Got My Cheek Slapped and Don't Know Why

[Billnpatti]

115 grains of powder is a LOT of powder. If I were looking for a target load, I'd be starting around 60 grains and slowly working up in 5 grain increments until I found what it likes. I seriously doubt that you are getting complete burning of all of the powder that you are loading. Some of it is probably being wasted by being blown out of the muzzle before it has completely burned. Some may tell you that 3f is too fine for your caliber of rifle but it is not. It should work just fine. But, some larger caliber rifles do prefer the 2f over the 3f. You just have to figure which powder your particular rifle wants.

By reducing your powder charge, you will reduce or eliminate the cheek slapping. That is, providing you were not experiencing cheek slapping before. If your stock comb is too high for you, you can get cheek slapping. Also, if you are shooting from a different bench and the bench is different and causes you to scrunch up to see your sights, that, too, can cause cheek slapping.

If you decide that it was the gun causing the cheek slapping and not a different bench, etc., the first thing I would do is to start with a charge of 60 grains and work up an accurate charge that does not exceed 100 grains.

If you want a ball park estimate of how much powder your gun will shoot before it starts blowing unburned powder out of the barrel, you can calculate the volume of the bore by the following equation:

Pi x the bore radius squared multiply that by the length of the bore. Take that number and multiply by 12.5 and you will have an approximation of how much powder you gun will shoot efficiently. This is not a dead nuts on number, just an approximation but it will give you an idea of where you will start wasting powder. For your rifle it will be 3.1416 x .29 X .29 X barrel length X 12.5

 

[BrownBear]

Truth time, as opposed to theory and preference?

The TC manual lists 120 grains of 2f for their Big Boar 58 caliber. Apply the 10% reduction recommended for a switch to 3f and you have 108 grains. I know cuzz I've got two of the Big Boars and two of the manuals sitting right here in front of me.

Sure seems like a whole lot of scowling and chest puffing over 7 grains of powder! :rotf:

Can't lay my hands on my Lyman #2 manual at the moment to confirm, but to the best of my recollection they go even higher.

Paper tiger roaring for all it's worth. :wink:

Shoot what the gun likes and your shoulder (and now cheek) can stand, and leave the theorizing to folks who don't even own 58 cals. :yakyak:

 

[crockett]

Getting back to the original question...do you have any feel for why the accuracy dropped? Was the cheek slapping causing you to shoot less accurately or was the gun itself less accurate? I am just throwing out thoughts....when was the last time you scrubbed the bore. used a scrapper to scrap the breech plug face? I've read around a ring of residue can sometimes build up. I'm wondering if such did occur, would it increase recoil and reduce accuracy? I don't know, maybe someone does.

 

[BrownBear]

Getting back to the original question....

Now you're talking! :applause:


Those are good questions.

I'll add another:

Any change in what you were wearing, Semisane? A thicker or thinner coat could have caused you to shift where the butt was resting, which might have changed the alignment of the comb to your cheek. I'm real careful about where in my shoulder I arrange the butt on guns that boot back, and some clothing combos make that harder than others.

 

[cynthialee]

That is what I was saying!

 

[Col. Batguano]

that's a great formula to have.

So for a 44" 45 cal the amount would be 87.5 gr
in a 34" 45 cal the amount would be 67.6 gr.

Yet we still get incremental increases in velocities if we increase our charges beyond this.

I also suspect that the number of grains to use (before it goes unburned) is higher in a gun with a vent hole (because some gas gets vented through it) than it is in a percussion gun, where most of the gas is kept in the barrel.

And, there is the variable of load; conical vs RB, tightness of patch, granulation of powder etc.

 

[BrownBear]

...3.1416 x .29 X .29 X barrel length X 12.5....

Let's see now....

With a 32" Green Mountain barrel the math sezz 105.683424.

Dang, Semisane, you really moved over the line with your 115 grain load! :rotf:

 

[Billnpatti]

I made an oopsie. I should have said that the factor was 11.5 not 12.5. Therefore for your 44 inch .45 cal, the maximum efficient load would theoretically be 80.5 grains. So, use 80 grains as the theoretical maximum effective load. For you 34 inch barrel, it would figure out to 62.2 grains. So, use 60 grains as your MEL.

I must emphasize that this in not a hard and fast rule. It does not take into effect the different burning rates of the different brands and grades of powder. It is a generalization. The name of the formula is the Davenport formula. It was put forth by a man by the name of Davenport who was an expert rifle shooter at Friendship. He has passed away. It is not a perfect formula but it will get you into the ball park.

 

[Billnpatti]

Hokay Dokey. I made a mistake. So shoot me. I said to use 12.5 as the factor. I was wrong. The correct factor is 11.5. Using the correct factor, the maximum effective load would theoretically be 97 grains. I must emphasize, as I previously did, that this is just a theoretical number, not a hard and fast number. It does not take into account the differences in the burning rates of different brands of powder nor the different grades of powder. It is a generalization of what is the approximate Maximum Effective Load for a given barrel. The Maximum Effective Load simply means the point at which that particular barrel would start to eject unburned powder. It has nothing to do with what the maximum load the gun will withstand. It has little to do with the most accurate load for a gun. Although when you are not burning all of the powder charge, there exists a good possibility of significant variances in MV. This will effect accuracy.

The Maximum Effective Load is just that, the Maximum Effective Load and nothing more. The
Davenport formula gives an approximation of the MEL. Is it a useful number? Well, I find it to be so but not everyone cares what the approximate MEL is for their barrel. It's not for everyone but it is there for those who know how to use it. What is my conclusion about semisane's gun? I'd say that there is a good chance that any more than 100 grains in his barrel and part of the charge will not be burned inside the barrel but will be part of a nice fireball outside the muzzle. But, that's just me.

 

[Semisane]

Regarding all of the speculation with respect to excessive loads, unburned powder, etc., I've chronographed a number of loads out of this barrel for my own edification.

Here are some of the results.





Note that the first chart is with Liquid Wrench Lube (which is all I use these days) and the second one is with olive oil lube. I have found with a good bit of experimentation that velocities with olive oil are consistently higher than with Liquid Wrench (30 to 50 fps, depending on powder and charge) and accuracy with Liquid Wrench is consistently better than olive oil.

Also, I've proven to my satisfaction that I get the best accuracy in this barrel with the ball just touching the charge (no powder compression), regardless of powder type or charge.

 

[BrownBear]

If I have to join the parade of speculators I'll point this out:

That same TC manual that lists a 120-grain 2f charge for a 279-grain round ball also lists a 120-grain 2f charge for their 560-grain Maxi Hunter.

My speculation gland sezz there's a weeeeeeeeee bit of wiggle room on that 120-grain 2f charge with round balls.

 

[Billnpatti]

It would be interesting to chronograph several lighter loads leading up to the 120 grain load and plot them on a graph to see if there is a significant bend in the line before getting to the 120 grains. The MEL does not mean that you will not get more MV after the MEL, it only means that the rate of increase in MV is not proportional to the increase in powder charge.

Perhaps I could improve upon the Davenport Formula by accounting for the variation in the burn rates for the different brands and grades of powder. Let's see....as the burn rate increases, the breach pressure increases and the dwell time of the ball in the barrel decreases and...uh, I see the need for a little calculus here....well....would it be possible for me to obtain the burn rates for all of the powders on the market or even for the more common ones? Hmmmm, not likely. I guess that means that even though it would be possible for me to develop an improvement on the Davenport formula that would give the exact MEL, it is highly unlikely that you will ever see The Martin Formula for the exact MEL. :haha: What the hell, who cares? :idunno:

 

[BrownBear]

"Enuff" for me is expressed in trajectory over 100 yards.

When you actually own a 58 caliber and shoot it, you'll find charges in the 70-80 grain range are around 2-3" high at 50, dead on at 75, and around 8-10" low at 100. Not good at all.

In order to get the kind of trajectory I need for hunting you have to be up in the 110-120 grain range with 3f and proportionally more with 2f to achieve 1" high at 50, on at 75 and 4-5" low at 100.

That just the nature of the world when you get above 54 caliber, and the #'s keep going up as you go up in caliber. With my 62 calibers I need 140-160 grains of 2f to achieve comparable trajectories.

Guys shooting in Eastern woods and Midwestern creek beds can do just fine with 50 yard shooting. But folks in the West who need to shoot further or need a bigger hunk-o-lead in serious bear country need more. We're eating canned pork and beans if we don't. Lewis and Clark learned that things are a weeee bit different out West, and the lessons are good today. While they managed to kill bears with volley fire and a whole lot of running and shouting and tree climbing, the lone Western hunter doesn't have the luxury.

East is east and West is west. And bigger bores don't follow small bore rules.

 

[nkbj]

It shoots better in December... what kind of coat were you wearing then?

 

[ZUG]

This is not meant as a "dig" or insult so please don't take it as such. I noticed the last time you shot this rifle your target was dated 3/12 and the last target date was 5/14 that's a two year difference. I know for me in two years I have put on about 15 pounds and it shows in my face. My trap gun does not fit the same as it use to and I had to take a bit off the comb. You MAY be experiencing something similar or may be not - just saying :v .

 

[hanshi]

That's the reason they have girl names. :rotf:

 

[Semisane]

That's the reason they have girl names. :rotf:

Now there hanshi, I believe you've finally diagnosed the problem. :hatsoff: Perhaps I will call her Fickle.

 

[crockett]

ZUG- that's pretty astute of you to notice that time on the targets. I notice there is also a two month difference, March and May. If Louisiana is anything like Florida- that can spell a really big difference in temperature. Turkey Season in Florida always starts around St. Patrick's Day and driving out to the turkey woods in the pre-dawn dark I'm bundled up from head to toe. It's COLD. By the end of the season in April it can be hot on some days, trungling back to the vehicle over the hot sun warmed sand flats... so...... I'm wondering if the March groups shot earlier were done wearing heavier clothing that absorbed some of the recoil and in some way reduced the slap against the face.

 

[BrownBear]

I suspect you're sniffing the right trail.