Design of an "ACCURATE" Cast Boolit

[TCLouis]

Both the original Lar45 358 180 RNFP and Lee's C429320 nose shape interfere with the throat in my guns before the max length of the round is reached. I have to use the rear crimp grove on the 429320 and seat below the crimp goove on the 35 caliber bullet. Is there a method to get meplat, longest nose and ACCURACY without going to the SWC design? The truncated cone seems to meet the criteria, but FEW of this bullet style are available so theree must be a reason.

Some of you designers have produced great custom boolits for us in the Lee 6 banger custom molds.
Is it a matter of luck or scientific design principles?

[Buckshot]

...............Rifles, carbines, pistols, and the cartridge they use may vary widely in throat and leade dimensions. What are you using these in?

.............Buckshot

[45 2.1]

Some of you designers have produced great custom boolits for us in the custom mold.
Is it a matter of luck or scientific design principles?

PM me and i'll discuss it with you.

[Bass Ackward]

Both the original Lar45 358 180 RNFP and the C429320 nose shape interfere with the throat before the max length of the round is reached. Is there a methot to get meplat, longest nose and ACCURACY withoug going to the SWC design?

Some of you designers have produced great custom boolits for us in the custom mold.
Is it a matter of luck or scientific design principles?


TC,

Fitting a throat can be a challange. And there is a lot of .... luck involved. Isn't one guy in a hundred that nails it. And even if he does, he can loose it again in as little as 200 rounds. That is the idea behind bore rides. Guidance until throat fit occurs or bore supports.

Or choking. If you can't touch and you can't fit the taper on the leade, choke. This is popular because it works. Most chokers never notice that their throats are walking (wearing). Just realize what you price you pay by choking. The more sizing that HAS to take place to get the bullet down to bore diameter, the faster that wear occurs.

The biggest challenges to fitting a throat is that you will be trying to fit an ever changing set of dimensions. So to some guys, throat fit is over rated. Usually the angles will stabilize, and all you need do is seat out farther to make contact or minimise the jump. The best and longest fit occurs at this time. This is the problem with fitting a new gun. It is also a problem with fixing a bullet length with a crimp unless you have no choice.

You CAN make the throat fit the bullet if that is what you are asking. One of the simplest ways is to just put some abrasive on the olgive portion "only" and fire lap a few.

If you want no abrasive down the bore there is another way. Load a dummy round and tap the primer pocket. Use a case that is only neck sized so the chamber supports the case and apply a light lube. Screw in something that you can get a good handle on and apply abrasive to the taper part of the bullet. Insert it carefully and then just gently turn it by hand. It will only cut as far as the chamber will allow the case to move forward. (headspace)

Works like a charm for that .... one ..... bullet. But that is why you see so many guys favor this design or that. Or .... they use one design for years and suddenly they change their mind and start touting another design as best. Their throats are in various stages of wear and one design fits better at that time. Same thing with forcing cones in a handgun. When a bullet fits, it shoots with the widest possible margins for error of all reloading variables. When it doesn't fit it is finicky requiring time to experiment.

If you don't want to change your gun, (I wouldn't) you need to change your shells. Shorten brass or crimp heavier. If we are talking a taper problem, then even .005 of OAL can make a difference. The distance that you are worring about may be very little and be gone in 500 shots. Don't forget to keep trying that dummy round every so often so you know when you can go back to normal length. Even sizing smaller can help depending on where you are making contact. Put some LLA on a bullet so you can see contact and play around with it.

[45 2.1]

Fitting a throat can be a challange. And there is a lot of .... luck involved.

Hah! Learn the basics and follow them, not to much luck involved either. Knowledge is what you need.

[Bass Ackward]

Hah! Learn the basics and follow them, not to much luck involved either. Knowledge is what you need.

Bob,

I am talking about "perfection" as opposed to real world. There are too many variables out of your or my control.

Mold temp or mix change can change the length of a bullet and thus the contact point. Sizing down farther than the mold throws, lengthens a bullet. Throat wear will always make changes requiring a change in seating depth. Lube build up in the dies. How you trim your brass. Etc, etc. Most guys when they set it up believe it is there for the rest of their life. So after all the planning, the fit is still a lot of luck. If you have the camming action of a bolt rifle, you can within reason finish off the fit.

That is why the bench resters have to stand up to put their weight on a bolt to close their actions. When you set up like that, you can actually "feel" the difference in fit when you close the bolt and bullets were seated to the same depth. So there is a difference that can't be compensated for unless you reject loaded ammunition on the line.

Isn't that the theory behind breach seating. Get passed throat fit and alignment?

[45 2.1]

Bob,

I am talking about "perfection" as opposed to real world. There are too many variables out of your or my control.

Mold temp or mix change can change the length of a bullet and thus the contact point. Sizing down farther than the mold throws, lengthens a bullet. Throat wear will always make changes requiring a change in seating depth. Lube build up in the dies. How you trim your brass. Etc, etc. Most guys when they set it up believe it is there for the rest of their life. So after all the planning, the fit is still a lot of luck. If you have the camming action of a bolt rifle, you can within reason finish off the fit.

That is why the bench resters have to stand up to put their weight on a bolt to close their actions. When you set up like that, you can actually "feel" the difference in fit when you close the bolt and bullets were seated to the same depth. So there is a difference that can't be compensated for unless you reject loaded ammunition on the line.

Isn't that the theory behind breach seating. Get passed throat fit and alignment?

Treating the symtoms doesn't work John. There are several ways to fix most anything if the gun was made right to begin with. Learn the basics of how and why, then boolit design follows.

[Bass Ackward]

Treating the symtoms doesn't work John. There are several ways to fix most anything if the gun was made right to begin with. Learn the basics of how and why, then boolit design follows.



Bob,

When you say that about the gun makes me wonder if we are saying the same thing with the difference being more in the form of terms or accuracy expectations. I know you understand this but maybe I need to clarify my opinion for others.

Accuracy is dependent on both bullet design and bullet fit. Neither is a panacea.

Bullet design .... is NOT the same as bullet fit. Bullet fit can occur with a weak design. All bullets will fit upon firing one way or another.

You can have either bullet design or fit without having the other. Bullet design is all you have if you are not contacting metal within the confines of a single specific throat. Fit improves ignition and has alignment right from the start without necessarily maintaining balance if the design is weak.

Bullet design .... maximizes advantages for strength for aiding centering and alignment during any jump until bullet "fit" is established. (If the sizing isn't too great and hopefully maintaining bullet balance during the sizing / engraving process.) IF bullet fit (and thus support) is not established when chambered at the begining, then obturation takes place upon firing. Obturation is "uncontrolled" fit and possible design change. The more obturation that has to take place, the more vulnerable you become to dimensional change like the base moving out of square. Choking .... minimizes the obturation process by minimizing distance to .... bullet fit.

You can get 1" at 100 with a lever using cast. But it is a much more finicky process and I find it to be less reproducible because of all the variables relying on design alone. You can theoretically get 1" at 100 yards with a handgun too, but it is much more difficult to reproduce yet than with a lever.

I can get 1" groups from either a good bullet design .... or good fit out of a turn bolt. But if I want better accuracy, or on a more reliable and reproducible basis, or at a higher velocity level, I need both fit and design with minimal sizing to bore. So .... unless the mold and design are made for that specific gun, at that specific point in it's life cycle, you will need to seat out to follow it, or have a camming platform to create or enforce fit. It is pure luck if you are able to get fit even close without a bolt.

So it was TC's last question of the first paragraph I was answering really. Science and design to a point and then luck there after if you can't cam it in.

[45 2.1]

Bob,

When you say that about the gun makes me wonder if we are saying the same thing with the difference being more in the form of terms or accuracy expectations. I know you understand this but maybe I need to clarify my opinion for others.

Accuracy is dependent on both bullet design and bullet fit. Neither is a panacea.

Bullet design .... is NOT the same as bullet fit. Bullet fit can occur with a weak design. All bullets will fit upon firing one way or another.

You can have either bullet design or fit without having the other. Bullet design is all you have if you are not contacting metal within the confines of a single specific throat. Fit improves ignition and has alignment right from the start without necessarily maintaining balance if the design is weak.

Bullet design .... maximizes advantages for strength for aiding centering and alignment during any jump until bullet "fit" is established. (If the sizing isn't too great and hopefully maintaining bullet balance during the sizing / engraving process.) IF bullet fit (and thus support) is not established when chambered at the begining, then obturation takes place upon firing. Obturation is "uncontrolled" fit and possible design change. The more obturation that has to take place, the more vulnerable you become to dimensional change like the base moving out of square. Choking .... minimizes the obturation process by minimizing distance to .... bullet fit.

You can get 1" at 100 with a lever using cast. But it is a much more finicky process and I find it to be less reproducible because of all the variables relying on design alone. You can theoretically get 1" at 100 yards with a handgun too, but it is much more difficult to reproduce yet than with a lever.

I can get 1" groups from either a good bullet design .... or good fit out of a turn bolt. But if I want better accuracy, or on a more reliable and reproducible basis, or at a higher velocity level, I need both fit and design with minimal sizing to bore. So .... unless the mold and design are made for that specific gun, at that specific point in it's life cycle, you will need to seat out to follow it, or have a camming platform to create or enforce fit. It is pure luck if you are able to get fit even close without a bolt.

So it was TC's last question of the first paragraph I was answering really. Science and design to a point and then luck there after if you can't cam it in.

No John, you need to rethink a lot of what you've said because some of it isn't true. You might think it is, but you need to really spend some time with it and you would see that. Levers can make most bolt guns run for the money if you understand how to fit them up. All you have to do is get the boolit into the bore straight to get accuracy. That problem differs with individual boolit geometry and several other factors.

[Bass Ackward]

No John, you need to rethink a lot of what you've said because some of it isn't true. You might think it is, but you need to really spend some time with it and you would see that.


Bob,

Even if you are not correct about your theories, you are absolutely correct about me. If the chips were down and money was on the table, with my limited knowledge base at this time, I would NOT reach for a lever to do my best paper punching.

So .... maybe I still have something to learn. That is the exciting part that keeps me going.

[Buckshot]

Levers can make most bolt guns run for the money if you understand how to fit them up.

..........:hijack:

............Bob, maybe a more "Accurate" statement would be " SOME levers can give SOME bolt guns a run for the money". I don't know about that 'Most' word :-). I have seen some pretty outstanding accuracy from some leverguns, being as they were just that: Leverguns.

Yet I have also seen leverguns send thier owners into coniptions. I had a very nice M93 (made in 1906) in 30-30 that was an absolute joy to reload for and shoot. All the accuracy a person could stand from an iron sighted rifle. My brother has it now, or actually my nephew does. By the same token several years ago I bought a M94 Win 30-30. I owned it maybe 3 months then sold it as it would never respond, and I wasn't interested in dealing with:

Levergunitis.

An old friend had a Marlin M94 in 357. It shot everything and anything like a pig. Didn't matter HOW much he paid for jacketed slugs, or who he got his cast from (he didn't cast). Everyone had recommendations for him. Try this, try that then one day for some reason he took out his penknife and cut out a strip of alum pop can. He stuck it over the barrel under the magazine band and it became a shooter.

Another friend with a M94 Win 30-30 had good luck with it. Nice shooter. He put a Leupold VXII 3-9 on it. I showed up at the range one day and he said "Look at this". At 100 yards he put 5 Lee C309-113F's into an honest inch at 2100 fps. I said how lucky can you get with 5 fliers all clumping together like that :-) He showed me the other loads leading up to it and they were about as good. The next Tuesday he fired 4 more groups at 100 yards with the same load (23.0 H4198 + dacron) and the average for them was 1.65".

Certainly there are some pretty bad shooting bolt guns right out of the box, out there too and there are known fixes if the problem isn't a major mechanical one.

You give me a choice between a bolt action and a leveraction. Both have chambers on the same axis as the barrel, both correctly headspaced, both with the same bore, groove and twist and I'll take the boltgun in an accuracy match. With it I won't have a 2 piece stock, no magazine running through the forend, no barrel band tying the mag tube, barrel, and forend together, and no barrel lying in the same forend the mag tube is running through.

Kind of a K.I.S.S. thing. The perfect boolit being used, notwithstanding.

My initial reply to the accuracy question:

"...............Rifles, carbines, pistols, and the cartridge they use may vary widely in throat and leade dimensions."

I think is possibly simplistic, infered but not written is the fact that one of the boolits listed, with an accuracy issue in the original question, may in fact be the bee's knees shot in something else.

.................Buckshot

[Char-Gar]

Hummmm.... Methink we need some standard terms with fixed definitions. All of this bullet design vs. bullet fit is giving me a headach. In my simple mind bullet design is to enhance bullet fit. Bullet fit/support is what makes the bullets play follow the leader. Providing of course the twist, alloy, lube, powder and charge are all correct.

In short a properly designed bullet will fit better than a poorly designed bullet.

I have been shooting rifles for many, many years and none of you will convince me that across the board, leverguns are on par with bolt guns for accuracy. Some leverguns can be tweaked to shoot very well, with accuracy that will scare some bolt guns... "some" being the key word here.

Remove the tube magazine, attatch the forend to the frame and not the barrel and use a through bolt to attatch the buttstock and will will have a under lever action single shot rifle, that will shoot with any rifle in the world. Unless you do those things, the standard levergun will be an also ran.

[45 2.1]

Ric and John-
Methodology is what determines what you get with cast. Just because you haven't been able to get results that are beyond the norm doesn't mean that it's not possible. There are at least a couple of guys on this site that can do the lever accuracy thing I spoke of besides me. Compare apples with apples if you want to compare things. One MOA isn't that hard to get with a properly put up firearm, levergun or bolt, if you know how to do it. Half that or less is in the realm of someone who has enough knowledge to make it happen. Read my tag line.

[Bass Ackward]

Half that or less is in the realm of someone who has enough knowledge to make it happen. Read my tag line.


Bob,

I understand your point. A lot of people stop with levers before they maximize potential. Put me on that list .... and for a reason. Others need to know me to understand what I am saying.

For consistency and reproducibility, I like to have steel in the throat very close to my slug along the whole length so there is nothing to have to have to obturate (deform) any more than necessary. That lead slug is much stronger when it is supported by steel. That slug should slide out of that case and not feel the transition. Ideally the slug should not have to size a whole lot to get to bore. It should be just slightly larger to initiate and maintain a seal. And when chambered the olgive should rest against the rifling so that there is no space to jump. This way I can use a slow powder and still get consistent ignition and be as gentle on the bullet over all as possible in every respect. This is as close to breech seating as you can get. Sometime, that takes a little force to achieve and I know but one platform to do that. My "cast" rifles are built like that just for that reason. And once done, cast have limits that are well beyond most tinkering levels.

Everyone is different. I admit I am getting lazy. I got tired of making stuff work. Once those conditions I described are met, an idiot can lauch slugs accurately. The slugs don't have to be perfect either. I don't have to weigh within 1 grain or any such. And I have multiple powder selections from which to choose. Cast ..... perform like jacketed.

You only need perfect slugs when they have to obturate (deform) the exact same way each time which of coarse they won't if ignition varries or one weighs more than another or any number of things that can and do go wrong. That's why choking works. Or tapered slugs. You have to get contact (alignment) somehow. Especially when you want to go up in velocity.

Tinkering (therapy) for me is reserved to handguns and levers where my accuracy standards are much more relaxed. That is until 44man came along. :grin:

[45 2.1]

Thats fine John, but I don't do it your way and get extremely good results from the method I use without a lot of fuss and muss. There are more ways than one to achieve results.

[scrapcan]

Ok Guys, this is a nice discussion,

at least on one side. Thanks bass, buckshot and Chargar.

Now to the other poster, 45 2.1

Teach us something or quit bantering. It doesn't help the rest of us to gain useful knowledge if it is not shared. I for one have a couple of rifles that I am beleagured with and need some more tools in the tool box. One is a worn 98/22 in 8x57. I have tried everything except a very heavy very long bullet to reach the leade.

So if there is a better bullet design, to get a better fit, then share it. You can't possibly have the time to discuss this issue with everyone by PM, so maybe you can share it with all of us.

I agree with Bass on the fact that there is a difference. Case in point is the wadcutter in a 38 special. Not necessarily the best design from a flight stand point, but if it fits the gun it will shoot very nicely. and if given a slight center nib it will even buck the wind and produce good results and more than normal bullseye pistol ranges.

To the rest of those reading this I am sorry for being impatient, but as many posts have been made there should have been more explanation. I said it once before and will say it again, please share or write a book. If you write a book I will by it and try to gather information that way.

Jeremy

[45 2.1]

Ok Guys, this is a nice discussion,

at least on one side. Thanks bass, buckshot and Chargar.

Now to the other poster, 45 2.1

Teach us something or quit bantering. It doesn't help the rest of us to gain useful knowledge if it is not shared. I for one have a couple of rifles that I am beleagured with and need some more tools in the tool box. One is a worn 98/22 in 8x57. I have tried everything except a very heavy very long bullet to reach the leade.

So if there is a better bullet design, to get a better fit, then share it. You can't possibly have the time to discuss this issue with everyone by PM, so maybe you can share it with all of us.

I agree with Bass on the fact that there is a difference. Case in point is the wadcutter in a 38 special. Not necessarily the best design from a flight stand point, but if it fits the gun it will shoot very nicely. and if given a slight center nib it will even buck the wind and produce good results and more than normal bullseye pistol ranges.

To the rest of those reading this I am sorry for being impatient, but as many posts have been made there should have been more explanation. I said it once before and will say it again, please share or write a book. If you write a book I will by it and try to gather information that way.

Jeremy

And here I was being nice. I suppose you could get these other fellows to tell you how, but here you are wanting me to fix you up. I guess their suggestions didn't work. OK, have you at least made a lead throat slug of your rifle and measured it? No, then if you want it to shoot good that would be a start. Mid South Shooters Supply offers two boolit molds designed by Oldfeller and I especially for large throat 8mm military rifles. You could try that also. You need to read the past posts on these subjects because its all been covered before, several times.

[steveb]

I myself will take the levergun everytime with limitations and all. I have always loved them. I know many folks that just love bolt actions and they have never interested me in the least. If we were all the same life would be boring I guess.:Fire:

[Dale53]

I have bolt guns, single shots, and lever guns. Bolt guns are, by far, the easiest to get to shoot well (under 1" at 100 yards". My old "Heavy Varmint" bench rest rifle is a genuine 1/4" rifle (won't even get you in the door at present day bench rest matches). However, it did teach me a bunch about reading conditions that is applicable to all other rifles because is was so consistent.

It is comparitively easy to get a match single shot under 1.5" at 100 yards. I have a BPCR Browning 40-65 that has shot a minute of angle at 500 yards witnessed. My schuetzen rifle (Peregrine .32/357 Dell) is a genuine 1/2 minute rifle.

My lever guns are utility hunting guns. My 25/20 Marlin will do, on demand, ten ring accuracy at 50 yards on the NRA Smallbore fifty yard tartget. I have done nothing to it except a trigger job and load developement with cast bullets (I bought 500 jacketed bullets with this rifle years ago when I bought the rifle and still have them all). I don't need anything better out of this VERY reliable rifle. It is a superb squirrel and small game rifle and just flat fun to shoot.

My 45/70 Marlin is the first issue modern rifle with standard rifling. The first day of testing, the Lee 340 gr ahead of an appropriate charge of 4198 gave me consistent 1.5" at 100 yards. I quit developement and just shoot it. I require nothing better of a hunting rifle. I did nothing to this rifle but a trigger job and mounted a wide angle scope and OF COURSE, had a recoil pad mounted!!:mrgreen: I might mention that this rifle was bought used (probably because it hurt so much with heavy loads due to the knife sharp curved plastic butt plate:twisted: ). I really don't know how much it was fired before I got it. A friend picked it up at a gun show, He knew I wanted one. I looked at it and bought it. Unfortunately, my state (Ohio) does not allow rifles on deer. All of my deer have been taken with .44 magnum revolvers....

Match rifles are NEVER good enough as there is always someone out there that will take the extra step to beat you. Practical rifles, on the other hand, do not necessarily need extensive developement. Good enough is good enough.

YMMV
Dale53

[Bucks Owin]

..........:hijack:

............Bob, maybe a more "Accurate" statement would be " SOME levers can give SOME bolt guns a run for the money". I don't know about that 'Most' word :-). I have seen some pretty outstanding accuracy from some leverguns, being as they were just that: Leverguns.

.................Buckshot

My sentiments exactly.

For example, the Win M-94 isn't even on the same porch as the Win M-70 accuracy wise. Yet among other leverguns, the M-94 seems to hold it own.....

Apples and oranges here,

Dennis

(Although the long discontinued M-88 might give the 70 a run for it's money "out of the box"...)

[felix]

My motto is to use only BR guns for groups, and consider all others as game-getters or score-targets (on the hoof, beer cans, shotgun shells, rocks, etc.) only. ... felix

[scrapcan]

45 2.1

I am glad that you read my post the same way as I was reading yours. Go back and read your entries as if you were someone trying to gain a little knowledge. Who presented some info to build on?

And Yes I have tried to use the knowledge gained from my short tenure as a member here to search the forums and apply what I find. And if you look a the original post, I am not the only one who was interested in finding information and obviously was not the only one who had not found it. Thus the original question that was asked.


By learning what you all have to say about boolit design, we could apply that to molds already in existence and that we may have in our collection. The road is not only through new custom cut lee moulds, that is only one road. I have a couple of moulds that I am trying to get to work for the 8mm I spoke about. They have not worked thus far (and I have a pound slug and a couple of drive slugs for my mind to not understand and a cerrosafe cast of leade/chamber/beginning of barrel). I am trying to learn why they may not be working. I am leaining toward a very large chamber neck dimension and a long throat that may not accept a bullet of diameter to fill the neck. It may need a different barrel of which I have 3 others.

I remember years ago the bantering of cast bullets and Veral Smith and his findings. We may not agree with whatever is written, but he was willing to share the info even if it did cost us. I would do the same if you would like to offer a book, under copyright, and for a fee. I am sure that there are many others that would do the same, as reflected by the number of people who have said they have this book or that book.

Don't just wax and waine about the right way and not lead us to some knowledge. I kept waiting for you to share some knowledge and all we get is that there is a better way, but no explanation or link or indication as to what the original thread would have been called.


I would like to learn alot more from you guys here with more knowledge than is available elsewhere, but you gotta offer it up before I can learn. I am ready to learn when you are ready to teach.

Jeremy

edit for spelling

[Char-Gar]

Manleyjt... Be careful with your plurals, (you guys) as most of us are willing to tell you everything we know for certain and even run a good bluff on the things we think we know for certain.

The above thread has been way to esoteric/zen/secretive for my understanding.

There are so many variables in cast bullet shooting it is difficult, if not impossible to talk, about the most accurate cast bullet design, unless we also talk about what it is to be used for (range etc) , and from which rifle it is to be fired.

[scrapcan]

Chargar,

Sorry about that. I think most of the members offer everything they have without a second breath, and I am thankful for that. I think everyone here has something to offer. That is where that statement came from. And I have learned a bunch that is not written in one of the manuals I can buy. I know there is way more available from "you guys".

[Buckshot]

.............There are some simple basic principles to good cast boolit accuracy, which mirror the same in jacketed shooting.

Consistancy, first and last. Then fit.

Without consitancy, boolit fit is imaterial unless you're shooting at 10'. Getting a good boolit fit is easy if it's you and one rifle. It's especially easy if it's a modern one with reasonable throat, leade, bore and groove dimensions. Since we went that far, we'll also say that the chamber is looking the same way the barrel is, and the chamber dimensions and especially the neck area isn't outsized.

To that end, for such a rifle as above, all the mainline mould makers have us pretty well covered. But being that rifles coming off the line one after another is an individual, we get to experiment a bit. So we get to shoot more and buy goodies, otherwise it would be so boring.

Interesting that Glen, one of the Burrito shooters had been given about 13 lbs of cast, lubed and sized slugs. His 1903A3 sporter shot them like a champeen. Alas and alack he finally ran out a couple months ago and he had been a tough nut to crack during our matches. What the problem was, was that he'd been unable to identify WHOSE boolit design it had been. No one could identify them.

So as a default he cast up a bunch of Lyman 311291's. Everyman's 30 cal. A well balanced design that's somewhat of a benchmark. His sporter did NOT like them verily, amen. Same size, approx hardness but a different lube. Bummer:violin:. He was then forced to experiment, because Glen also liked to win, as do we all but he REALLY likes to win. He also really hates to cast, as it cuts into his TV time.

So two weeks ago he'd cast up a bunch of Lyman 311332's. He loaded 20 of the 311291's and ditto the 311332's. Same load, same batch of cases, sizing, lube etc. With the sporter on bags (Lyman 48 rear, tunnel insert front sight) at 50 yards, 10 of the 291's were in the 10 ring vertically strung. Same thing for a 2nd attempt. The 1st 10 rounds of 332's pretty much obliterated the X ring. Pretty much the same for the 2nd 10 rounds, but a couple 'just' out.

Glen is all happy now. Done experimenting. As a possible interesting side note, the powder was Hercules Lightening, made in 1939 of which he'd been given an 8Lb unopened jug so he's still using the same charge. Sizing was .309". My Remington 1903A1 also will not accept a slug larger then .309". In this case, both slugs fit the throat, just that it didn't favor a normally very fine shooting design. With such a rifle it wasn't a big deal to find another it DID like.

So far as fit goes on an individual basis sometimes we HAVE to compromise. A good example is a M1897 Rem RB I have in VG+ condition with a like new barrel. With the RCBS 7mm-168 or Lyman 150gr Loverin unsized @ .285" it's an exceptional shooter. However the fired casenecks just about mike .300" ID, yikes! The throat is .287". That slug engraves in the .275" bore, and the groove is .285". With a caseload of WC872 it produced groups running 1.5" at 50 yards and 2400 fps.

I can live with that from an iron sighted RB with a 16lb trigger. Might even tighten up some with a .286-.287" slug. I'm not stressing it though. However, even annealed, the caselife is about 12 rounds before the neck splits. Don't know how it'd do with a boolit that DIDN'T engrave. Obviously the slug is helping to align things, even thorugh the cases are necksized only.

So that's an outsized chamberneck. I have another couple wierdos in the form of a couple Austrian M95's. Actually a M95 and a M95/30. Differences are on the outside. On the inside it's a .316" bore, a .332" groove and a throat and chamber that will accept a case with a .338" slug! So first off, the grooves are a whopping .008" deep. That is a LOT of lead being swaged as it enters the barrel for even a .332" slug. In the 2nd place to make it worse it will chamber a .338" slug as we try to plumb the OD of the throat.

I'll confess to not having slugged the throat but it will not accept a slug as cast, at .340" (RCBS 338-210). The fact is, it shoots MUCH better with a boolit sized .335" then it does with one closer to throat size at .338". I haven't tried one sized smaller like .333/.332" nor larger at .339" to really 'fit' the throat. I just don't see in this case bigger being better, but I'm sure the culprit is the bore/groove rather then fitting the throat, as doing so IS good cast boolit practice.

One final example of a rifle (actually carbine) that shoots pretty good for the limited attention I've given it, that has EVERYTHING wrong so far as cast boolit wisdom is a Brazilian contract Comblain, made in Belgium by E.Nagant. Thanks to copied info supplied by Floodgate, via a very extensive file he sent, I think it is an 1874 model made in 1888 or so.

It has 4 lands and grooves of equal width, a consistant .433" bore with a RH 16" twist. Now the oddities begin. At the muzzle the groove is .455" (.011" deep grooves) and at the chamber mouth it is .465" (.016" deep grooves) so it has a tapered or progressive depth groove. Still not bad other then pretty deep grooves. It takes a short 42mm long, rapidly tapered cartridge case with a very short neck to hold the boolit, which is supposed to weigh 385 grs.

Major issue here is that the chamber has no neck :shock: That's the way it was made! The chamber just tapers down but where the caseneck is, the chamber just continues it's taper down untill it meets the grooves:veryconfu In this instance, the caseneck clearance may be measured with a ruler! Almost like shooting a 30-30, with 30-30 ammo that has had a 38-55 reamer run into it.

http://www.fototime.com/34EA4235E0A4A6D/standard.jpg

This was very early on is trying to get it shooting :-) The 2 cases on the left were a couple I cobbled up to chamber. They were pretty casual as I used all kinds of stuff to mangle them into shape. The 2 on the right are after being fired. No neck anymore!

Another cast boolit no-no was although the groove was .465" I used an as cast 300gr Lyman at .460". A full .005" undersize.

http://www.fototime.com/7AF13C1EFB9843B/standard.jpg

Chamber cast. As you can see there is NO necked part. It just slopes down to the grooves. Egads, what were they thinking?

http://www.fototime.com/8F2D7613C6820E4/standard.jpg http://www.fototime.com/FB833F810B2C0FE/standard.jpg

First time out with 20 mangulatoided brass 32 ga shotgun hulls. A boolit that was .005" UNDERSIZED for the groove, floating in midair in a chamber that would almost allow the boolit to go in sideways and it produced the groups on the left. All were 10 shot groups at 50 yards except the Blue Dot load. I used 3 of those to get on paper.

Considering everything, those groups are practicly match grade! Especially the SR4759 group. It's a wonder they weren't going through sideways. A further conumdrum is that there was no leading at all.

While this isn't a lesson on the Comblain it was the best example I had where having almost everything wrong didn't turn out too bad. Er, considering.

It's best to fit the throat and at least bump the leade (Engrave IMHO if possible), have a slug cast of a suitable alloy for the load, a good lube and that is at LEAST .001" over the groove, snugly held in the caseneck of a well centered case. If the rifle exhibits oddities and outsized dimensions you may have to allow for them and try someting different.

................Buckshot

[Bass Ackward]

Richard,

Amazing the techniques you guys use to get / keep something blammin. Science unto itself.


Manley,

There are certain design principals that seem to produce better or less finicky cast bullets in more guns. At one point it seems that you are asking about that and then it seems you want to know how to establish "fit" for something already designed.

Did you get what you needed?

[scrapcan]

Buckshot and Bass ( and others)

thanks for throwing more info out. I tis interesting to see what you are able to do. I have the a 98/22 I mentioned before that is just whipping me. The next step for me is to order one of the big 8mm moulds from Midsouth.

I have tried all the standby "BASICS" that I can glean form whatever source I can. hard,soft, long,short, fat, skinny (sounds like dating as a teenager doesn't it), thicker neck reformed military brass, thin neck reformed commercial brass, factory brass, fast powders slow powders. I have been working at it for a year and a half. 4 different bullets, 4 different designs. I think I just have not found the magic pill.

Bass,

I am gradually amassing more info than I really need on this subject. As buckshot said in his ost a rifle is nt shooting a design that has been successful for others and I am trying to figure out why.

I am beginning to think that I should be happy if I can hit a pie plate at 100 50 percent of the time and just enjoy shooting the old girl.

What had me gigged up was the postings that say no no you are wrong but then nothing is given to let me chew on.

I know from Buckshots post above that he thinks about things and will jump out of the box and try something else, I also see that from many of the more experienced members here. You guys are always willing to send a few kernels to help grow a crop. That is what I was asking of 45 2.1, I am a firm beliver that if you tell someone they are doing something wrong or need to do something different you should be able to offer and explanation.

I will make another thread in the military rifle section when I have a chance to post some actual measurements. Until then my bantering should just cease, I will continue to gather info and seek specific help at a more appropriate time.

Thanks guys for putting up with the likes of me, your help and knowledge is truely appreciated. sorry for being so long winded to say very little.

Jeremy

[Buckshot]

...............A readily available slug you might try is Lee's design for the M95 straight pulls in 8x56R. I have the mould but havn't cast from it yet but I understand Lee sized it to match the jacketed slug these carbines used, ie: .329". I know of several who have sized it down for use in outsized 8x57's. It's an inexpensive mould as a SC and is not a special order number.

I'm going to have to get my copy fired up as a CZ24/47 I bought has a generous throat and didn't do very well with some 8mm's sized .325".

.................Buckshot

[StarMetal]

Buckshot,

You're right about that Lee bullet for the 8x56R, it cast out at .329 from WW's so there's no doubt you can size it to above .325 that you didn't have luck with in your 8x57.

Joe

[cherok9878]

manleyjt, if you put out a request to the board for some boolits of the size you need and offer to pay for the shipping, you may get some boolits to test without buying a mould. Just thinking out loud...........larry

[scrapcan]

Cherokee9878,

thanks for the suggestion. Had not even thought of that. When I get a chance to look at the slugs, chamber cast, and measure a few fired cases I may have to ponder that a little more.

That is what is good about the forums here, you all keep us on our toes with ideas.