slanted crown on Winchester 94

[dogbarlow]

I am finally getting around to troubleshooting the poor accuracy of this rifle and I think I found the problem. It looks like the crown on my model 94 is not square with the barrel. Check out the attached pics. I made jig and inserted it into the bore of the rifle and measured the gap. It measures .007". This seems pretty extreme to me. I am the original owner of this rifle and this is aparently the way it left the factory.

 

[Medic!]

That would tip a bullet.

 

[drstrangelove]

Easy fix. Talk to Velzey

 

[jbett98]

Isn't that called Kentucky windage?

 

[whitney]

Your jig appears designed to measure the barrel end and not the bore where the bullet leaves the barrel. The bore is actually slightly recessed below the end of the barrel, the bullet leaves the bore before it reaches the end of the barrel. I do not believe this is the "smoking gun" so to speak.

Can you describe the difficulty you are experiencing with this rifle.

~Whitney

 

[dogbarlow]

Your jig appears designed to measure the barrel end and not the bore where the bullet leaves the barrel. The bore is actually slightly recessed below the end of the barrel, the bullet leaves the bore before it reaches the end of the barrel. I do not believe this is the "smoking gun" so to speak.

Can you describe the difficulty you are experiencing with this rifle.

~Whitney

Hi Whitney, Large grouping is the problem. At 70 yards I can just barely hit a paper plate reliably. The jig is .300" diameter so it's a good fit for the .30-30. I made the jig to confirm that the crown is not square with the bore. When the jig is in the bore it appears to make contact on one side of the crown and leave a gap on the other side. If I could gauge the end of the bore I would do that but I don't know a method. Is there a trick/tool to do that? Kevin

 

[thorborg]

Could be a crown issue, but I think I'd look a little closer to the bore edge for the tattletale, I guess that puts me in the @whitney 's camp.

 

[dogbarlow]

I just pulled off the barrel and chucked it in the lathe so I can run the dial indicator along the edge of the bore. I read about .008" variation per rotation. I think I will go ahead and cut a new crown.dial indicating the bore edge

 

[F2CMaDMaXX]

Hmm, and that's just measuring the crown? Well, it would certainly seem off-center, though i can't comment for how much difference this makes in practise.

 

[whitney]

Hi Kevin, What you describe sounds like the barrel is not cut off straight. Is the gap between the barrel and your tool always in the same place? or.. does your tool "appear" to wobble around the end of the barrel?

The recessed area below the end of the barrel may have been manufactured on a lathe and there may be some undetectable defect. Take a look at this tool https://www.midwayusa.com/product/1007273822?pid=684575
This tool fits the bore and makes the crown (recess) concentric with the bore, even with the gap you measured this tool will dress the recessed area so point of bullet departure from the barrel is true to to the bore.

A couple things to note, and correct me if I missed the mark. Your tool does not appear to address the concentricity of the bore to the recess due to the angle of the bore. The flat edge of your tool indicates how perpendicular the end of the barrel is to the bore.

You will have to use your imagination a little bit.......if you cut off the barrel with a hacksaw and did a poor job the tool from midway will still cut an angled recess that is concentric to the bore.

Follow on questions:
Are you using factory ammo or are you using reloaded cartridges?
If reloaded are you using jacketed bullets or cast bullets?
If cast bullets are they the proper diameter for your bore? ;; Slug your bore if this is in question.
Cast bullets are problematic if they do not fit into the rifling.
What does your target look like? Are the holes round, asymmetrical, or elongated. If you look at the backside of a paper target the hole should exhibit a even punch or basically look the same all the way around. You could have round holes but the bullet may have a bit of yaw on it and drag one side of the paper over.

One last thing.. can you make a tool similar to your gauge but take off the flat top and extend the spindle about two inches.
If you can attach a test dial to this tool you can measure the concentricity of the recess (crown) before committing to a cutting tool you will likely use only once.

~Whitney

 

[dogbarlow]

View attachment wobbling crown.MOV

 

[whitney]

View attachment 785150

HOLY COW !!

 

[dogbarlow]

Hello Whitney, Thanks for thinking about this. I like that tool you linked to and I'd order one but I have the barrel chucked in the lathe already and I'm scheduled to go shooting Wednesday so I'm going to cut an 11 degree crown on this unless someone stops me. I use factory ammo and the holes in targets are round. The bore is a nice clean and tight .300". I think that last video of the wobbling crown/bore edge convinced me that I'm onto something.

 

[whitney]

Hello Whitney, Thanks for thinking about this. I like that tool you linked to and I'd order one but I have the barrel chucked in the lathe already and I'm scheduled to go shooting Wednesday so I'm going to cut an 11 degree crown on this unless someone stops me. I use factory ammo and the holes in targets are round. The bore is a nice clean and tight .300". I think that last video of the wobbling crown/bore edge convinced me that I'm onto something.

Agree with all. Just out of curiosity can you slide your tool into the bore and indicate radial run out? I think you are on to something I am concerned your bore is not centered in the blank. ID is not Concentric to OD.

If it indicates good with your tool in the end of the bore then the bore is strait and cutting a crown is easy peasy. I am definately interested in your results.

~Whitney

 

[dogbarlow]

View attachment new crown.MOV

 

[RVTECH]

Just a thought but have you considered using a ball stone to cut a 'sub' crown in the muzzle ?

This would square the muzzle regardless of the runout you show in your video.

I read about a similar problem many years ago and this was done and it solved it.

 

[dogbarlow]

I did consider that approach but since the barrel wasnt difficult to remove and I have a lathe...

 

[RVTECH]

Well, your crown now looks good.

What is the rough spot on the barrel just behind the sight ramp?

 

[dogbarlow]

new crown being indicated along the bore edge

 

[dogbarlow]

Well, your crown now looks good.

What is the rough spot on the barrel just behind the sight ramp?

I think thats a blob of grease from the steady rest. I greased it up pretty heavy.