This is a pretty broad topic but I assume that most people, including myself have biases we bring into the initial bullet seating depth on all “new” or “new to us” rifle/barrel. What’s your starting point before you start to go further in or further out and how is it impacted by bullet design?
I guess this is more directed to long guns and shooters looking for small groups but any opinion is valuable. Thanks, Bill.
A “Measured Response” is as effective as tongue lashing a stuck door.
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Using conventional cast bullets and lube, I start with the top driving band touching the lead/origin of the rifling. The only time it is not used is with a bullet with a bore riding nose. Then I start with the nose definately engraved checked with black marker.
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That is the definition of a manual art. science is "knowledge about the natural world that is based on facts learned through experiments and observation." It has to be 100% repeatable by anyone doing the same experiments without regard to place or time. Cast bullet shooting isn't there yet. IMHO, Ric
Ric, you're right. I wish I would have said it that way. I have a problem of getting my fur up when I hear anything that makes it sound like hand loading, casting, bench discipline and such as something mysterious or magical.
John made the case that the foundation for cast bullet accuracy today is in large part based a blend of fact, assumptions, traditional means, harmless conventional wisdom and suppositions. A lot of us do what we do because it gives us confidence. The downside is that some of it is pointless and its distracting us from what might be important.
A lot of bubbles would be popped if we could combine our efforts and put it in hardcover. Until then the contributions we make to the FS are that much more important. And if you are new and looking to learn keep asking questions. No chance you'll ever find someone who at one point in time didn't know the answer themselves but have since learned it.
To the original question raised in the OP about jump, jam or in between for seating depth; I start within thousands of sticking and work backward a few thousand at a time until the bullet base gets to the bottom of the neck or until accuracy fade. Happy new year to everyone. Bill.
A “Measured Response” is as effective as tongue lashing a stuck door.
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I have never had that issue, as the Savage FP rifle I have has a free bore of .310" I size to the next larger 1/2 thousandth larger. I use SAECO dies that come in 1/2 thousandths.
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Cast bullet shooting is an art, not a science. Your cast bullet will become a wad of bubble gum upon ignition.
Actually, the bubblegum phase happens much farther up the bore, likely an inch or more depending on the load. Once the bullet moves and encounters enough resistance from engraving to increase the powder gas pressure beyond the ultimate strength of the alloy, the bullet base can begin to rivet and/or bend in the throat.
The less "jump" or "run at the throat" that the bullet has, the higher the initial pressure and more steep the pressure curve. An analogy is an air or refrigerant compressor starting against a full load versus against no load due to a check valve and relief valve. More inertia from the bullet accelerating prior to taking the rifling form and less engraving resistance reduces bullet distortion, which is why relatively soft powder coated bullets with a tapered, self-aligning nose shape sized smaller than throat entrance diameter can be fired with full charges of rifle powder at maximum loads with decent accuracy and no riveting of the bullet base. Pressure may reach 55K psi but the bullet is 3" down the bore and running away from the gas at many hundreds of feet per second squared before that pressure level is achieved, so the bullet is fully-contained in the bore and has nowhere to go but straight ahead.
The same principles of jump, self-alignment, sizing, and ductile alloy can be applied to ordinary, lubricated cast bullets, but it is trickier and has lower limits than the powder coat allows. Still, if the bullet is raking off a bunch of metal on the abrupt throat entrance angle because it is too big, or is cast of a very hard alloy and jammed hard against the ball seat, the base will rivet and then draw down through the funnel of the throat, often not in any semblance of concentricity, balance, or squareness.
I say all that to recommend never sizing larger than throat entrance diameter, never jamming a cast bullet hard into the ball seat, never use hard, brittle alloys, and avoiding perfectly-matching bullet/throat angles which bring a sudden increase to engraving resistance and spike the powder pressure against the bullet's base. I know this is contrary to everything ever done in cast benchrest shooting, but it works very well in conventional, production rifles.
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Not everything (common knowledge or otherwise) one sees , reads and hears will get you what you want. Let the target decide.
Agreed that you need a number of groups shot consecutively under real or simulated match conditions to see the effects of COAL changes. My initial post was to see if there were any prejudices that you bring to the loading bench on the first attempt at developing an accurate load.
Cast bullet shooting is an art, not a science. Your cast bullet will become a wad of bubble gum upon ignition.
Maybe sometimes we mix the definitions of learned skills and art. To a newbie, laying bricks may look like an art, but for most, not all maybe, but for most people if they put in the time and effort they can become average or maybe even good at laying bricks. Some may think that casting quality competition bullets is an art. But maybe we aren't giving enough credit to the individual that worked in the field long enough that skills were gained (trained or self taught) that enabled them to exceed. Just look at the results of the Nationals this year the the number of sub 1" group aggregates that were shot. Look at all the .5's that were shot in the unlimited class.
When it comes to the performance of a mechanical object (mold, chamber, leade) science may have its part to play. Larry is the only person I know that has can measure chamber pressure. If jumping to jamming shows no significant effect on pressure some would have to give credit to that. Maybe n my old age I'm getting more cynical about the use of the word "art" as if there are some things that only some can achieve. If I think the numbers are gathered correctly I take that as a solid foot hold that I can build on. And absolutely no offense to Geargnasher. I've been reading you post for years and you have helped me an others more than you could possibly understand.
My motive is cast accuracy. I believe it was Ken (if I am wrong and it wasn't Ken I apologize) who said that accuracy is defined in the first inch of travel. If I remember correctly, and I'm paraphrasing, if the necks are turned, the case is neck sized the anchor points of the tension of the bullet in the case and the tension of the grip in the leade/lands will at least start the bullet in the right direction.
My personal opinion is whether you call it art or learned behavior that's were the proper bullet seating depth comes into play. I was just wondering if there was a tendency to self seat the bullet or were you just short of sticking in the lands. Sorry for being lengthy. And I apologize if I offended anyone. That was not my intentions. Thanks, Bill.
A “Measured Response” is as effective as tongue lashing a stuck door.
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Bill,
"Some may think that casting quality competition bullets is an art. But maybe we aren't giving enough credit to the individual that worked in the field long enough that skills were gained (trained or self taught) that enabled them to exceed."
That is the definition of a manual art.
Science is "knowledge about the natural world that is based on facts learned through experiments and observation." It has to be 100% repeatable by anyone doing the same experiments without regard to place or time. Cast bullet shooting isn't there yet.
IMHO, Ric
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Question for the peanut gallery…the CBA has X members. What % are active match shooters? And what % are handgun shooters whose main interest is the alloy and casting speed and read the Fouling Shot, hoping there are more articles focused on those interests?
My main interests are single-shot rifles and double-action .45 Colt pistols. I shoot pistol to refine my eye-hand coordination. The Fouling Shot articles on .45 Colt and .44 Special are of constant interest to me.
I know the question about match shooters comes into view every so often. I read all the match reports to see if there are alternate powders to use in these days of shortages. And the articles on handgun shooting, especially hunting with handguns, are eagerly read.
I shoot the Elmer Keith Memorial Match near Spokane, WA whenever I can. The last few years have been cancelled due to COVID19. Targets are swinging steel, set at 140 yards, 200 yards, 250 yards and 600 yards. This is limited to iron sights and a maximum of a 10 1/2 inch barrel. It is a fun match with great people to talk with, I also like the challenge.
This question about percentage of shooters in the active match category may not be relevant today with the lack of primers. There is an active group of competitors in the Pacific Northwest and several are dropping out until primers are available at reasonable prices. We are seeing fewer competitors because they cannot reload for practice and do not want to shoot a match strictly for practice.
Farm boy from Illinois, living in the magical Pacific Northwest
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I realize there will always be isolated exceptions, but I've seen best accuracy, regardless of bullet design, with the bullet seated to the point where it slightly engraves. "Slightly" has no standard definition and is interpreted differently by different shooters. "Slightly" to me means the bullet barely engraves and the cartridge can be extracted without any change in OAL (no crimping).
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Don't know anything about the handgun long range steel but when I was shooting the long range BPCR steel matches, me and my buddy would show up the day before or at first light on match day to get sight settings for all the targets. And then enter them in our super-secret data books for the match. Then we had the data for the next year and all we had to do was to verify and maybe fine tune.
When I started paper patching my Shiloh 45x 2.4, I quit worrying about OAL and whether the bullet touched the leade or not because I patched to bore. With some experimenting, I found a charge of Goex fff that the rifle liked and then bult the wad column such that I could shove that 550 grain missil as far up the bore as possible and still be held in the mouth of the case without falling out when the case was held upside down. Usually only about 1/4 " of the bullet was in the case after thumb seating.
During that time I bought Goex by the case so the lot would be the same. Any new lots, new load developed.
Ten shots, 185 yds. Shiloh 74 Sharps.45 x 2.4 Paper patched to bore, 85 grains of Goex FFF off of sticks prone 
Iron sights
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Well, I have breach seated for a 32-40 and a 38-55. Both dedicatedt target single shot rifles and they both would dang near poke those castings down the same hole at 100. So this feeble mind reasoned that the closer that I could get to that method with my 45 x2,4 the better it would shoot.
1. That 550 grainer is automatically aligned with the axis of the bore perfectly every time. forget about concentricity and all that.
2. Eliminates agonizing over seating depth and OAL
3, As well as making neck tension a thing of the past
It had a noticeable positive effect on the accuracy of the 45 x 2.4. Those PP 550 grainers will outshoot the GG most every Time.
when the shooter is paying attention.
R
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Indeed. It's why I cut to the chase in ASSRA competition and breech seat for my .32-40's, both High Walls, one of which is a Pope. Going to take it a step further this year and start using the false muzzle on the Pope and muzzle load. Alignment in the throat/leade is guaranteed, and chasing that kind of alignment with fixed ammo is a challenge.
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The SAAMI Twist is a variation of the test fixture loading procedure. The procedure is described in the manual. Of course using a standard firearm, the load procedure is modified slightly. I picked up the terminology from Dr. Oehler some years back. I use the modified SAAMI method he taught me.
Sitting at the bench with the rifle, action open, on bags I have the ammunition in a loading block or a 50/100 round MTM ammo box with the bullet up sitting on the bench to the right. With the right hand trigger finger and thumb a case is removed from the box keeping the bullet up. It is tapped lightly on the bench then twisted back and forth a couple times with the finger and thumb. That is the SAAMI part and the 'twist". The variation is next as the case is inserted into the action case with the rim/head against the bolt while keeping the bullet up at an angle forward. The amount of clearance in the action opening and scope dictates the angle. The cartridge is gently placed on the follower. The bolt is then slowly closed.
The "SAAMI Twist" simply keeps the powder, especially in low density loads, to the rear of the case.
LMG
Concealment is not cover.........
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I use a cleaning rod with a flat jag. Measure the distance from the bolt face to the muzzle. Insert the bullet and measure from the tip of the bullet to the muzzle. This gives me the minimum OAL. Same as Ric for bore riders. For tapered bullets I'll try seating longer until there is light resistance when closing the bolt. I haven't found a sweet spot or a sour spot within those parameters.
John Carlson. CBA Director of Military Competition.
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My FP has a free-bore of ~.3085 measured with both a pound cast and a chamber side tamped seating of an unsized bullet.
So the front band of my 311299 is seating against the wall at the end of the chamber. The seating depth variable I have with this chamber/mold combination (bore-rider) is how much crush I put on the driving band as it hits the end of the chamber before the free-bore.
The crush can be see with damage to the driving band on dummy rounds as well as with felt bolt resistance as John described.
I can jump it, kiss it or crush it into the free-bore. Or at least crush it until the neck tension allows the bullet to slip back into the case.
To be honest I’m a little bit squishy about seating out to where “light resistance is felt when closing the bolt” or “into the lands until you see engravings “. The person doing the hand-loading, the bullet taper (non-bore-rider) and/or the hardness of the alloy used makes this seem awfully subjective.
I’m crossing over from jacketed benchrest and in that discipline we know exactly where “jam” or “push back” is and best accuracy is found within .009” of “jam” position on barrels with less than 600-700 rounds through them.
I’ve talked to a couple guys who shot at the Nationals and they described the neck tension they used as light. Light to the point that it almost sounds like each round seats itself as the bolt closes.
I got a lot to learn.
A “Measured Response” is as effective as tongue lashing a stuck door.
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Cast bullet shooting is an art, not a science. Your cast bullet will become a wad of bubble gum upon ignition.
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"The less "jump" or "run at the throat" that the bullet has, the higher the initial pressure and more steep the pressure curve."
That is the theory that has been around for as long as I remember. The analogies supporting it, for the most part, all sound reasonable. However, I have not been able to verify higher pressure occurs and/or a steeper pressure curve in actual pressure tests with cast bullets seated firmly into the leade or seated off the leade any reasonable distance.
A cast bullet, even a "hard" cast bullet, is much softer than a jacketed bullet. The pressure needed to swage down and engrave the lands into the bullet is much less. That swaging down and land engraving happens very early, at the beginning actually, of the pressure rise. It seemingly, so far at least, has little if any measurable effect in the pressure or pressure curve with normally sized cast bullets that are not larger than the chambers throat.
LMG
Concealment is not cover.........
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I agree with both Bill and Ric in the two posts today. I also agree that that there is little scientific method applied to improving cast bullet shooting. But that isn't because shooting cast bullets is somehow different from other areas where applying the scientific approach to figuring out truth from myth has allowed great strides and great improvement.
The reason that there few instances of scientific methods being used to improve results is that cast bullet shooter, in general, aren't interested in doing experiments and repeating other shooters experimental results to sort out what thing might improve performance.
Larry's post above, by using a scientific approach to find the truth about an aspect of CB shooting, discredits a perfectly reasonable sounding theory about pressure rise. These things can be done -- we just don't generally do them, and when they are done we tend to disregard the results and go back to our previous belief.
Instead of experimenting with enough shots fired to have repeatable results most CB shooters would rather rely on three other approaches to try to improve.
1. Seek perfection with absolutely perfect bullets carefully sorted by weight, careful powder weighing, elaborate case prep, indexing bullets, cases and even primers, etc.
2. Depend on old rules handed down as the conventional wisdom. A perfectly perfect base is needed with sharp edges even when covered with a gas check. Don't let the base of the CB hang below the neck in the case. Make sure your rounds are concentric. Make sure your crown is perfect. The way to improve your groups is to eliminate fliers -- believe that small groups don't have fliers without ever looking at them. Find the sweet spot for your rifle by ladder testing with a series of single five shot groups. Tune your load to your rifle by depending on single three shot groups being a valid measure for what the load will actually do in a match.
3. Use logic without checking your assumptions. Think real hard and reason out what happens to a cast bullet from case to target. Reasoning that since the muzzle is the last thing the bullet touches, a less than perfect crown will cause inaccuracy. Reason that variations in bullet weight or variations in case weight (thus volume) obviously will affect accuracy. Reasoning (without considering the numbers involved) that variations in neck tension affect accuracy.
None of these three approaches will help us improve what we know about CB shooting, nor shrink our groups. Many of the above have been shown to be worthless more than once starting with Dr. Mann 120 years ago and by others since then using a scientific approach. However, the typical CB shooter disregards information that shows that what he had been told by good shooters and believed up until now is false. Worse than disregarding experimental information he is often hostile to it. We don't like to change our beliefs. This is just human nature and people in science or engineering research have to guard against it to make progress.
Until we change our approach there will be little improvement in cast bullet performance.
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I thought all cast bullets should be jammed against rifling/throat for best accuracy. When you figure out how to shoot the cast bullet jammed into the lands...then you can experiment with jump to rifling. Should be easy to figure out after that.
Shouldn't we be talking about more perfect bullet fit and alignment. Happy New Year
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Yes, bullet fit and concentricity relationship of the bullet and the bore, are what some would call “constants” in the equation.
Several of us would man a table at an annual gun show where the CBA was the main subject, not selling guns. We did have quite a few show attendees stop by and ask questions. In the early years, we would have example guns from each CBA BR match category along with sample targets. If a table visitor showed enough interest, we eventually brought up the fit and concentricity topics….and that’s when the eyes glassed over.
Eventually we stopped displaying the sample guns and targets. Why? The primary interest of table visitors was what alloy to use and how fast can the production rate of handgun bullets be improved? Most explained that they shifted from jacketed to cast, due to the perceived cost differential.
Back in the early 80’s and through the 2000’s, all I used were cast bullets at handgun silhouette matches, in revolvers and XP-100’s. Lots of good natured kidding from my shooting friends about using those “stinky” bullets. Maybe the lube smelled, who knows. But today some of those nay sayers are using CB’s. The reason…cost. This includes straight walled and bottleneck cases. In the bottleneck category there are MANY different case designs.
Question for the peanut gallery…the CBA has X members. What % are active match shooters? And what % are handgun shooters whose main interest is the alloy and casting speed and read the Fouling Shot, hoping there are more articles focused on those interests?
Tom
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Good info on the Sharps loads, thanks!
My 418-grain Brooks mold is a dual diameter design and I patch to 0.410” but not to bore. Maybe I should look into that. I wrap the bullet and then pass it through a .410 CB sizing die, just to tighten up the dry patch.
I can recall various forum posts (elsewhere) that described the base of the bullet being in the case only 1/10th to 1/4 inch. Included were several veggie or poly wads to get the desired relationship between bullet and chamber contact.
The round is a .40 cal. 2 1/2 or .40-70 Sharps Straight. I was given “permission” to buy a case of powder a month before I retired. All of my local load development shooting is done at 200-meters. I do need to get out to shoot and load test more!
Tom
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