Re-choking obsolete .410 shotguns

Shooting Industry, Nov, 1990 by William Schumaker

For years there was no easy solution for restoring single barrel shotguns. Once the original choke was either blown out via obstructions in the barrel, or the tapered tubes that screwed onto some of the muzzle-slotted collets cracked and were no longer available, the shotgun was useless for its purpose. Then came B-Square's heavy roller type swaging tool with which our shop has re-choked numerous single barrel shotguns.

Each has been a character of its own. Regardless of the measurements from the basic bore into the tapered choke, performance is not always responsive to exact dimensions. Differences in ammunition also influence patterns. Barrel wall thickness of the Mossberg Model 183KA .410 ga. shotgun pictured here was approximately 3/32" making swaging slow and difficult.

It's important to read the instructions carefully. Thin walls can be ruined by excessive roller cinch-ups and rotations under too much tension. The best approach has been for our customers to provide the ammunition of preference, and pattern-fire the gun with a temporary taped-on front sight after each slight swaging. When the desired pattern is reached, stop swaging, re-crown the muzzle slightly and reinstall a front sight of proper height.

Winchoster Warning

It's important that we pass on to our customers a recent Winchester notice on their M-100 rifles and carbines. Cease firing these immediately! Call Winchester Products Service, toll-free 1-800-852-5734, or write Winchester , Firearms, P.O. Box. 10, Cottage Hills, IL 62018. This is one we gunsmiths can't handle. Don't try ! The factory states the firing pin in the M-100 rifle or carbine may break due to use and metal fatigue. (and become lodged in the breech bolt face). If this occurs the firearm could fire before the action is locked, causing severe damage to the firearm, and possible injury or even death to the shooter or bystanders. Safety-wise this type of lethal possibility can't be over-emphasized ! The Winchester Model 100 firearm was introduced in 1960 and discontinued in 1973. Parts and service are no longer available, nor is an authorized replacement firing pin to safely fix the firearm. DISCONTINUE ALL USE of WINCHESTER M-100's, until further factory contact.) Winchester is reviewing alternative remedies. A solution is expected within three to six months. WARNING: "Do not replace any firing pin with a new firing pin unless authorized by Winchester."

Many Gun/Firearms publications have carried this notice. Gun owners are urged to take heed and notify their friends and all shooters known to have an M-100.

Other Firing Pin Problems

In gunsmithing, firing pin problems are almost endless. Fortunately we can correct the majority of them, but a few offer the same type of hazards the M100 Winchester rifles might. While .22 rimfires don't generate the lethal possibilities as often as center-fire ammo, no injury possibility should be overlooked. Semi-automatic .22 rifles of some makes and models occasionally break firing pins that jam the front section into the bolt face, thus leaving its point to protrude sufficiently to indent and fire a rim-fire cartridge before the bolt can fully close and chamber the round.

Flying bits of high velocity ruptured .22 rimfire cartridge cases could strike the shooter, and especially by-standers on the right side of ejection port. The value of wearing large lens shooting