Operation of the Point Forming Die - Corbin Bullet of the Point Forming Die LEFT: Swaging the bullet...

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Transcript of Operation of the Point Forming Die - Corbin Bullet of the Point Forming Die LEFT: Swaging the bullet...

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    External punch

    PF-1 die

    Press Ram

    Ejection pin(Internal punch)

    Stop Pin

    Punch Head

    Operation of the Point Forming Die

    LEFT: Swagingthe bullet to finalshape in the pointforming die. Theejection pin ispulled downbecause the StopPin engages aslot in the punchhead.RIGHT: Ejectingthe finished bullettakes place whenthe ram isretracted.

    The internal punch has ahead which stops thepunch at a given depth inthe die. Shorter headsmake longer bullets andlonger heads makeshorter bullets.

    Light bullet

    Heavy bullet

    TOP: Swaging strokehead of punch contacts shoulder in ram.BOTTOM: ejection strokestop pin pushes punch forward to ejectbullet.

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    Punch Head


    Hex Bushing

    Punch Tip

    External Punchand Floating PunchHolder retainers fortype -M or -S dies

    (Type -H externalpunches areretained by a hexbushing withoutthe ring)

    Floating Punch Holder

    The FPH-1-M punch holder fits boththe Series II and Silver Press, andholds the external type -M or -Spunch (which is the same punch,used with both -M and -S dies), withthe ring and retainer bushing shown.

    The FPH-1-H punch holder fits theCSP-2 Mega-Mite, CSP-2H HydraulicMega-Mite, and CHP-1 Hydro-Press.No ring is used.

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    Base Guard BulletsThe BG design uses a.030-thick copperdisk to scrape foulingfrom the bore.

    Base punch for BG has a small depressionin the exact center, which forms anextruded lead rivet to hold the disksecurely on the base. The conical-shapeddisk flattens and expands in the die toprecise bullet diameter.

    Hollow Base, Lead Tip Bullet being finishedin the LT-1 die.

    The LT-1 lead tip forming die must be usedwith an internal punch matching the bulletogive, and anexternal punchmatching the bulletbase. The LT-1 canbe used withjacketed or leadbullets to form afactory-finishedappearing tip.

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    In the Mega-Mitehand press, thereare three ejectionbars to matchthree standardlengths of internalpunches. Thecombination of ejection bar and punch resultsin a constant length when properly matches.Short punches use the taller bar, and viceversa. In the Hydro-Press and HydraulicMega-Mite, one ejection bar can be used withall punches because the ejection point is setby a position sensor, rather than being fixedby the press stroke.

    Retraction pin (1/4 inch diam.) fitsunder the retraction spring.

    Ejection bar (fits through the ram,under the internal punch head)

    Hydro-Press and Mega-MiteEjection bar and Retraction pinassembly













    Ejection Swaging

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    Flat Base Internal Punch (usedin CS-1, LSWC-1, CSW-1 dies)

    Dish Base Internal Punch (usedin CS-1, LSWC-1 for shallowconcave base shape)

    Cup Base Internal Punch (usedin CS-1, LSWC-1 for paper-patched bullets, some handgunbullets)

    Hollow Base Internal Punch(used in CS-1, LSWC-1 for leadblack powder and somehandgun bullets)


    BWC Keith Conic 1-E




    Bullets that can be made in a single die using the punch cavity toform the nose (no point forming die required)

    From Left: Target Wadcutter, Button Nose Wadcutter, Keith SWC,Conical SWC, 1-E round nose SWC, 3/4-E round noseSWC, and Auto Loader SWC.

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    Jacket and core length determine bullet styleThe same length jacket (first two on left) can make open tip or leadtip bullets depending on core length. From left: open tip, lead tip.The same core length (last three on right) can make various pistolbullets with different jackets. From third left: full jacket soft point, 3/4-jacket, and half-jacket (about twice as long as a gas check).

    Ring Die

    Rimfire jacket


    Drawn case

    Punch (fits press ram)

    Drawing a rimfire case is like reducing abullet jacket. Fired .22 case is placedover the tip of a punch, and pushed intothe draw die (RFJM-22) to unfold thehead and decrease the diameter.

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    Two-die set for rifle or handgunbulllets consists of (1) CS-1-RCore Seater, and (2) PF-1-R PointFormer. The Knock Out Rod isshown at right (one KO Rod fitsboth dies).

    CS External Punchesshowing jacket fit.

    PF ExternalPunch

    EC-1-R Econo Swage Die

    Retainer Bushing

    Knock Out Rod

    Internal Punch

    Die Body

    Corbin Screwless Lock Nut

    External Punch


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    The 6mmand 224jacketmakers usethe samedie, butdifferentpunchesand ejectorring andtubeassemblies.


    Knock-out rod

    Ring die insert

    Type -R punch(224 calibershown)

    Make a short core to fit main jacketcaliber (may require long punch head)

    Seat the core in the inner jacket usingproper caliber CS-1 die. Insert into theouter jacket. Note lead extension.

    Swage a smaller diameter core to fit intothe inner jacket (use CSW-1 die for thesmaller caliber. Core must extend beyondjacket selected.

    Seat the assembly in the outer jacketin the normal size CS-1 die. Finishin PF-1 die as with any bullet.

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    Spitzer (Tangential Ogive) Bullets are measured incalibers of radius. Illustrated is a 3-1/4 S ogive. Thenose is part of a circle with a 3.25 caliber radius.




    4-S LT

    CB Int. punch

    Swaging a paper patched rifle bullet(1-E nose, Cup Base)The LSWC-1 die forms the nose in a punchcavity. The edge of the punch leaves ashoulder on the bullet. The paper patch canbe wrapped slightly over this shoulder tohelp prevent tearing when fired.

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    Post-point HP bulles can be swaged in two ways. First, youcan use a custom SWC punch to form the bullet shown abovein a single stroke. Second, you can use a separate post-forming HP punch to seat the core, then form the ogive in apoint forming die. This eliminates the SWC shoulder.

    1 2 3

    1. Core toolight orjacket toolongpunch hitsjacket edge.

    2. Almostcorrect.

    3. Perfect fit

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    Lead tip bullets can be made more precisely by using the LT-1Lead Tip Forming Die (do not confuse the TIP forming die withthe POINT forming diethe point former refers to the entire

    ogive or nose curve, and the tip ONLY refersto the very end of the point or ogive).

    The LT-1 die has an internal punch (shown)which shapes the lead extruded from thejacket end when you form the ogive. Very lightpressure is used to avoid putting a shoulder inthe jacket from the punch edges.

    SPIRE point is a termused to describeconical or angled riflebullet noses. It isessentially a jacketedconical style with along nose.

    A conical nose bulletgenerally is of theSemi-Wadcutter

    style, having ashoulder and a lead nose.

    The TRUNCATEDCONICAL or TCstyle is a cut-off(truncated) coneshape. It can bemade without ashoulder, in theTC point form die.

    The KEITH nose isa TC SWC bullet,with a lead noseformed in apunch.

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    Seat Core Curve Open Base Roll Base Flatten Base

    Making a FMJ Bullet in PF-1 Die

    CS PFBaseRoll

    Core Swage Die (CSW-1) also similar to LSWC-1 Lead Semi-Wadcutter die in concept.

    Core Seating Die (CS-1) also similar to LT-1 Lead Tip Former inconcept.

    Point Forming Die (PF-1) also similar to RB-1 and BT-2 dies (partof RBT-2 set) in concept.

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    Conventional Boattail Bullet

    Streamlined base directs muzzle blast gasin a laminar flow pattern, breaking up in front of thebullet, contributing to larger groups.

    Rebated Boattail Bullet

    Shoulder acts as a spoiler todeflect muzzle blast gas in a ring,leaving a clear path in front of thebullet , aiding smaller groups.

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    1 2 3

    TOP: FormingHollow Point inthe core seatingoperation, usingexternal HP CSpunch.

    BOTTOM:Forming theogive in thePoint Formingdie changes theshape of the HPcavity.

    Hollow Point Bullet Making

    1. Core Seating punch is too small for the jacket wall thickness orlength of core. 2. Perfect fit. 3. Core Seating punch is too large forthe wall thickness (may fit with a heavier core or thinner jacket).

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    Bullet Reducting Die (BRD-1)

    Guide bushing

    Ring Die (constriction)

    Ring Die (mouth)

    BRD Punch (fits pressram; die fits press head)

    Maximum practical reduction of a bullet isnormally about .005 inches.

    Paper Patched BulletsABOVE: 1-E CB LSWC style, can bemade in a single stroke in theLSWC-1 die.RIGHT: Smooth ogive 1-E CB bulletmade in two dies (CSW-1 and PF-1)to eliminate the shoulder.

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    Secant Ogive Bullet - used in U.L.D. (Ultra-Low Drag) design


    Same curveattachedtangent toshank makesbullet too long

    Secant isoffset andmoved backfrom tangent


    Open Tip

    Multiple Jacket Bullet

    The Multi-jacket design provideseven more protection than thepartition style, launching a wadcut-ter within a streamlined airframe.

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    The SPIRE POINT bullet would be called a conical in shorter,pistol styles. It uses a straight, angled nose rather than a curvedogive nose, joining the shank at an angle.

    Sabre-Tooth Core Seating Punch This punch is alwaysused with hollow pointlead tips to avoiddamaging the sharpedges of the punch. Theedges of the jacket arejust barely cut, so thejacket opens quickly onimpact along each nick.

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    BPK-1 Bullet Polisher Kit

    The mounting bracket isused to fasten the vibratormotor t