More Knight Peregrine Problems

[ElDiablo]

Maybe I'll buy a bore scope and post some pics. I'm not 100% sure it's pitting, but it sure doesn't look good.

What makes you think it’s pitting if you’re not looking at it with a borescope? Just feels like it’s rough?

 

[Verde]

Broomstick,
I thought it shot fine at 100 yards.
First shot on edge of bull. Second next to it. Third to the left.
This target is after I cleaned the gun and returned to range. I had sighted it for an inch high at 100 yards.

 

[Verde]

Boomstick. Sorry, spell check got me.

 

[Cedarmtnqlguy]

What makes you think it’s pitting if you’re not looking at it with a borescope? Just feels like it’s rough?

I'm not 100% sure of what it is. It's not that far down the barrel, maybe 6-8 inches, so I'm just seeing it when I hold the barrel up to a light and look through it. It's in the grooves, not in the lands. It could just be from rough tooling passes through that area. Everywhere else looks very smooth. At first I thought it could just be a patch of severe fouling, but I don't think that's the case.

I need to get a bore scope to see it better.

 

[mwwoodman]

I may be wrong, but I believe Knight barrels are made by Green Mountain. They are button barrels. You will rarely find consistency in a button barrel that will match cut rifling. Typical button barrel specs are -0.000/+0.002 and that is super sloppy for full bore.

 

[michiganmuzzy]

I may be wrong, but I believe Knight barrels are made by Green Mountain. They are button barrels. You will rarely find consistency in a button barrel that will match cut rifling. Typical button barrel specs are -0.000/+0.002 and that is super sloppy for full bore.

How do hammer forged barrels compare to cut rifling?

 

[mwwoodman]

How do hammer forged barrels compare to cut rifling?

I've never looked close at hammered barrels to inspect the bore. I'd think not as good because when you load full bore, microns can make a difference. I even lap cut rifled barrels to make them perfect.

 

[DavidAR10T]

I've never looked close at hammered barrels to inspect the bore. I'd think not as good because when you load full bore, microns can make a difference. I even lap cut rifled barrels to make them perfect.

Michael W. Mayerl​

Michael W. Mayerl said that hammer forging can hold a tolerance in diameter within 0,01mm = 0,000394".
I'm a single point cut Dapper Dan man, myself. BUTT!!! There is nothing smoother {surface image} than a HF'd piece of rifled pipe.

 

[michiganmuzzy]

Michael W. Mayerl​

Michael W. Mayerl said that hammer forging can hold a tolerance in diameter within 0,01mm = 0,000394".
I'm a single point cut Dapper Dan man, myself. BUTT!!! There is nothing smoother {surface image} than a HF'd piece of rifled pipe.

My BIL is also a big HF fan. He is a huge Ruger fan and has been shooting bench rest cf and reloading nearly forever, it seems.

 

[Cedarmtnqlguy]

What makes you think it’s pitting if you’re not looking at it with a borescope? Just feels like it’s rough?

What makes you think it’s pitting if you’re not looking at it with a borescope? Just feels like it’s rough?

@ElDiablo
What do think? These are the patches I was seeing when I looked down the barrel. Pretty ugly.

 

[ElDiablo]

@ElDiablo
What do think? These are the patches I was seeing when I looked down the barrel. Pretty ugly.

Damn! That’s ugly!! Appears to be damage/tool marks.

 

[Mnt monkey]

Man I was just expecting some tool marks that's pretty crazy I've never seen that myself

 

[Cedarmtnqlguy]

Damn! That’s ugly!! Appears to be damage/tool marks.

Yeah that's what I'm thinking too.

 

[ElDiablo]

Yeah that's what I'm thinking too.

That’s a “new” barrel?!

 

[Cedarmtnqlguy]

That’s a “new” barrel?!

Supposedly

 

[DavidAR10T]

Send it back with the url to this thread.

 

[jsteurrys]

I would be sending that back. That is downright unacceptable.

 

[Ga.Smokey]

Looks to me like that barrel picked up a chip on the button and dragged it thru.
Pretty poor machining practice there.
On the copper seals that I make for turbine deck valving to seal high preasure side parts "we require a minimum of a 16 finish for proper seal."
"All surfaces should be perpendicular to the center line within .001"
Quoted from general electric notes.
If you can imagine both ends need to be square to both mating surfaces.
A16 finish is the nicest finish you can achieve without using polishing compound..
Basically a 220 paper smooth finish.
If your surfaces aren't smooth and slick the copper will grab and tear building up voids under the washer.
It's my opinion that a properly machined copper washer can be reused multiple times. In the right conditions.
The copper should compress then stabilize.
We replace when the lift of the valve no longer meets specs when torqued.
In our case headspace.
Threads by nature in straight pitches will have blow by .
A class 2 has .002 to .004 tolerance range in pitch diameters.
Stack those up highs / lows and Threads get pretty sloppy. As much as .008 of clearance in exstream cases.
No real good way to stop that.
I use grease myself.
It's a pain and messy but works fine to help fill the voids.
They had this problem years ago.
the old timmers solution was a brass chamber plug that was replaced every time the gun was loaded thru the breach. We call them cartridges today.
I think the modern brass modules solve this or masks this as good as any system.
Never going to cure the thread leakage on its own merits with out going to a tapered thread where head space would be near impossible to set consistently.
My opinion is that the selling surface needs to be at the bottom of the Plug.
Muzzle loading ignition blow by is just a fact of life. We all have to deal with.....got to run deer thirty here in Ga.
John