Originally Posted by br45zy
I have a 300 RUM that may be a candidate for it and I am looking for some shooters with first hand experience fire lapping a barrel and the results they saw.
My opinion has always been to not do it but this rifle has been a little frustrating. It's factory Remington barrel that has less than 100 rounds through it and copper fouls badly after only three to four shots, enough so that accuracy noticeably drops. Clean cold bore and second shot accuracy is very good and consistent. I had it bore scoped and it looks OK from end to end just not great.
Thanks for any help or advice.
I personally Never recommend fire lapping is a last resort because it laps the throat and does very
little for the rest of the barrel.
The fact that the barrel shoots good the first couple of shots tells me that you need to do a good
Do a shoot, and clean after every shot for 20+ rounds and you will start seeing an improvement
on the fouling issue. It takes time and patience but is it worth the effort and improves the entire
bore not just the throat.
As you shoot, you should start to feel the improvement in the bore and the number of patches
to come clean should drop to 1 or 2.
It is not unusual for factory barrels to take more than a custom barrel so don't take a short cut
and start firing 2 or 3 shots and then cleaning. The purpose of the shoot and clean method is to
shoot 1 bullet in a clean bore and let it smooth the barrel out evenly end to end.
Fire lapping enlarges the bore at the throat and reduces bullet fit causing lower pressure and velocity.
hand lapping can do this if it is over done breaking it in only wears the high spots and fills in the
machine marks left from the rifling process.
Some custom barrels are very tight even after lapping because the barrel maker allowed for this
and reamed and rifled the barrel .000001 undersized.
J E CUSTOM