Thursday, July 16, 2009

I have always understood that one never should shoot a monometal, or monolithic, solid in a double rifle. Why is this? (question from CalPappas.com)

Dear Cal:
It was good to talk to you at the SCI convention. It took awhile to put two and two together and realize you were the same guy who writes the Doubles Column for the African Hunter magazine. When we were taking you had some Barnes monometal solid bullets in your hand and were planning to run tests on them. I have always understood that one never should shoot a monometal, or monolithic, solid in a double rifle. Why is this and what will they do to a double?
Don M.
Las Vegas

Don:
Greetings from Alaska. I remember our discussion well.
I arrived home to a fairly comfortable -10 and went to the shooting range. In my memory were all the fairy tales I, too, was told of monometal bullets. Some of the stories I remember was that the barrels will "blow up," the rifling will be seen on the outside of the barrel, and (my favorite) the rifling lands will actually come out of the muzzle! (I also recalled the stories about Damascus-barreled guns and rifles and how they will blow up is shot with smokeless power.)
I had to break many years of nearsightedness and use some logic to think. What could cause a barrel to "blow up?" Oversized bullet diameter is one. Too much powder or a powder that is too fast for the cartridge are two more. Too much bullet weight is a forth. Any of these will cause higher than normal pressures and will perhaps cause a barrel to burst. (That is why the Brits had their proof house to show a rifle or shotgun was safe to shoot after it was tested with a higher than normal charge of powder and lead.)
All of the above is true. In addition a barrel that has been weakened by pits, rust, a crack in the steel, or if the barrels are too thin will also cause bursting. But (and this is the logic part) ANY barrel shot with one or more of the above conditions in place could cause bursting.
On the flip side, if your bullet (monometal, lead, or jacketed) fits the bore of the rifle, if its weight is correct, if the powder is of the correct type and charge, if the rifle is in sound condition, and if the velocity is to original specifications, how could anything go wrong?
With that in mind, I shoveled the snow off my standing rest at my 50-yard range and set up some targets in the stand. I must admit I was a bit nervous from all that I had been told and began by shooting two bullets at a low 1000 fps after checking he bullet's measurements against the bore and chamber cast of my vintage John Wilkes .600 nitro express.
No problems. Two more with the same results. Then, four shots with lead bullets, four with Woodleighs, and four with Barnes banded monometal. I gradually worked up in velocity to the regulated 1900 fps. With the three bullets the targets were about the same. The rifle's recoil seemed to feel the same. The action opened as easy with all three. And, the rifling lands remained in the barrel.
Now, a word on mono-bullet types. There are three basic types of monometal bullets I know of. The first to come along was a turned solid, of brass or bronze (I'm not much into metal specifics). These bullets generated the highest pressures as the shaft of the bullet was in complete contact with the bore. The banded solids (such as produced by Barnes) are turned .002-inch undersize and the bands allow for less of the bullet to come in contact with the bore of the rifle. Also, the bands allow displaced metal to flow into them--something the solid-shaft turned bullets do not allow for. Last of all, and a relatively new design, are the banded bullets with many smaller bands--or grooves--cut into the bullet.
The only problem I have with any monometal bullet is the non-traditional look of the nose. I did not have any problem with the shooting but understand I only shot less than two boxes with my rifle only. I took careful measurements and would not have shot them if the bullets did not match the bore. I understand the solid-sided monometal bullets will generate higher pressure than the banded solids. I do not have any experience with these bullet types.
And, I also shoot my Damascus-barreled guns and rifles, too!
Good shooting,
Cal