Originally Posted by rscott5028
I generally don't like cutting, bending, etc if I can't accurately and repeatably measure before and after.
Assuming I knew enough and had the tools to do the straightening piece at home, I'm not sure how I'd measure the straightness of the bore from end to end?
Gary/Jim - How do you measure the straightness of your bore?
Good advice !!!!
I will try to explain the method used to straiten barrels.
Before Lasers, the excepted method was to have a Master Gunsmith place the barrel In a
special barrel press aimed at True north and looking through the bore they would apply more
and more pressure with a hand wheel about 2 feet in diameter with the barrel held between
The hand wheel was graduated so he could apply more and more bending pressure to the
barrel and releasing it to measure rebound. the trick was not to over bend it while looking
through the bore and moving it up and down the length of the barrel.
This process was a highly skilled method and was very efective in its day.
Now barrels are checked for straightness using optical methods (Lasers ETC) and mostly
for quality control and rejected if the straightness is out of spec.
I once had a barrel that had fell over and been ran over that was slightly bent to be re
barreled. On the outside It was impossible to see the bend because it was so slight. but
when held up to the north while looking through the bore you could see that it was bent.
And about where , But With out the equipment it would be almost impossible to straighten.
Very few custom barrel makers If any straighten barrels because of better drilling processes
and the cost of straighting barrels in more than the barrel blank.
I don't know what percentage of factories are still straightening barrels any more, but with there
quality and numbers made it's no wonder that they are generally bad with an occasional
Straighting without specialized equipment would be hit and miss and it is easier to replace
a barrel that is not straight than to fool with it and risk poor accuracy.
When "Properly" placed between centers they can be measured very accurately and dealt with.
My preferred barrel maker has a tract record of nothing but straight barrels(.0000 to .0015)
and a rare one that might be .0025) end to end.
The issue on how much straightness is nessary (Some barrel makers say that .007 to .010
is OK), but as allways straight is allways better.
I have tested factory barrels that had over .050 total run out that would not shoot at all, so
they do exist.
I hope this explained the process.
J E CUSTOM