands caused instability.

[HPT]

I agree with not enough pressure to obturate. 2 ways to increase pressure is more powder or more bullet weight. Increasing the charge would build more pressure but may have to push the bullet too fast for its design (plain base).

A similar dia p-patched or gas check bullet would probably work if the pressure was increased - in this case would have required a smokeless load as I can't fit anymore BP in the case & maintain correct length

[bobv]

This thread is very interesting and I can see that PP is more complex than I thought :veryconfuand I can see alot of testing to be done which is OK , because I like trying new things. I guess the first thing I've got to do ,is get the right boolit...Will be checking this site alot more in the futur
Thanks for the help
Bob

[montana_charlie]

when you shoot with BP you patch and size a bullets that rides on the lands and when you use smokless , you size to ride in the grooves...right?
Bob,
What you said closely follows the 'rule of thumb' for paper patching.
The first trick is to figure out which method you want to use...so you can get the right mould.

If you plan to shoot smokeless, a diameter that will be patched to groove (or very close to it) would be appropriate.

If you will use BP, you can go either way.
Shooting patched to bore is the most prevalent (popular) right now, but some BP shooters do patch to groove.

For reasons having to do with the shape of my chamber and the thickness of my case necks...things which I don't want to change...I have been working to find good loads using patched to groove bullets. Results have been getting pretty decent, lately.

CM

[bobv]

Well, my education into PP is coming along, a lot of reading mostly on this site, which has a ton of info, anyway today I received a bunch (20) of boolits from a friend at our gunclub who is into BP & PP a big way..actually that's all he shoots in his 45-70.So he send me 10 cast in a Bullafo Arms mold (540g) and 10 from a Kal Tool & Die mold (556g) both are paper patched and sized to .451, also any Onion Skin patches so I can try them out in my rifle ( Pedesoli 1874). So now I've got something to work with . I also ordered The Paper Jacket by Paul Mathews plus an other book on cast bullets by the same author. Anyway it looks like I'm going to be reading and testing a lot in the near futur:smile:
http://www.hunt101.com/data/500/medium/DSC04644.JPG
Bob

[bobv]

This morning I was reading some articles ( again!!) at bpcr.net and I noticed the use of ''Over Primer Wads and also the use of LP primers. Can someone tell the reason for the use of these items
Thanks
Bob

[Don McDowell]

Softens the blow of the primer flash, and makes a more uniform ignition of the powder.

[bobv]

Ok. so where is it installed..between the primer and flash hole or under the powder at the flash hole exit..and what about the LP instead of LR..??
Bob

[Lead pot]

Don is correct.

A smokeless load will obturate a bullet. Even a jacketed bullet that I have recovered shows the telltale ring on the bullet shank where the gap of the case end and chamber end was.
When shooting a PP bullet with smokeless powder there are a few things that you need to change compared to using black powder because the acceleration is a lot slower using smokeless than black even though the smokeless load will generate more chamber pressure.
It's the sudden acceleration that upsets the bullet more so then the chamber pressure.
When you use smokeless you need to seal the bullet base so the gas wont seep past the bullet side and cause gas cuts till the bullet starts to upset to fill the bore and groove as it travels down the barrel. To do this you need to patch that bullet as close to groove diameter as possible and still being able to chamber that round tight into the lead. With the .22 rim fire they use a cup based healed bullet to accomplish this. Sort of like they used to do with the mimi ball to seal the bore of the muskets for ease of loading and also seal the bore to retain the gases.
Or use a softer alloy so it upsets faster. Using wads with a smokeless load to help seal for gas is not advisable, dont do it! because the wads might work down below the bullet base and that wad will be an obstruction and dangerous mishaps will happen.
I had recovered bullets patched with smokeless patched to bore diameter and they showed full engraving into the grooves, but you wont accomplish that with a hard alloy.
The other way is using a reduced load with a fast burning powder like the loads that Lyman used to list in there loading manuals for lead bullets. I don't know if there are still reduced load listings for lead bullets in manuals because I haven't picked up a new manual except a resent one from AA. But there is a reason for the reduced loading for the lead bullets. It up sets the bullet faster because of the faster acceleration of the bullet using the fast burning powder.
When you load for a lead bullet PP or GG you must put the speed of light velocity out of your mind if you do this you will get good results.
Follow The loading manuals specs!!

[Don McDowell]

Some punch them under the primer , others put them under the powder.
I have had some excellent results with large pistol primers.

[montana_charlie]

Ok. so where is it installed..between the primer and flash hole or under the powder at the flash hole exit..and what about the LP instead of LR..??
I don't use the practice, myself, bcause I haven't reached the point where the difference would matter. But here is what 'they say'..

Some use wads to soften the primer energy, and some use LP primers for the same reason. Some use both.
Some put a wad under the powder, and some cookie-cut it into the pocket when they prime the case.

The thickness of the paper used as over-primer wads (in the case, and in the pocket) has gone through an evolution lately...according to what I read.
Case wads were often said to be newspaper, or tissue paper. Now, it seems that heavy stuff...like construction paper...is providing even more 'cushion'.

Similarly, paper thickness in the pocket has been increasing.

LP primers are used in the belief that they are less powerful that rifle primers.
One of the problems with LP primers is that they are shorter than LR's. So, if they are seated in the bottom of the pocket, the firing pin may not reach far enough (on some rifles) got reliable ignotion. On the other hand, if they are seated flush, there is the possibility it will move forward when hit by the firing pin and cause erratic ignition.

When it does light the charge, the primer is slammed back against the breech face...and some worry about 'cratering' around the firing pin.

The (recommended by some) cure is to cookie-cut thick paper into the pocket. The thickness makes up for the difference in primer cup depth, and adds even more 'cushioning' to the burn.

Now, you know all that I know...and all of my informaton comes from 'book learnin'.

CM