I have a couple of questions

[HollowPoint]

Question (1) When a paper patched cast bullets exists the barrel, does the paper get peeled off of the bullet from the front to the back due to the wind resistance that hits the bullet nose as it flies through the air or does it get peeled off from the back to the front due to the gasses that forced it out of the barrel?

Question (2) How far up the nose end of your cast bullet would be considered optimum for the top edge of the Paper-Patch? I guess what I'm asking is, where should the patch begin so as not to get scraped off by the edge of the chamber mouth when cycled through a bolt action rifle.

Why am I asking???

I'm thinking of giving paper patching another go. I've got a bullet design in the back of my mind that incorporates the new Boat-Tailed Gas-Checks I've been working on. Before I spend any time with it I'd like to get some idea of the dynamics of how the bullet sheds the patch when it exits the muzzle.

If it peels off from the back end due to the hot gasses that push the bullet forward, I'm thinking that the bottom edge of my paper patch can be ended at the lube-groove just above the Gas-Check. If the paper patch is peeled off from the front due to the resistance that the front end of the bullet (and the top edge of the paper patch) meets as it exists the muzzle, then a slightly different nose profile will be needed.

If it's peeled off from the back to the front of the bullet I thought I might be able to mill an indent in the Cherry/Reamer at the part of the bullet just above the section of the cast bullet that will actually make contact with the rifling. This way the top edge of the patch can be positioned within that indent to keep it from getting damaged before it's been chambered.

If it peels off from front to back, such and indentation might prevent the patch from peeling off as it should.

I'm sure by now that every paper patched bullet design one can think of has already been tried at some point or another; which makes it highly likely that the design I have in mind may have already been tried too but, I'm thinking more along the lines of a "Bore-Rider" type with a Boat-Tailed Gas-Check thrown into the mix. This way, only a short section of the bullet will be covered by the paper patch; as apposed to nearly the entire length with a twist at the bottom of the bullet.

I just thought I'd ask.

HollowPoint

[Goatwhiskers]

If I'm understanding you correctly, there is absolutely no reason that I know of to PP a GC'ed boolit. One of the reasons for PP is to eliminate need for a GC, actually I think it works better, just a little more labor and you can push 'em same as j-words. GW

[HollowPoint]

Maximum Velocity from full power loads would be my only reason for paper patching. That's if I could eventually work up such a load that would give me "MOA" repeatable accuracy at extended ranges. Otherwise a conventional cast bullet pushed to its maximum velocity and accuracy would have to do.

Another reason, as described by at least one other paper patching affection-ado I've heard of on this forum is to mitigate deformation at the tail end of a given cast bullet by the hot gasses that pelt the cast bullet at any time during its trip down and out of the barrel.

I'm still holding out for an answer to my original questions. I hope it's not something that requires ultra-slow-motion photography to find out. I may never get an answer.

HollowPoint

[Green Lizzard]

i think it gets shredded length wise by the rifling and peeled from the front explodes into confetti at the muzzle (just my guess)

[HollowPoint]

Hi Green Lizzard:

I've tried to picture in my mind the process that takes place as the paper patch peels away from front to back and back to front. With Boat-Tailed bullets, there's a phenomenon that occurs in which the hot gasses from the burning powder flow forward along the surface of the bullet and eventually accumulate out in front of the bullet causing the projectile to have to break through that wall of turbulance before it continues on to its destination.

There's a name for this phenomenon but I can't think of what it is right now. It's not as prevelant with flat base bullets as it is with Boat-Tails.

I mention it because if the paper patch peels off from the back to the front it would be ideal for the bullet design I had in mind. If the paper patch peels off or comes unravled from the front to the back, I'm not sure what effect it may have on the paper patch shearing off of the bullet.

Unless I can get the answers I was hoping for, it may be that this might be one of those "Try it and see" kind of things.

HollowPoint

[bigted]

so there is a video of such somewhere. it is very interesting ...being a slow motion action of the muzzle at the exit of the boolit and the patch getting the boot. cant remember whether it goes from front to rear or rear to front...I do know that my patch's resemble a confetti fair at the shot. I never get any pieces larger then the base or the bottom of the rifling in strips.

from the old school you depend on the rifling cutting the patch so that when it leaves the barrel it confetti's in fine shape.

as for where to stop the patch up front on the boolit...just over the o-give enough so the boolit and patch get a good start into the rifling without stripping the patch. there are many things to know and account for to make a go of patching smokeless powder...

first is to fill the throat with as large a boolit and patch so the cartridge will chamber without effort. to accomplish this the easy way is to measure the mouth of your fireformed case in your chamber...this measurement needs a patched boolit around .002 inch smaller then the case mouth...that is after slightly flairing the mouth of the case so you measure the real neck diameter not the former crimp.

as for the boat tail boolit I can see trouble in the offing with the gas cutting being the largest problem...flat bottom boolits can be protected with a wad or filler to keep the fire damage to nill but with a boat tail boolit I can see the boolit and mostly the patch getting fire cut very quickly.

anyhow try getting ahold of "montanacharlie" here as he will prolly be able to direct you to the video that will blow yer mind.

[HollowPoint]

I'll google "Paper Patch slow motion" to see if I can track down that video you mentioned.

I've already test fired the Boat-Tailed Gas Checks I've eluded to and had absolutely no leading issues. As for gas cutting, I'd have to be able to retrieve a fired bullet wearing these specialized gas checks in order to scrutinize it in detail.

Provided the fit of the paper patch and bullet are correct, I really don't think that "Gas-Cutting" would be an issue.

I have paper patched before with my 44 magnum but, I wasn't able to improve on the accuracy any more than with plain cast lead bullets so I abandoned my efforts. Now I want to test some paper patched bullets with my 30 caliber rifles to see if I can do any better.

Once I get a little more input I'll post a computer rendering of the Paper Patch bullet design I'm thinking of. I don't want to do it now because I don't want to take the chance of someone Krapping on my idea before it's even been tried.


I found the video! A picture truly is worth a thousand words. It appears that the paper patched bullet in the video was blown loose from the back and then as it continued its forward travel the paper begun to unravel from the front to the back.

That's great news for me. If this video is a good indication of the dynamics of how paper patches shear off of a cast bullet in flight, I think my idea may actually work the way I was hoping. It means that the "Indentation" (similar to a crimping-groove but deeper) I planned to mill in the part of my cast bullet just above where the first driving band will go will most likely not have any affect on successfully getting the patch to peel off of the bullet.

In theory, it may however allow me to tuck the front edge of my paper patch into the "Indent" so as not to damage or alter the patch upon chambering and allow me to patch in more of a straight side-to-side manner rather than diagonally.

It was that diagonal angle and the curve of the ogive that really used to give me fits.

http://www.svartkrutt.net/news/nh_vis.php?id=21

HollowPoint

[bigted]

kewl ! I hope you have the best of luck with the tapered base boolit and I am looking forward to your report on how it works and accuracy.

as for the patch design...I've never had a moments problem with the angled patch ends but I wrap wet and dry so the patch shrinks very tight.

the advantage for me in using patched boolits with smokeless powder is the speed I can push them at. as long as the patch is between the lead and the barrel steel then they can be pushed as fast or faster then the jacketed bullets and...as a matter of fact...I use the hornaday loading book for my loads and have no problems so far. mostly 45-70 but my pre 64 .375 H&H really runs good with both 250 and 300 grain patched boolits. the 375 run hot enough that I don't want a steady diet as my shoulder is fond of staying in the condition it came in from the factory.

I take a un-patched boolit and rotate it in the muzzle of my rifle and patch just ahead of this ring about 1/16th inch so it gets into the rifling before it gets tempted to shuck the patch...doesn't take but only 1 or 2 of these and the following lead smears up the barrel and sub sequential lead mining job to remove it to ensure that the lead and steel are separated from each other via the paper.

again good luck with your project and I look forward to reading about your success thusly....:drinks:

[303Guy]

I've done a bit of test tube firing and have found that some patches will confetti while others will cut into long strips and others will come off in postage stamp sized pieces.

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The last photo shows what happens when the patch goes too far over the ogive. Not sure it's a problem though.

[HollowPoint]

I've done a bit of test tube firing and have found that some patches will confetti while others will cut into long strips and others will come off in postage stamp sized pieces.

6977269773

The last photo shows what happens when the patch goes too far over the ogive. Not sure it's a problem though.


303Guy: Is there a correlation in the kind of accuracy you've gotten and the way the patch is peeled off of the bullet?

It would appear that as long as the patch comes off, it's a good thing; for me anyway.

I have done a bit of research on paper patch bullets; including the stickies and write-up here on this forum. I can see the logic in the way folks here do their paper patching the way they do but, it just seems to me that there will always be other ways of do things. Wether those "Other Ways" are any better or not generally can't be known unless we try them.

The design I have in mind may just crash and burn. I was just hoping to minimize the patching time and maximize the shooting time and bring my paper patching efforts into the 21st century in the process. (if possible)

For those of you who viewed the video in the link I provided, did you notice the plume of hot gas that flows forward over the surface of the bullet from back-to-front? On a Boat-Tail Bullet that "Plume" of air is much more pronounced, so I'm thinking that if that forward moving "Plume" of high-pressure hot-gas alone doesn't remove the patch, it will dislodge the patch to such a degree that milling an Indention (similar to a crimping groove but not really) in my bullet Cherry in order to tuck the front edge of my patch into it will not keep the patch from peeling off as it should. This is really the assumption I was hoping to confirm. It appears that this video has done just that.

Once I've drawn up my computer rendering of the bullet design I had in mind, I'll post it for all to see. In the mean time I'm still working on a similar bullet project that involves no paper patching.

HollowPoint

[CJR]

HollowPoint,

Glad to see you're interested in hi-vel PPCB. I've been working only with hi-vel PPCB for awhile now and enjoying every minute of it. My best subMOA accuracy @ a chron'd 3000+ fps is with a LBT 150 LFN sized to 0.301-0.3015"D, PP to slightly over ogive and sized to 0.308" and charged with 50gr. W748. Because of the velocity, I can never find any strips of paper on the ground. And I've been on my knees looking real hard and getting all kinds of weird looks at the range. Funny what PP shooters will do. When I touch off the round, I get a small fog-like cloud for a second or so.

Recently, I achieved sub MOA for three rounds of my new 180 gr. PPCB design (slightly modified NRA PP design), at about 2600-2700 fps (not chrono'd yet). Load was 46.5 gr of W748 with PP back about 1/4" from ogive but PP in contact with the chamber's forcing cone. Life is good! Any way, first two (2) 180 gr. PPCB at 100 yds were touching, almost same hole, with the 3rd round about 0.5-0.75" away. I'm delighted with this 180 gr. PPCB design so far. No Sierra Match bullet has ever done that in my factory rifle in 308 Win. I've got a bunch of more lube tests planned to maintain my subMOA group sizes for at least five rounds.

Finally, I've found that when my PPCB are spinning at close to 200,00o rpm (3000+ fps), the centrifugal force is significant to remove the PP cleanly. The best advice I can offer is from the Roman saying; "He who perseveres is victorious!" Hang in there, it will all come together and you'll be laying them all in a tight group at 100 yds or longer range. In time, your rifle will tell you what it likes.

Best regards,

CJR

[HollowPoint]

Greetings CJR:

I'd love to be able to get MOA or better from my rifles. If I'd been able to do that the first time around I'd still be paper patching.

Since taking up bullet casting I've dreamed of coming up with a lighter weight 30 caliber bullet I could use for coyote hunting out to three or four hundred yards reliably. I can get tight groups out to two-hundred yards but consistent accuracy at longer ranges has eluded me.

If I can't get the paper patching to work for me at velocities above 2000 fps, I'll just stick with Gas-Checked alloyed cast lead bullets. I know that getting good accuracy with paper patches is doable. I think my problem is more that lack of patience rather than the lack of following the common-sense protocols of paper patching.

I'm waiting on a new lathe to be delivered. I can't really do anything other than prep some mold blocks until it shows up. It'll give me time to think things over before I dive into another project.

HollowPoint

[303Guy]

I haven't range tested those. I've been looking at symmetrical boolit entry into the bore and boolit to throat fit. I'll shorten the patch to eliminate that joiner.

[CJR]

Hollowpoint,

A member of the NRA, in the 70s,competed up to 1000 yds with PPCB. The accuracy of the NRA PPCB design equalled or BETTERED jacketed match ammo at that time. So hi-vel long range accurate PPCB is VERY doable. In my view, keep in mind that the bullet design (i.e. like the NRA designs) must first be an accurate design, i.e. long bearing length to minimize in-bore yaw with a reasonable short nose, proper longitudinal location of CG to CP, etc.. Likewise, CB quality must be the highest possible; i.e. either from a 1-cavity standard perfectly round mould or from multiple cavities that have been PRECISION cut so ALL cavities are ROUND. Any shift in lateral center-of-gravity (CG), either caused by a tilted/yawed CB or an oval CB cast in a sloppy-cut cavity heavily sized , affects accuracy. Bottom line is that the CB must be as accurate as we can produce if top target accuracy is desired. That's why precision made jacketed bullets perform so well. When PP, we cannot ignore the laws of Physics and expect to achieve top accuracy. After we have the most precise CB that can be cast, we then need to assure that bullet concentricity/runout, of a loaded round, is minimal just like the BR people do.

Finally, what I've described above is not labor-intensive. Using accurate PPCB moulds gives a large quantity of high quality CB with a low rejection rate. Weight sorting improves their quality even more. CB sizing/PP/final sizing and load assembly is then very fast. Once you get set-up, you can crank out a LOT of accurate PPCB at a VERY LOW COST compared to $$$$$ jacketed match bullets. My PPCB accuracy is better than any other Sierra Match load ever fired in my rifle and I've fired a bunch of the Sierras. So hang in there! It's really worth the effort. Once it all comes together, you won't believe your first tight group @ 100yds.

Best regards,

CJR

[HollowPoint]

I'm thinking along the lines of a "Bore-Rider" design with just enough nose to keep the bullet centered in the bore on it's way out of the barrel.

Here's another question I've been looking for an answer to with regard to my Paper-Patching bullet design; or any other cast bullet "Bore-Rider" design for that matter:

When a Cast Bullet obtrudes from the pressures of the burning gun powder, does that obturation of the lead affect the nose of the bullet as much -or at all- compared to the amount that occurs at the body or driving band area of a given cast bullet?

My reason for asking is that if the nose of a "Bore-Rider" designed bullet also expands into the lands and grooves upon being fired, then I'll have to compensate for that by deliberately decreasing the diameter of the "Bore-Riding" section by the amount that the nose is expected to obturate.

I've been looking at as many of the various dedicated Paper-Patch bullet designs I can find on the internet. I really haven't found any that were described as "Dedicated" Paper-Patched bullet designs for 30 caliber rifles; mostly for the big-bore smoke-poll rifles with hollow bases.

It will be interesting to see if this pans out for me. Until I get all my ducks in a row, right now I'm just doing a little informal research and day-dreaming.

Thanks very much for your input. I hope I can come up with an accurate Paper-Patch load for my rifles in the near future; that isn't to awfully labor intensive.

HollowPoint

[303Guy]

I'd suggest that the bore-ride nose section needs to expand into the rifling to compress the paper so that it does guide the boolit, otherwise the boolit will likely slump to one side somewhere near the start of the bore-ride section. I did a test to demonstrate matching alloy strength to pressure using shotgun powder (so as to keep muzzle velocity low enough to capture the boolit) and found that the bore-ride section does indeed expand into the rifling without slumping the nose at the right pressure.

[CJR]

HollowPoint,

The NRA designs are PPCB designs and are full-length bore-riders with a short nose and have a gas-check shank. The NRA found later that gas-checks were not needed at 3000+ fps. For my latest 180 gr PPCB, I have been water-quenching the WW PPCB bullets to get the highest hardness for my initial testing to essentially eliminate any accuracy problems due to soft CB. My 150 gr LBT LFN CB (NOT a PP design) achieved 3000+ fps and had a hardness of 13BHN as measured with a LBT hardness tester. The laws of Physics tell us that when 50,000 psi pressure is applied to the base of the CB, the obturation starts at the base of the CB and moves forward. If the CB is too soft and accelerated too fast, the nose will set back unpredictably and most likely move off to one side because of the 200,000 RPM spin. So a reasonably hard CB and a slow starting acceleration with a Progressive powder (i.e. W748,W760, W780 etc.) minimizes nose slumping while still giving us hi-vel. If the nose slumps, accuracy is non-existent. Though I've never been able to recover any of my hi-vel PPCB, the NRA did recover their harder linotype PPCB and my understanding is that they observed light engraving on the body without nose set back. So apparently 13-16BHN or greater hardness is required for hi-vel PPCB.

If you are looking for PPCB designs that work, CastPics on this site, has a copy of the NRA Cast Bullet Manual which shows the proven NRA PPCB designs, i.e. 160gr & 196 gr. Likewise, I am working to get a Group Buy started for a Mihtec mould with the 160 gr. NRA PPCB. Miha is cutting some prototype moulds now.

Best regards,

CJR

[HollowPoint]

I've heard alot about the subject of "Nose Slump" since I took up bullet casting but, I've never met anyone who's definitively experienced it themselves. That's not to say that "Nose Slump" isn't a real factor when trying to attain high velocity.

I have read of some folks blaming "Nose Slump" for their inability to achieve the accuracy or velocity they were seeking but without being able to actually see the fired bullet after it was shot I'm thinking these folks were just looking for something to blame.

I mention all of this because it was my hope to be able to utilize my Softpointing-Tool to cast bullets with a soft pointed nose and a much harder belly. At the paper patched higher velocities, even with a BHN at the Water-Quenched Clip-On Wheel-Weight levels around 14-16 the expansion on the target should be more than adequate for a humane kill on a game animal.

If I cast my bullets with the softer Stick-On Wheel-Weights at the nose (BHN 9-10) and an alloy of about 20-27 for the remainder of the bullet, I think this would make for a superb hunting bullet; provided that "Nose Slump" doesn't factor in. With the nose of my cast bullet shaped to mitigate the chance of "Nose Slump," I don't think it will be a factor, even with a real soft nose.

Time will tell. Time and testing.

HollowPoint

[303Guy]

Capturing a boolit to examine for nose slump can be a bit tricky. After all, the boolit strikes nose first obliterating the evidence. But it can be done. One way is to use a fast powder so as to slump the nose without a high muzzle velocity so the boolit can be captured almost intact.

70022700237002570024

The first photo shows two identical boolits (paper patched) fired with different powder charges. The bottom boolit has obturated almost to the nose while the top one has no obturation at all (it started out that shape). The bottom boolit has even had the knurling ironed out. The second photo shows a half patched boolit (third photo) with a bore-riding nose section. The nose itself is too damaged to tell whether there was any nose slump or not. The last photo shows a boolit with nose slump. The give away is step in front of where the patch was. The nose was smaller than bore diameter yet has expanded to fill the grooves. The whole nose has expanded on impact so 9it is only the bore contact marks that indicates nose slump.

The first two boolits are from a test to demonstrate matching alloy strength with pressure. The noses were bore-ride as patched so the cores were under bore diameter. The half patch boolit was from a fire-polishing exercise in which the nose of the boolit was smeared with Autosol Metal Polish. The last boolit shows what looks like a long sideways seven - that's bore contact.

If I remember correctly, the first test for matching alloy strength was done with a slower powder. The alloy was quite tough, hence the lack of nose damage. The boolits were captured in ground rubber.

70026

Expansion with different alloys, some being quite tough. The softer alloys were at reasonable speeds so one doesn't actually need too soft a nose but a very hard body might well break or simply loose its soft nose. I'd suggest a tough but not hard body with a softer but tough nose.

[HollowPoint]

This is my initial computer rendering of the type of Paper Patch cast bullet I had in mind.

When I finally get around to actually turning the Cherry for this bullet mold I think I'm going to make the nose just a little more pointed; not quite as blunt as the rendering depicts.

It will be hollow pointed to accommodate the Synthetic-Tip and Boat-Tailed to accept the new specialty Gas-Checks.

The pic below shows what I was trying to describe in my previous post. The "Crimp-Groove/Indentation" is where the front edge of the Paper Patch will be tucked so as to mitigate the chance of the paper being scraped back upon chambering.

The bottom edge of the patch will end just above the Gas-Check.

I've shaped my "Lube-Grooves" this way in hopes of better grasping the inside face of my Paper Patch as the bullet makes its way down the barrel. Since I designed the bullet to wear a shorter patch than conventional Paper Patched bullets, with the Boat-Tailed Gas-Check bringing up the rear end, I'm fairly certain that the patch will remain in place until it exits the barrel.

My measurements were based on my K31. The overall length of the bullet is 1.125". If I measured correctly, the bullet should sit with the top edge of the Gas-Check right at the base of the neck.

This means that the very bottom of the check will be .25" below the base of the neck, the driving band section will be surrounded by the case neck with just .125" of paper visible above the mouth of the brass. The remaining "Bore-Riding" section will sit centered in the short throat of the chamber; I HOPE.

If it works, that will be great. If it doesn't, Oh-Well; at least I gave it a shot.

Right now it's only in the dream-stage. I haven't even made it yet.

I'll be back when I have.

HollowPoint

[303Guy]

Looks good. If I might say - initial failure does not mean the concept is flawed, only that something needs refinement. Remember the early days of rocket launch? Please do proceed with your plan. It looks promising to me and the idea of long range paper shooting appeals to me and that boolit looks just the ticket. I'm thinking the better the BC the lower the muzzle velocity needs to be which makes it all easier to achieve accuracy.

One suggestion; why not square the grooves on both ends. The patch can slip in either direction like as in boolit seating.

Just a thought; do the grooves need to be deep? Perhaps just paper thickness deep?

[HollowPoint]

Your questions about the lube-grooves are the same questions I asked myself as I was drawing up this rendering.

Initially I thought of just cutting the Cherry with a rough serrated edge in the area where the lube-grooves go. That should have been sufficient to hold the patch in place. In the end I just drew it up this way.

Since it's just a conceptual drawing, it's easy enough to tweak at any time during the drawing to the cutting-the-Cherry phase.

This is just an idea I've had in the back of my mind.

I guess I'll see if it will work once I get my lathe set up.

HollowPoint

[pdawg_shooter]

Only possible problem I see is the diameter of the nose section. Undersized as it is you stand a very good chance of the nose slumping or distorting under acceleration, with full power loads. I would much prefer a .302 nose section and a patch just past the start of the ogive. Always shoot better for me that way. Guess that is why I prefer the Loverin design for patching. As to the question about how the paper comes off, I dont really care, just so long as is comes off at the muzzle. Front to back or back to front makes me no difference. Guess I am just not anal enough LOL

[HollowPoint]

The bore of my K31 measures .300" exactly. If I can expect the Bore-Riding nose to exhibit even a slight amount of
obturation at the higher velocities these bullets will be fired, in my mind this means that at a diameter of .302"
I would really have to pound the bolt into battery just to get my cartridge to chamber; and when you factor in any obturation
that may occur, it kind of defeats the purpose of the bore-riding nose. Presently, the nose is a diameter of .298".

I'm using some thinner tracing paper for my patch medium. The body of my bullet measures .302" so that with
two wraps it will bring me up to .312". I can then size it to a diameter of .309".

Incidently; I mentioned this before at some point. The image I provided is just a computer rendering of what I had in mind. The final design can still be tweaked in any number of ways before it ever gets to the machining stage. I think I will take 303Guy's suggestion and square-up and shallow the lube-grooves. I'll also be making the nose slightly more pointed. For the time being, and given that this is just a test-flight (so to speak) that's about all the tweaking I'll be doing.

My concern with how the paper got peeled off of the bullet was due to the design I plan to try. Since the front edge of my patch
will be tucked into the top-most groove, I was afraid that if the paper patch was removed by the frontal wind-resistance it encountered when it exited the barrel, tucking the front edge of the paper might cause the air to flow over the top of the patch rather than catching the front edge of the paper to peel it away.

After viewing the slow motion video of how a paper patch is shed, that concern have been alleviated.

I'm still a long way from actually fabricating this bullet. My new lathe is scheduled for delivery today.
With any luck, I'll be able to start on it early next month. I want to finish my present Boat-Tail Gas-Check project first.
I've had to put it on hold while I waited for this new machine to arrive.

HollowPoint

[pdawg_shooter]

Every time I try to get a nose rider to shoot I had flyers, until I lapped the nose section out to the same diameter as I sized the body of the bullet to. Seems that if the nose in not supported it sagged or distorted under acceleration. When lapped out and parch to just past the start of ogive the flyers went away. I also use a powder slow enough to give 100% or a bit more load density, at the velocity I want. If you limit the pressure and velocity of your load it might be OK. But then why patch. Just gas check, lube and load.

[303Guy]

I tried a half patch once which an un-patched bore-ride front section. The 'lube' was polishing compound. Anyway, the bore-ride section had fully engaged the rifling, meaning it bumped up, right up to the ogive. It looked even so I figure the fact that is was bore-riding held it straight. I have only once field tested paper patched bore-rides and had one wild flyer out of an otherwise poor group. I don't know whether the poor group was due to nose slump or base distortion (or both). The boolits were a good fit in the throat but that meant part of the bore-ride core was under bore diameter. One day I'll repeat the test with stronger boolits and see what happens. This is the same rifle that gives me paper rings.

I too am planing on a new boolit mold and am leaning to the Louverin design but the problem I seem to have is throat shape and size. But at least two of my rifles like fat paper patched boolits.

[Digital Dan]

Little bit mystified as to why anyone would want grooves on a dedicated PP bullet. Patch theory is pretty simple. The patch is the predecessor of the copper jacket. Running the velocity up is dealt with by alloy. Latitude in form presents as a function of peak pressure. Success is much dependent upon dims as much as anything else.

[HollowPoint]

Assuming that we're patching and loading our bullets as uniformly and concentrically as possible, I'm having a hard time imagining how the nose on a Bore-Rider-Style of cast bullet can "Slump" at the nose if it's supported on all sides by the bore of the barrel. I have no doubt that such a thing can happen under certain circumstances. I just think that there may very well be other factors involved that would cause a Bore-Riding bullet design to "Slump" at the nose. (or any other style of bullet for that matter)

If it "Bumps-Up" upon acceleration, in my mind's eye I see it being further supported. If it's surrounded on all sides, there seems to be no where for the bullet to slump to; unless the "Slump" occurs immediately upon exiting the muzzle. If this is the case, then it has more to do with the tail end of our bullets than the nose.

I'm not discounting what you more experienced Patchers have experienced. I'm wondering if the uniformity at the tail ends of our bullets are affected by the patches themselves and maybe causing the flyers or the lack-luster groups. I'm wondering if in some cases, this kind of poor accuracy is blamed on "Nose-Slump" because there's no real way to tell.

I don't have any answers. Right now I just have a little time to wonder out loud about these things. I've seen the pictures of recovered bullets with what has been interpreted as possible "Nose-Slump" but, was the distortion induced by the impact of the bullet on the target factored in before we reached the conclusion that it was "Nose-Slump?"

You guys that have been at this for a long while and have now gotten to the point where you can put together accurate rounds, I'm thinking that a good percentage of your success may be due to the experienced you gained at wrapping your bullets uniformly rather than the bullet style itself. Here too, I have no real insight. I can just picture your adept fingers who's muscle memory has been refined to the point where that paper goes on the exact same way nearly every time you patch a bullet. The odd flyers you get now days is due to those few bullets that weren't wrapped exactly like the others.

I'll guess I'll just have to make alot of the mistakes that your experience is trying to keep me from making in order for it to really sink in. Wish me luck.

HollowPoint

[pdawg_shooter]

Little bit mystified as to why anyone would want grooves on a dedicated PP bullet. Patch theory is pretty simple. The patch is the predecessor of the copper jacket. Running the velocity up is dealt with by alloy. Latitude in form presents as a function of peak pressure. Success is much dependent upon dims as much as anything else.

The grooves give the paper something to grip and hold a bit more lube.

[pdawg_shooter]

Assuming that we're patching and loading our bullets as uniformly and concentrically as possible, I'm having a hard time imagining how the nose on a Bore-Rider-Style of cast bullet can "Slump" at the nose if it's supported on all sides by the bore of the barrel. I have no doubt that such a thing can happen under certain circumstances. I just think that there may very well be other factors involved that would cause a Bore-Riding bullet design to "Slump" at the nose. (or any other style of bullet for that matter)

If it "Bumps-Up" upon acceleration, in my mind's eye I see it being further supported. If it's surrounded on all sides, there seems to be no where for the bullet to slump to; unless the "Slump" occurs immediately upon exiting the muzzle. If this is the case, then it has more to do with the tail end of our bullets than the nose.

I'm not discounting what you more experienced Patchers have experienced. I'm wondering if the uniformity at the tail ends of our bullets are affected by the patches themselves and maybe causing the flyers or the lack-luster groups. I'm wondering if in some cases, this kind of poor accuracy is blamed on "Nose-Slump" because there's no real way to tell.

I don't have any answers. Right now I just have a little time to wonder out loud about these things. I've seen the pictures of recovered bullets with what has been interpreted as possible "Nose-Slump" but, was the distortion induced by the impact of the bullet on the target factored in before we reached the conclusion that it was "Nose-Slump?"

You guys that have been at this for a long while and have now gotten to the point where you can put together accurate rounds, I'm thinking that a good percentage of your success may be due to the experienced you gained at wrapping your bullets uniformly rather than the bullet style itself. Here too, I have no real insight. I can just picture your adept fingers who's muscle memory has been refined to the point where that paper goes on the exact same way nearly every time you patch a bullet. The odd flyers you get now days is due to those few bullets that weren't wrapped exactly like the others.

I'll guess I'll just have to make alot of the mistakes that your experience is trying to keep me from making in order for it to really sink in. Wish me luck.

HollowPoint

If you are loading to "normal" cast pressures and velocity the nose rider will work fine. If you are pushing the envelope. full length bullet support works best. A naked nose can and will distort in weird ways causing fliers. I load a 311284, with a short nose riding section, to just over 3000fps. Untill I lapped the nose out to .302 I had fliers in every group. After lapping...MOA for 5 shot groups consistently.

[Digital Dan]

A .50 caliber 800 grain swagged two piece bore rider. Nose is the harder alloy of .500 diameter, the base is pure lead of ~.505 diameter. It fired over a charge of 180 grains of Swiss 1.5FG and uses a chase patch and the gun so loaded is stunningly accurate. The nose does NOT obturate.

http://img.photobucket.com/albums/v298/muddler/Guns/Black%20Powder/DSCN3458.jpg (http://smg.photobucket.com/user/muddler/media/Guns/Black%20Powder/DSCN3458.jpg.html)

HP, I'd not fret a lot about the minutia of slumping etc. If you're going to make a mould, put it together with a conventional style and concentrate on the basics. Yes, imperfections of patch can affect accuracy, especially around the bullet base. If you are of a mind to drive a bullet hard don't use a cup base bullet as high pressure will deform the skirt upon muzzle exit. A flat base bullet with a short skirt folded under the bullet base in conjunction with a card wad of .015-.020" thickness will work well. Twisted tails cut after they dry will generate flyers with high pressure loads. Above all, make your dims right. For smokeless, groove diameter +.001" works. Make this happen via patch thickness and slug diameter, not sizing. Do NOT roll crimp. Taper crimp is good for repeaters, otherwise, no crimp at all.

[303Guy]

The nose slumped boolit I posted has impact damage. What identifies the nose slump are bore marks on the slumped nose and the the patch impressions behind the slump. That boolit had a patched nose which was a loose fit in the bore for a millimetre or two and the core was smaller than the bore.

70739
70738

[HollowPoint]

"If you are loading to "normal" cast pressures and velocity the nose rider will work fine. If you are pushing the envelope. full length bullet support works best. A naked nose can and will distort in weird ways causing fliers. I load a 311284, with a short nose riding section, to just over 3000fps. Untill I lapped the nose out to .302 I had fliers in every group. After lapping...MOA for 5 shot groups consistently."


pdawg:

Could it be that lapping out your mold to .302" and wrapping you bullets a little farther up the nose allowed the paper patch to be peeled away from the bullet alot more consistently and uniformly when fired rather than it having any thing to do with "Nose-Slump?"

I can picture a bullet exiting the muzzle and having the patch peel away at different rates as the bullet flies toward the target. Might these different rates at which the bullet sheds the Paper-Patch be the real culprit here?

If even a jacketed bullet can be affected by imperfections of their bases, how much more will a cast lead bullet with a piece of paper clinging to it for even a fraction of a milli-second to long on one side of the bullet while the paper on the other side of the bullet is in the process of peeling away. All things being equal, might not this rather than "Nose-Slump" be the cause of many a Paper-Patchers frustrations?

HollowPoint

[Digital Dan]

You might want to consider that a patch "peeling away" indicates a fundamental flaw in bullet/patch dimensions or patch technique. I've never seen an accurate patched bullet/gun combination which presents anything other than confetti like patch material upon firing, and I have seen a lot of accurate patched bullet guns work. This includes wrapped, chase and cross strip patches.

[HollowPoint]

I couldn't say one way or the other. I have very little experience with extended experimentation with paper patching. In my replies, I'm just wondering out loud.

The more experienced old hands at paper patching have to be doing something right in order to achieve the velocity and accuracy that they've eluded to. My sticking point is that "Nose-Slumping" may be being blamed where it's not to blame.

The best I can do right now is to try to envision the process in my mind; and I can't get it to make any sense. Although the results that the more experienced folks have gotten would tend to indicate that they may very well be right, what I'm envisioning puts the blame for flyers and large groups on the same factors we blame when loading jacketed or just about any good cast bullet that doesn't shoot the way we'd like.

Those factors include bullets loaded non-concentrically, paper patch wrapped non-concentrically, the patch peeling away non-concentrically, flaws in the bullets themselves, powder charge inconsistencies or any number of factors either by themselves or in combination with others that contribute to less than good performance.

I recall reading from a good source that, "To much knowledge wearies the soul." Even to the point that it makes this hobby no longer any fun. In the end I'm still going to try. If it works, that will be great. If it doesn't, so what. For me, the ultimate goal is to send a few rounds down range as accurately as possible. If this doesn't work, I know of a few other bullets that will.

HollowPoint

[303Guy]

HollowPoint, I think you are quite right, nose slump is only one problem we might encounter. If that patch isn't coming off at the muzzle we are unlikely to get good accuracy I should think. My point about nose slump is that as long as I am getting nose slump I won'y be getting any groups, let alone worrying about flyers. It's just that I discovered the nose slumping and reported it.

When I developed a load for my carbine I used my 'test tube' to check for patch fragmentation and one I had found the point it was occurring I loaded up and headed to the range and had a good day. What I look for in the test tube is patch fragments or strips spread around the impact point. Patch fragments that are too large or that get stripped off the boolit in the catch medium ring alarm bells. The latter means the patch is still on the boolit. I also look for lack of mid-section obturation and uneven rifling impressions and boolit base damage like feathering or dragging and out of square.

[pdawg_shooter]

If your bullet is sized .302 the rifling will slice the patch and all you will have is confetti. BTW the 311289s were patched to the start of the ogive before I lapped the mold. IMHO, the paper could not support the .297 nose enough to prevent distortion.

[HollowPoint]

"When I developed a load for my carbine I used my 'test tube' to check for patch fragmentation and one I had found the point it was occurring I loaded up and headed to the range and had a good day. What I look for in the test tube is patch fragments or strips spread around the impact point. Patch fragments that are too large or that get stripped off the boolit in the catch medium ring alarm bells. The latter means the patch is still on the boolit. I also look for lack of mid-section obturation and uneven rifling impressions and boolit base damage like feathering or dragging and out of square."

Now, this sounds logical to me. I can picture this kind of thing happening. That's doesn't negate the fact that others are having better results by doing it their preferred way.




"If your bullet is sized .302 the rifling will slice the patch and all you will have is confetti. BTW the 311289s were patched to the start of the ogive before I lapped the mold. IMHO, the paper could not support the .297 nose enough to prevent distortion."

I hope I'm not coming off sounding like I'm deliberately trying to be the antagonist with my presumptions or questions but, if the nose of a patched-paper-patched bullet with the dimensions listed above were to "Distort," and it's surrounded by the barrel on all sides, after it has bumped-up, the only direction it could "Distort" to would be length-wise toward the muzzle end of the barrel. The rear end of the bullet is being pushed forward by the pressure of the burning powder so it's not likely to "Distort" to the rear.

Does my description make any sense? This is just how I'm picturing it in my mind. If it does make sense then, it may not be the "Distortion" or "Nose-Slump" that's causing us problems. These are most likely just the side-effects of what's really causing the problems; and that's not necessarily lack of support at the nose of our bullets.

pdawg: is there any chance of seeing any of your fired bullets showing the type of "Distortion" you're referring to? It may be that I'm misinterpreting what you mean by "Distortion."

HollowPoint

[pdawg_shooter]

"When I developed a load for my carbine I used my 'test tube' to check for patch fragmentation and one I had found the point it was occurring I loaded up and headed to the range and had a good day. What I look for in the test tube is patch fragments or strips spread around the impact point. Patch fragments that are too large or that get stripped off the boolit in the catch medium ring alarm bells. The latter means the patch is still on the boolit. I also look for lack of mid-section obturation and uneven rifling impressions and boolit base damage like feathering or dragging and out of square."

Now, this sounds logical to me. I can picture this kind of thing happening. That's doesn't negate the fact that others are having better results by doing it their preferred way.




"If your bullet is sized .302 the rifling will slice the patch and all you will have is confetti. BTW the 311289s were patched to the start of the ogive before I lapped the mold. IMHO, the paper could not support the .297 nose enough to prevent distortion."

I hope I'm not coming off sounding like I'm deliberately trying to be the antagonist with my presumptions or questions but, if the nose of a patched-paper-patched bullet with the dimensions listed above were to "Distort," and it's surrounded by the barrel on all sides, after it has bumped-up, the only direction it could "Distort" to would be length-wise toward the muzzle end of the barrel. The rear end of the bullet is being pushed forward by the pressure of the burning powder so it's not likely to "Distort" to the rear.

Does my description make any sense? This is just how I'm picturing it in my mind. If it does make sense then, it may not be the "Distortion" or "Nose-Slump" that's causing us problems. These are most likely just the side-effects of what's really causing the problems; and that's not necessarily lack of support at the nose of our bullets.

pdawg: is there any chance of seeing any of your fired bullets showing the type of "Distortion" you're referring to? It may be that I'm misinterpreting what you mean by "Distortion."

HollowPoint

Thinking that the bullets always distort uniformly will get you in trouble. The rotation starts as soon as the powder burns. The acceleration keeps building up. The bullet can and does "sag" to one side more than the other if it is not supported. But I encourage you to try it your way. At least you will have a good idea of what is causing your fliers.