A few years back, I took a discarded unlimited barrel and cut it into equal 3 inch long pieces so Shooters could see how the bore actually wonders inside a blank.
I first scribbed a straight line down the full length of the blank. This gave a master references. After parting the barrel onto the three inch long pieces and facing them square, you could measured the groove diameter in relation to the ID to assertain the run out and it's relation to the OD.
crooked in different directions with its self.
"Ain't but one way to tell if a barrel shoots." Quote of Tony Boyer.
Sorry,, can't help myself.
So, what effect does barrel straightness affect accuracy?
How's this........."any deviation from straightness that is still within manufacturing tolerances will have no affect on a barrel's accuracy potential".
OOHHH, now you got me going but I think that should be "effect", or should it be ..will NOT affect a barrel's....
Someone help me here
OOHHH, now you got me going but I think that should be "effect", or should it be ..will NOT affect a barrel's....
Someone help me here
pablo
How do you determine what method to try first when not knowing the straightness of the said barrel? I would think, you would have to automatically assume the barrel isnt going to be straight? I always use the gritters method. Ive tried to rap my mind around why one would indicate at a point 20 plus inches away from the actual work. I just dont see it. some say the guns recoil better when the muzzle is in front of the chamber, but i haven't been able to feel a few thou misalignment in recoil myself, so i cant understand that either. I think the Gordy idea works so well because none of these barrels are straight. Some are better than other but none straight. Not to start another debate. LOL Lee
I'll give you a reason. When it's chambered with the barrel indicated at the muzzle and at the projected throat of the barrel and you change barrels to another barrel chambered indicated in the same way, more than likely point of impact from barrel to barrel to barrel will be within a few inches from one barrel to the next. When you start moving the muzzle end around to indicate in two points at the breech end of the barrel, there's no telling where the bullet is going to hit on target when you change from one barrel to another. Is this a problem? Not necessarily. But, match shooters do change barrels quite often when going from 100 to 200 yards when what they shot at 100 didn't work. I'd rather have a barrel indicated at the muzzle and at the throat, than one indicated by moving the muzzle end around. And yes, I have shot multiple barrels chambered both ways. I just don't see it makes a difference in how the barrels actually shoot which way is used to indicate the barrel in, but I do see it does make a difference in where that barrel's point of impact on target from one barrel to the next. That's my take on it and as in just about anything involved in chambering barrels, opinions vary. And that's all they are opinions. Very hard to prove by facts.
pablo
How do you determine what method to try first when not knowing the straightness of the said barrel? I would think, you would have to automatically assume the barrel isnt going to be straight? I always use the gritters method. Ive tried to rap my mind around why one would indicate at a point 20 plus inches away from the actual work. I just dont see it. some say the guns recoil better when the muzzle is in front of the chamber, but i haven't been able to feel a few thou misalignment in recoil myself, so i cant understand that either. I think the Gordy idea works so well because none of these barrels are straight. Some are better than other but none straight. Not to start another debate. LOL Lee
Very good post Paul!When I chamber I mount the barrel in the headstock between two spiders, pick out a Deltronic pin that fits the bore at the muzzle snug and one at the breech snug, then dial in on the pin at the muzzle and the breech. After adjusting the runout down to a thou or two I stop, pull out pin in the breech end and based on the pin size in the breech end I pick a bushing. After installing the bushing on the Grizzly rod I make sure it is snug in the bore and that it will push in the bore, from the breech end, four inches or so. I then take off the screw that retains the bushing on the rod and push it up in the bore to the throat area, pull the rod out and leave the bushing in the bore. I then indicate off of the id of the bushing with an Interapid long indicator and adjust down to about 2 tenths or less and chase it with the muzzle to get it down to less than a thou. I then push the bushing out with a cleaning rod and reinstall it on the grizzly rod and secure it with the screw. I then indicate the bore in front of the throat, if it will go in for an inch or so and not indicate out more than a thou or so I leave it alone and chamber it. If the inch in front of the throat heads toward the south forty I finish with the Gritters method and move on, I also mark the barrel so I know it isn't likely to shoot close like the straight ones will. No big deal here except to say that I've seen some high end barrels that would indicate out 4 thousanths or so in the inch in front of the throat and those barrels, in my opinion, demand the Gritters method. I've seen many of those shoot very well so I dunno how important being straight is except I would say the straighter they are the more I like it. LOL