dmacl

You'll want to slug your barrel and make sure you order properly sized conicals if you are purchasing single diameter conicals from a custom caster.[/quote]

You lost me here. Slug my barrel?

Pglasgow

You lost me here. Slug my barrel?
[/quote]

You need to know yourbarrel's land diameter. Barrels aren't always consistent for a make or model. Slugging will help you to determine your bore's precisediameter. Most folks are having them sized that size or just slightly over (one pass instead of 2 through the sizer). Cast bullets don't always come out of the mold the same. Depending on mold temp and so on. So they are sized to the proper final diameter. You need know what that is. If you don't, the bullets you buy may go down too hard and that can also affect accuracy.

I'd probrably mess up telling you how to slug your barrel. So someone who has done it should describe the process.

Hunter John

Pglasgow - Did I read that correctly that you've used as little as 20 gr of Pyro with a .490 PRB? Never heard of anyone using such a small amount...usually 50 grs or so for plinking.

Just curious, what kind of velocity and accuracy can you get with that load?

Pglasgow

Hunter John,

I used 3f Goex. I wasn't fer sure just how easy BP is to get where damcl lives. With 3f Goex the MV is around 930 fps. This is a close range load. to 35 yards. As far as accuracy, if I aim dead center of a bright 1" dot, I'm going to hit it out to 35 yards. This in my 1:48 hawken which barrel is very pitted.

I've shot 5 rabbits so far this year, ranging from 10 to 25 yards, all were head shots.

I also mix 4 parts powder with 1 part compressed cornmeal, load my flask with that. Before filling the powder measure, I shake the flask to ensure its mixed thoroughly before measuring the charge. On a charge this small, I recommend the powder measure that has a sliding funnel which just help to be more consisten. If one mixes the cornmeal set the measure to 25 grains so that there is still 20 grains powder. I have been able to shoot consecutively 25+ rounds without swabbing my barrel (even once) with this arrangement. I use olive oil as patch lube and walmart pillowticking. I don't bother to carry cleaning patches or cleaning materials while hunting.
I know its a small charge but think of it like a very long pistol. I really like thisload for kids learning muzzleloading.This load would be hard pressed to develop 2000 psi. Even so its a hunting load if the right game is selected. Also it has very low report. In fact, the only sound I am able to detect is the firing of the cap. Below is chart of the ballistics.

If you want be to chrony 20 grains pyro P and RS, it wouldn't be any trouble, but I would expect pyro P to have more velocity, maybe 975 fps

Hunter John

Pglasgow - Thanks for responding so quickly. Thanks to Cayugad, I've experimented a bit with using corn meal as a buffer for my conical loads and was impressed with the increased performance...both in the accuracy and velocity depts.

However, I've never heard of anyone MIXING the corn meal with the powder, only using it on TOP of the powder for a better seal upon ignition of the powder.

What is the benefit of mixing corn meal with the powder? Are you trying to add powder volume without actually adding more powder?

Thanks again for sharing the chart...I was surprised to see the relative velocity of such a small load. I can now understand why you like this load for "teaching the young-ins." Gotta try that with the kids in my family.

Thanks again.

cayugad

Ive never mixed the cornmeal ... interesting. I have done a lot of shooting with cornmeal as a buffer. I have recently been shooting traditional round ball with cornmeal and am real impressed with the accuracy. I've also shot some real light loads as well. 50 grains is usually as low as I go, but next time out maybe its time to experiment.

Pglasgow

Lee had mentioned how the cornmeal made it easier to shoot accurately without swabbing. I also tried the fillers and found more consistent as well as elevated velocities as a result. The elevation ofmuzzle energyin the hawken was greater as a percentage increase, i figure because of the condition of the bore.

So I thought I'd test whether mixing the cornmeal had the benefit of easier reloading. I'm not the first to do it. There were observations that confederate soldiers had meal mixed with their powder, though the explanation was that they did it to extend their meager supplies. In any event I can tell you that it does make a difference.You canshoot a considerablenumber of shotswithout swabbing. In fact, I've never swabbed while using this arrangement (the first time I tried it, I accidentally left my ball starter at home so all the prbs were loaded with only the ram rod AND i never swabbed!)

I tried 20 grains without the cornmeal and by shot7 or 8 I was feeling the difference. The mixture I used has a considerable quantity of meal in it, 20% by volume, I've even considered using a higher percentage. I really don't know how it works, it just does keep the fowling minimized and consistent shot to shot.

Oh and Hunter John, Muzzle energy is the key factor. For a given projectile, not exact mind you, a given quantity of charge yields a given quantity of muzzle energy. I used 20 grains, and got 336 ft-lbs. Or about 16.8 ft.lbs per grain. Multiply that by 30 and you will calculate pretty darn close the muzzle energy at 30 grains to be 504 ft lbs.

But yield per grain is not a linear function. For black powder, you will find the yield per grain for a given projectile will decline as the charge increase. I can think of number of reasons which influence this but there is only so much space.

It is also true that the muzzle energy is a function of the square of the muzzle velocity. So the square of the velocity with 30 grains should be pretty close to 1.5 times the square of the velocity of 20 grains.

(MV_30)^2 = (30/20) MV_20^2 = 1.5 MV_20^2

MV_30 = sqrt (1.5 * 930^2) = 1139 fps

If I guy does not change the charge volume by really large percentage changes, he can do a pretty good job of estimating velocity changes from changing charge.

Hunter John

Pglasgow - Very interesting. Have you noticed a difference in fowling between using the corn meal as a buffer (only on top of the powder charge) vs mixing the cornmeal in with the powder charge?

This has really got me thinking. Thanks for sharing your experiences with the board.

Pglasgow

Hunter John,

I haven't tested that, but since I used such a high percentage of meal in the mix, I think it would do a better job than the fillers I used in the past. Also when I used fillers, I was swabbing, Lee had yet to make his comments. Also do check the additions to my last post. Has a little info on predicting muzzle velocities from charges.