I’ll Take a Slug of That

Many old guns have bores that do not conform to what today are "standardized" dimensions. To get them to shoot accurately, you must measure the bore and match a bullet to it. Here is how to do it. Colonel Townsend Whelen (1877- 1961) is remembered by many for two things. The first is necking the 30-06 Springfield up to .35 caliber so it could accept heaver and wider bullets, making it a better choice for elk, bear, caribou, moose, and other large game that most of us never get a chance to hunt.

That wildcat round is now named after him and today formally recognized by the Sporting Arms and Ammunition Manufacturers’ Institute and firearm industry at-large as the 35 Whelen. The other thing Whelen is know for is being reputed to have said, "Only accurate guns are interesting." Col. Whelen was evidently never bitten by the history bug. In my humble opinion, guns don’t get interesting until they are at least 100 years old.

Perhaps we can forgive the good Colonel because back in his day, 100-yard groups covering one inch were usually something to be attained only after along load development process. The consistencies in powders, primers, and bullets we enjoy today were not available in his day and that is not to mention other improvements in bedding, barrels, sights, triggers, synthetic stocks, and loading techniques.

Today, oneinch groups without-of-the-box rifles and factory ammunition are reasonably common if the rifleman is able to do his part. That is not the case with old rifles in discon- This indicates the size of the bullet to be used. tinued calibers that are often well worn and far past their prime. Perhaps that is why they intrigue me as they present the gunsmith with numerous challenges.

The first is to bring them back to a shootable condition, then to work up ammunition that will simply function in the action, and then improving things to deliver a degree of accuracy. In some cases, this modest endeavor presents monumental challenges. Shooting old guns in obsolete calibers is not for the uncommitted. First, there is the cost of the firearm.

Some of the more "affordable" firearms like the Trapdoor Springfield, Rolling Block, Martini, and Snider will start somewhere in the neighborhood of $800 and go up from there. Of these, the Trapdoor and Rolling Blocks chambered in 45-70 Government are the easiest to find ammunition, dies, bullets, and cases for. The Rolling Blocks can be found in many calibers that offer a significantly greater chal-

lenge. The Snider and Martini are probably the next level of difficulty with their 577 Snider and 577/450 Martini-Henry loadings. Not as obscure as they were just a few years ago, the influx of guns from Nepal have made them common enough that reloading dies and components Once you are bitten by the old gun bug, things can get really interesting as many obsolete cartridges have to be made by converting other cases.

The conversion process will often involve turning operations to reduce the rim diameter and/or thickness as well as annealing and fire forming to larger caliber and chamber dimensions. In some cases, you may work for 435 caliber.

Since the barrel measures 0.442 inside it is very likely that accuracy will be poor. for them, while expensive, are available from places like Graff & Sons (Grafs. com, in Mexico, Missouri. hours to turn out one case and days to make up five or six cases just to take the gun out and fire it. Barrel Slugging To achieve any degree of accuracy, you cannot simply depend on commercially loaded ammunition to load a bullet that will fit the bore of your rifle or that the bore matches the stated caliber.

You will want to be sure to slug the bore and find a bullet that is at least bore diameter. Unlike modern guns, there is much more variation in the actual barrel diameters in old guns of the same model and caliber. These guns were built in the early part of the Industrial Revolution and tolerances, especially between manufactures, was not as closely held as they are today.

The chart presented here of typical caliber measurements provides examples of a given firearm’s listed bullet diameter for each chambering along with the actual bore diameters of guns that have been in my shop. In most cases they match up pretty well but some exhibit bores as much as 0.008 larger than the standard bullet, such as a Snider carbine which chambered for a .577 bullet but had a .585 caliber bore.

I’ve also encountered bores 0.015 smaller than the nominal caliber would take, such as a .69 caliber musket made by the Eli Whitney Manufacturing Company with a bore that measured as .675 caliber. These measurements highlight the necessity of determining the actual diameter of the bore of any old gun before heading off to the range and expecting it to be a tack driver.

I have to wonder how many old firearms have been sold off over the years because the owners couldn’t get them to shoot accurately because of a mismatched bullet to bore diameter. The process of slugging a bore is simple. You simply force an oversize slug of soft lead down the bore using a steel or brass rod. Depending on

Five shots yielded a group of 11 inches. This is a good example of the challenges in working with old guns and why slugging for an exact internal measurement is critical. the size of the slug and condition of the bore, this might require light taps or more substantial blows on the rod to force the lead slug down the length of the bore. It helps if both the slug and the bore are lubricated and I will normally use lubricated lead bullets of a slightly larger caliber as the slug.

After the slug has been forced down the length of the bore it is measured with a micrometer or caliper to determine its true diameter. Is doing this worth it? That depends on you. Shooting old firearms is a journey into the past. Typical Caliber Measurements (these may vary) Firearm Caliber Bullet Dia. Bore Dia.

Snider carbine 577 Snider 0.577 0.585 Snider rifle 577 Snider 0.577 0.582 71/84 Mauser 11mm Mauser 0.446 0.448 Gras 11X59R Gras 0.44 0.442 Werndl 11.15X58R 0.44 0.442 Eli Whitney Musket .69 cal. 0.69 0.675 1812 Musket .69 cal. 0.69 0.692 577/450 MH* 577/450 MH* 0.455 0.461 1870 Rolling Block 50-70 0.515 0.513 *Martini-Henry It is a lesson in firearms development and gives you insight into the evolution of design that resulted in the guns we shoot today. As a gunsmith, I find it both interesting and educational.

It shows me different ways others have approached designing actions and helps me to innovate when problem solving myself. Besides, it is fun to go to the local range and have the others there coming by and asking what that gun is that I’m shooting and being able to answer by telling them it is a Wendel, a Snider, a Martini, a Gras, or whatever. AG American Gunsmith Reader Services 1.