Well it went bang - too...

[gitano]

The threaded socket for the right-hand nipple of the 10ga has been buggered and the nipple sits fairly loosely in the breech, so I went to the local Sportsmen's Warehouse to see if I could find a replacement and get some percussion caps. I took the nipple with me so I could 1) make a close comparison, and 2) get the right caps. (It takes #11s by the way.) Turns out, the Italian-made Pedersoli uses metric-threaded nipples. Whoodathunkit? Since it's the breech itself that has been buggered, not the nipple, I will drill it out and rethread it to accept Imperial threaded (1/4-28) nipples.

So I loaded the 10ga as Alboy advised - powder; 3 over-shot cards; shot; 1 over-shot card. I put a #11 cap on... wait a minnit... cap won't fit because someone has been 'dry-firing' it and the nipple is peened out and won't accept the cap. Not a big deal. A few minutes with a jewler's file and all is well. (Note to self: No dry-firing.) I walked 'out back' and touched it off. It went bang. :) I have to say that 'percussion' is not as fun for me as flintlock. I can't tell you why, it just isn't. It didn't put an grin-from-ear-to-ear on my face. Don't get me wrong... It was fun. Just wasn't as fun as flintlock. I don't know why.

I started with a charge of 75 grains (by volume) of ffg, so I used the same device to measure the shot charge. 75 grains of shot by volume turned out to be 1.07 ounces by weight.  Since the 'proof' shot had been mild in recoil, I decided to up the shot charge to one-and-an-eighth ounce and increase the powder charge accordingly. That meant I got to do some math.:D  Here's the way that went...

First, let me list some numbers that I think every reloader should have pretty much committed to memory.

1) One pound (of powder for example) is equal to 7000 grains. Therefore,
2) 7000 grains per pound divided by 16 ounces per pound equals 437.5 grains per ounce.  (7000/16 = 437.5)
3) There are approximately 15.43 grains in a gram. Therefore, there are approximately 28.35 grams in an ounce. (437.5/15.43 = 28.35) This is not so important to know for those that never use the metric system, but it's only one number, and it CAN be good to know at times. I'll give an example later.

When I started this exercise, I was using shot that I had salvaged from some handloaded ammo I had bought at a garage sale. I wasn't sure what size it was. I could measure it's diameter and compare it to a chart of shot diameters, or I could weigh it and compare it to a chart of number-of-pellets per ounce. I decided to do both and check one result against the other to make sure I was on the right track with my loads.

I weighed 10 individual shot pellets and divided by 10 for an average weight of 0.0689 grams per pellet (the scale I use has grams for units) or 1.063 grains per pellet (0.069g*15.43gr/g = 1.063gr). If each pellet weighs ~1.063 grains, then dividing the number of grains in an ounce by the number of grains per pellet would yield the number of pellets per ounce. 437.5/1.063 = 411.57. Since I there aren't any "0.57" pellets, I'll round up to 412. Checking a number-of-pellets-per-ounce chart, I find the following:



By weight, the chart would say I have #8 shot.

I measured ONE of the pellets. It measured 0.090" in diameter. According to the chart, #8 shot is 0.090" in diameter. I'm thinking this is #8 shot. :)

Here's a little clarification on all that "by volume" vs "by weight" stuff:

Here is a "by volume" measuring device:






It is a "tube" in which there is an adjustable "floor" so that the volume of the tube can be adjusted to the amount stamped in the rod that moves the floor up and down in the tube. The 'funnel' tip on top is to facilitate pouring the contents into a barrel without spilling.

As I said, my initial shot used a charge of 75 grains, by volume, of ffg powder. Having poured the powder into the barrel, tamped it down, and topped it with 3 over-shot cards, I poured shot into the measure in the same amount. I then weighed the shot and that's where the 1.07 ounces figure came from.

NOW, since I wanted to up the weight of the shot charge to 1-1/8th ounce (1.125 oz), I needed to find out what the appropriate/equivalent powder charge should be. Since I know how many grams there are in an ounce (28.35), I can calculate how many grams there are in 1.125 ounces (1.125*28.35 = 31.89 grams). I then pour #8 shot onto my scale until it reads 31.89 grams. I then slide the "floor" of the "by volume" measuring tube to the bottom and pour the 1.125 ounces of #8 shot into the tube. Then I slide the adjustable rod up until the shot is JUST at the top of the mouth of the tube. I lock the slide in place and read the scale on the slide. It reads 85 grains. So...

I now have a setting on my measuring device that gives me an ounce and an eighth of shot (weight) and its appropriate charge of 85 grains, (by volume), of ffg black powder.

I hope to be doing some patterning today.

I said I'd provide an example of where using the metric system comes in handy. When HB purchased the 12ga for me, I was already thinking "round ball", not shot. When he traded his 10ga for my 12ga, I was REALLY thinking RB. However, while there are many molds for 12ga RB, there are VERY few for 10ga. Using the "gauge to bore" calculation (read here http://www.thehunterslife.com/forums/showthread.php?t=12493), I determined that the bore diameter of a 10ga was 0.775". OK... now how much does a 0.775" round ball weigh?

The first order of business was calculating the volume of a sphere 0.775" in diameter. Knowing the volume would allow me to calculate the weight as a function of the density of the material from which I intended to make the RB. Using the Imperial system of weights and measures, I would have had to calculate the density of lead in "slugs", the unit of measure of mass in the Imperial system, OR I would have had to know the density of lead in Imperial units. Try to find that on the web. It's like chicken teeth. However, the density of lead (and just about every other material you can think of) in the metric system of weights and measures is trivial to find. (Besides, I have that number memorized 11.32 GRAMS per cubic CENTIMETER. :) )

I had measured the bore in Imperial units - inches. So I needed to convert them to metric units that were the same as the units of density - namely cubic centimeters. 0.775in equals 1.9685cm. The formula for the volume of a sphere (also a good formula to memorize) is 4/3 * pi * r^3. In words: four-thirds times PI times the cube of the radius of the sphere. The volume of a sphere of 0.775" (or 1.9685cm) in diameter is:

1.3333 * 3.14157 * (0.775/2)^3 = 0.2437 cubic inches, or

1.3333 * 3.14157 * (1.9685/2)^3 = 3.994 cubic centimeters.

We can check to see if these are equal by multiplying the Imperial value by the conversion factor between inches and centimeters. That conversion factor is ~2.54cm per inch. Since we are talking about VOLUMES, we have to cube the LINEAR conversion factor. 2.54 cubed equals 16.3871. 16.3871 times 0.2437 equals 4.049 cubic centimeters. That's very close to 3.994. The difference is that all of these conversion factors are approximations. The two results 3.994 and 4.049 are well within the error of our measuring precision. NOW...

Since the volume of a sphere that is 0.775" in diameter is 4 cubic centimeters (cc), and I intend to make my RBs of lead, and the density of lead is 11.34 grams per cc, the NOMINAL weight of a 10ga RB is 4 * 11.34 or 45.92 grams. Recall how many grains there are in a gram - 15.43. Therefore the NOMINAL WEIGHT (in grains) of a 10ga RB is 15.43 * 45.92 or 708.5 grains.

There are two questions that RB weight of 708.5 grains raises: 1) How does that weight relate to my ounce-and-an-eighth shot charge, and 2) what will be the muzzle energy (recoil) shooting the RB at a muzzle velocity of 1000 f/s?

The answer to the first question is easy. There are 437.5 grains in an ounce. Since there are 708.5 grains in a 10ga RB there are 708.5/437.5 = 1.619 ounces in a 10ga RB (just shy of an ounce and five-eigths, 1.625). So, about half an ounce more than the shot charge I plan on using if it patterns well.

The answer to the second question is easy too but you have to know how to calculate kinetic energy. I won't belabor this thread any more by presenting and explaining that equation, but here is the answer: 1573 ft-lbs. Not bad at all.

REALITY is that the RB WILL be smaller than 0.775", but I don't know by how much yet, so these figures represent the theoretical maximums.

I assume you'll check all my arithmetic, Don.

Paul

[gitano]

So... I did two patterns. I'm OK with these even though they aren't "standard" measurements.

First, I loaded the charges mentioned above, except... for some reason when I filled the powder charge on the left barrel, the measure was only set to 75 grains, not 85.:frown But I went ahead with the ounce-and-an-eighth shot charge. The right barrel got 85 grains of powder (by weight) and an ounce-and-an-eighth of shot.

I have a nice target frame, and I had some large pieces of cardboard, but they weren't as large as I thought they were. They were only 24" in width instead of 30. :frown I attached one piece to the frame and backed off 25 yd. I couldn't get the "standard" 30 yd today. :frown Here's what that target looks like with 24" circle drawn on it.



There were 268 hits in the 24" circle. There should be about 461 pellets in 1.125 ounces of #8 shot. 268 is 58% of 461. So there is 58% of the charge in a 24" circle at 25 yd. I would have liked to have been at 30 yd and a 30" circle, but... That said, I'm pretty happy with that pattern. A little low, but that was probably operator error.

This shot, by the way, was rather 'pleasant'. Not harsher than the "test" shot from the left barrel with 1.07 oz of shot ahead of 75 grains by volume of powder. I was pleasantly surprised.

Here is the left barrel. All parameters the same except 75 grains by volume of powder. It kicked MUCH harder than the right barrel that had the 85 grain by volume charge of powder!



There were 334 hits on this target. That is 72% of 461 pellets. Clearly the left barrel is choked tighter than the right.

Even though the range was 'short' (25 instead of 30 yd), the smaller circle (24" instead of 30") kind of compensates. (The range was 17% shorter; the target area was 64% smaller.) Maybe I should explain. Since the range was shorter, the pattern would be 'tighter'. Therefore, having a smaller target would compensate for shooting from a shorter range. The range "error" was 17%. The decrease in target AREA was 64%. Therefore, had the shots been taken at "standard" range and at a "standard" target, the patterns very well could have been 'better' - at least 'numerically' better. In other words, if I had shot from 30 yards, there probably would have been more pellets - percentage-wise - in a 30" circle. I'm liking these patterns. THANK YOU AL!

I need to get some #5 shot - what I will be using for ducks and geese - and see how that patterns. #5 shot should have about 170 pellets per ounce. That's considerably less than the 410 of #8. It will be interesting to see how that effects the pattern. Maybe I'll go up to an ounce and five eighths (the nominal weight of the RB) shot charge in #5. That would be approximately 276 pellets. If the ratios stay the same, the right barrel should put 160 pellets in a 24" circle at 25yd, and the left barrel should put 199 pellets in that same 24"circle at 25yd.

The 85-grain by volume charge behind an ounce-and-an-eighth of shot is 'fine' as far as recoil goes. I'll chronograph it, and see what kind of velocity is being generated by that load.

This looks like it is going to be a fun shotgun to take after ducks and geese. Thanks again AL and HB!

Paul

[Alboy]

Strange on your patterns. There is a thin area or void in almost the identical area and shape from both barrels. I don't mean to suggest there is a cure or even a worry ; it is just strange.
 
I would also suggst that the powder load, despite felt recoil, may be the difference and not amount of choke in the pattern densities. Essentially you threw one considerably faster than the other thus creating a larger disturbance in the shot string.
 
If you know how, and I don't, to measure for choke I suggest you do so. Then again this is why we pattern shotguns, the one barrel may just throw tighter without regard to science.
 
Granted my experience in BP shotguns is limited to my own and Jim Haynie, we both have the same models and they came smooth bore in the CVA's while my Pedersoli came threaded for screw in chokes. What I am trying to get at is I think you probably have a cylinder x cylinder unles they have been jug choked since leaving the factory.

[Alboy]

PS1030 Pedersoli Magnum Double Barrel 10 Gauge Shotgun $850.00
Well balanced and authentically styled double barreled side by side shotgun. One piece European walnut stock is checkered on the grip and the fore-end and is satin finished with cheekpiece. The barrels are 30" long and are browned. Barrels are choked cylider on the right hand and modified on the left hand. Two brass beads are installed on the top rib and a loading rod is located beneath the barrels.Lock, tang and triggerplate are left polished bright. Overall length is 46 1/2" and the weight is 7 1/4 lbs. Made in Italy by Pedersoli. CHROME LINED BARRELS.
 
This was just copied from Dixie's catalotg so you may have chokes of cylinder and modified after all.

[Alboy]

Oh yeah - on dry firing
 
Get some sink faucet washers that just slip onto your nipples and are tall enough to take the hammer strike.
 

[gitano]

Thanks for all the very interesting stuff, Al. The 'void' is interesting. I'll have to keep an eye out for it, but from what I've heard, as soon as I change shot size, it's like starting all over. I'm not sure aout that, but until I have some experience of my own, I'll have to take it at face value.

The faucet washers are a good idea. I haven't dry-fired the thing, and don't really see the need, but it's good to know. The new Imperial threaded nipple is quite a bit bigger than the original. I think I'll have to replace the left one too, as the asymmetry bugs me.

I was hep to Dixie's description, but when I casually measured the muzzles, I got the same 0.768" for both. I'll check them again more carefully, and I have some inside gauges that can reach about 4". Maybe those will shine some light on the bores. However, in the end, as you well know, it's how it patterns that matters, not what the bore measures.

What do you think of the 85gbv charge for the 1-1/8 oz shot charge? What do you think about the proposed 1-1/2 or 1-5/8ths shot charges? So far, this has been a 'sweetheart' to shoot.

Paul

PS - I should point out that the "bottom" of the targets is to the right in the pictures, not the actual bottom of the picture. I suppose I'll rotate them around to the proper orientation when I get a chance.

Paul

They've been fixed. Now "up" is actually up.

Paul

[Hunterbug]

I'm glad that everything is working out good for you! Thoes look like some pretty decent patterns to me. It would also be great for you to take some grouse with too. Maybe Al has some idea of where to find loose non-toxic shot. I haven't seen any around here.

[gitano]

I'm not likely to take this gun after grouse. I have 'proper' grouse guns. :)

Sportmen's Warehouse up here has non-toxic shot.

I just bough 25 lbs of #5 lead. Should take care of things for me this year and next.

Paul

[Hunterbug]

How far down the barrel are you able to measure the diameter?   If I remember right, the choke is about the last 3 inches. If someone tried opening up the pattern a bit but only did the end, it might be tighter choked a few inches down the barrel.

[drinksgin (deceased)]

A few things, chokes are as much voodoo as science, I had a sxs 16, shot #9 modified or better , both barrels, any other size shot was from cylinder to worse, barrels were marked m&m.
I have found shot size can really change the pattern on some guns, but others shoot all sizes about the same, enough to make you wander off, mumbling to your self and kicking a beer can.
I did some repairs on a couple of percussion guns several years ago,both were suffering from dry fire itis, the nipples were flared.
I did not have any new nipples on hand so I bought a 48 piece assortment of zerk fittings, found some that had the correct thread shanks, punched the ball and spring out the bottom and turned the nipple down to accept a #11 cap.
The zerk fittings were SS, I suppose they are holding up as the people have never asked about another one.
Just another pore boy workaround.
Another thing, toilet paper will make over powder and over shot wads, too.

[gitano]

I'm well aware of "choke voodoo". That's why one has to "pattern" what one wants to shoot - powder charge, wad combination, shot size and shot charge.

The zerk idea is a great one, Don!

Paul

[drinksgin (deceased)]

Paul TOTW has a .750 Kirkland mold on hand.
Go, boy go!
Posted here  and in campfire, so you would not miss it.

[drinksgin (deceased)]

Paul, did you notice TOTW has .750 balls, 25 for $13.50, plus s&h?

[gitano]

Thanks, Don. Yeah I saw it. I'm TRYING to avoid having to buy RB when I have over 1000 lbs of lead wheel weights sitting in my shop. That said, I may well 'bite the bullet' and buy some of those.

I am looking at making my own mold using this: http://www.ebay.com/itm/400295794693?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

I think I can make one that works at least as good as the "Primitive" one that TOTW is selling.

Paul

[drinksgin (deceased)]

Do you know how true to dimension it is?
A .750 ball end mill cutter is $20 and would likely be very true.
As you will be cutting 1/2 of the mold at a time, you can stop short a few thousands and lap it to finished size after both halves are finished and the mold can be closed.