Firing pin, springs, FTF.

[sharpshooter]

Ok......I'll say it for the last time. While everyone has been side tracked by the mysterious shrinking case phenomenon, you have failed to address the lack of impact energy problem. Yes, it is there, that is the reason your problem is intermittent. The impact energy provided by that particular set up is "riding the fence" so to speak in terms of energy. When you get pierced primers from starting loads, or cratered primers, it is a sign of insufficient spring pressure on the firing pin in the fired position. With a lack of spring tension on the pin, there is less support in the "dimple " you just created, and subsequently when the charge detonates and creates 60K psi, it pushes the dimple back, either leaving a crater, or blanking it completely.

The reason you have FTF is because you still have a lacking on the front end. It can be caused by a few things, such as lack of travel or lack of spring energy. Lack of travel is the culprit 98% of the time. Lack of travel can be caused by: pin assembly out of adjustment,or (no adjust ability in your case ) decocking...in most cases about .040", too much protrusion, and trigger timing.
The biggest down fall of the one pc. FP assembly is there is no adjustment. The other problem is the spring is bare minimum. That is why I suggested a old style multi piece firing pin assembly.

I have studied ignition for over 20 years, and I have done lots of R&D and conducted scientific experiments on several other rifles besides Savage models. In those studies, I have developed a formula that will insure optimum ignition. It's very simple calculation of force X travel. You need a minimum factor of 4.0 and max of 5.8. Just from records and notes, the average specs for your model will put you in the 3.5 range......you don't have enough!

[Dave Hoback]

Ok......I'll say it for the last time. While everyone has been side tracked by the mysterious shrinking case phenomenon, you have failed to address the lack of impact energy problem. Yes, it is there, that is the reason your problem is intermittent. The impact energy provided by that particular set up is "riding the fence" so to speak in terms of energy. When you get pierced primers from starting loads, or cratered primers, it is a sign of insufficient spring pressure on the firing pin in the fired position. With a lack of spring tension on the pin, there is less support in the "dimple " you just created, and subsequently when the charge detonates and creates 60K psi, it pushes the dimple back, either leaving a crater, or blanking it completely.

The reason you have FTF is because you still have a lacking on the front end. It can be caused by a few things, such as lack of travel or lack of spring energy. Lack of travel is the culprit 98% of the time. Lack of travel can be caused by: pin assembly out of adjustment,or (no adjust ability in your case ) decocking...in most cases about .040", too much protrusion, and trigger timing.
The biggest down fall of the one pc. FP assembly is there is no adjustment. The other problem is the spring is bare minimum. That is why I suggested a old style multi piece firing pin assembly.

I have studied ignition for over 20 years, and I have done lots of R&D and conducted scientific experiments on several other rifles besides Savage models. In those studies, I have developed a formula that will insure optimum ignition. It's very simple calculation of force X travel. You need a minimum factor of 4.0 and max of 5.8. Just from records and notes, the average specs for your model will put you in the 3.5 range......you don't have enough!

Why do you think I stopped replying? You’re not the only one.

[KMW1954]

Ok......I'll say it for the last time. While everyone has been side tracked by the mysterious shrinking case phenomenon, you have failed to address the lack of impact energy problem. Yes, it is there, that is the reason your problem is intermittent.

1st I do not dispute what you are saying, as a matter of fact that is exactly why I brought this here to this forum and asked the question to begin with. Because I was looking for answers to the pin/spring question because I do not have the experience to diagnose or even identify it. As I also stated at the beginning that I believed it to be a cause of the issue. I kind of wish you would have explained this exactly this way from the beginning. Might have saved my hard head some long headaches.

I will also admit that yes I too was distracted by this brass and wondered if that could be causing a headspace issue and contributing to the problem. Again, like everyone else I have never seen this happen before and could not understand how this could be happening. I also will admit that I did not want to install those new parts being uncertain it would work.

I do appreciate you taking the time and breaking down this explanation, Not that I fully understand it but it does make sense now.

Unfortunately I am out of time and cannot obtain all the parts to convert this to the old style pin assembly. We start shooting league one week from Sunday. Though I will replace these springs with what I now have.

[South Prairie jim]

1st I do not dispute what you are saying, as a matter of fact that is exactly why I brought this here to this forum and asked the question to begin with. Because I was looking for answers to the pin/spring question because I do not have the experience to diagnose or even identify it. As I also stated at the beginning that I believed it to be a cause of the issue. I kind of wish you would have explained this exactly this way from the beginning. Might have saved my hard head some long headaches.

I will also admit that yes I too was distracted by this brass and wondered if that could be causing a headspace issue and contributing to the problem. Again, like everyone else I have never seen this happen before and could not understand how this could be happening. I also will admit that I did not want to install those new parts being uncertain it would work.

I do appreciate you taking the time and breaking down this explanation, Not that I fully understand it but it does make sense now.

Unfortunately I am out of time and cannot obtain all the parts to convert this to the old style pin assembly. We start shooting league one week from Sunday. Though I will replace these springs with what I now have.
You should make time, weak ignition causes accuracy issues. I believe Shapeshooter is correct.

[KMW1954]

Was able to make it to the range today. Shot a number of different loads at 100 yards hoping to fine one that will work for the first weeks league shot. Think I found one.
Also shot a total of 70 rounds with not one single failure.

10249

60gr VMAX with TAC, seated to 1.885" BTO with Remington 71/2 primers. 5 shots ea. round robin

10250

60gr VMAX with Benchmark, seated to 1.885" BTO and Remington primers. 5 shots ea. round robin
Center row black are 2 ea. of this same setup that were loaded with A2460. The two black within the red circle are 10 rounds of cheap 62gr Hornady HPBT that I was getting from MidSouth but haven't seen any for 2 years.

Thanks all!

[charlie b]

Congratulations. Glad it is starting to come together.

[Nor Cal Mikie]

"Broken record" on my part BUT, IMHO, .005 to .007 shoulder bump is too much. Case gets pushed forward in the chamber by the firing pin and you get FTF!! Nuf said from me. ;)
Happy New Year.

[South Prairie jim]

Was able to make it to the range today. Shot a number of different loads at 100 yards hoping to fine one that will work for the first weeks league shot. Think I found one.
Also shot a total of 70 rounds with not one single failure.

10249

60gr VMAX with TAC, seated to 1.885" BTO with Remington 71/2 primers. 5 shots ea. round robin

10250

60gr VMAX with Benchmark, seated to 1.885" BTO and Remington primers. 5 shots ea. round robin
Center row black are 2 ea. of this same setup that were loaded with A2460. The two black within the red circle are 10 rounds of cheap 62gr Hornady HPBT that I was getting from MidSouth but haven't seen any for 2 years.

Thanks all!

The rifle seems to exhibit 20% fliers, is this fairly common for your set up or something new ?

[KMW1954]

I believe a small amount is the rifle but most I admit falls back on me. In actuality switching to this 60gr bullet has made a measurable improvement over the 69gr bullets I was shooting last year. Plus some of what we see is me and rust. I have really not had the opportunity to shoot nearly as much this year as the past couple years. As it is now I am only able to shoot one day per week because the range has changed to winter schedule and when I am there working I've been having to work the 25yd pistol range. Last year I was shooting probably 3 days each week.

[sharpshooter]

The fliers are a sign of inconsistent ignition.

[South Prairie jim]

The fliers are a sign of inconsistent ignition.

Thats what I’ve experienced as well.

[South Prairie jim]

I believe a small amount is the rifle but most I admit falls back on me. In actuality switching to this 60gr bullet has made a measurable improvement over the 69gr bullets I was shooting last year. Plus some of what we see is me and rust. I have really not had the opportunity to shoot nearly as much this year as the past couple years. As it is now I am only able to shoot one day per week because the range has changed to winter schedule and when I am there working I've been having to work the 25yd pistol range. Last year I was shooting probably 3 days each week.
Do you set up wind flags when your tuning a load ? These are really important when evaluating targets.

[shoots100]

Also shot a total of 70 rounds with not one single failure.
Thanks all!
Great news, Have fun at the match and Happy New Year

SJC

[KMW1954]

Great news, Have fun at the match and Happy New Year

SJC

League starts week from today. Only have one more day to practice and get load dope. :behindsofa:

Safe and Merry New/Next Year to All!

[Robinhood]

Ok......I'll say it for the last time. While everyone has been side tracked by the mysterious shrinking case phenomenon, you have failed to address the lack of impact energy problem. Yes, it is there, that is the reason your problem is intermittent. The impact energy provided by that particular set up is "riding the fence" so to speak in terms of energy. When you get pierced primers from starting loads, or cratered primers, it is a sign of insufficient spring pressure on the firing pin in the fired position. With a lack of spring tension on the pin, there is less support in the "dimple " you just created, and subsequently when the charge detonates and creates 60K psi, it pushes the dimple back, either leaving a crater, or blanking it completely.

The reason you have FTF is because you still have a lacking on the front end. It can be caused by a few things, such as lack of travel or lack of spring energy. Lack of travel is the culprit 98% of the time. Lack of travel can be caused by: pin assembly out of adjustment,or (no adjust ability in your case ) decocking...in most cases about .040", too much protrusion, and trigger timing.
The biggest down fall of the one pc. FP assembly is there is no adjustment. The other problem is the spring is bare minimum. That is why I suggested a old style multi piece firing pin assembly.

I have studied ignition for over 20 years, and I have done lots of R&D and conducted scientific experiments on several other rifles besides Savage models. In those studies, I have developed a formula that will insure optimum ignition. It's very simple calculation of force X travel. You need a minimum factor of 4.0 and max of 5.8. Just from records and notes, the average specs for your model will put you in the 3.5 range......you don't have enough!

Fred or Dave question

Outside of ensuring smooth motion, insuring maximum or optimum firing pin travel and measuring spring force, how does one know if their setup falls between the factor of 4.0 and 5.8 that is prescribed. If that info is proprietary, I get it. For many of us trying to put conservation of momentum or coefficient of restitution(or whatever theory was used) to the topic, tweaks my/our minds.

[sharpshooter]

Well, it's pretty simple, but most people don't have the tools or measuring equipment to get the numbers.

Firing pin travel to the boltface, which is total travel, minus firing pin protrusion. (for example) .285" total travel......minus .035" protrusion, = .250"
Net spring force, which is force at full cock, minus sear drag. (for example) cocked 23.5 lb....minus sear drag of 4.2 lbs = 19.3
.250 x 19.3 = 4.825

[Rocketvapor]

Ditto on the Fred or Dave question :)
EDIT:
Thanks for the explanation Fred.
Plan on a range trip Thursday to test the wife's Christmas present.
Will take spare parts and tools, just in case.
I have a few new style pins, and pin protrusion is a whopping 0.060"
Two old style pins, one from an E-Bay bolt, don't know if it was adjusted or not and one just received from Gun Shack,
and both of those are set at 0.060".
Checked with a few different bolt heads, 223, 6.8, and 243.
0.060" plus or minus a thou or so for all.
I polished one of the NEW style to 0.047" protrusion and stopped there.
With the combination of the 3 piece thrust bearing and an external washer spring tension is increased by whatever 0.013" does.
10262
I will adjust protrusion on one of the OLD style to about the same, and not mess with spring length (1.900") for now.
Really seems 0.060" is the norm from Savage.
If you don't bother to check, you might let this go unnoticed, I did.
0.060" looks ridiculous.
10263
Guess I should have measured Decocking before putting the barrel on.
Can it be measured with pin in the bolt and in the receiver?
Trying to see blind and watching the Decocking lever (upper) for some difference in position as the pin transitions from the notch to held by the sear doesn't seem right. Maybe try and feel for the transfer to the sear?

[KMW1954]

You adamantly a couple times stated "one last time" which was not just dismissed by me, the one with the question, looking for an answer. Your first response was a short one sentence cause and effect back in post #12 w/o any real explanation. Yet the very last sentence in my very first post was that I had already purchased a new pin and springs which should have indicated that I already suspected this as a cause and agreed with you even though I did not understand the reason why at the time.. Once again exactly why I came to this forum asking guidance.

At the same I had also previously seen the picture posted in #8 and had conversations with Dave about firing pins long before this. Which I where I learned of the known problem with Savage bolt heads and firing pin holes being sloppy and why many have them bushed. To help eliminate the cratering around the pin dimple.

Post #17 I asked the question once again looking for clarity. Maybe I posed the question the wrong way. As here we are now at post #76 and not a single member can explain why these cases have behaved the way they did. Still not one here can believe that I say I measured these cases before firing and after failing to fire and that they have all gotten shorter after failing. Most are saying or implying these cases were too short to begin with when I know for a fact they were not. But once again that seems to be a complete separate issue and not related to the FTF issue. But still at this point I was questioning the firing pin and springs.

So then in post #47 I directly asked you to explain your response which you directly responded to in past #61 to which I directly responded to in post #63 and Graciously thanked you for the lengthy explanation. Also tried to express that at this time I have to make due as I do not have the time to order and wait for new parts as they would never arrive before we start out league. Then completely flabbergasted by the response in post #64 which implied I completely dismissed your advice. Thanks Jim!

Anyways I am able to proceed the way it is and get started with the league. I was able to find a load that this bullet seems to like and is shooting much tighter than the 69gr SMK I shot last year. This week I will be ordering new pin parts.

Lastly to your post at #70. Fliers are also a sign of an inconsistent shooter. Me! And I admit that fact. I have a lot of inconsistencies I'm working on! :redface-new:

[Rocketvapor]

This has digressed into a general discussion on pins with most not liking the new style.
Not just about you but general useful info.
Maybe not the correct thread for this.
Set one of the old pins for 0.045".
10264
One more quarter turn would be (-0.00893") or about 0.036".
That too short?

[charlie b]

Well, it's pretty simple, but most people don't have the tools or measuring equipment to get the numbers.

Firing pin travel to the boltface, which is total travel, minus firing pin protrusion. (for example) .285" total travel......minus .035" protrusion, = .250"
Net spring force, which is force at full cock, minus sear drag. (for example) cocked 23.5 lb....minus sear drag of 4.2 lbs = 19.3
.250 x 19.3 = 4.825

How would you measure sear drag? I can figure how to measure spring forces and rates.

Wouldn't it be easier to rig a test that measures FP force and impact (energy and impulse)?