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JFE
08-10-2006, 08:54 AM
I'm new to this site and searched the forums but didnt see anything on this subject. So apologies in advance if I missed previous threads on the subject and going over old ground.

I would like to hear views on whether there is an optimal design for the throat/leade of rifle chambers for shooting mainly cast bullets, but for jacketed as well.

Joe

Char-Gar
08-10-2006, 11:37 AM
I am certain there must be an optimal throat/leade design for cast bullet and I will be interested in seeing what the technical minded folks have to say.

Me...I just play em the way they were delt! A goodly part of the fun is trying to whip a rifle into shape and make it do what I want. I like to enforce my will on inanimate objects as I have never had much luck doing so on dogs, cats, wives and kids.

felix
08-10-2006, 11:54 AM
Quite simply the best throating would be a truncated cone design with boolit and throat matching with zero clearance. The angle would be sorta rounded at the junction of the leade and bore to eliminate any boolit tear. Some freebore would be desired, with minimum seat pressure within the case to make the alignment as perfect as possible. Adjust powder speed, primer, and boolit hardness to be commensurate with the leade angle for optimum ignition characteristics. ... felix

JFE
08-13-2006, 05:16 AM
Felix,

thanks for your reply. Your explanation seems very logical, however most of my moulds arent of the truncated cone type designs.

My rifle cast bullet moulds tend to be round nose style with a flat. A good example is my RCBS 45/70 405 FN GC. For these type of bullet designs, would a long shallow leade work better ? If so, any idea what angle for the leade ? For the throat itself I assume that this should be .002 over bore size ?

I would like to build a couple of rifles in the near future and would like to spec up the chamber/ throating/leade properly so that the rifles will work well for cast and jacketed.

Joe

JFE
08-13-2006, 05:32 AM
Sorry, that should have been .002" over groove (not bore) diameter.

Joe

Bass Ackward
08-13-2006, 06:27 AM
JFE,

It all depends. I would say different throat dimensions for different uses and cartridges. Obviously that no matter the dimensions, a smooth, gentle leade establishes the best conditions allowing the bullet to over come inertia the quickest / easiest and thus remove pressure from the base. But what is needed for a small capacity bottleneck set up for target work at higher velocities would be different from a straight sided throat set up for paper patching or black powder work. Do you want to maximize power? Accuracy? Light bullets or heavy? And do you even want to shoot hard or soft lead? Does the rifle type you will use have a camiing action or must the bullet jump? All of this would affect dimensions.

You would need to be more specific as to cartridge and intended use. Either way you go, you won't likely be able to fit a factory slug to the throat as well as a custom design simply because they are meant to be what they are, generic. But in truth, you don't really have to. While a custom bullet designed and fit properly works like a charm, it can be boring. And playing around with a factory design can be rewarding once the proper adaptations are made ala Chargar's comments.

JFE
08-13-2006, 09:03 AM
BA,

Apologies in advance for my lengthy response. Judging by the quality of the responses this really is the right place to ask questions about cast bullets, that's for sure! I'm really glad I signed up.

Thanks your comments. All are very useful and your questions assist in focussing the discussion. I have a diverse interest in cast bullets but mostly its for economy, practice and ultimately hunting. I'll try to be a bit more specific for this discussion:

1. Cast bullets used will be mainly hard alloy, quenched and gas checked
2. I like using cast bullets about .002" over groove diam.
3. Main interest is in larger bores (45 & 50 cal), with an emphasis on hunting use.
4. Velocities are expected to in 1600-2200 range depending on bullet weight and other factors.

I am looking at two projects in particular - one project is a 50/110 based on a modern 1886 action and the other is a bolt action in 458. As I understand it, 458's have significant freebore and in general with cast bullets they are somewhat handicapped, but please enlighten me if this is not true.

In the case of the 50/110, I am looking a keeping OAL at or below 2.80" and bullet weights in the range 450-700 gr. This will be loaded to full potential for hunting use.

The 458 would digest 400-500 gr cast and mostly jacketed in the wt range 350-400gr. I realise with abbreviated throating I wont be able to use factory ammo in the 458 (as it will be too high a pressure), but thats not an issue here as I will handload exclusively for this rifle.

Before I proceed with these projects I am looking to gather as much info as possible and I feel the throat / leade areas are quite important to get right, given the intended usage.

I have a few bullet moulds for the 45 but none for the 50 cal yet. I will probably buy another one or two heavier moulds for the 45.

All views & comments gratfully received.

Please shout if you need more info.

Joe

felix
08-13-2006, 09:18 AM
BA said it correctly! A truly set up gun-boolit combo becomes quite boring. Truncated cone boolits are the same as multi-band-diameter boolits which are quite common, but seldom advertised as such. Anything short of this design tends to detract from the ultimate accuracy (ignition), but, then, who really cares except those preparing for competitive situations where real money is on the table. Folks need to use a BR gun just long enough to get this accuracy syndrome out of their system. Once seeing how that feels, most of us can enjoy making the gun(s) on hand shoot to its best via boolit experimentation. That is the true hobby for most of us, if not all of us, on this particular board. ... felix

Bass Ackward
08-13-2006, 10:58 AM
1. Cast bullets used will be mainly hard alloy, quenched and gas checked
2. I like using cast bullets about .002" over groove diam.
3. Main interest is in larger bores (45 & 50 cal), with an emphasis on hunting use.
4. Velocities are expected to in 1600-2200 range depending on bullet weight and other factors.

Joe,

Let's take item by item.

1. You will get over that just as soon as you want to start hunting.

2. We all have our preferences, but I learned to listen to what the gun likes. One of the most accurate loads you will ever see is actually under bore size and outta round. I kid you not.

3. OK. Now we understand economy. I can't aford to shoot the biggies if I had to buy bullets. $50 for a box of 5 isn't my idea of practice.

4. Very realistic based on what you mention.

I shoot a 458X2 which is a 458 Win Mag, 7MM Rem Mag, etc cut off to 2". I can make my brass from any caliber built on that case. It has a shorter throat as it is designed for bullets up to 400 grains. If you get any caliber cut for a 500 grain bullet, you will be flubbed for 400 grainers and less if you desire "peek" accuracy unless you seat only the GC.

Take my 458X2. Because of the heavy brass, it is tough to get a seal from the brass on loads otherwise known as developing BP velocities. It likes to be run wide open. And in truth, no matter what throat you get cut, it will lengthen until the powder quits sand blasting the leade and the tool marks polished out. So what I am saying is that you want to undershoot a little from what you consider perfection and then let the wear establish your free bore. Then be cognisent that if you need to size smaller, you will be working on a taper that will require you to seat out even farther. No free lunch. There is a fela with one for sale on this board if you are interested in something like that.

The lever will need to load freely. It will dictate an OAL for feeding that you will find difficult to get around. Translation: Bullet jump is inevitable. The larger you go in diameter with the bullet, the shorter you make the jump on a taper. Picture that in your mind. Many people slug their throats in the begining and don't realize that powder wear is powder wear regardless of the bullet metal and tool marks from a rotary tool will always be there and eliminated, so never buy or build a mold on a new gun. Wait until it breaks in some before attempting custom efforts.

Regardless of caliber, if you want to go custom on the reamer, you can load up a dummy round and send it to the reamer company. Tell them you want a freebore of X and a leade angle of Y. (And a neck clearance of .005 or less.) They will grind the reamer to chamber THAT round at those dimensions. For a bolt gun shooting a straight case, I prefer a 3 degree angle on the leade and the ability to chamber .002 over groove. Once that polishes out, it will actually open to .003. This is because I can seat into the rifling and close my bolt to get ignition instead of relying on diameter to delay the bullet to produce ignition. Then if I want to go wide open, I can use a smaller diameter bullet. Because from my experience, the faster I go, the smaller in bore diameter my guns like. My guess is that it minimizes sizing in the throat and allows the bullet to over come inertia and get going faster to ultimately cut pressure on the bullets base. Sort of like using a slower powder. But that is my theory.

Help any?

felix
08-13-2006, 12:16 PM
Not theory, BA, it's fact! ... felix

helenajoe
08-13-2006, 01:34 PM
Hi,

This thread is interesting. I have a couple of Browning lever action carbines and rifles that are copies of original Winchesters. I've been told that these Browning lever actions don't have a throat in terms of the rifling is all the way to the chamber. Thus, this severely restricts what cast bullets can be shot.

For example, most 250 gr cast bullets can't be shot in a Browning 71 and ditto for heavy cast bullets in a Browning 86. Lighter cast bullets are OK.

The solution seems to have a throat reamed which will accomodate the heavier cast bullets. However, the few people who have had that done --- didn't seem to be very satisfied with the results and complained bitterly.

Why? It drastically affected the accuracy of their pet loads with lighter cast bullets which suddenly shot poorly. Which begs the question, is it worth reaming out a throat to accomodate heavy cast bullets, or will accuracy suffer?

I'm just an average joe and basically I play rifles the way they were dealt. However, I'm interested in what you technical minded people have to say on this matter with Browning lever actions.

Has anyone had good luck with reaming out the throat of a Browning lever action so they could shoot a wider variety of cast bullet weights? Also, I have a modern Winchester repo, Win 86 extra light, and I assume it, too, has no throat --- but I'd appreciate an expert to verify that.

Thanks,
helenajoe

felix
08-13-2006, 02:03 PM
HJ, don't even think about it. Leave the gun the way you got it, and get boolits to match the throat however short. Levers are not target guns! ... felix

Bass Ackward
08-13-2006, 02:15 PM
HJ, don't even think about it. Leave the gun the way you got it, and get boolits to match the throat however short. Levers are not target guns! ... felix


HJ,

I gotta trust Felix here. I have no experience and I wouldn't even know how to begin to advise on specifics. But I am not in favor of throating anything out any gun that I might want to shoot lighter bullets in.

My general rule is that if I need more bullet weight, I go get a gun with a bigger hole, not a longer one. If it's real short, it will open on it's own over time. It's called wear.

45 2.1
08-13-2006, 05:50 PM
Felix and Bass would be quite amazed to see what a properly loaded lever gun is capable of.

JFE
08-14-2006, 09:00 AM
Thanks for the comments. I'll try to take them one at a time:

1. Felix - "A truly set up gun-boolit combo becomes quite boring."

I've had some successes with cast but also some frustrations too. I'm still at the stage where I'm very happy with successes. Boring is good for the time being !

2. BA - Regarding hunting with hard cast, well I've done that quite a bit already. My hard cast slugs have even been used in a 45-70 to take Asiatic buffalo in Aussie and they performed much better than jacketed. In the same application jacketed bullets opened out up to the size of coat buttons and had no penetration to speak of, whereas the hard cast really performed well, even after smashing through an enormous amount of bone. The jacketed were 400gr Speers and the cast bullets were RCBS 45 405 FNGC and both were loaded quite briskly for a Marlin 1895. Quite frankly I was very surprised by the Speer's performance as up until then I had never recovered one in game - all had exited. But I digress, I'm sure I have a lot to learn from casting and varying hardness will be one of them. So far though this has worked, though it may be unneccessarily hard.

I tend to agree that to the extent possible, you should live with stock chambers, but in this instance I am building custom rifles and can specify the chamber. I am fairly sure that stock 458 chambers have a very long freebore and while it is possible to select cast bullet designs to suit, I think that it would likely mean quite long, heavy bullets and in turn this perhaps means limited flexibility cf what may be possible. I would rather tailor the chamber to something that will have a better chance of working with a wider range of bullets, be they cast or jacketed.

As you rightly suggested, I'll need to prepare some dummy rounds and then work out what is the best compromise. For the 458 Im sure that I will be looking at a relatively short throat (yet to be determined).

Regarding the 50/110, most cast and jacketed designs suited to this chambering are a fairly short design, so I expect with this one too, that the optimal throating will be quite short.

So in summary I should stick to .002" for the throat diameter and work on 3 degree leade. This seems like quite a shallow leade angle. Can you please confirm whether this is correct ?

BTW for both instances I am considering 1 in 20" twists so that cast have better chance of working. Views on this appreciate too.

HJ - strangely enough I also have a few Brownings too: 92, 71 & 86. So far I have only put cast through the 92. Mine has multi-groove rifling and is finicky about bullet design. However once you hit upon the right design it is at least as accurate as jacketed and perhaps marginally better.

I havent tried either the 71 or 86 with cast yet but I do have some thoughts to share. I was actually going to write a separate thread on this but since you raise the question here I'll share my thoughts on the subject.

My Browning 86 in 45-70 is an early 90's vintage SRC. Like yours it has no throat to speak of and this seems to be typical of new Brownings & Winchesters. This is a shame really as all the potential cartridge length available in the 1886 action cannot easily be put to good use. Personally I think that if the throat is properly optimised, the 45-70 would make a more flexible cartridge cf say the 45-90. For my use I plan to use cast in the range 250-475GR and jacketed in the range 300-400GR. The jacketed design I like best is the Speer 350 gr FN. This bullet has 2 canelures, is very hard and has a thick tapered jacket. I believe it was designed for the 458, so it should hold together well in big game. I havent quite made up my mind yet but I am considering throating the chamber to accept this bullet loaded to its rear most cannelure and then select cast bullet designs accordingly. I will take a close look at the how this compares with my existing 45/70 cast bullet designs before proceeding. I'll probably have a custom 450-475 gr mould made up and will ask advice on this when I get to that point.

I have no tips on 348 yet but I have been looking at a few cast bullet designs with no conclusions reached so far on what to go for. With this one I'd be more inclined to work with the stock throating.

Any further comments gratefully received.

Joe

45 2.1
08-14-2006, 09:09 AM
I have no tips on 348 yet but I have been looking at a few cast bullet designs with no conclusions reached so far on what to go for. With this one I'd be more inclined to work with the stock throating. Joe

LBT made me, some years ago, a 250 grainer for the Browning 71 that fits very well and shoots extremely well.

helenajoe
08-14-2006, 10:44 AM
Hi everyone,

Thanks for the heads-up advise on not altering the "no throat" chamber of Browning lever actions so that a wider variety of cast bullet weights can be shot. Sometimes it is best to compromise and live within life's limitations and the same can be said for not trying to alter guns. But since there are all types of people (foolish, stubborn, dreamers, etc.), it is sometimes tempting to "think" about reaming a throat in Browning lever actions.

With that said, I thought I'd share my limited experience with cast bullets in my "as is" factory Browning lever actions.

Model 53 carbine in .32-20 Win
115 gr cast bullets from a variety of molds seem to shoot pretty good.

Model 92 carbine in .357 Mag
Yesterday, I just loaded up some Lyman #358156 SWC gas-checked cast bullets (162 gr weight) and have yet to shoot them. I did discover one 92 carbine has a smaller chamber (maybe bigger throat) than the other 92 carbine I own. When the cast bullets were sized .357" they seemed to fit both carbines good, however when the bullets were sized .358", it only fit one of my 92 carbines. A bit extra crimp solved the problem but that just sized it back to .357", I think. Any advise on how much to crimp cast bullets for Browning lever actions would be greatly appreciated, especially since the "no throat" causes problems when the bullet is chambered.
I hope to soon try other cast bullet weights for my 92 carbines in .357 Mag so any suggestions will be greatly appreciated.

Model 71 rifle in .348 Win
I just obtained a few vintage .348 Win Lyman molds (#350447 casts a 183 gr bullet and the #350457 casts a 250 gr bullet), plus a vintage Herter's mold that casts a 190 gr bullet --- all these molds cast gas-checked bullets. I've been told that the Lyman 250 gr cast bullet won't fit my Browning because of the "no throat" chamber. I hope to cast some bullets from these molds in the near future when I can find the spare time. Meanwhile, this rifle shoots the Hornady 200 gr jacketed bullet very accurately.

Model 86 cabine in .45-70 Govt
I first tired NBC's (National Bullet Company) 300 gr flat point cast bullet and it shoot very poorly, however, their 405 gr flat point cast bullet shot 1" groups at 100 yds. Another 405 gr cast bullet that I was able to shoot 1" groups with was a moly coated cast bullet by Bear Creek Supply. Note: All of these loads are low velocity cowboy and plinking loads. I just acquired a Saeco 350 gr FP gas checked mold, so I'll be very interested to see how that cast bullet shoots. I've had pretty good luck with Sierra's 300 gr FP jacketed bullet at full powder loads. However, I've read in gun magazines that Hornady's new 350 gr FN (made for the .450 Marlin) jacketed bullet won't chamber because the long ogive contacts the "no throat" in the chamber. However, Hornady's 350 gr RN jacketed bullet will fit just fine. I've heard mixed reports on Speer's 400 gr FN jacketed bullet in terms if it will fit the Browning lever actions.

Well, that's my limited experience with cast bullets in Browning lever actions. Any tips or suggestions, especially regarding which cast bullet weights work best, will be greatly appreciated. The "no throat" chamber of these Browning lever actions sure throws a wrench into my fun but I'm learning to adjust.

Thanks,
helenajoe

Bass Ackward
08-15-2006, 06:53 AM
JFE Joe,

From my experience, everything pokes a hole. Cast are most effective when hardness is taylored to the game. I was making an assumption on what that game was. You have two choices for lead. Harden it or get more of it. Sounds like you got it covered.

A three degree leade is about what a good broken in gun will wear to and the maintain regardless of the angle you start with. As a gun get's "shot out" this taper will gradually wear to almost nothing. The 3 degree is so that you are close once you get the tool marks polished off and so you can fit a cast bullet sooner and figure it will be there for awhile. Otherwise they continue to walk on you as they wear in. I would say that you can go up to a 5, but if you plan on shooting any jacketed, you will have a 3 in 200-300 rounds anyway. It's up to you.


Helena Joe,

When I said that I didn't have enough experience with your no throat, I meant just that. I can't visualize it in my mind to offer any suggestion. That .... doesn't necessarily mean that nothing can be done. But it would take a good chamber cast to measure to tell you how to proceed. The worst thing I would want to do is throat beyond my OAL ability to feed. And the fact that two identical guns are different should show you "no throat" is not applicable to "both" guns. Understand?

My Br92 is a 44 Mag with a .430 bore. It has a fairly short throat but I can chamber a .434 bullet without resistance, but it has no front drive band. It won't start to shoot until .432, but does quite well at that point with virtually any design tested. I have one design that at .434 just eats a large hole with 10 shots that you can cover with a quarter at 50 yards. I just mounted a ladder sight from a 92 Winny on it to get rid of that %@&* buckhorn, so maybe 100 yards will be possible now and we will see.

You can design a trunicated cone with a wider front band that will reach out eventually and come close to touching a long throat. Or you can cut the band back for more clearance if needed to load a larger diameter bullet. My point is that in most cases, it is cheaper to build a custom mold, then to alter the gun unless you can do the work yourself. Most levers do their best work at .002 over bore. That sounds like .359 for you. But it would mean less of a front band in your case to work through both levers. There are always "limited" ways around these things. But you still need to see what you are working with otherwise you are guessing.

JFE
08-15-2006, 08:40 AM
BA,

thanks for clarifying your views on this.

I looked through some previous threads where you made comments about rifling type and impact on cast bullet hardness and performance, which I found fascinating. I'll review these posts first, collect my thoughts and post a fresh thread on this subject.

BTW is it OK to mention here that you use jacketed bullets or is that generally frowned upon ?

Joe

Bass Ackward
08-15-2006, 05:45 PM
BA,

thanks for clarifying your views on this.

I looked through some previous threads where you made comments about rifling type and impact on cast bullet hardness and performance, which I found fascinating. I'll review these posts first, collect my thoughts and post a fresh thread on this subject.

BTW is it OK to mention here that you use jacketed bullets or is that generally frowned upon ?

Joe

Joe,

I advocate from time to time the use of jacketed bullets as a method of barrel break-in and no one has chastised me for it. We just don't go over board with the subject because there are formats for that too.

twoworms
10-21-2006, 10:23 PM
My new 500S&W Encore with a 20" barrel has a boolite jump of .608" before the 440 Lee hard cast boolite gets to the lands. The barrel shoots like $*%#, its going back to TC or MidWayArms. I'm not going to try and find a load that shoots in a chamber like that.

Tim...