I just shot my Kodiak 45-70 double rifle and had terrible results. All of the bullets were "keyholing" the target. the spread would be 12" - 30" with all bullets hitting the target sideways. My first guess is that I am shooting too heavy of a bullet. I was shooting 500gr hard cast bullets with 45-47 grains of Varget and the same bullet with 40-43 grains of IMR 3031. No signs of pressure...good primers and no extraction problems. All loads performed the same... TERRIBLE !!! I still have no idea of how it regulates due to this.
The barrels are 24" long with a 1 in 18" twist rate. I am going to try 300, 350, and 400 grain bullets to see if this helps.
These guns are proofed for the Garrett 540gr 45-70 loads which confuses me . Are the Garrett's enough faster to stableize that heavy bullet or does this just mean that the gun won't blow up?
I want to shoot the heaviest bullet I can because I plan to rechamber to 450 #2 NE and a 300 grain bullet just doesn't seem "right".
Please express any thoughts as to my next steps. I greatly appreciate any input.
Thanks, Ghost

PS: I still love the rifle in spite of the initial problems. Nothing like the feel of a double !!!

Not knowing Jack about double rifle regulation or twist rates, I would bet dollars to doughnuts the gun is regulated for 405 grain bullets at std 45-70 velocities.



JMHO,



JohnTheGreek

Once upon a time Davide Pedersoli was stating that their Kodiak MkIV 45-70 was regulated for the 300 gr HP factory ammunition. They went on to say that they did not recommend the use of ammunition which surpass SAMMI spec of ~ 28,000 CUP in the 45-70.

That is all I know.

Keyholing is a stability issue, typically. What is the diameter of your cast bullets?

ASS_CLOWN

Timberghost,

How much leading are you getting with your cast bullet loads? Did you chronograph them? Are your cast bullets .001 or .002 over groove diameter? What type of lube are you using?

Was this a new rifle, or a used rifle (if it was used, did you clean the bores down to bare metal before shooting it)? I know that it is stating the obvious, but I have bought some used rifles that shot pretty awfully before a thorough cleaning (one particular Winchester 22 LR was keyholing at 10 yards before cleaning, but shot great groups after getting all the lead out).

I am sure that you know all the things to look for, but it never hurts to have a little additional input.

I have been working with an early Pedersoli double (Trail Guns Armory marked) that I got recently with the intention of doing just what you mention.

My rifle seems to shoot well with everything from 300 grains to 430 grains, but I haven't tried anything heavier yet. Best regulation seems to be with 300 and 350 grain bullets, but 405 works pretty well also.

The rifle came with a box of Buffalo Bore 430 grain factory loads, and they did fine at 50 yards.

I think that the rifle will do even better, but the trigger pulls were rather heavy (particularly the front trigger). This has been remedied, but I haven't had a chance to take it to the range again.

One "problem" though. As well as it shoots now, I can't bring myself to rechamber .

Jim

John,
At this point, I don't think the double rifle regulation factor has even come into play yet. I think I am at the stage of getting the bullet weight and velosity to match the rate of twist in my barrels. I do appreciate your input on the 450 grain slugs because I want to shoot the heaviest bullet I can. It would be nice if I only had to drop 50 grains or so. I am ignorant to wheather the stablization of the bullet goes away little by little or all at once as weight goes up or velosity goes down. I saw no improvment as I shot the faster rounds. I wonder if a jacketed bullet would help, or have no effect at all?
Thanks, Ghost