Primer Cratering

[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:

[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.

[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.

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?

[mnbogboy2]

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?

I don't believe any of the accutrigger models have an overtravel screw. A good check for sear interference with the trigger is to hold the trigger down and operate the bolt release through its full stroke. It should not "rub" the trigger behind the trigger sear. If it does something is preventing the trigger from moving back far enough. This is common where overtravel screws are used as in aftermarket triggers & the old three screw triggers.

[deertroy1]

I don't believe any of the accutrigger models have an overtravel screw. A good check for sear interference with the trigger is to hold the trigger down and operate the bolt release through its full stroke. It should not "rub" the trigger behind the trigger sear. If it does something is preventing the trigger from moving back far enough. This is common where overtravel screws are used as in aftermarket triggers & the old three screw triggers.

Thanks. I'll check.

[s3silver]

I'd stop worrying about it and shoot more :)

My Axis in .223 has cratered primers since the first day I got it. Well over 2000 rounds now and it still does it. Not any worse than when new. No ill effects on rifle or brass. Still shoots better than I do :)

Most of my Savage rifles crater primers even with lower charges or with factory ammo.. At first I was concerned too but started to pay close attention to the “normal” crater look to see if it started changing indicating pressures are increasing. As pressure increases the crater will start to look different. So far so good.

[sharpshooter]

I had to hunt, but I found the picture.

[s3silver]

I had to hunt, but I found the picture.

Haven’t tried it but is there enough meat on the Savage firing pin to grind down for a more blunt end and then readjust the pin protrusion?

[deertroy1]

I had to hunt, but I found the picture.

This is exactly what I ended up with but it ended up blanking primers. Thus part of the reason I want to convert it the multi-piece firing pin.

[Dave Hoback]

Haven’t tried it but is there enough meat on the Savage firing pin to grind down for a more blunt end and then readjust the pin protrusion?

Yes, even on the 1-piece pin. As protrusion starts at .055”+. Gives a go on the 1-piece. But the OP, already having done this, most likely is about out of room. And he said it was having ignition problems. The adjustable pin has room to accomplish this reshaping many, many times over!

I shape my pins along these lines, but slightly different. I reduce the diameter via bevel, but only .035” of the pin(the protruded length so the pin is still fully supported in the bolt head.) Then I the make the pin face surface flat(as the posted picture).

[deertroy1]

I did measure the pin diameter at 0.0678"