Quest for a Chicken Load

 

I continually seek more accuracy from my black powder cartridge ammunition because I enjoy the process, and in doing so, it might increase my shooting scores. If the top scores in silhouette matches are studied, it will readily be seen that the shooters on the upper end of the scoreboard have very respectable 200-meter chicken scores. You cannot shoot a Master score without hitting a few chickens. My current chicken load is a proven match performer, but as an old South African friend has told me, “You don’t have to be sick to get better.” With that philosophy in mind, I decided I would like a 200-meter offhand load having tolerable recoil and excellent accuracy.

I aimed to find a light bullet load with the same or better accuracy as my current 370-grain chicken load. A part of my inspiration was the Schuetzen shooters. They shoot fairly light bullets and will produce some groups near two inches (sometimes better) at 200 yards, depending upon the conditions.

BULLET SELECTION

My CPA Stevens 44½ rifle chambered in 38-50 Remington Hepburn was selected for the planned testing. As potential candidates, nine bullets were cast from a 20:1 (Pb:Sn) alloy. They were, of course, .38 caliber and ranged in weight from 285 to 370 grains. The selection contained bullets with the shank of the bullet having parallel sides, (cylindrical), to bullets that were gently tapered their entire length to allow for longer seating and increased powder capacity. Additionally, some of the bullets had tapered noses which were tapered along with a partial cylindrical body; specifically, two base bands of groove diameter followed by a constant taper to the nose, ending in bore diameter. This is my preferred bullet type, giving good chamber alignment and typically above-average accuracy. To clarify, the last two basebands are groove diameter (for my rifle .376), and tapering to the band at the nose being under bore diameter (.367).

After preliminary testing, six bullets were chosen for further evaluation. Eliminated bullets were either deemed too large in diameter or not enough taper, making loading difficult. Swiss and Olde Eynsford black powders were tested. Swiss has always been found to be a very good propellant, but I had little experience with Olde Eynsford. Olde Eynsford had good velocity and was clean burning with soft fouling. I look forward to future production and reintroduction of this powder. To all the folks that buttonholed me at matches and told me I needed to try Olde Eynsford…yes, you were right!

Since chickens are easy to knock over and paper targets are easy to penetrate, 1Fg granulation was tested for both powders. The larger granulation stacks up quicker and takes up cartridge case space. I was after accuracy, not “ram-tipping” velocity.

BULLET CONSIDERATIONS

The bullet length should be compatible with the barrel twist. A review of the Greenhill formula might be in order if your barrel has a slow twist or you are shooting a long bullet. Schwartz and Dell felt that the Greenhill formula may be invalid for bullets that are longer than three and one-half times the bore diameter.¹ Another good method to determine proper stabilization is to shoot through heavy cardboard at 200 yards and look for evidence of tipping. For shooting at 200 yards or meters, a long heavy bullet is probably not necessary. An effort was made during the testing to emulate Schuetzen shooters and use a relatively short bullet. The one short bullet (NEI 285) included in the test did not work out very well; see Table 1.

Bullet shape and length are interrelated. Long bullets with an unsupported nose of less than the bore diameter will generally not shoot as well as those with a “bore-rider” nose. I don’t know with certainty, but I think the long nose may bend to one side during acceleration down the bore and cause the bullet to wobble around the center of mass. Whatever bullet we choose to use, it needs to be of an appropriate diameter for both the shank and the nose so that near-perfect bullet alignment occurs in the chamber, leade, and bore.

Lyman has some good information in the 45th Edition of their reloading manual related to bullet shape.

Bullet shapes No. 1 and No. 2, do perform very well and are not very different from some of the historical black powder bullet designs. The Loverin design (No. 3) is well accepted by Schuetzen shooters and I have seen a few Black Powder Cartridge shooters using this bullet style on chickens. There is probably a bit of debate as far as bullet shape No. 4 with the long ogive is concerned. One of my Schuetzen rifles shoots the shape very well. It would not have been my first choice, but an old friend was having great luck with it, so I had to try this style. The RCBS-BPS 312-grain is very similar to this shape and did perform very well in my testing. Where the nose meets the bullet shank the diameter is 0.367 inch, which is equal to my rifle’s bore diameter. This close fit of the nose and the cylindrical section 0.001 inch over the groove diameter would encourage good bullet alignment. The bullets tested are listed in Table 1.

RCBS-BPS has a bullet shank or cylindrical bearing surface of 0.650 inch or 54 percent of the bullet length. Initially, I thought such a low percentage of the bullet shank as related to the total length was significant. However, all of the bullets tested ranged from a low of 51 percent to a high of 54 percent. What seemed to be an important factor relating to accuracy was that in addition to the bullet cylindrical section being equal to the bore diameter, the rear portion of the bullet noses were well supported in the bore. This allows the bullet to be better aligned or what Schwartz and Dell refer to as practical squareness. “This lack of practical squareness is one of the reasons why long ogive, short cylindrical section bullets perform poorly when shot as fixed ammunition.”1 This type of bullet can be prone to tipping during entry to the throat resulting in an unbalanced bullet. “It is for this reason that breech seating with a properly designed bullet offers increased accuracy.” ² Breech seating is not a practical method for silhouette shooting due to time constraints, but the concept of bullet alignment within the throat, leade, or free-bore should be borne in mind when selecting a bullet style or shape.

Some of the bullets selected for testing had nose dimensions less than the bore diameter. These were less accurate than those bullets with noses which fit the bore snugly. Oversized bullet noses did not seem to perform well either.

There are some special cases related to fitting a bullet to a particular barrel. If the rifle has an oversized chamber this requires an oversized bullet to obtain adequate results. Although the bullet might be oversized for the barrel groove diameter, the chamber should be filled. This may sound counterintuitive, but based on personal experience it most definitely works. This is not unlike the proper fitting of lead bullets to a revolver cylinder, where the chambers reside.

A bullet should be hard enough to retain the nose shape yet soft enough to obturate and seal the powder gases. Bullets with long noses, especially unsupported noses, require a temper of 20:1 or perhaps 16:1. I have talked to many shooters that have told me that long unsupported noses require a harder alloy. Jim Terry of Wyoming, has tested this empirically by shooting various temper Money bullets in his sawdust box. His work has confirmed the obturation of the nose was reduced and the original bullet shape retained with increasing hardness. He also noted the condition of the bullet base to ensure the bullets were not too hard which could cause gas cutting. There is a fine line between too hard and too soft.

TESTING PROTOCOL

In the interest of having the best possible outcome for each of the selected bullets, an Incremental Load Development Method or ILDM test (see Black Powder Cartridge News #115) was performed on each of the original nine bullets. The results from these tests were used to select the best powder charge. This was done so that the tests were as unbiased as possible. After casting, all bullets were weighed for uniformity and only those bullets which were plus or minus 0.1 grain were used in the testing.

After the ILDM testing, 20 rounds (plus sighter and fouler shots) were loaded for each of the six remaining bullets. All rounds had the same primers, neck tension, over-powder wads, and lubrication. As an item of interest, since the tested bullet diameters varied, an expander was selected for each bullet to allow for a .001-inch interference fit. This is minimum neck tension and works well in my rifle.

Since there were 120 rounds to be fired for the tests, the assembled loads were fired as two 10-shot groups for each bullet. Due to the large volume of shooting the testing was completed in two sessions. One of the 10-shot groups for each bullet was completed in each session. Very calm days were selected for testing. All testing was done at 200 yards from the prone position, firing off cross sticks. Two microfiber patches wet with 10 percent soluble oil solution were pushed down the bore to remove fouling. The chamber was mopped before loading to remove any residual moisture.

Data consisted of measuring and recording the ten-shot group sizes, best nine of 10 group sizes, total string measurement, and average distance from the group center based upon string measurement, see TABLE 2.

TEST RESULTS

My objective was to end up with a load having a light, fast bullet with a low recoil, but things did not go as planned. The best loads were the 370-grain load with the 335 and 312-grain loads also performing very well.

The 312-grain bullet load was a bit of an enigma. The string measurement was certainly good but the core groups were screamers with a few outside the core group.

RCBS chose to make this a two-cavity mould for the 312-grain bullet, which is nice since you can produce bullets quickly. I did have some minor issues with vent whiskers, which I was able to correct by cleaning the mould faces with some 800-grit sandpaper on a dead flat surface. With 48.8 grains of 1Fg Olde Eynsford, the load clocks 1,235 fps with only 10.5 ft-lbs. of recoil, similar to a 30-30 WCF with a 150-grain bullet. I also like this load for shooting reduced chicken targets at 100 yards. It appears RCBS has discontinued this mould, but it might be available on the used market.

The Schauf 335-grain tapered bullet with 53.5 grains of 1Fg Olde Eynsford has a velocity of 1,260 fps with 12.6 ft-lbs. of recoil. My current load with the 370-grain bullet charged with 51.2 grains of 1Fg Swiss comes in at 1,185 fps and 12.8 ft-lbs. of recoil. The 370-grain Schauf bullet is even heavier than the bullet I shoot at the 500-meter rams, so I did not come up with a light bullet chicken load and will stick with the 370-grain load. The good news is that this load also works well on the 300-meter pigs.

Accuracy and ability to buck the wind are the most important, and the 370-grain bullet meets both criteria. An accurate load has less apparent wind drift. Bore-rider noses and a conical section of the proper diameter improve bullet-to-chamber concentricity.

I did not meet my objective of developing a light bullet bullet load. However, I did confirm my current chicken load is a good one. I do plan to complete some additional work with the 312-grain RCBS BPS. I will try sizing the bullet to see if this helps, possibly double up the wads or include a beeswax wad. So little time and so much testing to be completed!

REFERENCES
^1. The Modern Schuetzen Rifle, Wayne Schwartz and Charles Dell, Christiansburg Printing, Christiansburg, VA 1999
^2. Lyman Reloading Handbook, 45th Edition, 1970