The .43 Spanish Experience
You will laugh, you will cry, you will turn to strong drink...
As always, contact me HERE with corrections, explanations, or other pertinent information about the .43 Spanish -OR- Remington Rolling Blocks.

Lost in time, a laminate stock 1879 Argentine Rolling Block followed the old retrobate home. Along with it came some non-descript cases, a Lee .439 push-through die, a 2-die set of Lee .43 Spanish dies, a box of .446 boolits, and a lingering question if it was worth shooting. The barrel is about 20", has a front sight base soldered over the dovetail for the original sight, possibly a Krag or 1903 rear sight, and it has a sparkling clean bore and chamber. After looking at some pictures of barrels, it looks like the barrel was shortened and rechambered. The octagonal segment of barrel seems awful short. It looks brand new, er, old. Then I finally decided to try and get it shooting again. Not sure if I'd have been farther ahead with a Jägerbomb or a Jäger-train, but fools rush in where angels fear to tread...

Shooting the .43 Spanish Rolling Block by Croft Barker ISBN-10: 0971512833
M1879 Argentine Remington Rolling Block:
The internet and firearms research with reference to the .43 Spanish Remington Rolling-Block and its ammunition, David A. Thombs & Stephen P. Barrett, pg 14-23 The Journal of the Historical Breechloading Smallarms Association, Volume 4, No. 4
Lee 43 Spanish Limited Production 2-Die Set 90765 Probably has the #17 Shell Holder.
RCBS #22 Shell Holder #9222 Buy this once.
Lee Powder through expanding die only #809991 (Does not have expander plug, but any Powder through die will work)
.439" diameter Lee Neck Expander Plug, Track of the Wolf
.43 caliber Lee Powder Compression Plug Track of the Wolf

Rifling Forms  use of cast bullets in 2 and 5 groove barrels
Cast Bullets in Rifles: Bullets, loads, accuracy – Part 4 of 4 page 105, NRA Illustrated Reloading Handbook, COL E.H. Harrison
While reviewing the ILH, I looked at the rifling kinds, and read the five groove (used by the .43 Spanish), then I noticed "Cast bullets should be chosen as for use in barrels with 2-groove rifling.” I report, you decide...


“2-groove rifling – To speed production, most M1903A3 barrels were rifled with only 2 grooves... Cast bullets with short groove-diameter body, the rest of the bullet bore-size, are guided positively by the abnormally broad lands, and shoot excellently in these barrels...”
“5-groove rifling -... Essential characteristic is not the number of grooves, but the equal width of lands and grooves. Lands therefore occupy half the bore. Cast bullets should be chosen as for use in barrels with 2-groove rifling.”

Weaver #90 Scope Base Installation
  Wow. Let's approach this cautiously. I didn't, and it required MATH plus tedious indication to correct a problem...

brstevns wrote that he successfully installed a Weaver #90 (#48090 for Marlin 39A, 39D) on his Argentine Rolling Block. It was as simple as putting the screws in and a little file work where the base touches the octagon part of the barrel. No problem...

In a sane world, the original rear sight screws (what size are they?) managed to fit within the mounting holes in the #90 base. No special diddling required, it seems. Well, the rear sight screws had been re-tapped to 10-32. The diameter of a #8 screw is .064, a #10 screw has a diameter of .090, so IMHO, something that fit in the original #90 holes at the original Center to Center, will have to deal with .026 extra outside distance between the screws. So I had to measure the outside of the mounting screws on the barrel (2.030"), measure the CtC of the #90 base screw hole (now already drilled for #10), then re-mount and indicate the scope base so I could wallow one hole out by .020, then the base fit.

NOTE: If you do have to open a mount hole, Measure the outer diameters of the original RB rear sight, minus one diameter, to get Center to Center. Measure the CtC of the #90 base. I suggest using a center drill to pick up center of the mounting holes on the #90. The hole will self-center on the 60 degree angle, then you can clamp the base down. If you need to elongate a drilled hole, think of using a mill, because it will flex a lot less and cut straighter.

43R Neck Expander Die (thanks to Guesser for identifying the model!)
  At one time, Lyman did make a 43R neck expander for the 43 Spanish. As of May 27, 2015, Customer Support could not find 43R in their parts system OR out in a trailer. It seems that there are a number of trailers or temporary storage that has stuff that is not visible to the Lyman system. A search by some Lyman folks in this menagerie did not turn one up, BUT that doesn't mean it isn't out there. My basement has stuff I've not seen (or found!) in years... But it is there...

NOTE: What is the diameter of the first and second steps of the 43R expander plug?

43 Spanish Brass
Not available in Wal-Mart... A few places make 43 Spanish, Captech (nee Jamison) and Bertram Brass make the case. Other places use the .348 Winchester to form cases. Note: The .348 Winchester uses a thinner rim than the original case. You can find 43 Spanish at Buffalo arms, Grafs , Midway, and others... Read up on Bertram Brass if you would.

Captech (nee Jameson) Current Production 43 Spanish Brass Measurements
43 Spanish from Captech (via Buffalo Arms). Very consistent.

Neck thickness: .010
Head diameter: .513
Case Length: 2.243
Rim Diameter: .595
Rim Thickness: .083

I was a bit flummoxed on measuring the rim thickness at first. It has a slight raised center. After wallowing in self pity, I simply measured case length, used the depth rod on the calipers to measure from case mouth down to top of rim, then MATH.... So... it appears this would fit into the Lee #17 shell holder. But my RCBS #22 will never know....

Shellholders
 Lee made two shell holders, the #17, which works for the .348 rim thickness, and the #18, which supposedly handles the .090 thickness. The #17 has been reported to have cracked during case forming. I bought a RCBS #22 and never looked back.

Extract from RCBS instructions for Case Forming and Trim Dies.
"Most RCBS Dies are manufactured with the standard 7/8-14 thread and are designed for use with a shell holder having a lip thickness of 0.125". The primary exceptions are the .45 Auto Rimmed, 11mm (.43) Mauser, and .43 Spanish. These must have a shell holder lip thickness of 0.150". Any variations of these dimensions may cause headspace or insufficient sizing problems."

Bore and Groove Diameter
  As with any period weapon, it's a good thing to either slug your bore, or better yet, cast it with Cerrosafe. My first cast EVER was of the RB muzzle. My particular RB has a bore diameter of .439, a groove diameter of .445+. This brings up boolit choice, as the venerable Lyman/Ideal 439186 is to be sized to .439, and that is the last word Lyman has on the matter.

Lead Alloy Strength
  For us using the .439 boolit into a .445 groove, a soft boolit is necessary. Aim for a BHN of 10, and see what happens. Black Powder works better to bump up the boolit due to it's rapid pressure rise.

Lead alloy calculators HERE
  Go to this post, look for "Lead Alloy Calculators 070612.zip" at the end of the first post. It is a little odd, but simple. Look at the various lead alloys (many!) plug in the weights (under the Weight column, "H"), if you want upgrade the prices (Unit Prices column "K"), and once you click out of one of the weight cells, it will re-calculate, displaying cost and BHN. If you have a mix with different percentages than the presets, fill in the percentages in the "Custom Alloy" row.

Lee Lead Harness Testing Kit
  This will start the flames... For MY purposes, the LLHTK works perfectly well. It is annoying at times to hold the loupe, but folks have used the cut-off top of a clear plastic pop bottle with a hole drilled or cut in the screw-on top to hold the loupe steady. Price is much less than the other lead hardness testers.

Lee Precision Lead Alloy Hardness Tester

pdawg_shooter:
"I slip the collimator into a 45ACP die, put the die in the press. Put the v-groove bullet holder in the ram. Run the ram up to the collimator and look through to gauge the size of the indent. "

When using FN boolits, I just choose a shell holder big enough for the base of the boolit to fit and run er up. Saves time filing away a flat spot, plus it probably doesn't ruin the boolit like filing on it does...

 Testing The Consistency Of The Commonly Available Cast Bullet BHN Test Equipment
"The Lee tester appeared to produce the most readings that were both consistent and closest to the actual laboratory results. Although individually other testers came in with slightly smaller standard deviations and numbers that came in closer to calibrated equipment, the Lee appeared to have the best combination between the two areas." When Lee makes stuff that works, I buy it.

Evaluations_and_Recommendations_for_Lead-Alloy_Hardness_Testers

Chamber Casting
 A(nother) chamber cast is in the near future, BUT take it as a matter of faith that you need to tap out the Cerrosafe casting a few minutes after it sets (looks like a bullet sprue puddle sucking in slightly). If you read the wrong information article from Brownell's, you might choose to wait far too long. At 30 minutes, the Cerrosafe cast is back to full diameter.... This demonstrated to me how important it is that brass cases shrink back from the chamber walls after the round is fired. I will ga-run-tee that if you leave the cast in the chamber for 30 minutes, you CANNOT beat it out...
11.15x58R Chamber Neck
  Pawing through my mould boxes produced an RCBS 44-370-FN. It cast some beautiful boolits (nose @ 439, bands .446),and I thought for a fleeting instant that I had figured it out... Not so. The chamber neck of the 43 Spanish (in my RB) was too small to accept the .446 sized boolit in the Captech (nee Jameson) brass. Two things will help me figure this out, first the Starrett Model #220 Multi-Mic (round and flat anvils included) to measure the case neck wall thickness, and the second is another try at casting the chamber....

Reaming the 43 Spanish Chamber Neck
Bent Ramrod wrote:
"I seem to recall that John Campbell wrote an article in the ASSRA Journal about reaming the neck only of a .43 Spanish chamber so that inside lubricated boolits of the proper size could be loaded into the cases. You might check with the Archivist for the American Single Shot Rifle Association and see if the article can be found and copied for you. I've just moved and am still in a chaotic state; can't remember where the file of magazines is. "

I posted a question in the ASSRA forum, nothing definite yet. The archivist responded, it will be Thursday before researching....

Neck Turning
John in PA wrote:
"Have you considered neck turning or neck reaming the brass? Removing .004" all the way around would pretty much get you where you need to be. Just a thought. I'm actually doing that to get a Marlin-Ballard Union Hill #9 in .40-63 Ballard up and running."

My initial thought was this was not going to be easy, but I see that Track of the Wolf has a .439" pilot for the Lyman case trimmer...

Forster Case Trimmer conundrum (Forster Collet Sizes for Original and Classic)
The Original case trimmer with a #4 collet should be a spot on match for the 43 Spanish (max .605" dia, Captech 43S rim is .595"), the Long (6 1/2") base, and a custom pilot for $22 (.437", .002 - .0025 under). Original Case Trimmers manufactured before June 1, 2010, required a Collet Housing enlargement to .610" when using the #4 Collet; those manufactured after this date already have this modification. This will not affect the use of the #1, #2, or #3 Collet. The Collet Housing can be opened at the factory at no charge. Please return the Collet Housing only, Do not send the entire Case Trimmer. Forster will open up your old .564 collet housing to .610" (or you can use a 5/8 or 16mm drill).
NOTE: Original and Classic Collets are not interchangeable.

Manly-Man Chamber Neck Recutting
Flintlocke wrote:
"In order to get a .43 Spanish Peabody to work with Bertram .43 and the required .449'' greased slug, I built a rear (chamber) pilot on the lathe  to fit the chamber to the rear of the shoulder portion and opened up the neck area of the chamber with a 15/32 twist drill (.4688 dia). This allows .003" expansion of the brass. Perfect job? No, but a little 400 emery cloth cleaned up the sins. I went from 20" groups at 100 yards with the .439 bullet to 3" groups with the .449 and once formed I can thumb seat the bullets without dies."

To rebarrel a Rolling Block??? HERE

Remmy4477
This rifle loves to eat brass, 8 case separations out of 60 shots total! At almost $3 per case I'm done with the 43 chambering. I should note that I am using BB stamped cases of the correct rim thickness, I believe the case separations are due to the fact this rifle has a very long throat.

ClaMar
Your case separation problem is a common one with the .43.  The rim recess is ~0.090", while the rims are in the 0.060-0.070" range.  The firing pin drives the case forward, the pressure makes the neck grab, and the base of the case moves backward.  I had the same experience with mine until I made a crude spacer that corrected the headspace.  Buffalo Arms made their brass with the proper thickness rims for several years, and that also solved the problem.

Spirolox Retaining Rings may be a way to add .030 to the rim. 43 Spanish has a base of .516 (or .512?) . Perhaps the WH51?