Keyholing suddenly! Ahhh! 17Rem...

Originally Posted By: DiRTY DOG Then I loaded fresh rounds using my RCBS Chargemaster. Same exact recipe as what worked before.



You happen to confirm what your Chargemaster says with another scale (a known accurate one/beam scale)?
 
THE EXPERT HAS SPOKEN




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Originally Posted By: RePeteOriginally Posted By: EJ ReichenbachIt's easy, your primers are fine there's no magic CARBON that's going to make your bullet keyhole.

Didn't say chit about "magic carbon". I was thinking more along the lines of neck tension like Dan suggested, especially since he's annealing every load. Course an expert like yourself already knows that over annealing can have the opposite effect of proper annealing. ie; cracked necks and brass not expanding enough to seal the chamber.
So that leads us back to starting with a bore scope which everyone else already suggested before you graced us with your sage wisdom.


In retrospect,,,, I knew better than to reply here.
You'd think I'd learn.
Wasn't pin pointing, I apologize if I have offended you.
 
Just looking at your cases, the primers look fine, I would say your at about maximum. When you look at the other end, it appears that your cases may be too long, or your chamber has some buildup in the area of the mouth of the case. They look like they have been crimped.

Other than that, I see nothing. Have you done any measuring of bullets or cases? That's what I would be looking at.

The split shoulder on the one case was probably just a bad case.
 
Originally Posted By: RePete
EJ Reichenbach said:
It's easy, your primers are fine there's no magic CARBON that's going to make your bullet keyhole.

Didn't say chit about "magic carbon". I was thinking more along the lines of neck tension like Dan suggested, especially since he's annealing every load. Course an expert like yourself already knows that over annealing can have the opposite effect of proper annealing. ie; cracked necks and brass not expanding enough to seal the chamber.
So that leads us back to starting with a bore scope which everyone else already suggested before you graced us with your sage wisdom.


In retrospect,,,, I knew better than to reply here.
You'd think I'd learn.


Over annealing hmmm.
Click to expand...
 
I don't know about neck tension, how could that suddenly change without me even taking the die off my press? Standard RCBS FL die set. Bullets seat fine, feels "normal" pressure when seating bullets.
 
If your cases are too long, you could be pinching the bullet. A hard carbon ring at the front of the chamber. These are hard to remove. Normal cleaning won't get these.
 
I will double check the case length but I trimmed a few thousandths off after the first firing. They were trimmed to the trim-to length... I did not change the cutting depth between the initial trim and the most recent trim, but I did measure to make sure it was still cutting correctly.
 
Have you re-verified the scale against another to make sure it is dispensing properly?

I also think you are doing too much case prep. Annealing every time could certainly have adverse affects on your brass. Maybe making your brrass too soft and allowing it to not seal in the chamber, correctly. Also, bumping back the shoulder on a fireformed case is silly. That is counter productive to accurate loads, IME.
 
I have not verified my scale, but even moderate fluctuations would not cause keyholing, right?

I was under the impression lots of benchrest shooters anneal after every firing. My brass might be too soft?
 
Originally Posted By: DiRTY DOG
photo17_zps4d8c9d55.jpg



Brass/primers
July182013088b_zps90792631.jpg


Case mouths, 2x fired brass, annealed every reload.
July182013089b_zps7b929653.jpg


From the above pics.
1. I personally don't buy into the bedding of the first inch of barrel theory. The only barrels that can actually be called free floated are those with nothing touching them anywhere including the first inch infront of the lug. I would remove the bedding infront of the lug so nothing at all was touching the barrel itself. You would be amazed at the difference it can make. I have a Cooper Pheonix in 6mm i purchased used. I wouldnt shoot at all, it showed some promise but no consistency what so ever. I took it to a wise old gun smith who told me to put it in his mill and remove Coopers bedding infront of the lug and go shoot it again. I did and with that being the only change I made, that rifle shot 5 different test loads using two different bullets under 3/4 MOA the very next trip to the range. It will shoot about anything I feed it now. It won't do much for your keyhole problem but I bet your consistency and over all accuracy improves.

Also,
The gap between the barrel and stock looks nice but did you create it with bedding the action up or did you open the channel in the stock by sanding? My only CZ doesn't have clearance like that and I don't recall seeing one with quite as much without extra work, IDK...

2. Anyone else notice the line above the web of the brass? It's common but yours looks a bit extreme. Looks like your about to separate cases. Could be over sizing.

3. Case mouth looks rolled in. Are you attempting to crimp? I would back off the seater die and remove any and all crimp created by it, you shouldn't need it. That little bit could deform the already small and delicate bullet causing problems.

Stop annealing after every firing, it's unnecessary. I would also clean that rifle until the patches came out as clean as they go in. Pay special attention to the chamber end and the first few inches of barrel.

I'd like to see a spotless bore, no bedding infront of the lug and pictures of a target and brass from a box of factory ammo fired thru the rifle, no reloads of any kind.
 
1. Yes I removed the bedding under the barrel soon after I took that pic. The barrel is completely free floated now. I free floated using Devcon only, I simply wrapped some electrical tape around the barrel before laying the action in the bedding compound. Perhaps a little too much, oh well. Did zero stock sanding to achieve that.

2. Maybe that's just exadurated by the macro lense and the reflection?

3. I'm not attempting to crimp. Without moving the die from tbe press , I simply adjusted the seating stem depth up/down to accomidate first the 25gr bullets, then 20gr, then back to 25gr. And that's when my problem started. You may be on to something there, I had not considered it might be crimping the mouth... Would that cause tumbling bullets?? Hmmm...

4. Factory ammo is $49.99 plus shipping for 20 rounds. I will never buy factory 17Rem ammo.
 
Couple of points.
Yeah there is a noticeable pressure ring on the fired cases especially the one on the left that appears to have been high pressure as evidenced by the flattened and cratered primer.
The fired brass appears to have a taper at the mouth-will a bullet slip freely into the neck of a fired case? If it won't then the cases are too long and need trimming. Overly long cases increase pressure because the neck doesn't have room to expand and release the bullet normally. But I don't see how high pressure could cause keyholes.
How far will a bullet in a loaded cartridge or dummy cartridge enter the muzzle before it is engaged by the bore/rifling? If it goes in really deep the bore is probably oversize.
I also don't see how 'over annealing' could be an issue unless the neck is so soft that it collapses when seating a bullet. Don't see how soft brass in the neck area could cause keyholes either.
Since the bullets are striking the target in a near 'group' they are destabilizing not too far in front of the target.
It seems your cleaning protocol is more than adequate to me.
So destabilizing= oversize bore/barrel, improper(too small) diameter bullets, too slow a twist for bullet length, or velocity is too slow. Of all the possibilities I think an out of spec barrel is the most likely. I think this rifle will need to be rebarreled. Question is whether or not CZ will step up- I like and own several of their rifles but have never had to use their customer service.

[beeep] just had another thought-could CZ have used a .204 barrel on that rifle inadvertently? Would the bullets bump up and be marginally stabilized?
 
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Those jackets are very thin on 17 cal bullets so any deformation could lead to problems. In your target pics, is that gray splatter around the 4 o'clock bullet hole like your first top picture?

I know factory ammo is expensive but it's the process of elimination to determine if it's the ammo your building or the rifle. You would know pretty fast what the problem is if the factory ammo put 10 rounds into an inch... Or the factory ammo was shotgunnin like your reloads... If it were mine, It would be worth the 50 bucks just for interest sake.

Leads me to another question. Have you ever shot factory ammo thru it for an accuracy base line?
 
Bedding, neck tension, nor excessive pressure is going to cause tumbling.

Not getting enough twist or another type of disturbance (to the bullet) must be the cause.

I still say if those groups posted (with the multicolored dots) were at 100yards... The tumbling had to start late flight. A tumbling bullet will not stay on path & no way it would shoot near moa @ 100yards.

Go back out today & try again
 
Originally Posted By: DiRTY DOGIs it possible my barrel is so fouled with copper after only 20-30 shots of 20gr V-max that it caused this horrible accuracy followed by keyholes at 40-50 rounds?

Remember, I cleaned the bore "super good" with Wipe Out 2x plus 2x with SC immediately before this problem started.

Is the dreaded myth true about 17Rem's requiring cleaning every 15-20 rounds?!

I do have Sweet's 7.62, it's what I have always used in the past until I recently picked up this can of foaming Wipe Out I keep hearing about. I do a fairly good job of cleaning my bores correctly with Sweet's and SC, using a single piece coated rod and 20+ patches, and never letting the two chemicals mix etc. I do it "by the book" best I can.

Is my problem simply caused by massive copper buildup?! I can super clean the bore using Sweet's but I won 't make it back to the range for a couple days.

YES!!

I had a similar thing happen to me a few months ago.

.224" bore, 14" twist, 3,500 fps benchrest rifle - I was testing for max loads. Groups were in the mid 1's to mid 3's.

I also had a bunch of new cases that needed to be fire-formed. They were loaded with 55gr softpoints that I use for just this purpose. So I was shooting at little things on the ground near the targets and started missing them - I went back to the targets and shot a few groups = 6" and half the bullets were sideways.

Now, no one will believe that a 55gr softpoint will keyhole from a 14" twist, but these were. It was because the barrel was plain filthy, and fouled badly.

When I clean barrels that are this dirty, I plug the chamber, stand the rifle on it's butt, and fill the bore with a good cleaner like Hoppe's #9 and let it sit and soak for a day or two.

Rifle shot fine at the next outing.

 
Originally Posted By: coleridgeBedding, neck tension, nor excessive pressure is going to cause tumbling.

Not getting enough twist or another type of disturbance (to the bullet) must be the cause.

I still say if those groups posted (with the multicolored dots) were at 100yards... The tumbling had to start late flight. A tumbling bullet will not stay on path & no way it would shoot near moa @ 100yards.

Go back out today & try again

Yep.



Travis
 
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