I'm posting this question for my father in law. He has a 1955 Husqvarna in 30-06, Crown Grade, with Monte Carlo Walnut stock and ebony cap. He recently put a muzzle brake on it.

He's had a hard time making it shoot consistently. Using the same ammo, one day will give him a 1/2" and the next week it's 1.5" (all at 100 yards). We've done a lot of thinking about causes. One thing that really threw us a curve was when we discovered that the old front sight had come off. One day we saw naked barrel metal at the muzzle (next day while cleaning). We think the best groups happened while that sight was working itself loose.

He's tried the following, in various combinations:
A business card shim at the end of the stock.
Cleaning up the barrel channel for a proper free float, with and without the shim
Super-tight stock screws
Loose stock screws

We suspect that the loose screws and/or the loose sight had a positive effect. Maybe creating the right vibrations, or dampening them.

We just can't pin down the right set of factors to give us the consistency we're hoping for. Can anyone help us out? In your experience, what has produced consistent groups? We're not necessarily looking for the magic 1/2" groups, but we'd love to get the same thing every time, whether it's 1/2" or 1.5"

Thanks for taking the time to read this. I hope there's an answer, and I'm sure this is the place to find it.

Gonzo:

With the same Ammo? Same lot, same box, etc.
Factory ammo can have inconsistencies in my book, regardless of how much better they are compared to the older days.

Is the rifle being used with open sites, or a scope. If your father in law has eye sight like me, with open sites, one day I can Be Daniel Boone, and the next day shoot like Diane Feinstein. Nothing to do with the rifle.

If it is being used with a scope, then I'd go back to suspect of the ammo, if the screws etc are all tightened down. Sometimes, something too tight can actually put pressure where it messes up accuracy. I had a 22 mag marlin that shot bad. I removed one of two screws holding the rifle and the stock together. Groups shrank because the forward screw was holding down the rifle too tight. Turned out to be that the screw was just a hair short of what it should have been. ( Screwy huh? No pun intended)./

Last thing I would look at is the muzzle brake. If the rifle was shooting fine before it was installed, then it may be contributing. You did not say what kind you had installed. I personally prefer to download ammo, than add a muzzle brake, if recoil is bothering me.

Did the factory or some clown at the store, mix up your ammo. I bought a couple of boxes at the store of ammo one time in '06. Ten shells were 150 grains, and the other ten were 180s. In several boxes. I am sure some clown at the store was mixing them up just to get his jollies.
I can't imagine that being a factory screw up.

Just some input, Good Luck.

seafire,

Thanks for trying to solve the riddle. I thought my post was pretty complete. Thanks for asking the questions. Here's the answers:

1. The rifle is scoped, no obvious malfunctions.
2. All factory ammo. I'd say the bad days were more like 2" with ammo bought at the same time as teh .5" stuff. He usually picks up about 5 boxes at once from a place that orders it by the thousands
3. I'm 99% sure that the rifle shot as inconsistently before the brake as after. As for the brake, it appears to be fit correctly.

Gonzo,

I would try changing the scope on it, and see what that gives you.

Other than that, as far as the ammo, if it is Winchester, Remington or federal, the Q/C should be fairly consistent.

Are you a handloader or a know one? I think that if the scope does not turn out to be the culprit, I would have to blame the ammo at that point, as the most obvious.

When I started handloading, hassles like that disappeared ( almost at least). However if they did appear, usually it was something I was screwing up at the load bench. Hope a resolution appears quickly for the problem.

Good luck !

Did you control the inside of the stock? These old Huskie stocks ofter get inside cracks, which disturb accuracy. Bedding would perhaps be the solver of the problem.

Best regards,

Fritz