Roundball Velocity Potential

[FL-Flinter]

ok... mark, you first !!

and, ya... the eggwhite work's.

Told ya so.

[9.3X62AL]

OK, got the scale out and I stand corrected--220 grains for the .530" RBs. I don't recall perzactly where the "272 grain" figure came from, probably the 58 RB (I have one of those rifles, too).

I set this project aside not long after my original post, due to eyesight going south with a cataract. That has been resolved, so I'll be back at it soon with chronography to assist.

The rifle is capable of decent hunting accuracy with the 55-60 grain loads--cloverleaves at 50 yards, and under 2" CTC at 100, before my eye played out. The objective remains to obtain as much velocity at tolerable recoil levels as possible, as long as accuracy remains reasonable. Once that is accomplished, I'll replace the 20th Century sighting equipment with something more period-correct, using the sight heights from the existing set as best possible. MANY THANKS for all the commentary and guidance!

[John Taylor]

ok... mark, you first !!

and, ya... the eggwhite work's.

That would make my head hurt. I work for a living and don't have time to sit and think of numbers all the time. Just be practical and go out and shoot a few elk and see what works best. If you can't find any elk then try bear. Length wise on a griz would be a good place to see about penetration.

[buckweet]

That would make my head hurt. I work for a living and don't have time to sit and think of numbers all the time. Just be practical and go out and shoot a few elk and see what works best. If you can't find any elk then try bear. Length wise on a griz would be a good place to see about penetration.

ha. your right john... makes my head hurt.

shooting a grizz lengthwise....lol !!!!!

[475BH]

Ever hear the one about the guy who left his brass measuring device at home one day at the range, and used a shotgun shell cut to what he thought was 75 grains of 3F, so he double charged it, only to find out that it was really the 130 grain shell. Ha ha, I about laughed my.. no wait, that was me.

Yeah, if you think 130 is a bit much, I don't recommend 260!
ON the bright side, my home made rifle stayed together just fine, I kept all my teeth, and I fumigated for mosquito's with all the smoke that came out!

That's good humor.
I use a 45-70 case, they hold 90 grs. of FFFg
Works a lil better than that big adjustable thing.
BTW reminds me of last year after deer huntin, couldn't get the deer load out (after 2 months). So went rabbit huntin (.54, 90g. FFg) I must of had some lube soaked up by the powder and when I spyed a rabbit, leveled on it at 50-70 yds. There was so much smoke I had to lay down in the snow to see if I hit the rab., all I saw was a rab. running back and forth about 20' then took off and ran into the brush about 50 yds. to the left. I think he was scared from all the smoke that just showed up in his beloved swamp. And instead of the normal boom, there was just a light pow.

[bearside]

Greetings, I'm a first time user of this site so bare with me.
I was looking into information in regards to a correct powder charge for my
newly finished .62 cal. Jaeger that I intend on using for black bear.

I found several great answers on prevousily posted threads dating back to
2005 ( 9.3x62AL) and more from 2009, all of which I wish to thank.

I've been involved with blackpowder guns, both shooting/hunting and making
of said guns but have never put them against a chronograph. I've taken deer
with .45 cal, .50 cal ( patched round balls ) and also with my N.W. Trade gun
of 28 ga. ( .54 cal. ball ) All are flinters by the way.

However I am now facing a different critter in a black bear. I've started with
the " OLde rule of thumb " 1 gm per cal. but felt that that was too little and
have worked up to 85 grs of 2FF of GOEX pushing a .610 round ball with
a .015 patch greased with bear grease.

In applying the Davenport formula ( found on this site, thanks be to those )
I find that the suggested grms should be around 104 grs of 2FF. The barrel
is a Getz barrel and has a length of 31" but only 30" of usable bore because
of the plug, etc.

My range for this hunt will be between 25 to 34 yds and from elevated tree
stands over two bait locations. I don't have access to a chronograph or a
means to check foot lbs. However at 34 yds the .62 cal ball neatly past all
the way thru a 6" x 6" piece of free stand block of wood and continued on
into my backstop.

The gun and/or me shoots consistant using the 85 grs both at the 25 and
34 yds range.

So my question is this, is the 85 grs good enough to bring down mister
bear ( this implys that we are placing the shot in the vital zone and hope-
fully taking a leg bone out also ) or do I need to increase to the 104 grms
as per Davenport formula. The present load is comfortable to shoot and
is pretty consistant as mentioned. ( p.s. I also shoot an orginal .500 PBE
using 136 grs of 2FF with a very large/heavy projectial so I know recoil
and are not afraid by big recoils )

I plan to start this Friday ( 9/10/2010 ) to hunt so I don't have alot of time
to make adjustments.....any advice????

Thanks ahead,

John Drescher

[waksupi]

I shoot 95 gr. 3F Schutzen in my .62. I live in griz country, and don't feel under gunned at all with this. At the ranges you shoot black bear, you have plenty. Find your most accurate load, and use it.

Greetings, I'm a first time user of this site so bare with me.
I was looking into information in regards to a correct powder charge for my
newly finished .62 cal. Jaeger that I intend on using for black bear.

I found several great answers on prevousily posted threads dating back to
2005 ( 9.3x62AL) and more from 2009, all of which I wish to thank.

I've been involved with blackpowder guns, both shooting/hunting and making
of said guns but have never put them against a chronograph. I've taken deer
with .45 cal, .50 cal ( patched round balls ) and also with my N.W. Trade gun
of 28 ga. ( .54 cal. ball ) All are flinters by the way.

However I am now facing a different critter in a black bear. I've started with
the " OLde rule of thumb " 1 gm per cal. but felt that that was too little and
have worked up to 85 grs of 2FF of GOEX pushing a .610 round ball with
a .015 patch greased with bear grease.

In applying the Davenport formula ( found on this site, thanks be to those )
I find that the suggested grms should be around 104 grs of 2FF. The barrel
is a Getz barrel and has a length of 31" but only 30" of usable bore because
of the plug, etc.

My range for this hunt will be between 25 to 34 yds and from elevated tree
stands over two bait locations. I don't have access to a chronograph or a
means to check foot lbs. However at 34 yds the .62 cal ball neatly past all
the way thru a 6" x 6" piece of free stand block of wood and continued on
into my backstop.

The gun and/or me shoots consistant using the 85 grs both at the 25 and
34 yds range.

So my question is this, is the 85 grs good enough to bring down mister
bear ( this implys that we are placing the shot in the vital zone and hope-
fully taking a leg bone out also ) or do I need to increase to the 104 grms
as per Davenport formula. The present load is comfortable to shoot and
is pretty consistant as mentioned. ( p.s. I also shoot an orginal .500 PBE
using 136 grs of 2FF with a very large/heavy projectial so I know recoil
and are not afraid by big recoils )

I plan to start this Friday ( 9/10/2010 ) to hunt so I don't have alot of time
to make adjustments.....any advice????

Thanks ahead,

John Drescher

[northmn]

Two things on your 62 Jaeger. The English had the Baker rifle which made its name in the Napoleanic wars and used about 110 grains of whatever. 2f would work. Several Black bears in my neck of the woods have been shot with 20 ga Northwest Trade Gun Replicas, whcih are about 62 cal. They usually used about 90 grains of 2f. I built a 62 for an individual who used it (I think before the finsih was dry) to sh0ot a large 200 pound plus 8 point buck with about 70 grains of 3f. As to loads for a 62, 1/2 the ball weight is often recommended for a hunting load which would put you in the 160 grain charge range and which few use. I use about 90 grains in my 20 bore which is quite accurate and about 90-100 in my 58. If I were worried about enough punch in a 62 I would try the English Baker load of 110 grains of 2f. They made some very long shots with that rifle. I would also bet that 85 grains will put down any black bear you are likely to see.

Northmn

[fishhawk]

HEY! that you Wet john? standing on the rock in the peshtigo river? steve k

[bearside]

Thanks for your quick responce. Your info has eased my mind some as to my load. being
that my range is rather short I now believe that this combination will do the job. All I know
is that I don't want to be on the receiving end of that load/ball at 34 yds....right!

[bearside]

Ya thats me, " Wet John " nice seeing your reply. have sort of fell away from the N.W.
Company and the rendevous stuff but still making and shooting those firesticks. Perhaps
see you down the trail one of these days. Keep your powder dry and your hair on.

[bearside]

Thanks for reply and easying my mind as to my load. Blacks are not as tough as Griz so if
you feel safe with 95 grains I'm sure the 85 grains will lay down a black bear just fine. If
the range was greater than the 25-35 yds I would probably increase grains but since it
shoots point of aim now, I'll just rest my mind with the 85 grains and my practicing shots.
Again thanks for your advice.

[SamTexas49]

Ok, reading all this is kinda interesting!

But with out this "equipment and calculators" I recall an Old gent way back in the 70's tellin me that when you see them "red beads" at the end of your barrel after a shot then you got the "right load" for busting critters!

As for "ball size" arent we alwasy told "bigger is better?"

I had for a while a semi-kit gun (cant recall the manufacturer) full stock Hawkin in .62 cal !!
320gr RB !! Never got to take any game ( I did hunt with it cow Wapiti) but loved shooting steel targets!!! There was never any question when I hit then things! Best shot was on the 25yd squirrels, had hit 4 out of 5 ( had to nearly go to 50yd line to retrieve them) took my last shot and "Missed" but the ball traveled so close to it that the air turbulance turned the squirrel on its plate!!! ( used 60 gr 2F at 25yr )

[9.3X62AL]

Again, thanks to all who posted and assisted with my original question, and helped to chase it down a few rabbit holes as well. I am not one step closer to getting that Hawken field-ready for hunting, largely due to California's condor-cuddling bullsquat taking a deep and comprehensive DUMP on lead-bullet game-taking. And it is getting worse, with measures before the granola-based legislature to force ALL hunting venues to use non-toxic projectiles. Between the bullet bullsquat and the coastal fishing closures, this Kabuki Theater of excremental excess might drive me out of this Worker's Paradise. I am genuinely starting to loathe what my home state is becoming.

[Nobade]

Just in case you didn't know it, BPI products has bismuth round balls in various sizes. At least I think that's where I saw them. Might be useful for you. I also have seen folks getting good results with 58cal. ball guns using 9/16" brass balls and a thick patch. Make a box to recover them and keep using them over and over. And yes, CA is somewhere I would lo longer want to be. Sure was fun back in the 1980's though. The Frontstuffer shop in Fontana holds good memories for me.

-Nobade

[crossxsticks]

Fred, thanks for your reply, a 50 is my cal. to shoot I was hopeing some one would do the math for me LOL

Math is not my long suite. That is why I became a lawyer. But, the Davenport formula is worked by using some of that darn math they tried to teach me back in HS.

The Cubic area of the bore would be done this way:

Take the bore diameter( or groove diameter and then calculate both cubic areas. Then subtract the area created by the lands, to get the actual true Cubic area of a rifled barrel. Generally, the difference is measured in a couple of grains, and is not worth the extra brain power used.) and divide it by 2 to get the Radius of the bore. (r)

Area of a circle is determined by the formula A= PiR Squared. Pi= 3.1416. So, Multiply the Radius by itself(to square it) and then multiply that number by Pi to find the area of the circle the diameter of the Bore of your gun.

Now Multiply that number( area) times the 11.5 to get the amount of powder in one inch of your bore. Multiply that number by the length of your barrel to get the total capacity for your whole barrel.


Example:


( .50 cal. divided by 2 = .25; times .25 = .0625; times 3.1416= .19635; times 11.5 =2.2580; times 28(barrel length)=63.22 grains of powder.)


If you want to know the cubic space inside one inch of a .50 caliber rifle, you can use .50 as the diameter, or measure the actual land to land dimension, and then the groove diameter, and then the groove depth, to work out EXACT the cubic area of that particular bore.


Here is how to calculate the Davenport Formula:


.50 divided by 2 = .25


.25 x .25 = .0625


.0625 times Pi( 3.1416)= 0.19635


.19635 x 11.5 = 2.2580


2.2580 x 28 inches( barrel length)= 63.22 grains of powder.


___________________


Assume you are shooting a 28 inch .50 caliber rifle barrel. The cubic area of that bore will be 28 x .19635 = 5.4978 cubic inches.


Now, because you do have grooves in that barrel, you can refine that a bit more.

Assume that the actual groove diameter of your gun is .501" ( my .50 caliber rifle's actual bore diameter)

Run the Davenport formula and you get:


.501 divided by 2 = .2505


.2505 x .2505 = .0627502


.0627502 x 3.1416 = 0.197136


0.197136 x 11.5 = 2.267064


2.267064 x 28 = 63.477792 grains of powder.


A cube of anything is determined by multiply the height times the width, times the depth, of the object. When you need to compute the cubic area of a cylinder, or other non-square object, it gets a bit more involved.


Now assume that the bore diameter is actually .490, and groove depth is .0055"( .501 minus .490 divided by 2 = .0055")( again, my gun's actual bore diameter)


Now assume that there are 6 lands and grooves, of equal width. The circumference of that bore( .490) is .769692" Divide that by 12( 6 grooves and 6 lands) and you get the width of the lands and grooves to be .064141".


To adjust the cubic area to correct for these "obstructions", you need to subtract from 5.519808 the area occupied by those 6 lands, that are .064141" wide, and .0055" deep.

So, multiply 6 time times .064141 times .0055 = .0003527"

5.519808 - .0003527 = 5.5194553 Cubic Inches


______________________________

If we ran the davenport formula using the Land to land diameter( bore diameter) of .490, we get:


.490 divided by 2 - ..245


.245 x .245 = .060025


.060025 x 3.1416 =.1885745 square inches. ( for a circle that is .490 in diameter.)


.1885745 x 11.5 = 2.1686067 grains per inch


2.168067 x 28 = 60.720987 grains of powder.


So, if you use the smaller diameter of the bore( land to land[.490]) The Davenport formula will give you only

60.72 grains of powder in that 28 inch barrel.

If you use the nominal .50 caliber, the formula gives you

63.22 grains of powder in that 28 inch barrel.

And, if you do all the math needed to actually get the ACTUAL cubic area of that barrel, you get a figure in between those two, 60.7, vs. 63.2! That is a difference of 2.5 grains, and half( assume that the lands and grooves are of equal width) that is only 1.25 grains!( Approx. 61.95 Grains!) Not enough to bother about, NO?

[Hanshi]

In the old country jaegers were often very large caliber. Their powder charges weren't heavy since a large ball doesn't need that much velocity for power and penetration. Their hunting distances were normally quite close. This practice continued in America until most large game was shot out. The need soon became economy; smaller ball but at higher velocity for distance. The last deer I killed was with a .62 smoothbore and 70 grains of 3F. Judging from the results, I'd have done just as well with 60 grains.

[9.3X62AL]

They are known as "ITX Roundballs", TomBob Enterprises markets them and BPI shows them as being available. Not cheap, about $1 each--but they will keep me hunting with THB! Many thanks, Nobade! Damn the condor cuddlers, too!

The Frontstuffer was a great shop, indeed. So too was "Muskets to Magnums" in Moreno Valley.

[Green Lizzard]

that davenport thing made my hair hurt

[GARD72977]

Reading this has me thinking. Since SWISS is a hotter powder, will it have as much FPS increase as the barrel length increases as a powder like GOEX?