Post by: Skychief on June 22, 2010, 10:37:22 PM
My question is: If I shoot .690's with thicker patching, will these strike 3" higher than the .715's at 25 yards (everything else being equal)?
Thanks for any feedback.
By the way, my smoothbore has a short barrel (28").
Skychief.
Post by: Uncle Russ on June 23, 2010, 02:29:49 AM
Quote
My question is: If I shoot .690's with thicker patching, will these strike 3" higher than the .715's at 25 yards (everything else being equal)?
Well sir, I personally don't think there is enough weight difference in a .690 and a .715 to make all that much difference when you say, "everything else being equal".
Three inches is a lot at 25 yds. and the weight difference in a .690 and .715 is not all that much, although I would have to look to see exactly how much it really is.
Should it turn out to be as much as 40 / 50gr then there is the possibility it just might work, but I doubt it.
My first thought is to increase velocity or use more powder, unless of course you've got a load that is really grouping well but just happens to be impacting low.
If that should be the case and you insist on "everything else being equal" take small amounts of the front sight down to raise that impact.
This would also apply to the .690 as well as the .715.
There are times, and I've been there, where you don't want to touch anything... just raise, or lower, the POI, and sight adjustment is still the most practical and easiest way to accomplish this.
Uncle Russ...
Post by: Swamp on June 23, 2010, 05:29:44 AM
Post by: Longhunter on June 23, 2010, 08:40:57 AM
Post by: pathfinder on June 23, 2010, 09:39:40 AM
Post by: hankaye on June 23, 2010, 08:48:30 PM
Borrowed this from Bob's Blackpowder Notebook:
Substitute your Ball measurments for those used in the example an off ya go...
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Weight of a Roundball (Long Method) If the diameter of a roundball is known, the weight can be calculated. Using the .3950 in. ball from the exercise above, we proceed to:
1) Convert inches to centimeters:
Diameter = .395 in. x 2.54 centimeters per inch
Diameter = 1.0033 centimeters
2)Extract the radius:
Radius = Diameter divided by 2
Radius = 1.0033 divided by 2
Radius = .5017 cm
3) Cube the Radius:
Radius cubed = (.5017)3
Radius cubed = .1263 cubic centimeters
4) Then:
Radius = cube root of .1263
Radius = Cube root of (3 x Vol.) divided by (4 x pi)
.1263 = (3 x Vol.) divided by (4 x pi)
.1263 = (3 x Vol.) divided by 12.566
3Vol. = .1263 x 12.566
3Vol = 1.5868
Vol = 1.5868 divided by 3
Vol. = .5289 centimeters cubed
5) Find the Weight in grams:
Since Volume x Mass = Weight
.5289cc x 11.34 gm/cc = 5.9982 grams
6) Convert grams to grains:
5.9982 grams x 15.4324 grains/gram = 92.57 grains
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Weight of Round Ball (Short Method) A short-cut method of determining the weight (W) of a roundball when the diameter is known involves the use of a constant.
W = 1502.6 x (Diameter x Diameter x Diameter)
Example for a .395 roundball: W = 1502.6 x .395 x .395 x .395 = 92.6 gr.
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Have fun
Post by: waksupi on August 22, 2010, 09:48:41 PM
Post by: Capt. Jas. on August 23, 2010, 06:09:37 AM
When you establish a consistent load you are satisfied with, then bend the barrel.
Post by: Buzzard on August 23, 2010, 08:50:03 AM
Post by: Captchee on August 23, 2010, 09:52:42 AM
You didn’t say what smoothbore you have .
Is it a trade gun , Tulle , Bess , English fowler ? Was it built for you ?
The reason I ask is that sometimes the issue isn’t in the barrel but in the hold .
Before you do any filing or bending . Try sliding your face an inch or so back from where your now setting your cheek . This will cause you to need to rise the barrel alittle more so as to align the sight .
I have seen guys file the front sight near off , trying to raise a group . When all they needed was alittle different hold
Post by: Gordon H.Kemp on August 23, 2010, 10:24:40 AM
Post by: waksupi on August 23, 2010, 11:27:34 AM
Post by: Capt. Jas. on August 23, 2010, 12:20:18 PM
The farther back your cheek sets on a decreasing plane comb, the lower you will shoot because you are in effect lowering the rear sight which is the eye. Maybe adding a cheek pad instead?
Post by: Captchee on August 23, 2010, 05:50:55 PM
Quote
Won't sliding his face an inch or so back from where he is now setting his cheek cause him to have to remove his cheek from the comb to see the front sight? (If this is a decreasing plane comb)
all depends if the gun was built fo him with the proper drop then yes . if it wasnt then no .
if the gun was built proper. when its shouldered and with your head un moving you should be looking right down the barrel flat .
unlike modern shotguns with very little drop .which you step into . Ie you have to bring your eye down to the plain of sight ..
also depending on the gun . the design may not call for a forward shooting style . possably and erect one or even a back like with the Tulle
Post by: Capt. Jas. on August 23, 2010, 07:22:08 PM
I am probably just worn out and cant think today.
Post by: markinmi on August 23, 2010, 08:23:28 PM
Post by: Captchee on August 23, 2010, 08:52:07 PM
Quote from: "Capt. Jas."
Even if the gun was not built to fit him, if he brings his eye lower (backward on the stock) either it will shoot even lower or he wont be able to see over the breech. Exception would be if he was crawling the uppermost nose on a pied de vache stock.
I am probably just worn out and cant think today.
ok think on this
Lets say your eye is level with the rear sight on a rifle . IE you can look strait through the sight . Everything is 0 . You bring the front blade up and all is good right ?
Now lets say you are looking down at a positive angle . Basically your line of sight is just a little high . Now whats going to happen is your eye isn’t going to give you a true reference. When you bring the front sight up . What looks like level is actually a little low because of your line of sight .
So if your face is alittle farther back . Thus little lower .. Your line of sight is not strait down the barrel . Thus the front blade must come higher in order for you to get a sight picture .
Or think of it this way .
Your shooting an O to R barrel with ohm? A 16 in octagon section . Your current line of sight lets you see the full 16 inches . So you bring the blade up and use the top barrel flat as a reference . But your shooting say 10 inches low .
As you move you face slightly back , you see less of the length of the flat even though you can clearly still see the flat . because you see less of it , you have to raise the muzzle more , in order to see the front blade
Post by: mark davidson on December 13, 2010, 12:18:37 PM