Keyhole

[RetiredArmy]

Factory savage 204 ruger, unknown round count as I have put 200 rounds through it since I got View attachment 1072409 on a trade about a year ago. Has shoot good, mounted new scope today, put target at 50 yd s to get on target. First shot on a clean barrel with proven load keyholed. Checked bore, brass every thing look good, adjusted scope from the key hole, shot the two on the right. Went to 100 yd s everything seems normal. Better then 1/2 in groups. Any idea what happened?
204 ruger
SS wet tumbled 2x fired hor brass
rem 71/2 br primer
25.3 gr bench mark
Sierra 39 gr blitzking
Thanks Bill

 

[Dusty Stevens]

You need a borescope to see what the barrel looks like before we go any farther. Here in a bit we’ll be blaming it on non weight sorted primers, and no annealing

 

[RetiredArmy]

You need a borescope to see what the barrel looks like before we go any farther. Here in a bit we’ll be blaming it on non weight sorted primers, and no annealing

Dusty,
I have a lyman, will take a look when I get the barrel cleaned up. I'm no expert when looking at a bore, when I cleaned it last i scoped it to check that it was clean an d things looked fine. But like I said I'm no expert. P.S. I don't do either of them.
Thanks Bill

 

[lpreddick]

Not enough RPMs will do this. Twist and MV determines RPMs. Twist was good for the other bullets. We have all loaded a case with less than was planned.

 

[Bojo]

I have a savage 12 fv 22-250 . Heavy varmint 12 twist .I bought it from.a guy who won it claims it was never shot and it looked super clean without wear. One of my friends gave me a bunch of sample bullets in baggies of 5 of different brands and weights. One of them (I cannot remember which ) thru 2 bullets almost right thru the bull sideways at 100 yards. Wish I could remember which bullet. It chews everything else up just fine

 

[rwj]

Odd that the grease wipes on the two round holes do not show any signs of the bullets engaging the barrel rifling...

 

[drover]

Drop down to 32 or 35 gr bullets and the issue will go away, the 12 twist is marginal for 39/40 grain bullets.

Nice picture perfect keyhole though.

drover

 

[Dusty Stevens]

Did you measure the bullet dia? @rwj got me thinking its a 17cal bullet maybe?

 

[TheOtherZilla]

Here's my story. Factory Savage 12, Accustock etc etc.. Shot great with my hand loads, [39 Sierra] like 1/4" at 100. Shot it for several years. Then for unknown reasons accuracy went away.. Couldn't hit squat.. Took it to the range and a shotgun patterned tighter than this rifle. Then the key holing began. Not every round but.. Tried some 32 grainers and they wouldn't make it to teh 20 yard target... My gunsmith scoped it and the barrel is toast..

 

[RetiredArmy]

Did you measure the bullet dia? @rwj got me thinking its a 17cal bullet maybe?

Yes sir, 5 out of 5 measured .203. A new bronz brush seems to move through bore a little easier than I rember. Might just be in my head, not sure what to look for on the bore scope to tell if barrel is shot out.
Thanks Bill

 

[Dusty Stevens]

Look to see if theres rifling in the barrel first thing

 

[joshb]

Did you measure the bullet dia? @rwj got me thinking its a 17cal bullet maybe?

That was my thought, too.

 

[B Nettesheim]

It could be just one bad bullet.

 

[RetiredArmy]

Look to see if theres rifling in the barrel first thing

There's some in there, not a smooth bore yet. No gouges, bures. A bunch of tool marks.still working on cleaning to bare metal.
Thanks Bill

 

[hogpatrol]

Wet tumbled brass, wet powder maybe?

 

[RetiredArmy]

Wet tumbled brass, wet powder maybe?

Dried in dehydrator for 50 min. Have not had a problem with any other rifles. Any thing possible.

 

[RetiredArmy]

It's a 1-12 twist, I've got some 32 grain blitz kings I'll give them a try after deer season ends. It was clean, the 39 grain is all I've shot out of it since I've owned it. Has always shot well. Even today it shot well except the key hole. Thanks for all the replys, keep them coming I like the 204, but it wouldn't take much for me to try something new!!
Thanks Bill

 

[hogpatrol]

I am curious as to why they went with a 12 twist, when an 11 or 10 will handle just about every factory loading. I shot a friend's handi-gun .204 and it keyholed EVERY factory loaded round, regardless of weight. Here's the last group before I gave up. From this chair, if it's not a 10 or 11 twist, it's a wheel spinning operation. Having said that, if you change barrels, go with a faster twist.

 

[RetiredArmy]

hogpatrol, I'm going to play with it some more in time. If i stay with 204 i will go to with a 10 or 11 twist. Another 6mms br Norma might just got the bill.
Thanks Bill

 

[pacificman]

As mentioned ...I also think ya got a bad bullet. I once had a box of Sierra bullets that was missing the lead
inside the jacket...glad I found it when seating it in a case before shooting.