first shot through clean barrel key holes

S

schmidtb

Guest
Factory barreled .223, 77 gr. Sierra in a 1 in 7", started to key hole first shot after cleaning......following shots group very well........this condition started after several hundred rounds, cleaning every 15-20...........
Barry
 
I have a bull barrel 223 with a 9 twist...If I clean it too good
the accuracy goes out the window..So all I do is patch it out
after every 100 shots..Works great for me..:D
 
Some suggestions

1. Verify twist rate of factory barrel

2. If you like the way the rifle groups after the first shot,use the first shot as a fouler.

3. Try different bullets,(70gr or 80gr)

4. A new barrel will likely fix the key holing problem.

These are just a few suggestions.



Glenn
 
schmidtb said:
Factory barreled .223, 77 gr. Sierra in a 1 in 7", started to key hole first shot after cleaning......following shots group very well........this condition started after several hundred rounds, cleaning every 15-20...........
Barry
Click to expand...

The Sierra HPBTMK should be stable at 1:7

Is there any chance of oil or residue left in barrel/brake/sup/FH after cleaning???

al
 
I read, somewhere, that the first shot from a clean barrel will have lower velocity due to the lack of carbon in the barrel.
If this is true and the bullet you are shooting is just on the edge of stability when the barrel is dirty then the velocity may
be low enough on the first shot the bullet will not stabilize.
Does this make sense to anyone? Or am I totally wrong, again?
 
No, you're not wrong. The first bullet from a clean barrel differs in velocity. Bottom line is that the first bullet keyholes. That indicates insufficient velocity but it may be something else - something terrible. I don't think it's terrible but rather a light load...a load the rifle sees as a light load. That the problem is a new problem is somewhat odd. Different bullets or powder should be considered (what you're using now opposed to what you were using before), along with seating depth.

Is the bullet fully keyholed or just slightly?
 
My guess is.....

Larger than normal groove diameter, letting gas blow by the bullet (more than normal). The extra gas destabilizes the bullet when it exits the muzzle. After bore is fouled, it seals better, no tumble. Had a 243win factory barrel that did this, barrel took about 10 shots to group well.
 
Dusty Stevens said:
he does it like the world record holder Jackie told him to and all other methods top gunsmiths use are inferior.
Click to expand...

I thought I was the only guy who recognized him....... sad day when you gotta assume a new name just to give advice......
bill larson
 
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friggin' "hobbyists" ......... ennybuddy can see from match reports that "self" is the best gunsmith out there excepting blarson, them "hobbyists" should just crawl back in their holes eh....useta' be a hobbyist name a' Phil Bower who'd come on here, man those real gunsmith's shore showed HIM a thing or too......and then there was J and F and GD and .....

Ahhh, I'll just shut up and go down to the shop now. Let the big boyz play.

Last nite I set up a barrel in the lathe gordie style, took it out, set it up again, took it out and now I'ma' go stick a bit in it cuz ALL 3 TIMES it came back to the same index.....


weird huh?


al-hobbyist-inwa
 
Paul,
Evidently your experience with the sport has been different than mine. While I may not always agree with all of them on every point of discussion, virtually all of the men and women who compete at Visalia, and every one else that I have met in the sport, would easily fit into the categories of ladies and gentlemen. Posters on web sites, are another matter. Sometimes they become more aggressive behind their keyboards than they might in person.

As to the OPs question, I have no idea, because I have not had it happen to me, and because I don't know anybody that it has happened to. Beyond that, the information is a bit sketchy.
Boyd
 
Possible solution

schmidtb said:
Factory barreled .223, 77 gr. Sierra in a 1 in 7", started to key hole first shot after cleaning......following shots group very well........this condition started after several hundred rounds, cleaning every 15-20...........
Barry
Click to expand...


Listened to many experienced bench shooters, posts on this site and a Sierra Bullet Tech who suggested a "super" cleaning of the bore...especially the throat area.......Wipe Out and many strokes with J-B........shot a local weekly match today......amazing what can be done with a lot of elbow grease ............no sign of key holing......return of very small groups, and a smile on my face......turns out that just using Champions Choice on patches and a bronze brush was just not enough........even though the patches appeared clean......Wipe Out showed evil copper was still present.......valuable lesson learned.
Savage LRPV, .223, 1-7", Sierra 77 gr, case load of Varget, WSR, Weaver 36X.........shot weekly at St. Thomas Sportsman Club, PA. join us, we had 35 guns this morning.........Barry
 
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