JPH45 Cast bullet Performance.

[Fred M]

JP
I have bee following your trials and tribulations with cast bullets. Fact is cast bullets are very accurate and can hold their own with with jacketed bullets. Some cast bullet with Black Powder have set world records.

From what I read you know how to make good cast bullet and very knowledgeable about cast bullet handloading.

It only makes sense that the problem is not with the bullet and loading procedures but with the rifle.

Since I got that new Ultra 25-06 I have gone over that action and lock up with a fine tooth comb.

The most disturbing accuracy killer is the lateral clearance of the under lug and the fit of the locking latch.

The clearance in under lug on my rifle 0 .0105 or 0.0052 on each side near the latch recess and 0.002 on each side behind the hinge pin.

The barrel will torque when fired and vibrate with each shot. What I will do is, I will solder four strips of steel shim stock on the under lug  and fit them with a stone to a perfect fit. This will remove the lateral play which right know is clearly visible.

I have already stoned the latch to near  max contact. You can check this contact by looking at the latch release when the action is open you will notice that the release is all the way to the top. When you close the action and the latch does not make full contact you will be abble to  move the release button up and down.

That is one reason why some Handies open when fired. A bit of red lip stick on the lug recess will tell you where to remoe some metal with a very fine stone. The hinge pin too can be shimmed back against the standing breech if is has slack.

When blue printing a bolt action for top performance it should always include the removal of sloppy clearances in front and back of the bolt to elliminate vibrations.

I think that a great deal of inaccuray can elliminated by addressing these two items. Fred M

[JPH45]

Thanks for the info Fred, I am guilty of being slack in tending to the mechanics of my gun. The lock up is consistant and the action is tight when closed. I will take some machinist blue and look at the amount of engagement on the lugs. I found a trigger job to be the single most beneficial tuneup I have performed to my rifles. I hope that Ultra shoots well for you. Later, JP

[Fred M]

JPH45.
Some enterprising hot shot machinist could parrell the under lug with a 0.001 taper to the bottom on both sides and do the same thing on the receiver. Solder on two pieces of oversize shim stock and and then mashine the shim stock to a perfect fit with no more than 0.0005". clearance.

I did the shim stock treatment with a needle fille and a honing stone. Not with solder only with JB Weld just to give it a try. I got a very good fit in both front and back. If you do it with solder you should take out the ejector springs and use low temp 475F solder.

As you know there are only two places that hold the handy together during firing. The hinge pin and the barrel latch. The shims on both sides do only reduce vibration and with those big canon balls you guys shoot you get lots of it. Ouch :lol:  Fred M.