J,
Have you tried 2% tin/WW? I've used it a lot in 45/70 and I noticed no differance in accuracy compaired to 20/1. No leading, also. Not sure of the hardess but, I think between 10-12 BHN

Frank

J,
How did they cast? Did the mold fill out well? Did you have to raise the casting teperature? That alloy has almost trace amounts of tin in it. 

Frank

   J. Louis,

    I can see from the information that you've shared thus far under this heading that you have put in some serious time towards solving the riddle of "Accuracy".

   I shoot the same Hoch bullet at 200 yards and was wondering if you would happen to know the Ballistic Coefficient of the Hoch 322-200.  I would ask Dave Farmer, but one can't always reach him on the phone when he's busy in the shop.
If anyone else would know, I believe it to be you.

   Thanks for your time,

    Creedmoormatch

                            Choose Civility

Quote:


  Hi John Boy:   I really appreciate your getting back with this additional information.

  As I mentioned to Mr. J. Lewis, I'm already shooting the Hoch #322-200 bullet, but have never known the B.C.  The reason that information would be helpful, is that, often times I need to "zero" my rifle/s at 100 yards distance, even though I compete at 200 yards.

  By using the Lyman Cast Bullet Handbook published ballistics charts and knowing my particular M.V. , bullet weight, and bullet B.C. , I can pick-up from the charts what the "bullet path" will be, i.e., bullet drop in inches.  When I get to the competition at 200 yards, it's simply a matter of adding the necessary M.O.A. elevation to my scope to off-set the bullet drop, shoot a few "sighters" to fine tune and I'm good to go.

 Of the three components used in the charts, the B.C. is the least precise and may be fudged, but it I knew the exact the B.C. for the Hoch bullet, that would remove just one element of uncertainty.

 Thanks again and best regards,

 Creedmoormatch

                         Choose Civility

  Hello Frank ;

      What I was indicating to John B. is, that heretofore, I was just looking up the "Bullet Path" in the Lyman Charts; 1)using the known Hoch bullet weight after having weighted then, and; 2) using the muzzle velocity after having Chronographed then, but not knowing the B.C., I was using a "best guess" approach based on the length and nose configuration as seen in Lyman's materials.

      For instance, the Lyman bullet No. 323471 (actually an 8 MM) has a published B.C. of .475 (taken from the Lyman chart), and bullet No. 323470 has a published B.C. of .187.

     Referring to Lyman's chart, and using my chronographed M.V. of 1300 f.p.s. the No. 323471 bullet if "zeroed" at 100 yards will drop to minus 23.68 inches at 200 yards; whereas the No. 323470 bullet if "zeroed" at 100 yards will drop to minus 27.03 inches at 200 yards; for a delta of 3.35 inches.

One-half of the delta equals 1.675 inches which, when added to the shortest drop of 23.68 inches, equals a total bullet drop of 25.355 inches.

    So on the day of the 200 yard match, I would simply add 25 1/4 inches of elevation (1/4 M.O.A. EQUALS 1/2 inch change to P.O.I. @ 200 yards distance) to my scope setting which is zeroed at 100 yards; make a few "sighters" and fine tune to a 200 yard zero for that relay.

   The information that John B. provided to me earlier will now allow me to short cut right to the actual calculations.

   Frank, thanks for your input of the subject.  Every little bit helps.

   Regards,

   Creedmoormatch

                      Choose Civility

I have to agree with John here we get way to carried away with what it says on a graph or a program some egghead who never shot a rifle much less a single shot designed. If it worked that way we would never have to shoot just plug our superior numbers into the computer and tell them where to sent the big money prize. 
Here is an easy way to move your rifle from 100 to 200. Take your rifle zeroed for 100 yards and put the cross hairs on the bottom a 200 yard offhand target adjust the scope to the top of the target sight in on the center of the target, fire a shot, adjust to center, fire for effect. 
A friend taught me that stunt years ago and I'll guarantee it came from practical knowledge not the computer. 

40 Rod

40Rod, I think you got that backwards. If your 100yd. sighted rifle was fired at the top of a 200yd target it would hit the bottom and you would move your crosshairs to the hole and be on target.

40_Rod wrote on Apr 1^st, 2011 at 8:56am:

I'm quite sure that this is backwards. To move the crosshairs UP we have to turn the elevation knob clockwise = DOWN. If we do this and then put the crosshairs on center of the target and shoot, the bullet will be way low.
I think we must start at the TOP of the target and move the knob CCW = UP and the x hairs DOWN.
1knob rev. = .025" = 50 clicks = ~12.5" at 100 yards, ~25" at 200 yards.
joe b. often wrong, never in doubt