Tod,
I've been busy and just now seeing your post here. I'll add my 2 cents worth based on my experience with the heavy beasts. Which is my favorite class to shoot in BTW.
My question is the rails themselfs. Which is better.....rounded rails or sharp rails? The current setup has a sharp 60 degree beveled rails.
first let me say that the front to rear weight distribution for a HG that is on the heavy side isn't as critical as a LG. My LG I have a specific place that I index to place it in the front bag when firing. HG jsut isn't that critical because you are talking about a lot more weight to begin with. Maybe you only have 25% rear weight. But 25% of my current 74# HG is 18.5#. That is obviously more than the total weight of a LG. For the record my current HG is more than 25% on the rear, but I don't have the exact numbers either. But 18.5# is nothing to sneeze at for weight on a rear rest.
Over the years I've tried about everything. My next to last HG had round drill round blanks glued into milled slots into an old Six fiberglass stock. 2 rails in the front (1/2" dia x 5" long approx) and 1 larger one in the back (3/4" diameter x 5" long approx). There was also weight added to the rear of this rifle along with the steel glued sleeve used to bed the first 12-14" of the barrel. Total weight was around 40-45# if I remember correctly. I never really got comfortable with the round rails. The tracking part was jsut fine. But when making windage adjustments you always had to settle your rifle into the bags more with the rounded rails than a square rail rifle IMO. Because the rounded rails I believe would ride up and over the area of the sand bag that was holding it in place.
So on to my current HG. Don't know if you are familar with my setup or not so I'll give you the 10 cent tour. McMillan HBR stock (5" front and 1 3/4" rear??), standard pillar bedded BAT 2x10 action with multiple 30" barrels for it (6.5x55AI, 30 BooBoo, 338 Yogi), and my rails are about what you are talking about. I have (2) 303 SS plates bolted to my stock. In the front the plate is 5/8 x 5 x front of trigger guard to end of forarm in length. Then I have (2) 1/2 square rails screwed into the SS plate. These had been polished with a buffing wheel. On the rear I have a 1/2 thick 303 SS plate that is 1 3/4" wide by the length of the buttstock. There are 2 more 1/2" sqaure rails screwed into this plate also.
I have shimmed these plates and worked on these rails to slick them up to make for a smooth ride over the years. FYI.. I've used this setup and tweeked it sinse this rifle was first built in '99. The weight of these SS plates and rails is #22 of extra weight on my rifle. It does make it sit higher so you have to adjust your shooting posture and stool height to accomidate for it. But after all these years of tweeking and working on it, I've got it now to where if it doesn't return into the 4" white patch everytime I know that I have done something wrong myself in pushing the rifle back forward with my shoulder. And you can disrupt and control a 74# rifle. I don't care what anyone says about HGs. Oh, anyone can shoot that thing. Yea they can... but it still takes the nut behind the bolt to "shoot" it and you do have to pay attention to these guns a lot more than the average man thinks. Example... if your front and rear rests are 24" apart C-to-C and you move the rear rest .0006" in any one direction.... that is worth 1" at 1000yds. As you can see it doesn't take much to move .0006". And the current world record is jsut over 3".
Also....1 1/2 inch or 3 inch rear rails?
I really don't think you will see of feel a difference between them. The 3" will obviously give you more leverage to counteract agaisnt the rifle twisting while operatiing the bolt. But if your disrupting the rifle that much while reloading the rifle your going to need a lot more than 3". Work on the sticky extraction and smooth bench technique rather than trying to control it mechanically. As I said above I've got 1 3/4 on the rear of mine and if it doesn't return to battery.... its my fault all the way in the gun handling.
Work on your bench technique with a video camera while blowing out case or practicing. You would be surprised what you can see in slow motion. Every move you make at the bench should be deliberate and smooth. That will quickly turn into instinctive motion and you will then have good spped at the bench. I can rip 10 round down range a lot faster than needed. I have to force myself to slow down now it so smooth.
I'll try to dig up some picture to post of my setup for you to reference.
Good luck!
Steve
P.S. Eric its been awhile sinse I've heard from you.
Tod, adding a comment here.... take note of Jeff's suggestion about adding your stop on the bottom of your rifle and not at the end of the forarm. Simple geometry says less leverage equals less diruption of your front rest when 74# gets moving forward and you try to stop it. That was one of the first things I did to improve my setup after the initial build. It will be a work in progress for awhile as you figure things out and improve them. Then the system jsut starts working really good.
