The purpose of this article is to relate my experience in achieving satisfactory accuracy and case life with a .43 Spanish Rolling Block. This rifle/ammunition combination needed special attention in a couple of areas that shooters might not anticipate. John Walters reports good sales of .43 Spanish wads, so there must be a lot of us Spanish Roller nuts around!
A friend purchased a .43 Spanish military Rolling Block. The action was tight and felt like new. The metal was in good condition except for a few small pits on the barrel at the wood line, but had no finish. The bore was excellent. The wood was in good shape. He thought about using the action as the basis for a silhouette rifle, but later sold it to me. I decided to determine its accuracy potential as issued. I read several articles about similar rifles. One author indicated a very long throat, requiring seating the bullet almost out of the case. Another made a case-forming die, which I planned to avoid by using Buffalo Arms brass. I began with a chamber cast, finding a good, tight .43 Spanish chamber, with the exception of a longer neck. The chamber length is 2.560-2.565 in. The throat had a long taper beginning at the case mouth. The chamber was slightly off center. Rim recess (headspace) was 0.090 in. Both breech and muzzle had a 0.440 in. groove diameter. Dave Gullo said the long neck and thick rim recess was typical of these rifles, and suggested his .43 Spanish basic brass trimmed to chamber length. He indicated reports of excellent accuracy from similar rifles. The rifle stood in the corner until my wife asked for Christmas ideas. I suggested a Lyman 439186 mould, Lee dies, and .43 Spanish basic cases. She followed my suggestions (she orders more stuff from Dave than I do). Bullets cast at 0.440 in. and 377 grains. The lube grooves were small, so I pan-lubed them with a softer than normal beeswax/oil mixture and turned my attention to case forming. Here I found a problem. I had assumed Lee dies could be used for forming longer cases, but found that the die was bored only a little longer than nominal length, preventing forming the shoulder with the longer neck. After some thought, I forming the shoulder by running cases into a .40-70 SS sizing die. This produced a shoulder sharper than the chamber. My method wasn’t particularly accurate. I worried about headspace (0.030 in. difference between case rim and rim recess), but hoped the bottleneck would hold the cartridge in place like a rimless case. After neck sizing and trimming cases to 2.555 in., I made a dummy round and determined an overall length of 3.250 in. slightly engraved the rifling. It was an impressive-looking cartridge with a neck almost 0.8 in. long, looking a lot like a long-necked .44-77 or short-bodied .44-90. 84 grains of Goex FFg powder gave 0.060-0.070 in. compression. I seated Walters wads over the powder and compressed the powder with the bullets. Initial shooting showed promise. Using a blow tube, most shots were in a 3.5 in. circle at 100 yds. Velocity was 1400 fps, with about 40 fps total variation. Shots impacted at the correct elevation and 3-4 inches left of the aiming point. My best group had 4 shots in 2 inches with the 5th shot 2 inches higher (a normal problem for me with open sights). Recoil was milder than a light .45-70 with 500 grain bullets. The barrel cleaned with three patches. Cases were another story. They stretched up to 0.025 in., and one split at mid-body. I assumed this was caused by my case forming technique and hoped neck-sizing would eliminate further stretch. After neck sizing and trimming, the next loading used the same ingredients. The fire-formed cases held 90 grains of GOEX FFg. Velocity averaged over 1475 fps with a total variation of 40-50 fps. Accuracy continued in the 2.2-3.5 inch range. Most cases stretched around 0.020 in., and two more separated. At this point, I concluded the rifle/ammunition combination was unsafe and stopped the test. The rifle sat in a corner while I pondered my next step. I didn’t want to sink much more money into the rifle, but it showed enough promise that I didn’t want to give up. I thought about machining a headspace control ring and soldering it into the rim recess, with a section at the extractor removed. A friend suggested a simpler solution, headspace rings the right thickness for each cartridge case, with inside diameters large enough to slide onto the case but small enough to be retained. I adopted a variation to test the concept. He machined a case rim 0.030 in. thick and removed it from the case with a drill bit. I smoothed the edges, opened the inside diameter enough to slip over a case, and thinned it to 0.028 in., which allowed the hammer to fall without dragging on the breechblock. After checking for insipient separations of the remaining cases and finding none, I reloaded. I installed the headspace ring, chambered and fired a cartridge, and measured 0.003 in. stretch. I fired the remainder of the cases using the ring with no case failures. Case stretch ranged from 0.003-0.005 in. Twelve of the fifteen shots fired quickly were in a group 1.7 in high and 4 inches wide, with the others out due to sighting errors. Cleaning was easy, with no hard fouling near the throat or muzzle. Two more firings confirmed minimal case stretch, so I expect reasonable case life. I ordered 20 more cases from Buffalo Arms. I cut the front off the sizing die with a diamond saw and lapped the inside front edge so I could set the shoulder properly (I imagine Mr. Lee would not approve). Now I had a different problem. The new cases had a rim thickness of 0.080 in. No problem-I made a 0.008 in. headspace ring, and Dave thickened the rims on the older cases. Case stretch is minimal when I use the headspace ring. Without the ring, cases stretch from 0.005-0.010 in., giving case life adequate for casual use and plinking but too short for serious BPCR shooting. Further testing with 94 grains of Elephant FFg powder (a 1997 lot) produced 1450 fps, with standard deviation of 22. Accuracy is as good as GOEX, with my last two five shot groups in the 2.2-2.5 inch range. I’ve since purchased another .43. This one has an octagon section on the barrel and appears unissued. The blue approaches commercial quality, and the barrel looks new. I’ve verified that the chamber is the same length, and ammunition loaded for the first rifle fits. Headspace is also identical to the other rifle. This rifle remains unfired. I consider this a successful test! It’s fun to overcome the problems and see how well a 125 year-old rifle with an excellent barrel can shoot. I believe this rifle is capable of better than 2 MOA accuracy. I plan to install a permanent soldered-in headspace ring as a convenience. In its current configuration, the rifle would be excellent for hunting. With target sights, a trigger job, and a heavier bullet, it may produce competitive accuracy for BPCR shooting! What did I learn? I knew better than to fire the rifle with thin case rims causing excessive headspace. Also, the makeshift case-forming technique I used had enough variability to contribute to the case stretch problem. Both suggest the need for taking a more cautious approach to shooting old rifles where available components may not match original specifications.
Get out there and shoot those old Rolling Blocks. You may be surprised at the accuracy!