chronographing the 20 bore

[cgg]

I went to the range this morning and brought my chronograph along because I was curious about the muzzle velocity of my 20 bore smoothbore round ball load.

I only fired about a dozen rounds through it, but I thought some of you folks might be curious about the velocities I got.

The gun is a 20 ga. fowler with a 38" Colerain barrel, a Chambers Round Face English lock, and the touch hole liner drilled out to .070" with a #50 drill.

I was shooting a cast .595 ball (that averages about 319 grns) with a .023" cotton/canvas patch and "moose milk" lube. This is a tight load and needs a short starter to start it but loads easy enough with the wooden rod. I cleaned the gun after each string so each load started with a clean barrel.

70 grns of Goex3F--the most accurate load and my hunting load:
1273 fps
1270
1251

80 grns of Goex3F
1419 fps
1381
1375

I also tried a little 2F I had with me--

80 grns of Goex2F
1258 fps
1238

100 grns of Goex2F
1357 fps

With that big heavy ball I figure any of these loads should kill a deer within 60 yds. YMMV--have fun

 

[paulvallandigham]

The 70 grain load will put a ball through a deer at 100 yds. :thumbsup:

Find and use the load that gives you the most Accurate group at your chosen limit for hunting game. Then stick with that. The Fastest velocity is not always the most accurate. Accuracy is more important, even shooting these pumpkin balls, than velocity, considering that most deer are shot at well under 50 yds.

You can expect to hear an audible THUMP when the ball hits the deer. Its sounds like hitting a pillow with a baseball bat.

 

[Ft. Jefferson]

Yep, your right on the mark. My 20ga. chronied as follows.

80gr-2f 1160fps
80gr-3f 1400fps
90gr-3f 1540fps
100gr-2f 1420fps
36" bbl with 600rb
i settled on 75gr-3f for deer and 90gr-3f for elk. I've killed a couple of each with this gun and that big ole ball gets the job done very well indeed.

 

[George]

Good stuff, thanks to both for posting.

My hunting load is 80 gr. 3F Goex, hard card wad, cushion wad lubed with beeswax-lard, a .600" ball, .015"-.018" patch in a 46" barrel, and it averages 1475 fps. I get just about the same results with the same overpowder wads but a bare ball and overshot card.

Spence

 

[CoyoteJoe]

Thanks to all of you for some very useful info! :hatsoff: