If I Get a New Barrel, Should I Replace My Bolt?

Typical service life of a bolt depends on MANY factors, but anywhere from 4000-15000 rounds is a good place to start before you start seeing issues. Not necessarily bolt failure, but other issues are possible before a complete failure happens.

Lots of things can give your bolt a shorter life than expected. Simple cleaning neglect can shorten the bolt life and sacrifice performance. Cheap ammo or reloads that are not in spec can hurt too. Primers being blown can erode the hole where the firing pin sits and wear the bolt too early. If you reload and feed your gun a steady supply of hot loads, the lugs on the bolt can wear too fast also. A cheap barrel extension won’t have radiused edges and will accelerate bolt lug wear.

When we re-barrel a gun, we clean the bolt and look closely for obvious wear. Wear on the lugs, firing pin hole erosion or wear on the bolt face calls for a replacement bolt

Then we check the firing pin hole. A .0625 pin gage should clear the hole, and a .0645 shouldn’t.

The stem of the bolt is measured as well. On a new bolt this dimension should be not less than .2503. Too small of a stem can cause short cycling in an AR. If the bolt is less than .2499, we replace it.

Headspace is then checked. If it doesn’t pass, we replace it.