Primer Cratering

[deertroy1]

I'm shooting handloads. I size to give about .001" - .002" clearance.


Beating a dead horse again BUT, ever consider the brass (on factory ammo) being too short for the chamber? Not a head space problem it's an ammo problem.
When the trigger gets pulled, the case gets pushed forward in the chamber by the firing pin, primer goes POP, rounds goes off and case gets pushed back onto the firing pin. Primer tries to move back out of the pocket, gets pushed back into the pocket and craters.
New bolt head, new contoured firing pin and you've STILL got the same problem? Hmmm. Keep throwing $$$ at it.
Keep at it till you find the right ammo OR learn to roll your own.
Like Charlie says "I'd stop worrying about it and shoot more".:cool:

[deertroy1]

I would try what he is suggesting but the pics everyone posted on this no longer show.


Honestly, I think you need to pay attention to sharpshooter.
https://lh3.googleusercontent.com/NQFSpyU9_jBFPN0BUF5h6lvTSaMkIp-E1wFFS-2NHZOHEqv3QKNqYQHqYvzAHDJaMKamMw=s113

[deertroy1]

Not jamming bullet.


Are you sure you're not jamming the bullet?
I would try backing off and increasing jump. You say you're not loading hot so seating a bit deeper into the case shouldn't be problematic.

[tomme boy]

Could not just keep shooting mine. It was blanking primers. Sent it back to Savage and they replaced the bolthead and firing pin and spring. Typical Savage. Bolthead was dished and rough.

[deertroy1]

According to sharpshooter the problem is too big of radius. If I take the pint off wouldn't that increase the radius more. Does someone have a drawing explaining this more?


Two things:
1. The link in post 10 tells all we need to know about setting FP protrusion.
2. You don’t have to “grind” the FP tip, You can simply take the point off it by rounding it on a sharpening stone, or emery cloth.
Best of Luck

[olddav]

Large radius will leave sharp edges. A smaller radius will blend into the shaft of the pin (I Think).

[deertroy1]

I'll try and make a sketch.

[deertroy1]

Is this what you mean:


https://i.imgur.com/fI8GxqHl.jpg

[deertroy1]

So I made my firing pin look more like the photo on the right and it helped a lot with the cratering but didn't stop it entirely. I then made the firing pin a little more blunt but it failed to ignite the primers. I put it back more to what it is on the left and it fires okay but the cratering returned?
I also get really erratic velocities with this rifle (ES of 50 - 100fps is not uncommon). I've tried about everything I can think of but nothing works.
I then reviewed a diagram of the bolt assembly and noticed I had forgot to install a small ring between the firing pin spring and the bolt retainer spring. The spring has been missing for over a year but luckily I found it under my reloading bench and reinstalled it. I haven't had chance to shoot it since.
My question is: do you think the elimination of this little ring could be why my ES is so high?

[Stumpkiller]

On the radius of an ogive the larger the radius the pointier the tip.

https://www.tmtpages.com/draw/HelpfilesBas-5/nosedetail%201.png

[deertroy1]

I thought what you pictured is what I'm after. I'm sure a machinist/gunsmith could pull that off. Too bad I'm a carpenter! LOL!

[Dave Hoback]

Honestly, I think you need to pay attention to sharpshooter.
https://lh3.googleusercontent.com/NQFSpyU9_jBFPN0BUF5h6lvTSaMkIp-E1wFFS-2NHZOHEqv3QKNqYQHqYvzAHDJaMKamMw=s113

I agree. Bushing is the best way. I don’t bush though. I use a PTG bolt head, and I put a narrowing bevel on the the last .035” of pin(protrusion), giving a smaller diameter to the tip. My primers look perfect.

[deertroy1]

I agree. Bushing is the best way. I don’t bush though. I use a PTG bolt head, and I put a narrowing bevel on the the last .035” of pin(protrusion), giving a smaller diameter to the tip. My primers look perfect.

I put a PTG bolt head on. It made no difference!

[olddav]

Did you check the headspace after installing the new bolt head?
Did you check the firing pin protrusion after installing the new bolt head?

[deertroy1]

Did you check the headspace after installing the new bolt head?
Did you check the firing pin protrusion after installing the new bolt head?

Yes. The bolt head was installed prior to installing the new barrel. Firing pin protrusion is 0.053"

[tobnpr]

I also get really erratic velocities with this rifle (ES of 50 - 100fps is not uncommon). I've tried about everything I can think of but nothing works.
I then reviewed a diagram of the bolt assembly and noticed I had forgot to install a small ring between the firing pin spring and the bolt retainer spring. The spring has been missing for over a year but luckily I found it under my reloading bench and reinstalled it. I haven't had chance to shoot it since.
My question is: do you think the elimination of this little ring could be why my ES is so high?

High ES/SD was not reported in any of your prior posts, this is new information.
Usually, but not exclusively, high ES may be due to inconsistent ignition. You say you've "tried everything". I'm not familiar at all with the 6 Remington...but, did you change primers? Powders? What's your % of case fill? I think more info on current load data, and what you've tried prior, would be relevant in seeking a solution.

[Dave Hoback]

I put a PTG bolt head on. It made no difference!

I’m sorry deertroy, I didn’t mean to insinuate the bolt head “helped” anything. Was just stating what my setup is. The firing pin diameter IS the problem.

[deertroy1]

I’m sorry deertroy, I didn’t mean to insinuate the bolt head “helped” anything. Was just stating what my setup is. The firing pin diameter IS the problem.

I only read your post as you trying to help Dave. Unfortunately, these post don't always reflect gratitude. Thanks.

[mnbogboy2]

All good posts here. When these options are tested and tried we often dig deeper to the less obvious problems.
One may be trigger function/settings. Another may be operation of the bolt/firing pin itself.

Is the trigger aftermarket? The overtravel screw even on a Savage factory screw set too tight can cause the sear to "rub" on the trigger giving variable primer strikes. Pin protrusion can be inconsistent possibly the cause of other issues like ES.

Same problems can happen with bolt/firing pin if dirty, rough, rusty, gunky or worn cocking pin problems exist.

Other "long shot" problems may be sear interfering with stock pillar.
Little things are often the hardest to spot. Just the trigger touching the trigger guard can cause issues.

My .02,
Randy

[deertroy1]

All good posts here. When these options are tested and tried we often dig deeper to the less obvious problems.
One may be trigger function/settings. Another may be operation of the bolt/firing pin itself.

Is the trigger aftermarket? The overtravel screw even on a Savage factory screw set too tight can cause the sear to "rub" on the trigger giving variable primer strikes. Pin protrusion can be inconsistent possibly the cause of other issues like ES.

Same problems can happen with bolt/firing pin if dirty, rough, rusty, gunky or worn cocking pin problems exist.

Other "long shot" problems may be sear interfering with stock pillar.
Little things are often the hardest to spot. Just the trigger touching the trigger guard can cause issues.

My .02,
Randy

I converted a non accutrigger model to accutrigger. I guess there could be something askew. Can you give more information about the over travel screw?