looking from a different angle

awhile back i was hot and heavy on getting SPRINGER barrels dead nuts straight,,and still am.
my first theory was to spin it up in a lathe and get it with in a few .000's.
and that worked ok..much improvement was made to the accuracy of the gun.but still wasnt the answer.
now im doing them different..no lathe involved..i think that was just an illusion..altho i made a big improvement that way.
now i set the barrel up on a mill table (being a SPRINGER barrel the hinge end of it has two flat surfaces that "guide" it straight into the tube".
clamping the flats down on the table will show you if the barrel is bent left/right..when an indicator is run the length of the barrel.
thats easy enough to check..BUT the up/down (droop)  of a barrel is tricky...cause most break barrel guns.have a angeled mating contact surface (where the barrel and spring tube seat).
what im doing now is..using a sine bar(really accurate angle finder)..and  getting the reading on the spring tube angle.
then i set the barrel on the mill to THE SAME reverse angle of the tube.
this duplicates the barrel as if it was in the "fire" mode with the gun.
i "smear" the indicator up and down the barrel and i can see if ..and  how much that puppy is drooping..or if its shooting for the stars...a few trips back and forth between mill and hand press...and i got a jamup...surenuf..straight (for the tube i checked) barrel.:)
i know this is a bit much..but the barrel is "THE LAST WORD"...the lead sees before dropping that tree rat...or not dropping it....and... damn..if i can do it..im gonna...and me gun will be a better shooter for it.:)

[shadow]

Amazing is all I can say Fix, keep us updated and throw some pic's in if possable. Ed

[DanoInTx]

I am a real novice when it comes to machine shops and such, but one thing came to mind....what if the barrel is tapered?  Or are you reading from the bore?

It's ok to tell me to shut up if I am completely missing something here, which I most likely am:)

[DanoInTx]

Hehe, I wasn't joking, I honestly have no real clue about these things.  I can use a lathe to make a rod smaller, I can use a mill to make a plate flatter, that is about where my expertize in such matters ends...I am a sheet metal smith, fiberglasser and wood carver, machinist I am not.  I DO however understand what you are trying to do, and it sounds like you know ALOT more than I do:)  I was thinking though, if you could somehow run a rod tightly through the bore, then measure the end that was sticking out you might have something...., but how do you make a rod or whatever fit tightly in a rifled bore?  Lazer? (shrugs)

[JMG]

Hmmm I was just looking at McCaster Carr at there Delrin rod.... closest size would be the .1875". I am thinking that if you could put a piece of rod in the breech end and then themuzzleend and then were able to make yokes to stand off the rods at 90 degrees.... with a string you could see which way the barrel went. My question is this... most barrels with rifling have a choked section somewhere down the length, but if you could get something to stick out either end wouldnt the measurement to the string be accurate for barrel straightness?

John

[DanoInTx]

Good idea except .1875" Delrin rod would be pretty flexable, but then it sounds like Fix is concerned with the angle caused between the barrel bore and the top of the reciever...or hopefully a lack thereof.  I have only ever checked this with a long straight edge laying on my scope rail, but it wont work with a tapered barrel my way, unless you had two straight edges and measured/compared the gaps at the muzzle...then you could check for correct windage, but would need a different way to check for elevation....and then if it's a quality Chinese gun such as my B30 you finish off by setting the gun between two chairs and jumping on it till it's straight!?  Man I hated that gun.........

More importantly, if it works for you that is the way that you should do it. Often times there is more than one way to do a job. Doing it in a way that you are comfortable with is the key to success. ;-)

[DanoInTx]

I couldn't agree more:)

[CharlieDaTuna]

Paul, you truly amaze me and I read every one of you posts. I really envy you and the precision that you can work with, not only with the airgun's that you play with but (reflecting back) your vocation as well. It is far beyond the capabilities of  the average machinist as I see it. I sure wish we lived in close proximity to each  other but I think you would get tired of having me around...lol.. If I were forty years younger, even maybe thirty, I'd really invest into some high quality precision equipment and get the education and hands on to do just some of the things that you are capable of. Thanks for all that you contribute to our forum.

[NMCA_Ron]

Bob, ain't it amazing how some people just have a gift for these sorts of things?

Ron

[CharlieDaTuna]

I'm not nsure about it being a gift. It takes years of education, study, apprenticeship and hand on experience to aquire those kinds of abilities. I think it's more of a desire to be the best at what it is that a person likes to do. I've always felt that if you are in a job that you don't like or enjoy doing, your doing the wrong job. I don't think there could be anything more miserable than getting up every morning looking forward to going somewhere or doing something that you hate. Life is just to short. You can just about bet Paul like and enjoys doing what he does.