Garand port pressure

Guns Magazine, Feb, 2006 by Jett John, Don Miller

Q: You mentioned in reloading for the M1 Garand to stay with powders with medium burning rates. I don't reload and shoot my Garand with whatever factory ammo is on sale. Is all factory ammo safe for use in a Garand?

Don Miller

via e-mail

A: If you stick with the full metal jacket or match-grade ammo like Federal Gold Medal, American Eagle or Black Hills Gold Match, you'll have no port-pressure issues. Today's hunting ammo is mostly loaded with the slower-burning powder necessary to maximize velocity and will be cause the action to operate too abruptly and may result in Op-Rod failure. I fear there is really no good way to tell if hunting ammo is safe for a Garand.

There is something you can do, however. McCann Industries (132 South 162nd, Spanaway, WA 98387, 253/537-6919, www.mccannindustries.corn) makes a nifty no-gun-smithing gadget to mitigate port pressure problems with the Garand. McCann provides a gas nut drilled out to accept one of five provided hex-head screws drilled out with different size jets to vent excess gas. Just replacing the gas piston nut with the modified McCann nut turns the M1 Garand into a manually operated straight-pull rifle. Screw in the gas jets in decreasing order of gas jet holes until the rifle operates and ejects normally. Reloaders can benefit too by not having to chase or have brass damaged while working up loads.