Breaking in a New Barrel

Breaking in a new barrel

There are many different procedures given for breaking in a new barrel, all of them claiming to be the best way to ensure accuracy. For example, some recommend firing a single shot, then passing a patch coated with solvent (Hoppes no 9 or similar) through the barrel and repeating this process five or ten times. After that, one is recommended to fire 5 (or 10) shots and then swab the barrel clean with patches until the patches emerge totally clean. After that, the barrel is deemed to be ready for shooting.

What, however, is the rationale behind this process, and does it actually work ? The truth is that it probably makes no difference whatsoever in a modern gun. It won’t do any harm, but you probably won’t see any benefit either.

Many advocates of the breaking in theory argue that the first round down the barrel has small pieces torn from its jacket by any sharp edges and burrs left in the rifling by the manufacturing process and that you need to clean these out. I can put forward a couple of counter-arguments to that, the first being that modern engineering practices and techniques shouldn’t leave any burrs ! If you pay good money for a rifle, you have a right to expect that it has been properly machined and these days that ought always to be the case. Cutting a groove, cleanly and accurately, isn’t difficult. A second argument would be related to the efficiency of a patch at removing any fouling. Can a cloth patch pushed through the barrel by hand exert anywhere near as much force as a second shot would ? Putting a second round through the barrel is probably a far more effective way of cleaning out any remnants of the first round  !

Another argument for the breaking in process is that it fills up any pores in the barrel, and somehow changes the metallurgy of the barrel steel. Utter rubbish ! If any modern steel was to undergo  metallurgical change due to the passage of a patch and cleaning rod through it, then it wouldn’t be fit for purpose. A bullet would wreak havoc with it !

From a metallurgical point of view, there is nothing to be gained by ‘breaking in’ a properly made barrel manufactured from decent steel. That description covers just about every rifle made today: any company that made lemons went out of business years ago. By all means break in a barrel if you feel you ought to (wearing sackcloth and ashes if you really must) as it won’t do any harm, but the reality is you’re just wasting good shooting time.

SC. Training Officer SPR&P Club