cayugad

I was shooting a .58 caliber Green Mountain Barrel mounted on a Thompson Center Renegade. The load was 100 grains of Goex 2f and a 284 grain Speer roundball. The patch was pillow tick and I used moosemilk as the lube.

Over all I was very happy with this five shot group at 50 yard with the open sights. The load seemed accurate and had a lot of down range thump.

I then decided to test the cornmeal theory. I loaded the same powder and ball but this time added 20 grains of Quaker brandcornmeal in the rifle. I shot a six shot group. The final shot I adjusted the POI to see if I could hit the bullseye.



not to bad. I think the cornmeal might give a little advantage. I just need to shoot more.

Pglasgow

cayugad,

If you chronied the cornmeal filler loads, you might lift an eye brow. I was able to achieve an increase of 130 fps with the filler in the hawken. The grouping is fantastic in your photos,good shooting.

Phil

Hunter John

Man, if you hadn't done that, you'd have a 1 hole group there. Thanks for so quickly trying the PRB / Cornmeal experiment.

Still can't get over what a difference just adding 20 gr of cornmeal makes That combo could compete with some centerfire rifles out there![&:]

Awesome shooting!!!

Sharp Shooter

Cayugad, How doese that compare to using a wad? Doese that cornmeal act as a wad? That is a good group there. I still plan on buying a 58cal for my GM. I do not know if I am going elk hunting though.

Have you thought about trying that cornmeal with heavier chages in your 58cal just to see what happens?

cayugad

Sharp Shooter - yes, the corn meal acts somewhat as a wad. Thanks to others testing with meals- wads - no wads what have you, they found that they actually get a faster (up to 100 fps or more) projectile using the meal as a wad.

As for trying cornmeal with a heavier charge in this rifle, I think 100 grains of Goex 2f and a patched roundball out of this roundball rifle is about as much as I care to push it...

Pglasgow

I agree. The cornmeal is elevating pressures by restricting some of the blowby. It makes the 100 grains more like a heavier charge, perhaps more like 115 to 120 grains. I got 17% more energy at the muzzle with filler so its like adding 20% more powder.

I have found that Pyro P is a very efficient propellant for roundball. To achieve higher velocities without additional recoil, one could givePyro P a try with filler. With the 270 ballet 60 grains 3f BP propelled to around 1300 fps while the same volume of Pyro P to 1490 fps. A major difference. Pyro P loves light projectiles it seems. The difference is a 30% increase in muzzle energy.

Based on this experience, I would think that 80 grains Pyro P should deliver comparable muzzle velocities to 100 grains 2f Goex and with far less recoil. Can't say to what extent with will affect grouping.

Phil

cayugad

Well I will have to try the rifle with some Pyrodex P, Triple Se7enor Goex 3f next time out. Before when it was patch and ball, it always shot the best group with simple Goex 2f.

lemoyne

cayugadI have an 58 cal. underhammer that takes 30 gr volume to shoot its best.Lee

cayugad

So your loading a 30 grain filler.. how interesting. I was wondering what would happen if I went even more then the 20 grains. I guess I will have to try that as well. Thanks for the heads up...

cascadedad

Dave, you did your initial testing using 20 grains fillerwith your Ultra Mag, correct? Going from 50 to 58 cal, you will need to add about35% additional filler to keep the same filler "thickness". So, to have an equivelant filler you would need about 27 grains of filler for the 58 cal. Dats purty close to 30. Hope I did my math right.