Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Listen to Kiff. Kiff is wise, he is also talking to the guys that are making it work. Some people argue with success based wisdom.Dave L Kiff said:Story : A customer called one day and told me he had a well known gunsmith chamber two barrels with the same 6mm Dasher .2704 NK and a .104 freebore . He and his son loaded .105 Hybrids very precisely . One rifle shot fantastic , great accuracy and velocity right on par touching the lands . The other shot poorly with pressure and flyers , very unpredictable . It also had a shiny rub mark on top of the unfired loaded round when cycled and ejected where the other rifle did not mark or rub the projectile . He and I wondered how could this be , I had folks call me and tell me they had the same problem . They were frustrated to the point they swore the reamer was undersized on the throat diameter . I would have folks send in there reamers to check them to find every thing was OK and to print . Well I had Brian plug cast and check the size on the barrel , to my skeptical surprise the barrel that shot lights out at 600 with a .104 fb had a .2434 groove with a .2366 bore . Now the barrel made by the same company , reamed with the same reamer that shot poorly had a .2429 groove and a .2365 bore . Now here is what has been causing a terrible debate for a long time . The question asked by many shooters is why do some folks have great success with the old fashion .104 freebore designed for older Berger's and .107 Sierras and 105 Hornady bullets and some have to purchase throaters or Dasher finishers with .123 to .130 freebore or more . Well here is the real scoop . If a groove is .2429 and you have a bullet that measures .2434 and a reamer @ .2437 you will have a solid band running down the 1-30 lead angle that resembles a bullet mold for about .018 to .023 depending on the reamer angle tolerance . Now if your lucky and have that rifle with the larger groove like Brian's second rifle . Well your out kicking *** on the range with a .104 freebore not even knowing what the hell the guy on the forum is complaining about and shouting he needs a .130 freebore and has to jump the same bullet .030 to get it to perform . Well guess what , Brian ordered a .2436 throater and lengthen his sons throat out .035 and now the tight grooved barrel shoots very close to his .104 touching and both are using the same loaded ammo . Now you all know where the shiny rub mark came from and why its hard to predict what freebore will work and how to determine OAL on Hybrids . Jack Balon sent in some 105 Hybrids that he could not use , I measured them and to my surprise I had to eat crow . You see I had told every one that I had never seen a Berger that measured over .2434 and to my surprise they measured .2439 . Now try swaging those puppy's down a .2429 groove and not have any pressures . You see that's where the .160 freebore comes in . Please don't think one of those sloppy brand X reamers will do the trick at .2445 . You see its not the O.D. cut of the freebore ,its the solid non interrupted portion of the lead angle that causes the problem . That's why a long jump with a maturing pressure helps gradually swage the bullet parallel into the lands and grooves . Well getting late , time to go home . Hope this helps in determining freebore length and understanding that you may have a rifle that is not performing , with bad pressure and all you need to do is push the freebore forward or you may have a rifle that use to kick butt with the older bullets but you put it aside because the keyboard jockeys said it just would not work. My .02 cents . Thank Dave
762willdo said:Try this... After pulling the trigger say "one alligator" before releasing the trigger forward, you may be surprised.