Berger 105 Hybrid Sticking

[D.Kiff]

Bugman , I will check in a few . I am not at the PTG now . My Grandson is leaving to go back to Texas tomorrow and I was up late last night and again early this morning . I am finishing a 30 PPC + P Bench rig for him. Its a sweat little rifle built on one of the Farris P. rifles that June sold me . I have only used this office computer a few times as I live at the shop , at least that's what my wife tells me. I looked real close at a Hybrid that a customer jammed and engraved in a short throated Dasher this morning and the bold Ellipse Ogive did not engrave at all but it did leave a shiny ring like cjames . I have seen this before . On the bold elliptical portion of the bullet that measure's say .2432 pushed into the throat at .2435 and a genital lead of 1-30 the projectile is not engraving at all it is swaging high on the cylindrical non grooved portion of the 1-30 angle transition . You take a .2435 or even the sloppy .2439 parallel and subtract the groove depth diameter of .243 or .2429 and you have a solid un- grooved slight transition band running at a angle until it feathers into the cut groove . Depending on the angle it could be quite long and a reamer that is radial stoned blending the parallel and angle junction would show it more. . The larger throat diameter will compound the problem ever so slightly because it doesn't keep the projectile in parallel and lets it drift off center into the cylindrical band . That small band in the transition is like a swage . The customer that sent the bullet in that I looked at had two barrels chambered with the .104 freebore same reamer same barrel company . The one that did not swag shinny shot the Berger's great , I would bet it had a larger groove ( don't know ) . The reason the longer freebore's work , folks are just touching to just off the lands and some have jump ( not forcing 10 pounds of potato's in a 5 pound bag ). Also witch barrel has smaller grooves and larger grooves. This jump is a lot like the bore rider throats I grind that are breaking records...... I will shut up and check for your message ..... Thanks Dave

 

[BoydAllen]

Dave,
Thanks for that last post. I learned quite a lot from it. You can believe that it will be filed away in the secure section of my long term memory.
Boyd

 

[D.Kiff]

Boyd , you already know all this as you and I discussed it all 20 years ago ,,,,,,, don't you remember ???? All fun aside, Have a great weekend . I'm going shooting with my Grandson . I'm outa here .....Dave

 

[expiper]

Hi Dave,,,could you please give us a drawing of the "bore rider" throat and a 1.5 degree so that the many posters on here could see the differance ,,,thank you Roger
PS,,,hav fun with your grandson,,,nuthin like a day at the range

 

[D.Kiff]

Roger , Ill get them to you this week from the shop . Thanks Dave