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Today’s the day I take my new Winchester Model 1873 in cal. 44-40 out to the range to begin load development. This is the first of a fairly extensive series of posts, a sort of prequel where I talk about a few aspects of the testing. For example, in a true ladder test we will normally be concerned with finding vibratory nodes in our ammo/chamber/bore system. We typically move the bullet in and out of the case, beginning with a soft jam into the rifling. Then we look to the weight of the charge, generally moving it by 0.10 grains at a time (by weight). Finally, we concern ourselves with the bedding of the rifle. Typically we insist that the barrel be free-floating, although we can adjust things by moving any point of contact back and forth along the length of the barrel. As you can see, there are a number of balls in the air during this process. Depending upon the cartridge, a real ladder test can actually burn out our barrel by the time we are able to identify the right set of conditions to build our ideal, or at least best, load. That’s all in a working day for smokeless powder benchrest competition; we won’t even begin to talk about case preparation here. Obviously, we begin with identical case trim lengths for all cases, but we’ll leave it at that for now.
So, what are the constraints that confront us as we transition to black powder, as well as the limits of antique metrology, and finally the effects of the primitive technology in the delivery system? I should note here that we will for now eschew the assistance of a chronograph, utilizing instead published data and basic analytics. The chronograph will be of use at a somewhat later stage of load development.
For now let us begin by establishing the seating depth of the projectile. I will be using Missouri Bullets hy-tek coated hardness-optimized cast lead projectiles weighing 200 grains and in round nose flat point form, with a crimp groove. Because of the nature of black powder, the primary consideration here will be safety, so the charge and the bullet depth will first ensure that no airspace exists inside the cartridge case. If necessary, a filler of some kind will be employed, although to eliminate variability we want to limit our choice of filler material to an inert disc such as a massless fiber overpowder wad. We must also take care to incorporate a uniform degree of compression to the cartridge structure, and a uniform crimp pressure. Observing these criteria will ensure that we have eliminated all variability from our equation as far as bullet seating depth is concerned.
The next item to consider is the charge weight; here we confront the limits of the antique metrology available to us. To wit, black powder is typically measured by volume, utilizing a brass or other natural materials powder flask, and a similar powder measure, transferring the charge to the individual case using a drop tube and a funnel. In this situation, we may continue to use this metrology at the coarse granularity dictated by the cartridge construction. For example, it is completely acceptable to select a reasonable interval between charge levels using this technology, say, 2 1/2 grains by volume. However, upon identifying promising nodes among the charge levels we must transition from volume measure at the 2 1/2 grain unit to mass measure with 0.10 grain intervals over the vicinity around the supposed node value. I will be using Swiss powder exclusively, in both 2 FG and 3 FG granularities.
Lastly, and I do mean lastly, we must take into account possible imperfections in the muzzle crown that may have accumulated over the 140-odd years the gun has been in use, as well as the location of the barrel bands and forend pressure points. I would very much prefer to take the rifle as it comes to me, rather than go about monkeying with these structural details, but we’ll see what happens with seating depth/construction and metrology. I think it is unrealistic to apply modern expectations of accuracy and precision to this system as a whole, especially sight unseen as yet exclusive of any results whatsoever. But I will state that I hope for eventual minute of angle 3 shot groups, at least for now. My range opens at 10 AM local time on weekdays, so that will conclude my opening remarks until I can provide some preliminary results.
Online
MOA in an original ’73? If so, you’ll have not a 1 of 1000, but a 1 of 10,000. Of course no harm in striving for that goal. Original owner would have been pleased with 5 or 6 MOA. Can’t blow a ’73 up with BP; can’t even load 40 g. into a modern case, except by compression. Hard-cast bullets will not expand to fill rifling, which was an assumption in the use of BP.
All very interesting. As suggested, there are a lot of variables that go into assembling bench rest shooting loads. Less of these would be applied to a 140 year old Winchester. In my testing, the bullet is a big variable. The weight, size and what it is made of. Clarence raises an important point about a hard cast bullet. I would sure want to have a supply of soft lead bullets to include in the testing. Other variables for me are various powders and of course primers can make a difference (brand; regular or magnum).
I am eager to hear the results of the testing.
The Good Wife is still on the warpath after I spent $1200 without consulting her (on ANOTHER GUN!!??!!). On the theory that it is better to beg forgiveness than ask permission I’m in the doghouse along with my beloved Ridley, a sweet little pittie whom we rescued. In the name of domestic peace I will buy my membership on payday next week, so although I have images none can be shared yet. However, here are the preliminary results of today’s shooting.
Range was 25 yards, wind was light, less than 4 mph. Ambient temp about 65 degrees F. HSM Cowboy Action loads @853 FPS. 12 target roundels, with the following 3-shot groups recorded using a Ransom bench rest and rear bags:
1.5″
1.6″
1.6″
0.80″
0.80″
4.0″ (only 2 shots on paper)
2.6
1.5″
1.05″
1.0″
2.0″
3.80″
Frankly, the only reason groups were larger than 1 inch was because I’m still trying to figure out how to aim with the iron sights. I expect groups to shrink with a little more practice to routinely at and below 1 inch. Now this is 25 yards only, so not to get carried away, but after 134 years I do believe we have a hummer barrel!
The only functional issue I encountered was some kind of blockage in the magazine. I continued to load single rounds and cycled the action, but when I tried to insert a second cartridge it simply jammed up and froze, so fed the rounds one at a time through the entire loading and firing sequence. I’ll take it apart later and get to the bottom of it.
‘
So twelve, three-shot groups were tested? All rounds tested were the same (the HSM Cowboy Action rounds)? Seems odd that group size would range from .8 to 4.0.
steve004 said
So twelve, three-shot groups were tested? All rounds tested were the same (the HSM Cowboy Action rounds)? Seems odd that group size would range from .8 to 4.0.
For preliminary testing, 3 shots would suffice, but it’s really misleading to call it a “group,” as that term has always been understood for evaluating accuracy. Up until sometime in the ’70s, a “group” always meant 10 shots, but after that it seems gunwriters began to think shooting 10 was too time-consuming & 5 became the norm.
A few thoughts. Point of aim was 6 o’clock, point of impact was the bullseye. I’m not sure I need to go to all that trouble developing a load after all; the gun shoots! She’ll likely shoot whatever I give her. So at this point all I’m looking for is a good, smokey load for CAS. Put on a good show to make up for holding everybody else up. This will always be a challenging gun because of the unwieldy length and weight, and the somewhat greater energy required to work the action compared with the slicked-up competition guns I’ve cycled. It feels like an anticlimax but I think this research has reached a successful conclusion. Hundred yard MOA remains a viable objective, but I don;t think I need any longer to follow through with all the dtama I suggested in my opening remarks. Let me know if any of you disagree.
November 7, 2015
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clarence said
steve004 said
So twelve, three-shot groups were tested? All rounds tested were the same (the HSM Cowboy Action rounds)? Seems odd that group size would range from .8 to 4.0.
For preliminary testing, 3 shots would suffice, but it’s really misleading to call it a “group,” as that term has always been understood for evaluating accuracy. Up until sometime in the ’70s, a “group” always meant 10 shots, but after that it seems gunwriters began to think shooting 10 was too time-consuming & 5 became the norm.
Three shot groups may tell us something but quite often they lie. Even a mediocre modern hunting rifle is occasionally capable of “MOA” three shot groups but few can herd ten or even five into an MOA group, even with one of those telescopic sight thingys. I’ve always been impressed by the performance of vintage Winchester leverguns but IMHO the best hover around 2 MOA. Nowadays I’m pretty happy with anything under 2” at 50 yards but that isn’t fair to the rifle, loose nut behind the butt simply can’t see like he used to. Best way to get a 120-140 year old rifle to shoot like it used to is to load ammunition like they had back then. First step to learning how to shoot BP is forget most things you learned about smokeless powder.
Mike
Hi Clarence, Steve004; the range of groups sizes my fault entirely, as I struggled with the sight picture presented by the irons. I am spoiled by really, really good scopes. Most of the time I was in the groove but a couple of times not so much. I found that my eyesight was an issue, as I couldn’t ever see the 3rd shot; but if I just let the gun do it I got nice, tidy groups. When I tried to introduce my own improvements the groups grew. The 4-incher was my very first group, and I was still nervous about the bolt coming through and into my skull, so I didn’t achieve much of a sight picture, and one of the 3 shots missed the target altogether. The 3.8″ group was the last of the day and i was tired, plus increasingly concerned about the blockage in the magazine, so I just tossed it off to complete the day. Happens. The rest are consistent, utilizing the benchrest fully, and concentrating on the principles of marksmanship. I already feel very comfortable with the iron sights after only the one session, so I am confident I can get the groups all down to the one- or sub-one inch level at 25 yards, probably next outing. The real question is to be found at 100 yards. Two issues there: one, my eyesight; two, my eyesight. When I try it next time out, it will be very much in the spirit of the Zen archer, and we’ll see. As for groups size, it’s well-known that grouping shots should be done as a time series, so one should shoot maybe a hundred shots in an afternoon, measuring the points of impact of each relative to say, the x-y crosshairs superimposed on the target roundel. Then you will obtain a statistically significant dispersion plot for that load under those conditions. But who does that? I shoot 2-shot groups to eliminate the obvious losers, then 3-shot groups among the remaining candidates and I don’t sweat it. If you’re rested and fresh, 3-shots does test the gun; any more and you’re testing your nerves, not the gun.
TXGunNut, I am still takin my baby steps with black powder. I know a lot about smokeless, save those crazy compound loads, which even I am not crazy enough to even try. I started out expecting shotgun patterns from an old gun with who knows how many problems. The fact that I got consistent small groupings instead is incredible. When I stumble across a barrel that just wants to shoot, we call it a “hummer,” load development becomes moot, for the most part. Pretty much anything will do, and especially given the large targets at close range found in CAS. I’d like to punch out a sub-MOA at 100 yards, but that’s just me, my ego wants that; I’ll try starting this week with my next excursion, and keep on tryin but it ain’t remotely necessary anymore.
Waitin on the Kroil to work on that magazine end cap. So far, no joy. I cannot imagine what could be blocking the magazine; it felt just like it was full less one. I could insert my single round into the sidegate and cycle the action with the lifter retrieving it and chambering the round, firing, and ejecting. But if I tried to put in 2 rounds, the second jammed most of the way in, but wouldn’t completely enter the magazine. Had to pry it out with a screwdriver in order for the lifter to work again. I’m wondering if the magazine isn’t already almost fully loaded; but why then doesn’t the spring push the rounds back into the lifter? Don’t really have a screwdriver that fits the end cap, so will really need it to loosen up on its ow from the Kroil before what drivers I do have will be able to turn it. Then remove the spring and follower, then fish a cleaning rod down there to see what obstructions might exist. I surely don’t want to have to pull the magazine tube from the action end!
OK, found the magazine follower accessible from the open action and raised lifter. There is no ammo in the magazine. This entire blockage might be an Illyushin. Hesitant to try loading the magazine in my in-home shop. Will give it another go when I go back to tackle the 100 yard range later this week.
November 7, 2015
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James-
If you want to use a ladder method for BP load development I would recommend measuring the amount of compression, in thousandths of an inch, a loaded round (and wad, if used) applies to the powder column. You will likely find your Swiss powder requires less than Goex for example and other powders will do well at other levels. This is a number you can use, actual weight or volume means very little. If you find the correct compression amount for your 44WCF and decide to reload for the 38WCF you will have an excellent starting point for your new loading adventure.
Mike
Hey Mike, yes compression is a well known technique in bench rest, where arbor presses are used to seat the bullet at a precise depth and degree of pull (not necessarily compressing the powder, but it can be used for that too). So far, with black powder I have been operating on internet wisdom, i.e., “. . .some compression is necessary for black powder, but don’t exceed about 1/4 inch” That’s been my rule of thumb, so I compress using a marked dowel between 1/16″ and 1/4.” However, thus far it has been an aid to uniformity among the cartridges to eliminate as much as possible mechanical sources of dispersion from uneven pull forcesd. I like your idea of applying bench rest precision where I have been rule of thumbing it.
If you want to use a ladder method for BP load development I would recommend measuring the amount of compression, in thousandths of an inch, a loaded round (and wad, if used) applies to the powder column. TXGunNut said
Compression is discussed at depth in Paul Matthews’ Loading the Black Powder Rifle Cartridge, best book on this subject I’ve ever found. His experience was vast–I watched him (& his wife) shooting BP silhouette when he was in his 70s.
For me, MOA accuracy in a lever rifle – or any rifle with fairly crude open sights – would not be possible. I know people who shoot sub-MOA groups in vintage rifles (e.g. the Krag) but they are using receiver sights with fine front beads.
Anyways, I’m gonna take her out again tomorrow, this time for the 100 yard range. I guess we’ll see!
Steve asked 12 ea 3 shot groups?? Also what is the difference between groups? Powder increase or compression. Any powder ladder test I do on smokeless rifles I increase the powder charge by .2 grains.
November 7, 2015
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steve004 said
For me, MOA accuracy in a lever rifle – or any rifle with fairly crude open sights – would not be possible. I know people who shoot sub-MOA groups in vintage rifles (e.g. the Krag) but they are using receiver sights with fine front beads.
Steve-
Like anything else Winchester, never say “never”. I’ve seen pretty remarkable accuracy from some old 94’s, including some with less than perfect bores. At one time I could crowd the 2” mark at 100 yards with receiver sights so an exceptional shooter with an exceptional rifle and a carefully developed load could possibly pull it off.
Mike
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