How big a bore is too big?

[mark davidson]

Rollingb, Man, I just asked a simple question in an honest desire for information about really big bores caue I have NO EXPERIENCE with them. I am perfectly capable of pouring in more powder and trust me my shoulder can stand it. I am also quite capable of setting my sights. I managed to set me .54 well enough to slam 7 deer with it last year at various ranges. The trajectory is flat enough that a clean six o clock hold at 50 yards and a 12 o clock hold at a hundred will put a prb in the bullseye at either range. Most of my other shooting experience is with center fires. .45acp is a good example of what I do not want in a rifle. A 230gr projectile that hits well with a typical sight picture out to 50 yards is almost completely unusable at 100 yards cause the trajectory is so bad you have to hold up so much that the target disappears behind the muzzle. Add another couple of hundred feet per second and the same projectile becomes practical on out to 100 yards in the .460 Rowland version of the same round. The .45 acp as a caliber simply cannot be made to perform well with a practical sight picture at both ranges. If a big .72 cal can be loaded to the point that it is perfectly usable with a reasonable sight picture up close and at extended ranges like 100 yards, then I will for sure go with the bigger .72.  There comes a point that a round is simply too big and drops like a rock very quickly with even a very stout powder charge. I just figured some of you on here might have shot the big stuff enough to tell me of one has an edge over the other or not. Simple question; simple answer.

[rollingb]

Rollingb, Man, I just asked a simple question in an honest desire for information about really big bores caue I have NO EXPERIENCE with them. I am perfectly capable of pouring in more powder and trust me my shoulder can stand it. I am also quite capable of setting my sights. I managed to set me .54 well enough to slam 7 deer with it last year at various ranges. The trajectory is flat enough that a clean six o clock hold at 50 yards and a 12 o clock hold at a hundred will put a prb in the bullseye at either range. Most of my other shooting experience is with center fires. .45acp is a good example of what I do not want in a rifle. A 230gr projectile that hits well with a typical sight picture out to 50 yards is almost completely unusable at 100 yards cause the trajectory is so bad you have to hold up so much that the target disappears behind the muzzle. Add another couple of hundred feet per second and the same projectile becomes practical on out to 100 yards in the .460 Rowland version of the same round.

I think you've just answered your own question, and remember that the ACP is "limited" because of it's "case capacity" when compared to the .460,... if trajectory was governed soley by "calibur" then a .458 Win. Mag would have the same trajectory as the old .45-70 Springfield round.

Velocity has "everything" to do with trajectory,... so where is the confusion regarding "calibur"?  

There comes a point that a round is simply too big and drops like a rock very quickly with even a very stout powder charge.

The "law of physics" will certainly disagree with that statement,... and you even contradicted it by using the ".460 Rowland vs .45 ACP" example.

 

I just figured some of you on here might have shot the big stuff enough to tell me of one has an edge over the other or not. Simple question; simple answer.

The simple answer is,.... the bigger the ball, the bigger the "edge",.... and the bigger the "RECOIL" factor, due to the increased powder-charge needed to retain a reasonable "velocity" with a bigger ball.

I hope this helps answer your question.

[Bigsmoke]

Mark,
OK, here is my experience with the .62 and .69 and .72 with 1:104 shallow, wide groove, narrow land rifling.  Frankly, I cannot tell much difference in trajectory.

Africa, a fellow with one of my rifles shot a duck off a pond at a lazered distance of 240 yards.  Boom, no duck! .69 cal.  Same guy, same gun, shot an eland at 140 yards, went down like a truck hit it.  His observation was that his tendency was to shoot over critters, as he had difficulty believing it would shoot so flat.  Probably 200 - 225 grains Ffg.

Me, .72 cal, 200-225 grains Ffg, bison, 100 yards, hit it hard enough to roll it all the way onto its back.  Same gun, approx 250 +/- yards uphill, hit a 12" square gong, 200 grains.

Me, .62 caliber, 165 grains Ffg, won a distance shooting contest at 200 paces.  Target was a ram silhouette.  Hit right where I aimed.

Guess what I am trying to say is that in my opinion and experience, if the rifle is designed right, with the right rifling, it will definitely reach out and touch something.  Right where you want it to be touched.

In all honesty, as was already mentioned, there are no degrees of dead.  Once the lights are out, that's is.  However, I think that it is a much better kill to hit the critter so hard that it just slams it into the ground and lights out, rather than hitting it and it walks off for 50 - yards and then gradually expires.

Roaring Bull, the book has already been written.  It is The Sporting Rifle and its Projectiles, by James Forsythe.  Good luck finding it, they are getting pretty scarce.  Buckskin Press republished it in the 1970's.  Have seen a few originals, but they generally run in the $125 - $150 range.  And Buckskin Press has gone the way of the carrier pidgeon and the dodo bird.  Extinct.

[mark davidson]

Rollingb,  Very good point and well taken on my end. I see the light now and the answer was obvious, velocity!  I just did not know that the bigger and heavier .72 could be gotten up to enough velocity safely and practically to make it have a similar trajectory to a smaller calibur with lighter projectile. With centerfire stuff one has the option of changing bullet weights to change velocity and trajectory. It seems that if one is going to shoot the prb then the weight of the ball is consistent leaving only powder charge and velocity to be played with to achieve a desired result.
  Wyosmith, I'm not sure I can stand up to an 8 bore! :-)  Truth is I may decide I can't handle a 12 bore and I will for sure shoot one if I can before I drop the cash for one.  What would you compare recoil on a .72 cal with say 200 grains of black powder to? I shoot a lot of 3 1/2" 12 guage rounds duck hunting and I have shot a few 10 guage rounds and I have owned a .458 magnum rifle and shot it a good bit. Is the .72 similar or heavier in recoil or lighter or what do you guys think?  My .54 with up to 120 grains of BP is pretty mild in my opinion and the 90 grain load is a pussycat.

[Uncle Russ]

If a modern 3" 12 gage with a Turkey load is not bothersome to you, the 12 bore muzzleloader will not be either.
In fact, with muzzleloaders, the recoil is usually a lot nicer just because you can build it (or have it built) to fit YOU perfectly and put a butt plate on it of 2"-2 3/8" wide, which REALLY spreads of the recoil so it's not at all painful.

I share this same thought.....and I have for some time now.

FWIW: Over the years, like many others, I went through a stage where I was a big bore fan when it came to centerfires, ie .300, 35 Whelen, .338, .375, .416, etc, etc, and, depending on the stock, some of these things can, and will, kick your fool head off if not pulled in tight.

In the past 15 / 20 years, since my entire shooting passion turned to muzzleloaders, I have shot some pretty big Black Powder guns too, but I have always seen the recoil as being quite different.

To me, the recoil of a muzzleloader is more of a p-u-s-h, as opposed to the slap, or smack, of a centerfire.

I do have a little bit of experience with a rifled .72 that belongs to my hunting buddy over in Olympia.
Jerry's load is 200 gr FFg every time he fires it! and I feel that the felt, or percieved recoil of that rifle, with that load, is somewhat less than my own GPR in .54 using 120gr FFg.

His rifle with that stock design is more of a push, while my own rifle is more a slap..... quite like the centerfires.

So, as Steve said, it's all in the stock..... at least IMHO!

Uncle Russ...

[jbullard1]

Very interesting thoughts
I looked at and drooled and slobbered all over a 62 Grand Rifle built by Matt Avance this past weekend. He told me about the same thing as far as the recoil, he offered to let me shoot it but I passed. If I had been really interested and had the cash I would have made smoke with it

[hawkeye]

I just got back from the range shooting my .62 Early Virginia rifle. It has a 42" straight octagon barrel. I had to up my charge to 110gr of 3f to get the balls to print on top of each other at 50yds.   Recoil with that wide buttplate wasn't bad but you do know you shot it. I'm hoping to get deer #2 with it this season.

[mark davidson]

Hawkeye,  What is the maximum upper end charge for a .62 and a .72?  In my reading it seems that 90 to 110gr. is  pretty standard for .50 and .54 cal. guns. What is standard and what is "upper end" on the bigger .62 and .72?

[hawkeye]

I'm not sure what the "upper end" really is but I'm close to what I consider it to be.  If I want to go more powder, I'm going to drop down to 2f.

[Bigsmoke]

I think Forsythe used an upper limit of 240 grains of "Fine Sporting Powder" in his 14 bore double rifles (.69 caliber), as mentioned in his book, The Sporting Rifle and its Projectiles.

I'd say a .62 with slow rifling and a 1 1/8" barrel would be 200 grains Ffg and a .72 with 1 1/4" barrel would be 225.  This is with 1:104 twist.  If a person were to use 1:144, you could probably squeeze in a few more and retain pretty good accuracy.

[rollingb]

I've always been lead to believe, that the general "rule of thumb" is to use FFG in rifle caliburs over .50, and in smooth bores with 36" (or, longer) barrels because of it's slower "burn rate" (when compared to FFFG).
So I would think (uh oh ) that using 110grs. of FFFG in a rifled 42" big-bore barrel must create some "rather high" breech pressure, and would be less efficent (in that long of barrel)  then the slower burning FFG.

Someone correct me, if I'm thinkin' wrong.

I use a 100gr. FFG charge (with roundball) in my .62 NWTG, but I don't use it for 100yd. hunting.

[hawkeye]

I'm going to try 2f next but right now I'm getting good accuracy with 3f so I don't see a need to switch. I also don't shoot a ton of consecutive shots either. It's my deer rifle, not my woods walk gun. That honor goes to my Brown Bess.

In my 20 bore NWTG, I shot 70gr 2f and a .600 round ball with great accuracy.  Even with my .75 Brown Bess and .735 RB, I max it out at 90gr 2f.  Smoothbore barrels tend to be thinner than rifled barrels and aimed shots with a smoothbore tend to be 25yds or less.

[Mitch]

been shooting 75+gr of 3f in my smoothbores forever-seems to work fine and I'm not worried about breech pressure-have you looked at the breech thickness on most fowlers?