Steve F.in MD

With the variety of powders and barrel lengths that one can encounter I am wondering why there has been no conclusive data posted about the effeciency of propellants in various bbl lengths?

I don't mean velocity, I mean at what point is the powder is not being completely burned in the barrel. It would seem like this would be the most effecient load for a given rifle. Any more would be wasted. I understand that the best accuracy may not come from the load that provides complete burning of the powder, but it would give a very good starting point to start backing down the load.

Maybe this research has been done and I just missed it?

lemoyne

Well,since their are so many variables like the tightness of the load to barrel,the rate of twist,weight of powder[size of powder load] weight of bullet,the heat and intensity of ignition,that what you are asking for would be different for every gun.
So instead I suggest an old black powder method that my Grandfather used;stretch white paper [such as butchers paper]out for about 20 ft on the ground starting 3 ft in front of the muzzle,if you don't collect any UNBURNT powder then you may assume reasonable efficiency. This won't work for pellets you have to have someone stand to the upwind side and watch for smoke trails if you get a smoke trail your pellet is burning in the air after it leaves the barrel. Hope this helps . Lee

cayugad

I always shoot mine over fresh snow to learn about powder amounts. I found in my 22" barrel rifles like my Wolverine, sometimes 110 grain will all burn off and sometimes there are small traces of powder. So I am guessing that air temperature and humidity plays a part in all of this equation also. Also there is a point where accuracy just goes haywire.

A person I sometimes run into at different shoots tells me the best way to find what the true max of powder a rifle can use is by using a chronograph. He said at one point you will notice that even the addition of extra powder will no longer increase the speed (or so very little, it is of little value) of the projectile. I think this is the point you're trying to make and I agree.

One thing I will add is I shot 120 grain of Goex 2f loose from my Black Diamond XR and it burns up every little bit of that powder. That rifle has a 26" barrel and is one of the most accurate inline rifles I have ever shot.

I really do wonder now, just how much of an influence such things as air humidity, air temperature, maybe even elevation, play on the rifles over all ability to use an effective powder charge.

eldeguello

All rifles are individuals! Therefore, anything published along these lines would have to be generalities, which may or may not apply to the one you've got.......

IF you chronograph your rifle while working up loads, it will be as obvious to you as unburned powder grains on the snow when the addition of more powder stops giving you a higher MV - this is the crossover point, beyond which YOUR rifle is no longer efficient.....

roundball

Although this doesn't answer your question Steve, I thought I'd toss this out as food for thought:

IMO, Idon't believe shooting over anything white will show unburned powder...I believe powder that is not burned inside the bore is consumed inthemuzzle flash...subsequently, I believe what falls to the ground is morepowder residue, not unburned powder.

My .02 cents...

Roskoe

I kinda agree. The point at which the chronograph tells you that you are increasing the charge without any appreciableincrease in velocity is the point of diminishing return. I really don't pay much attention to the "soot on the snow" indicator.

sproulman

we use snow or white bed sheet. you may be right. i noticed that the small length barrels have a lot of powder in snow or white sheet than the longer barrels. those small length barrels are loud too.could be residue, i dont know but snow or sheet gets bad if they are shooting real high amounts of powder.

short_start

That's something I've questioned myself, Steve, though variance from load to load, not to mention rifle to rifle would limit the usefulness of such information.

It does seem reasonable to assume that substituting a smaller amount of a faster powder (3f for 2f; or Pyro P for RS) would be more 'efficient' when shooting a carbine. The question is, whether the faster powder would yield any more velocity. Would the increase in efficiency out weigh the effect of having to reduce the overall charge weight when using the faster powder? Probably not, butthe faster powderwould be easier on the wallet and easier to clean up after.
Bob

Steve F.in MD

Thanks for the input. I just think a rule of thumb could be developed along the lines that a 26" bbl can GENERALLY burn 120 grns completely. A 24" can burn 110 grns, and a 22" can burn 100 grns. Maybe this is asking too much but it semms like there are plenty of techno geeks out there crunching numbers about ballistics who could develop this type of info.

alleyyooper

I have discovered since I have reached those gray haired years that faster isn't always better. For that matter neither is more powder.
My plains rifle loves a load of 85 grains by volume triple 76 490 RB and a 100% bees waxed 15 thousands patch. More powder just monkeys up the works and less drops off a bit more at 100 yards.
Al