Chronographing Shot?

[Nuthatch]

I've heard some folks saying that shot should be moving at about 1000 fps. So how does one figure that out? Seems that by the time you put the chronograph far enough away from the muzzle to not pick up powder, cards & such (typically at about 5 yards), the device is at risk of getting shot itself. Are people just guessing at velocities?

In working up a load for hunting with my .50 smoothbore, I noticed that the recoil is much softer than shooting round ball. A round ball doesn't kick much but it is abrupt. Shot seems to be much more of a push -- more push than a round ball but far softer and less abrupt. This has me a little concerned that I'm not getting enough pressure to really get that shot out there at lethal speeds. And since cards & wads aren't nearly as difficult as a patched ball to get down the bore, it would be good to have a sense of the projectile speed before firing on a live animal.

In case it matters, for a hunting load, I'm loading 1 oz of #6 bismuth in a .50 smoothbore percussion, which fits level in a 75 grain powder measure. Powder charge has been at 50 grains Pyrodex RS (FF). Cardstock & leather over powder & cork over shot -- all soaked in a thin grease/oil mix.

 

[Sparkitoff]

I used a make-shift slanted piece of metal with wood base to protect the chronograph device. Before shooting over the chronograph, I shot a few times at paper to figure out the spread and if I could see any of the wad material hitting the paper. When I was done with paper, I shot over the chronograph with plastic straws in place of the metal guides that come with it. I do remember it was either 20 something or 30 something feet where it worked best. I did not measure the powder precisely but rather used the same scoop I used for the 1-oz of shot. If you figure the velocity loss for the yardage to impact (over chronograph) I came up with 1103 FPS average for this particular gun and load. I didn't care what the velocity was specifically, but rather used it as a baseline for increasing powder or shot (or both) to try to stay near what a nitro-powder load would do. The 7/8-ounce scoop of powder and shot actually lost velocity and average 998 FPS, while the 1 1/8-oz scoop of powder and shot was virtually the same as the 1-oz square load. (This is all in a 20g). Hope some of this experience helps you figure out what you want.

 

[nhmoose]

Use a Lab Radar chronograph. It is behind the gun many amateurs own them. When my current sky screen type quits I also will have one.

 

[Historian]

I shoot at 3-5 feet away from Chronograph, I do use the plastic cover that came with mine to protect it from the wads or stray pellets but have not had any issues concerning those. The only main issue I have is it does not like bright sunny days. On those days I shoot under a large tree to shield it from the sunlight. Mine likes about 18 inches above the Chronograph. Otherwise it reads just fine. In my 20 ga's I usually shoot 3Fg or sometimes 2Fg. Anywhere from 65-85 grains. I use leather OP wads and wool felt soaked in Olive Oil and Beeswax. Again no issues. I would try bringing it closer and using a clear plexiglass cover. Do make sure the device is anchored well in place though. Also shooting free hand can cause irregular readings which is why I shoot from a bench rest on a small folding table. Hope this helps.

 

[tallpine]

A proven way to test the lethality of a smooth bore is to try it on an empty bean can at about twenty yards. If it will shoot through a bean can it will kill a turkey.

 

[megasupermagnum]

Use a Lab Radar chronograph. It is behind the gun many amateurs own them. When my current sky screen type quits I also will have one.

Lab Radar does not work with shotguns. I have yet to meet or read about someone who has had even mediocre success. Lab Radar themselves say just don't try, it's futile. The technology can not work with multiple projectiles.

Use a standard skyscreen chronograph. Accept that if you send enough rounds over it, eventually something will hit it. If you do it right, this can be years, if not decades. For shotgun specifically, don't use the skyscreens, and shoot close. 4' is a good distance. Don't shoot too low, about a foot over the top is good. If you can, place a 4x4 block of wood in front of the machine, to block any wads. I've shot quite a few rounds over mine with no block. Eventually a card wad did connect, but only knocked the plastic name plate off, no damage.

I hate to speculate on your load, as being a 50 caliber changes everything. There's nothing special about 1000 fps. At pretty much any speed, you should be ok on rabbits and squirrel. #6 bismuth might be a bit small for longer shots, or game like pheasant. For ducks and pheasant, #6 is pretty small no matter how you cut it, #5 is a lot better. For turkey #6 bismuth should be about perfect.

 

[nhmoose]

Thanks for that info, good to know. My current setup has a piece of steel angled up covering the front so nothing can hit the chrono. I guess my next one will have a remote screen so I don't have to walk forward every shot to read the front screen.

 

[Historian]

If yours is capable like mine of Bluetooth tech readings, the shot to shot info is sent straight to your phone. Again keep the distance short and the height between 12" to 18" and you should be good to go. I have yet to have any issues if you use the guards. You can make a protective screen out of plexiglass using small L brackets to make the 90 degree face. Good luck and good shooting.

 

[Nuthatch]

Thanks for the responses. In my case, I'm not worried about the wads hitting the chrony. In fact, I didn't even consider that. I set mine about 5 yards in front of my bore because, with patched balls, the patches & unburnt powder were messing up the reading when I only put it a few feet away. I'd get 600 fps and 1900 fps readings & everything in between. Once I set the chrony out 5+ yards, things got way more consistent.

Sounds like I'm probably overthinking it. As megasupermagnum pointed out, my powder load is probably fine to do whatever damage needs to be done (turkey head in this case). So my focus should likely be on pattern density & how to improve that. Thus far, at 25 yards, I only get about 10 pellets in a paper plate. Still have some work to do, I think.

 

[megasupermagnum]

Oh wow. Yes, I wouldn't hunt until you can put 100 on that paper plate. Is there a reason you are using bismuth? #6 is about perfect for turkeys, but #7.5 lead will allow you to get more pellets per ounce, and penetration is about the same. There's a millon ways to load a shotgun, but since you have listed what you have, try one load. Assuming your cardstock is about .030" thick, load 5 of them over the powder. Then use 1 card over your shot. Don't use any lube. Try that, and see what happens. Also, get a big sheet of paper, and shoot at 10-15 yards. Make sure you are centering your pattern on the target. Just because it was sighted in with a ball does not mean it is sighted in with shot.

 

[Nuthatch]

Oh wow. Yes, I wouldn't hunt until you can put 100 on that paper plate. Is there a reason you are using bismuth? #6 is about perfect for turkeys, but #7.5 lead will allow you to get more pellets per ounce, and penetration is about the same. There's a millon ways to load a shotgun, but since you have listed what you have, try one load. Assuming your cardstock is about .030" thick, load 5 of them over the powder. Then use 1 card over your shot. Don't use any lube. Try that, and see what happens. Also, get a big sheet of paper, and shoot at 10-15 yards. Make sure you are centering your pattern on the target. Just because it was sighted in with a ball does not mean it is sighted in with shot.

I’m in CA. Lead is for rangework only. I have a bunch of lead #8 from an old dive belt that I can play with. But #6 and #8 aren’t similar enough. Those 8s are great. But 6s are pretty bad. I’ll see if I can get the 6s to work this weekend. And, if not, maybe just chuck a patched ball at the birds this year or at least until I get it wired.

 

[megasupermagnum]

I'm sure you can get #6 bismuth to work. I shoot #6 lead, but I'm shooting much heavier payloads. You can only push a 50 caliber so far, and 1 ounce is already up there. 25 yards might be pushing it, but you should be able to at least get to 20 yards. Try the wads as I said, you might be surprised. There's other tricks too if you really want to get into it. Some people even make paper shotcups. You could even try 50 caliber sabot's if you wanted.

 

[Nuthatch]

Sabot - That’s brilliant. Will have to watch for plastic fouling. But otherwise, why not? Thanks.

 

[Nuthatch]

Well, I sent some shot down range yesterday and got the pattern to tighten up on the #6. Oddly the sabot worked great but very unexpectedly. I had to cut the two petals off and then load it on top of the shot. Maybe my homemade wads just weren’t tight-fitting enough to really compress under pressure. So my loading was powder — cardboard & leather cards OP — shot — stripped sabot. 40 gr Pyrodex & 1 oz #6.

20 yards is a max range. So this is still stickbow distances. But I’ll take it. I still don’t know what kind of speed it’s producing but it certainly feels more punchy with the tight-fitting sabot on top vs just some sort of card or cork wad. I’d like to find something a little more traditional than a plastic sabot. But I’ll take it for now.

The upper target also shows some patched ball from the same rifle. There’s some human error in some of those shots but being able to hit the target at all from 100 yards with a smoothbore on the first try was a pleasant surprise

 

[megasupermagnum]

Mmm, that still doesn't look good. I wouldn't take a shot at 20 yards with that anyway. Did you try just card wads only? I've done wad seal testing in the past, you can probably find the thread. With card wads, you will need at least 1/8" thick stack of card, more is better to get a good seal. You want your wads larger than the bore diameter. A 1/2" wad could be too small for your 50 caliber if that is what you are using. A 9/16" punch works well for 50 and 54 caliber wads. Leather worked really well for me, but again, if you are using 1/2" punch, it's probably too small diameter. You will also want to look into "Skycheif" loading a shotgun.

 

[Nuthatch]

Mmm, that still doesn't look good. I wouldn't take a shot at 20 yards with that anyway. Did you try just card wads only? I've done wad seal testing in the past, you can probably find the thread. With card wads, you will need at least 1/8" thick stack of card, more is better to get a good seal. You want your wads larger than the bore diameter. A 1/2" wad could be too small for your 50 caliber if that is what you are using. A 9/16" punch works well for 50 and 54 caliber wads. Leather worked really well for me, but again, if you are using 1/2" punch, it's probably too small diameter. You will also want to look into "Skycheif" loading a shotgun.

Yes, wads only was all fine with lead #8s. Just not the #6 bismuth. The wads I cut were with 1/2” punch but swell up a little bigger than that. But, yes, I’ll be trying a new punch at around 9/16 & see how that goes. I’m happy with that pattern but only relative to what I was getting.