Wild flyers

[stagpanther]

Interesting you mentioned two damaged case mouths--and you had that many keyhole fliers. Connection? I would think at least possibly. I'm scratching my head trying to figure that one out in a bolt gun--AR or AK--all the time, but a bolt gun, hmmm.

 

[flyboyjake]

I just talked to Tim at Hornady. He actually mentioned a guy with a 28 nosler trying to push them over 3200fps that was having problems (who could that be). Said they weren't really intended for that velocity, lol. If that's their position, they should probably say as much, but I know people are making them work even faster.

In any case, he also said a barrel with cut rifling in it's early stages can damage the bullet at high velocities due to the sharper edges of the rifling. He said in every case in their testing, over time the barrel was able to shoot them after the rifling became "bullet lapped". He mentioned hand lapping will likely fix this. Further, a hot barrel with these conditions will obviously tighten up and cause further damage during shooting.

I'm going to bore scope the thing to make sure there aren't any glaring defects. I don't really care to shoot my barrel half out to make these work, but I'll probably use up what I have left at the lower velocities that work, and see if it works higher in a couple hundred more rounds.

Thanks for everyone's help.

Here's a pic of those necks by the way. Happy thoughts your way if you've got an idea as to what's don't it. Seems to only be the higher pressure rounds. Who knows, maybe it's something I'm doing during extraction...

 

[stagpanther]

Your cartridges look like they are encountering a hang up upon cycling--that could easily damage a bullet and knock off the concentricity I would think. I'd try to figure out what's going on with that (unless you think the damage was after ejection).

 

[T. O'Heir]

That's not a key hole. It's torn paper.
In any case, key holing is caused by undersized bullets, an over sized barrel and sometimes insufficient velocity. A lack of lube on a cast bullet does it too. None of that applies in this case.
What's the load? Excessive velocity might well be your issue. Fastest MAX load for a 180 on Hodgdon's site is 2914 fps. With a 70.8 grain compressed load of Retumbo.

 

[flyboyjake]

I'm perplexed with the case neck too. The only time I put enough force into the bolt handle to cause that cans of damage without knowing it is when camming the bolt down, during firing, or on a sticky extraction (it's a belted case, and I don't use the collet die to size the base every firing). I'm pretty certain it's not on cartridge loading though. That's a lot of force to do that with a bullet in there too...

I promise that is a key hole. You can see the boat tail clear enough, and I have a Target with another. I'm running a Max of 68gr of h1000. I've got a 28" barrel. Right at 3000 was my expectation. I'm going to try a lighter load at a distance. If it doesn't group as well as it does at 100, I think it would dentate bullet damage or instability. I dunno.

 

[FrankenMauser]

That looks like ejection damage, to me.
The cases would not do that while a bullet was still seated.
And, if you look at the full size image, it looks like at least 50% of the cases have at least one ding/dent in the case mouth that should correspond with spring-loaded ejection.

I don't see it listed above... What action is this rifle based on?

 

[stagpanther]

It's a bolt inferring from what he's written, I think.

 

[flyboyjake]

It's a Savage 111. I've not experienced it before, but it's probably from me ejecting a stuck case. I'm going to pay more attention and try to note the orientation when it comes out bent though.

 

[stagpanther]

I have the same gun in 300 win mag--also a belted case--haven't seen that yet, I'm guessing a sizing issue--or does this also happen with factory ammo?

 

[Mobuck]

"Could the rifling be gummed up enough with copper in 200 shots"

200 shots through a 7mm mag w/o cleaning?

 

[old roper]

flyboyjake, who's barrel are you using?

 

[flyboyjake]

I clean it, just not for copper fouling. But I did the other day before testing again. No change really. It's a McGowan barrel