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Sizing, swaging, bullet obturatoin
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(I also posted this on Graybeard - swaging) but since I've seen some folks from Shooters.com here I thought it would catch a some good responses here.

One of the concerns in cast bullet shooting is obturation (sealing) of the bullet in the throat of the barrrel. With jacketd bullets the typical arrangement is that of a straight taper is met by the curvature of the ogive giving a circular line of contact around the bullet to the bore. But with lead bullets there is more to conisder, because of the softness of the lead. Some have found that by carefully matching the taper of the throat with the taper or form of the bullet gives greater accuracy.

What I am looking for is knowledge or experience in creating this match between bullet and bore. Casting a bullet requires a mould of a particular shape. It is a major undertaking to make or modify the cavity to make a change since it is irreversable.

Could then, a press be used to swage all or part of a cast bullet to modify the shape or diameter of the nose of the cast bullet, to modify the shape or diameter of the bullet where it seals, or to modify the major diameter (as in sizing/lubricating) of the cast bullet?

Perhaps this could be done with a modified nose punch for one of the common lube/sizers?

Going in a different direction, Lee has come up with a neck sizing tool that (I have only read of these) compresses from the sides to get the neck of the brass to a specific diameter. This leads to the question of could not a similar technique (radial instead of axial) compression by swaging - as a technique used with existing forms of bullets?
 
Posts: 621 | Location: Virginia mountains | Registered: 25 December 2002Reply With Quote
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trk--

This subject has had some discussion at Shooters from time to time, and now has some currency for me as well--given that 9.3 caliber molds are more than a little scarce. I'm pondering whether to swage down .375" caliber castings or try to "bump up" .358's. I'm leaning toward the former solution, since it would accomodate gas check designs as well as plain bases. What I think will work is to size and lube castings at .375", then run them through a .368" (throat diameter) die to get them ready to load.

Anyone with experience in this venue PLEASE chime in with info. I'm thinking that the filled lube grooves won't collapse during swaging.

As for "bumping up"--I don't think the 450 sizer would last very long with a steady diet of bump-ups with harder alloys. Corbin's does sell swaging die sets for those J-word bullets that are usable on O-frame reloading presses, and I would think that such a press or a bench vise might be a better fixture for heavy swaging or reforming than the sizer/lubricator. Dunno what die or forming jig could be used, but if such a tool were available I'd be all over it for the .366 bullets.

Deputy Al
 
Posts: 299 | Location: Yucaipa CA | Registered: 21 December 2002Reply With Quote
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trk, Deputy Al, This topic has also surfaced from time to time in the Cast Bullet Assoc. journal. From what I recall, there are four options: Some sort of fixture (nose punch of sorts) that mounts on a Lyman/RCBS lubrisizer; a press mounted device (elaborate nose punch) that reforms the forepart of the CB; or a press mounted die (and punch) which tapers the CB to fit a particular throat; or a mould that casts a tapered bullet. The press-mounted die and punch used to be available from Ed Wosika (the original Hanned Line), but a skilled machinist could fabricate one as well. Btw, the CBA article claimed that results from the press- or sizer-mounted "punches" were inconsistent and that such tools were fairly expensive. I certainly agree with the last part, but not the first: My Hanned die gives very consistent results as long as the CB's aren't overly hard. As for a tapered mould, there are several Lyman and one Saeco "off-the-shelf" design that work very well. However, you may well require a custom design. Hope this helps, ...Maven
 
Posts: 6 | Location: Kingston, New York | Registered: 25 December 2002Reply With Quote
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I do both-- taper size and bump checks for flatness when using 8mm's for 30's [don't ask].

I accomplish a taper by running the as cast slug into the Lee sizer-- in my case a 309, just far enough to put on the profile I want. In my case a Lee 180 made PB goes from 309 to 311 at the base. I take a wad of tissue/toweling litely moisened and run it down the exit hole. Then I use a 312 rod to tap out the slug. Actually it goes quite fast once you establish a rythmn. Have an idea for what I call the Lee Yoke to make this setup return the slug-- mentioned this once on Shooters but nobody fired on it.

The bump could be accomplished in a Lee Yoke setup, but now I use a faced off 312 rod in an 06 case-- setting the mounted check on that pad and running that slug into the seater [Lee Collet] which will hold a Lyman nose punch-- just give it a little play. You adjust by thread length on the seater die-- I usually bump to square/flatten checks-- but do bump the whole slug at times. Very controllable and repeatable-- you might have to tap your die body to release that slug when using more than moderate pressure.

While I've got you on the line Tim, could I see that data on the software too? Thanks.
 
Posts: 1529 | Location: Central Wisconsin | Registered: 01 March 2001Reply With Quote
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Another thought on obturation...

I always run my check dia at least a half thou over the origin dia of the throat. In some guns this isn't possible-- my Marlin MR-7 06 for one-- which I hold at 312. Most all of my check dia's are at least 310+ though.

This where good lube also comes into play. What lube does at origin is blow FORWARD to some extent-- like the guy with his finger in the dike. What good lube also does is seal the land engravement dia on that slug down the tube [varies down the average tubes we normally use]. I've done the torture testing... some lubes won't accomplish this. LBT Blue, Taurak [don't bother with it] and Gray 32 made it thru the last testing out of six formula's. I have a new version of my own which was fired at 2600+ that shows promise too.

Nother thought. Look at the Quik load data--it shows bullet movement before the hammer drops fully. I think in most cases the bullet is well engraved before peak psi is reached. I note in some slow fuel loads with the 06 the bullet is 1.5" down the tube before the peak is reached. And actually I think if your loading your cast as most accuracy shooters do-- the bullet is more swaged than anthing, and compressed and length shortened. I do not think the forward ogive swells/bumps on heat treated slugs.
 
Posts: 1529 | Location: Central Wisconsin | Registered: 01 March 2001Reply With Quote
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Deputy Al, I fantasized about a 9.3X62, but chose the coward's way out with the better availability of everything for .35 Whelen. Despite smears by a number of gunwriters the .35 Whelen gives no trouble with its "lack of shoulder" EXCEPT WITH REDUCED LOADS. After 9-10 firings with light CB loads my Forster case gauge shows excessive CASE headspace, and occasional misfires occur. Of course, the solution is to start over with a new lot of free .30/06 cases. Does the sharper shoulder of the 9.3 prevent head to shoulder shortening after repeated firings with reduced loads? Also, am I correct in assuming that .375 gas checks will work for 9.3 bullets? After all, .30 checks work on cast bullets from .301" Carcano up to .314" fat .30s.
Regards, curmudgeon
 
Posts: 99 | Location: Livermore, CA, USA | Registered: 22 December 2002Reply With Quote
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Curmudgeon--

I'm not sure what gas check would fit on whatever .366 mold that might turn up. I've only seen the drawings on the NEI website for their molds, and I'm guessing that .375's would be the appropriate critter. Dunno for sure.

.375 molds are pretty common, so that's probably the direction I'll go--swage them down to throat diameter.

First thing to do--fire form some casings from 35 Whelen brass. 28 bucks per 100 for the Whelens, or 71 bucks for Norma 9.3 x 62......kind of a no-brainer, that one.

The CZ will be coming to Winnemucca, even if all I can cobble up is J-word bullets. I really think this will be a GREAT cast bullet project rifle, but getting started with cast bullets is a little like the traction coefficient of wet ice on Teflon--NONEXISTENT.

Deputy Al
 
Posts: 299 | Location: Yucaipa CA | Registered: 21 December 2002Reply With Quote
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A number of years ago Handloader Magazine had an article about using C&H standard swaging dies to true up 357 cast bullets. He was pushing a hollow point into the usual SWC to fill any possible air pockets and at the same time he was trueing up the base.
As I remember he was very empathic about having lube in the grooves so they would not collapse while the bullet was being swaged.
It's my guess that you might find a set of old Mity Mite dies that could do the swaging in your reloading press.
I use all of my cast bullets that don't meet my standards and run them through a Corbin swaging rig to make full and semi wad cutters for 45 Colt, another die to do the same for 45 Auto Rim, another die for making 357. I've enjoyed making and shooting plain base bullets with knurled sides for lube, gas checked knurled for lube, and Corbin's basegard without lube. A 45 caliber wad cutter makes an impressive hole.
I've not done any rifle bullet swaging in the Corbin.

Does Lee make their sizing die, the push through, in the diameter you need? If they have a die that's close you could lap it out to fit.
I wonder why the gun writers beat up on the 35 Whelen for not having enough shoulder. I've got a 375 Whelen that I had made for the sole purpose of shooting lead alloy bullets. This rifle has never had a shoulder problem and handles lead alloy bullets wonderfully.
I've used the Saeco, Lyman, RCBS molds for the 375 with what I think of as outstnding accuracy. The premier bullet is a 300 grain from NEI. This bullet has a long bore riding nose with a narrow band up front to center the bullet in the rifling. My results show it as being very functional. I think they can put that narrow band on most bullets with the appropriate nose.
This is a bit of a hodge podge, I hope it helps.
Jim
 
Posts: 5797 | Location: Richmond, Virginia | Registered: 17 September 2000Reply With Quote
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Curmudgeon -
With you cases showing head space at 9 - 10 loadings with light loads, wouldn't they reform out to specs by firing a heavier load, ie fireforming? Are you full length resizing, or neck sizing only?
Am I missing something here?
 
Posts: 922 | Location: Somers, Montana | Registered: 23 May 2002Reply With Quote
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Waksupi, All you are missing is my laziness. As I shoot on a large public range I can get all the once-fired brass I can use. In fact I only save R-P because that is what my donors leave most often. :-) I form .35 Whelen from .270, first expanding them to .30, then .35. Because of the greater length of .270 cases, by the time I get them up to .35 Whelen they are not too short, as would be the case if I started with .30.06 cases. For full power loads with J-word bullets I use factory .35 Whelen. I am so blessed in brass supply that I never bother with annealing. I neck size in a true neck sizing die, but the reduced loads get shorter and shorter in head to shoulder length. I never have been bothered by this phenomenon with any other caliber, nor with full power in the .35 Whelen. Regards, curmudgeon
 
Posts: 99 | Location: Livermore, CA, USA | Registered: 22 December 2002Reply With Quote
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I was going to recommend the same thing - full power loads. I too collect brass at a public range & am getting pretty selective on what I pick up.
 
Posts: 621 | Location: Virginia mountains | Registered: 25 December 2002Reply With Quote
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quote:
Originally posted by Deputy Al:
Curmudgeon--

I'm not sure what gas check would fit on whatever .366 mold that might turn up. I've only seen the drawings on the NEI website for their molds, and I'm guessing that .375's would be the appropriate critter. Dunno for sure.

.375 molds are pretty common, so that's probably the direction I'll go--swage them down to throat diameter.

First thing to do--fire form some casings from 35 Whelen brass. 28 bucks per 100 for the Whelens, or 71 bucks for Norma 9.3 x 62......kind of a no-brainer, that one.

The CZ will be coming to Winnemucca, even if all I can cobble up is J-word bullets. I really think this will be a GREAT cast bullet project rifle, but getting started with cast bullets is a little like the traction coefficient of wet ice on Teflon--NONEXISTENT.

Deputy Al

Deputy Al,

I'm also planning on a 9.3X62, as a cast bullet shooter. I e-mailed NEI before Walt passed away, and they said to use .375" gas checks with their mold. I also wish there were a better selection of molds. That said, as this is an international site, perhaps the European or Australian members can let us know about other sources of 9.3 molds.

The CZ's are nice, there is a full stock 550 in the local shop in 9.3X62 that I always fondle whenever I stop by. That said I'll likely assemble mine on a VZ-24 action using a Lothar Walther pre threaded and deep chambered barrel.

There are lots of 9.3 shooters, check out the medium bore board when you get a chance.

As far as the suggestion of a 35 whelen, I went the slightly more work route of a 35 AI, then had it re-chambered to the lots of work or lots of money for brass option of the 350 Rigby. The upside is the re-chamber has cured the guns being picky about loads, and it really shoots. I just need to pick up a 250-280 gr mold to see what it will really do.

I've debated building a std whelen, but I guess I'm esoteric at heart, so will go with the 9.3X62 [Big Grin]
 
Posts: 7205 | Location: Alaska | Registered: 27 February 2001Reply With Quote
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Paul--

Thanks for the confirmation on the gas check size for the 9.3 mm molds--wherever they are! I am kind of an enthusiast for off-the-wall calibers, so I'm accustomed to dealing with "hard-to-find" components. I reloaded 30 Mauser and 9mm Makarov long before components were available, so I've "seen this movie".

I've haunted the Medium Bores site, and so far no responses to my inquiries on the subject. I suspect that most users of this caliber have a lot more use for heavily constructed large game bullets than for cheap practice ammo, but the caliber seems practical for a large range of uses.

Deputy Al
 
Posts: 299 | Location: Yucaipa CA | Registered: 21 December 2002Reply With Quote
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Deputy Al,

I here so many good things about the 9.3, as well as that I believe Hornady will be offering factory ammo in the future, that I just have to build one. That and the Lothar Walther barrels being only $150 odd plus shipping.

If you're looking for something different in a 35 bore, check out the 350 Rigby. It's old, having been introduced in 1904, and it's a neat round. Think of the 375 H&H case with no belt, 2.76" long, with a 45 deg shoulder, and you have the 350 Rigby. I've been making my brass by de-belting H&H cases, cutting the extractor groove deeper, fl sizing, trimming, then fire forming. I could by Bertram brass, but @ $3 a case, I'd rather not! So far I've found one really good load, 14 gr of unique pushes a 200 gr WFN gc @ 1400 fps and I'f shot 5 shot 50 yd groups of 1/2". 100 yd groups should be 1", but I always seem to get a flyer that opens it up to 2".

What part of California is Yucaipa in? It sounds like a Northern local, I lived in the bay area just shy of 30 years before moving up here, but never heard of Yucaipa.
 
Posts: 7205 | Location: Alaska | Registered: 27 February 2001Reply With Quote
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In case y'all forgot (easy fer some you 'old timers' - HAR!) the swage-o-matic is on castpics for your viewing pleasure. I have one, and it certainly is a marvel. Never used it, but might need it someday. Seems like a feller could manufacturer his own swaging dies if needed. sundog

http://www.castpics.net/RandD/swage_o_matic/swage_o_matic.htm
 
Posts: 287 | Location: Koweta Mission, OK | Registered: 28 August 2001Reply With Quote
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Paul--

Yucaipa is about 70 miles east of Los Angeles, not nearly far enough away. My house is at the base of the San Bernardino Mountains, so hunting and fishing is near at hand.

Deputy Al
 
Posts: 299 | Location: Yucaipa CA | Registered: 21 December 2002Reply With Quote
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I can't comment on sizing bases with collets but I have been sizing noses down. My 7.5 Swiss needs a nose diameter of about .2953" to chamber. The Lee 200 gr. bullets I use have noses that are .300". To get the noses to fit I use a 19/64 lathe collet. The nose is put into the collet about .03 from the first driving band. The collet is then closed to compress the nose. On long bullets like this one it takes a little force. These bullets are water dropped wheel weights. Time is also important so a rythm is crucial for consistent sizes. After the first sizing I open the collet and rotate the bullet about 60 degrees and close again to iron out the bumps left between the 3 collet sections. I can hold diameters to a couple of 10 thousandths with this method. These bullets shot with 13 grains of Red Dot shoot as well or better than my jacketed loads. I'm using military cases modified to use small rifle primers.

I did make a sizing die for the Swag-o-matic to try and size the noses down but the collet works much better. It doesn't deform the nose or the base.

I've also tried to size the case necks down in the collet but a mandrel is necessary to keep the neck round. I'm using a .32 ACP die for neck sizing now and expanding it up with a M die.
 
Posts: 8 | Location: Northern Colorado | Registered: 30 December 2002Reply With Quote
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Curmudgeon...I find it interesting that you have developed case headspace on the Whelen after firing....I think you said "Mild" CB loads.
What is considered a "Mild" load? In my mind, 'mild" would be about 1300 / 1500fps in light for caliber castings???
Would you elaborate a bit more on this? I have some 1962 LC NM brass that must have at least 50, maybe even 100 firings on each case, from what I call mild loadings...Do I have case headspace and don't know it? I have not noticed anything out of the ordinary, but after reading this I will be doing some serious checking.
Respectfully, Russ
 
Posts: 65 | Location: Washington State, Columbia Basin | Registered: 01 January 2003Reply With Quote
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Russ, My cast bullet loads are usually twenty grains of Alliant 2400 with a NEI 220 grain bullet @ 1700 fps. Also shoot some loads of seventeen grains of Alliant 2400 with a 255 grain Hoch bullet @ 1400 fps. After 9-10 firings I will have up to 20% misfires, though most will fire on a second attempt. Checking the offending cases with a Forster case gauge always shows that the case is short in head-to-shoulder length. At this point I dump the cases and start over with a new bunch of R-P .270 cases. (Actually, now that I can reproduce this situation at will, I now dump the cases BEFORE misfires start appearing.) I prefer .270 cases for forming .35 Whelen because they start out some .050" longer OVERALL than .30/06 and by the time they are stretched out to .35 cal. they are right at factory .35 Whelen length. As I have an endless supply of .270 cases at a large public range :-) I never bother with annealing. When I say that pressures of my cast bullet loads are "mild" it is a cop-out. I have little idea of actual pressures but I neck size in a true neck sizing die and never need to full-length resize. Full power loads never exhibit this increasing headspace. I have read in several sources that light loads can cause shortening head to sholder length in rimless cases, but the .35 Whelen is the first example I have seen, and I have loaded light cast bullet loads in 7x57 and .30/06 more than 30 times in the same neck-sized cases. Part of the reason that I use factory .35 Whelen cases for full power loads and .270 cases for reduced loads is that the differing headstamps help me to keep from firing a maximum load in a case with excessive headspace. Hope this helps, curmudgeon
 
Posts: 99 | Location: Livermore, CA, USA | Registered: 22 December 2002Reply With Quote
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curmudgeon I wonder if seating the slug against the leade thereby holding the head against the boltface would help?

You probably tried this..?
 
Posts: 1529 | Location: Central Wisconsin | Registered: 01 March 2001Reply With Quote
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Aladin, Seating the bullet out doesn't help the headspace situation, though my best accuracy is with the bullet seated out far enough to engrave.
 
Posts: 99 | Location: Livermore, CA, USA | Registered: 22 December 2002Reply With Quote
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Originally posted by curmudgeon:
Aladin, Seating the bullet out doesn't help the headspace situation, though my best accuracy is with the bullet seated out far enough to engrave.

So what must be happening is the pressure isn't enough to expand the neck brass to the chamber wall for a seal-- and the gas force pushes the shoulder back? Or is it from firing pin strike?
 
Posts: 1529 | Location: Central Wisconsin | Registered: 01 March 2001Reply With Quote
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Until Felix or Buckshot checks in with an explanation, it is a big mystery to me. In the meantime i'm just doing what works! Regards, curmudgeon
 
Posts: 99 | Location: Livermore, CA, USA | Registered: 22 December 2002Reply With Quote
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curmudgeon,
I have seen rimmed cases have primers backed out from low pressure loads. But I have never seen primers back out with rimless cases like 300 savage. I have had 300 savage case necks set back with low powder loads in my T/C. I would take 5 cases and check them after each shooting and see how much the set back is after each loading. Orygun
 
Posts: 210 | Location: Willamette Valley | Registered: 11 March 2001Reply With Quote
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Orygun, My .35 Whelen does not back out the primers with reduced, or any other, loads. The only backed out primers in rimless cases I have seen have been in well-worn milsurps while firing full power ammo, a situation that is easily fixed by partial full-length sizing. Partial full-length sizing creates a secondary shoulder which holds the case head against the bolt face and voila! a custom fitted case for a long chamber. Just for curiosity I should try partial full-length sizing in the Whelen with reduced loads. My guess is there won't be enough pressure to hold the case tightly to the chamber walls and the cases will still shorten from head to shoulder. Weather permitting, I should be able to confirm or deny my guess in about 90 days. As this never occurs with equally light loads in 7x57 or .30/06, I tend to attribute it to the Whelen's small shoulder not holding the case contacting the bolt face against the firing pin blow. It does not happen with full power loads in the Whelen. This is turning into a lengthy project. I still believe it is easier to dump the cases after nine or ten firings, but it will be nice to know :-). Regards, curmudgeon
 
Posts: 99 | Location: Livermore, CA, USA | Registered: 22 December 2002Reply With Quote
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