Firing pin, springs, FTF.

[KMW1954]

I’ve never had a problem with Hornday brass and I have my doubts that is the sole issue. Meticulously processed brass shouldn’t have issues if meticulously processed, it’s just a case with a seated primer and powder, as long as the flash hole is clear with a solid strike it will go bang every time. I’ve also never entered a season with a fully developed load, I’ve been close and know my nodes but still tinker from match to match.

1. This is my very first experience using Hornady brass so I have nothing to base a judgement on. Though I have read many mixed reviews.
2. No Meticulously processed brass should not behave such as this. Yet it did and the pcs. that did not fire all looked like light strikes. So here I have to agree. More going on than just the brass.
3. After fire forming and processing to start load development I never got through a complete session of testing because of the FTF issues. So would not try to draw any conclusions from these failed test firings.

[South Prairie jim]

1. This is my very first experience using Hornady brass so I have nothing to base a judgement on. Though I have read many mixed reviews.
2. No Meticulously processed brass should not behave such as this. Yet it did and the pcs. that did not fire all looked like light strikes. So here I have to agree. More going on than just the brass.
3. After fire forming and processing to start load development I never got through a complete session of testing because of the FTF issues. So would not try to draw any conclusions from these failed test firings.

Are you fire forming cases using a light powder charge or the full recipe ?

[KMW1954]

Are you fire forming cases using a light powder charge or the full recipe ?

Full charge of TAC with cheap FMJ bullets. When I state a full charge I am refering to the charge that would normally be used in the reload. Also aware it normally take two firing to get really good formed brass. Also before I start I measure every piece with the comparator and any and all cases that are shorter than target length get culled out. That is done just to shorten the process. But honestly I have not really seen much change from once fired in this rifle to twice fired.

[South Prairie jim]

Full charge of TAC with cheap FMJ bullets. When I state a full charge I am refering to the charge that would normally be used in the reload. Also aware it normally take two firing to get really good formed brass. Also before I start I measure every piece with the comparator and any and all cases that are shorter than target length get culled out. That is done just to shorten the process. But honestly I have not really seen much change from once fired in this rifle to twice fired.

You probably won’t see much difference on the target, lots of guys just load straight out of the box.( I know nbrsa long range champion that does) And I somewhat disagree with the post regarding Hornday brass being of poor quality. Case capacity from manufacture can vary changing internal pressure, case rim thickness can vary changing primer seating depth by very small numbers ( maybe undetectable) as well as case neck thickness can differ from others causing big differences in bullet hold/ neck tension that are easily seen on paper. But just brand name poo poo is questionable.
Q: if Hornday brass is so bad then why does Hornday factory long range creedmoor ammunition shoot so wel ?
I don’t mean to be argumentative, i think we’re just talking around the campfire sharing thoughts.

[shoots100]

1. This is my very first experience using Hornady brass so I have nothing to base a judgement on. Though I have read many mixed reviews.
2. No Meticulously processed brass should not behave such as this. Yet it did and the pcs. that did not fire all looked like light strikes. So here I have to agree. More going on than just the brass.
3. After fire forming and processing to start load development I never got through a complete session of testing because of the FTF issues. So would not try to draw any conclusions from these failed test firings.

So the issue stops when you change brass, You never had FTF issue's before using Hornady brass, your FTF issues stopped after switching brass, but the brass isn't the issue and there's more going on ?
Hornady brass sucks and it sucks even more when you reload it, as you found out, but aren't acknowledging that something so simple could be the reason for the FTF's.
How many in competition reload with Hornady brass ?
It's still a pig no matter how much lipstick you put on it.
Use quality brass that has been proven to work, especially for match use.
You won't be posting about FTF issues, you'll be posting about how boringly accurate and reliable your rifle is.


SJC

[KMW1954]

So the issue stops when you change brass, You never had FTF issue's before using Hornady brass, your FTF issues stopped after switching brass, but the brass isn't the issue and there's more going on ?SJC

Not sure why I am following this argument. Whereby my own conclusion the brass is an issue which is why it was put aside. Yet that does not explain the light strikes that are happening randomly. All I plainly stated is that there is more at fault than just this brass and no I do not believe it is the primers.

Yes this rifle has had primer issues in the past. When I first started loading for it I was using CCI400 primers until I started getting pierced primers with light beginning loads. Which I was informed here is a known issue because of the bolt head and primer pin. Switching to CCI450 eliminated that though I still see signs of cratering around the pin indent.

[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.



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



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!

[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

[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!

[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)?

[Robinhood]

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

Thanks Fred. Is the drag number an absolute or it just a constant that worked well in your calcs.

I appreciate all that I have learned from you over time.

"I actually regret getting involved in the first place. I’ll know better next time and just keep my big mouth shut."

I hate it when i feel like that.

[Rocketvapor]

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

I really hate posting here again, but could someone interpret my measurements on one of the dreaded New style bolt/pins?
Pressing on the bathroom scale with the cocking indicator touching my thumb in the BAS hole I get 23.5 lbs on the short spring, 32 pounds on the midlength spring, and forget it with the big spring, over 40 lbs.

Here's the "INPUT DATA" for the small, weak, worn out spring installed in an assembled bolt.
Force required to lift off cocking notch 24.5 pounds.
Force require to lift off Bolt Head @ full fall, 10.5 lbs.
Using this and a 200 pound industrial scale.


Pin measurements (from cocking indicator)
Cocking notch, 0.005" to indicator,
Cocked and on sear 0.028",
Fired 0.288".
Protrusion is 0.044-0.045"

I think there was a formula posted in one of these threads.
Found it.
Sounds like I will lose about 0.020" in pin fall (at full impact of primer) from a 0.045" protrusion, and about 4 pounds due to sear/cocking pin friction/drag.

So far, this rifle has had ZERO Misfires :)
(out of ZERO shots)

[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.

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.

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?