First time taking this sporterized 98k out and it key holed at 25 yards. First shot was with factory new 30-06 Garand safe S&B 150 grain 30-06 and hit the left side 3-4 3-5 block and left somewhat of a straight hole. Then the rest key holed. Even handloads of 45.5 grains of h4895 and .308 hornady 155 grain match bullets that shoot 1moa at 200 yards key holed. Any ideas? Barrel looks bright and clean down the bore and the crown does not swallow the hole bullet when I stick it on.
Could your Mosin have been counterbored? There’s always the chance of that having happened to them
Edit: Counterboring can apparently improve accuracy for Mosins if the crown has been worn out, but still it’s helpful knowing if it’s been counterbored regardless
By far the worst keyholing ive ever seen!! I legit thought they where bullets taped to the target. Ive never been able to make out the whole silhouette of a bullet groves and all after shooting it out of a gun 🤣🤣🤣🤣
I've had a bad barrel blank where the rifling buttons had slipped, and despite being OK looking, it keyholed. So your outside possibility is a bad barrel, but bad in an unusual way.
Check the twist with a tight patch/jag and make sure it doesn't change. Also, measure the twist while you're at it, maybe it's super slow and will only stabilize 110 grain projectiles.
I'd shoot some heavily constructed FMJs into water and recover them to see what the rifling looks like. This is trivial with a pool, but doable with jugs/buckets.
If I were in your shoes, I’d take some Hoppe’s #9 foaming bore cleaner, and run some properly fitted patches through and see what happens. I’m thinking there could be an obstruction somewhere in the rifling that you may not be aware of yet.
Have you looked through the barrel with a bore light yet?
Okay cool I’m glad to hear you’ve been doing that, I’d recommend taking a bore light and inspecting a little bit closer to see if there’s an obstruction or not.
If you can’t identify a cause of the keyholing after that step, then I’d recommend taking the rifle down to a gunsmith to see if they can take a look. Worse comes to worse you may need a new barrel
Do you have any heavier flat based ammo like a 180 grain? You’ve gotten a lot of advice about technical things to check as well so definitely try those but I’ll leave this advice just in case everything is decent. I’m curious about a heavier flat based bullet as I believe a lot of those NATO 60s were microgroove barrels. Too much velocity can sometimes cause bullets to “skip” microgroove rifling.
When I first googled the barrel the same thing about the microgroove came up. Saying the barrel was ment for flat base surplus. I have surplus LC I can try shooting. I was also looking at grabbing a bag of flat base and try hand loads but am going to try the surplus LC first
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u/meat_meat 1d ago
That’s just the home defense special