.50/20 Rifle Project – component set, tooling, presses, brass ++

ELR researcher

.50/20 Rifle Project – component set, tooling, presses, brass ++

Pic of cartridges
– left to right, .50/20 Oscar, .50 BMG, .50 T. W. The first and third are based on the readily-available, 20 mm, Vulcan cartridge case.

Actions – 05312019 UPDATE - the action parts have been shipped to Heritage to open up the threads to class 2 and then on to Parker Trutec to QPQ the receivers/bodies. These "fixes" should resolve any galling issues and get me back to offering two (2) actions. Set/all price back up accordingly.

, custom-design, screw action. (2) bolts and (1) receiver. Bolts and receiver are 4340 steel (raw stock from Fry Steel), pre-machining, through-hardened to 44 Rockwell C. Machined on state-of-the art, CNC equipment by Heritage Arms, Loma, CO. DROS’d in sunny So Cal, 100% California/US legal. [The image distorts the sizes, both actions are the same size.] Includes (2) custom, 6” long, polished SS, zero MOA, Pic rails by Murphy Precision (with attached hardware and side bar to attach ground lead for the firing system). Includes drive sockets for receiver and bolt and 1/2”-to-3/4” drive adapter for the larger. Includes pin spanner for bolt (large spanner pictured in error and not included - design changed to add machined hex in receiver and added the noted socket).

NOTE: The distance from the centerline of the action to the bottom of the cross slots in the included Pic rail is about 1.95”. The distance from the centerline of the 2.5” barrel block to its top surface is 2”. Therefore, depending on the scope mounting system used by the buyer, there may not be sufficient height to clear the scope’s objective lens – in which case a riser and longer rail mounting hardware will be required.

Barrel Blanks (total of 7, all un-chambered, un-threaded for brake):

(2) K&P 416R, .500 bore/.510 groove, 2.5” straight cylinder, 1:11 twist, 45" finished, pre-machining cryo’d by 300 Below, Sunnen-honed by Benchmark

(2) K&P CM, .500 bore/.510 groove, 2.5", straight cylinder, 1:11 twist, 45" finished, Sunnen-honed by Benchmark

(1) K&P CM, .500 bore/.510 groove, 2.5", straight cylinder, 1:11 twist, 30" finished (for interim development)

(2) K&P CM, .500 bore/.510 groove, 2.5", straight cylinder, 1:11 twist, approx 22" finished (for initial development and fire forming)

Brakes – (2) Advanced Long-range Systems/ALS, .50 cal

Tuner – custom, from Rifle Accuracy Systems/RAS

Chassis – custom, barrel-block design in 7075-T651 aluminum (raw stock from Jorgensen Steel). Machined on state-of-the art, CNC equipment by Heritage Arms, Loma, CO. (2) barrel blocks – one for 2.0” barrels and one for 2.5” barrels. Includes a pair of spring-back handles and a full set of hardware items for base chassis and barrel blocks. Includes a heavy duty transit box – the intent being to travel with the base in one box and the barrel-block-barreled-action subassembly in a separate heavy duty box (never built), mate up at destination. The rear of the chassis is 5” wide with 1” (square) side rails; the front is 9” wide with 1” (square and full-length) side rails. Design is intended to be used with a SEB Maxi rest with narrowed, side-support inserts to allow for the 9” footprint – I had one but sold it; rear rest of typical front rest design but used in the rear – I had a John Loh with 5” top but sold it.

NOTE: While this chassis was designed for this combination of components, the 4.5” long x 3” wide “hole” would accommodate a conventional action design where the trigger is as much as 11.5” back from the action’s front face (assuming that the front of that action is positioned just at the rear of the barrel block).

Firing System – wireless, electric, using Winchester, PA-520, 20 mm Vulcan electric primers; uses a spring-loaded, insulated, copper conductor; includes the associated power source (dual, 12V, rechargeable batteries), cable set, WiFi remote box, (2) “trigger” fobs, and charger. This design has been proven very (100%) reliable in firing the noted primers.

NOTE: The brass takes either electric or percussion primers (same primer pockets and flash holes), both of which are readily available. The action design in this ad is electric-priming ONLY. Also, the only “firing pin” that currently exists is installed in the spare bolt. I will prepare and assemble ones for the other two bolts prior to delivery.

Reamers and gauges (including a non-exclusive, non-commercial, right to the “.50/20 Oscar” design; print only for the “.50 T. W., not my design, unrestricted to me”):

".50/20 Oscar” – (1) removable-pilot rougher and (1) finisher reamer, both carbide and Inferno coated; (1) Go and (1) No-Go gauge, all by Pacific Tool and Gauge/PTG; all new, never used

”.50 T. W.” – (1) removable-pilot finisher and (1) resizer, HSS, by JGS; and (1) Go and (1) No-Go gauge, by Pacific Tool and Gauge/PTG; reamers used very lightly by designer/original owner, gauges are new, never used

Plus a PTG Uni-Throater , .50 cal, new, never used

NOTE: The action design is ZERO headspace (screw in the bolt until the cartridge stops in the chamber), so NO gauges are needed – they were purchased, and are included, in case the action design was determined inappropriate for my application, unlimited range shooting.

Custom Dies (2 sets, never used):

“.50/20 Oscar” die set – custom, forming and full length sizing with the required bushings; arbor-press-style seater die and base (for use with K&M Force Measurement arbor press); from Warner Tool/WTC

“.50 T. W.” die set – custom, forming and full length sizing with the required bushings; arbor-press-style seater die and base (for use with K&M Force Measurement arbor press); from Warner Tool/WTC

NOTE: After I completed photographing these die sets, I noticed that the sizers had somehow gotten switched, thus the “wrong” tags on each in the pic – those dies have since been physically swapped to their correct boxes. In any case, all the parts are there between the two boxes.


(99) pieces of each cartridge design, Warner Tool formed and turned, new brass. [Pic shows 100 each but I’m keeping one each for the memories.]

(33) pieces of new, unmodified brass (20 mm Vulcan), all but 4 have had primers installed, cleared, and those primers removed.


(98) pieces of GS Custom (GSC), 910 gr, (510910SP307) - http://www.gscustomusa.com/510910SP307.html

(43) pieces of GS Custom (GSC), 975 gr, (510975SP269) - http://www.gsgroup.co.za/510975sp269.html

(45) pieces of GS Custom (GSC), 1030 gr, (5101030SP258) - http://www.gsgroup.co.za/5101030sp258.html

(100) pieces of GS Custom (GSC), 1100 gr, (5101100SP097) - http://www.gscustomusa.com/5101100SP097.html

(400) pieces (approx) of South African 690 gr, M2 ball – for fire forming

Primers – approx 1950 pieces of Winchester, PA-520, 20 mm Vulcan electric

Reloading Equipment:

Press - CH4D Rock Crusher http://www.ch4d.com/products/equipment/presses/RC000), 2"-12 top thread for WTC dies, new; reworked by Warner Tool (to improve alignment); includes (2) CH4D #4535911 shell holders

Press stand - Corbin CSP-S, adjustable height (http://www.swagedies.com/mm5/merchant.mvc?Screen=PROD&Store_Code=CBST&Product_Code=CSP-S&Category_Code=H-press)

Custom interface plate between Corbin stand and CH4D press; built by Warner Tool

Press, arbor - K&M #ARPRASM special (longer length) with force measurement, including Mitutoyo digital indicator

Primer seater - M2 Precision (http://www.m2precision.com/products/primer_seater.html); modified to accept 20 mm Vulcan cases

De-priming tool with 20mm Vulcan case adapter - from Patrick Bieck

Flash-hole-drilling alignment bushings – (2) custom; takes a #27 drill bit (McMaster-Carr #3584A183), bit NOT included

Primer pocket uniformer body (custom) and 21/64" end mill, TiCN coated carbide (McMaster-Carr #8515A316)

Case trimmer - Wilson CTS-50MKIT; Ti-coated cutter (Wilson # CTP-50TNC); custom case trimmer mod (riser and larger end pieces added for the much larger Vulcan case) and custom case holders (one per cartridge case design)

Cartridge measurement base – custom (to fit Vulcan case, slotted on the bottom to fit standard calipers)

Other items (included in “all”):

Barrel vise – custom, accepts up to a 3” diameter barrel

Cleaning rod – Tipton carbon fiber, 62” long (front of handle to end), no longer in production

Transit case for smithing on development barrels and actions – Pelican iM3100 and heavy duty outer box

Weight, complete with 45” barrel, in 2.5” barrel block – approximately 155# [base chassis is approx 65#, barrel blocks are approx 15-17# each, 45” barrels are approx 61# each, complete action and rail (set) is approx 9#, and the brake is approx 3#.]

Length, complete with 45” barrel and brake installed – approximately 64”

No “performance data” are available on either cartridge in this or any other base configuration. Purchaser/reloader – as always, proceed with CAUTION! I will point the buyer to a source of very slow burning powder.

Why I’m selling – I’m too old and weak.

Priced as a set/all - $28,778 plus actual cost to ship (USPS ground for the actions, fully insured for the sale value; balance by carrier of buyer’s choice, fully insured for sale price); check or MO only, I do not do PayPal or wire transfers. Before you gripe about the price, my cost for the above was just short of $43,000. Alternate “set” (less action pieces, firing system, and electric primers) - $24,337 shipped directly to the buyer at actual cost to ship, fully insured for the sale value by carrier of buyer’s choice. Same payment terms. Because of the bulk of the items, a freight carrier and a custom set of heavy duty, cardboard boxes would likely be the least expensive.

Transfer of the actions must be conducted through your FFL and the actions must be shipped to the FFL – everything else will ship direct to the buyer. The FFL needs to e-mail me a copy of their license. After I confirm the FFL is current and that the FFL’s shipping address matches the ATFOnline database, and your check or MO clears my bank, I will promptly ship.

Please address detail questions to webmaster at elr-resources.com. Serious buyers, please e-mail for more pics (max 10 on this site) - please be very specific as to what you are looking for. Thanks for considering purchase of this excellent gear.


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Feb 7, 2019
Not in my budget, but made me drift off thinking of crazy cool ideas!!!
Have seen videos of the URSA, if I do buy the DT 416 might meet you