prairieboy
FNG
I went through this exact thing a number of years back with one of my t3s. I did figure it out. This is gonna be a long post
I bought 1000 pics of virgin lc brass(lc13 to be exact). I primarily use cci 450 primers and get generally excellent results from them. I prime with a hand tool and each primer is firmly and totally seated in the pocket, i don't care about measurements as long as there seated all the way to the bottom of the pocket.
The gun is a t3lite with 200 rounds through it at when I started with the lake city brass. I developed some loads and had the occasional failure to fire. They would go off on the second try usually or I'd put them in my mini 14 target where they would go off 100% of the time even after 2 misfires in the tikka. Miss fire on it too many times it would not. As the shoulder does moves.
I figured when the brass is fire formed this problem will go away. It didn't. It got worse. I eventually swapped bolts from one of my other tikkas and was back to the origional failure rate.
Then I went down the striker spring strength rabbit hole. I set up with a very accurate scale and measured all my bolt guns striker spring pressure in pounds. Remingtons, winchesters, Browning, tikka. I found that the tikkas were the lowest. My half dozen tikkas were all the same except this one 223 bolt was 2 pounds less than the rest. That included one that had seen at the time over 3000 rounds and was still fine. Bad batch of springs I assume.
Tikka sells the spring on an assembled firing pin assembly only.
I bought the kit(2 actually to make shipping worthwile) with a oem strength spring and a 10% plus power spring. Built jaws to take the spring off the bolt for the vise at work.
Tried all 4 springs and all were weaker than what a good oem should be. Keep in mind these are/were stainless steel springs. Emailed the dealer here in canada. They put me in contact with the manufacturer in Australia. Honestly didn't look like they tested things properly, they sent me new springs from Australia. Twice. All weaker than oem as per my testing. Never even shot them just on the scale.
Then he says we will give up trying to make a stainless spring, and will make music wire springs. He send me some of those. While disassembling the firing pin assembly for the 25th time the little collar that is part of the retension system seized half way off the pin while the vise was opening. We bent the pin trying to get it off. I think it was one of the after marked collars that came with the kit, and not the oem. It did go on and off a bunch of times before this, trying every spring they sent me(it was always at least half a dozen)
So I went ahead and bought a new firing pin assembly. I never got to try his music wire springs. This new assembly had the same spring strength on the scale as all my other tikka bolts.
So back to the brass and primers. Cci primers are among the harder ones to set off priming compound wise. 450s have a thick tough cup. Lake city brass is very thin in the neck shoulder area. Also very soft. Borderline over annealed. This combo just deadens the firing pin fall. It will litterly push the shoulder back a measurable amount with a few misfires.
I took a fired piece of remington brass and lake city and dryfired/misfired on each 10 times. The lake city comes out looking like 222 brass. The shoulder on other brass will move also but nowhere near as far.
The fix? A federal 205 primers. Never another issue in 100s of rounds. The thin soft brass in a firearm with lower end striker power needs an easier to set off primer simple as that.
The whole time this was going on I also shot a load with lapua brass through this gun. Thicker necks/shoulders. The same 450 primers. Never an issue even with the spring that was down 2 pounds in strength.
The issue is a combination of thin soft brass, hard to set of primers and a firearm with just enough striker strength to keep your bolt lift smooth.
I bought 1000 pics of virgin lc brass(lc13 to be exact). I primarily use cci 450 primers and get generally excellent results from them. I prime with a hand tool and each primer is firmly and totally seated in the pocket, i don't care about measurements as long as there seated all the way to the bottom of the pocket.
The gun is a t3lite with 200 rounds through it at when I started with the lake city brass. I developed some loads and had the occasional failure to fire. They would go off on the second try usually or I'd put them in my mini 14 target where they would go off 100% of the time even after 2 misfires in the tikka. Miss fire on it too many times it would not. As the shoulder does moves.
I figured when the brass is fire formed this problem will go away. It didn't. It got worse. I eventually swapped bolts from one of my other tikkas and was back to the origional failure rate.
Then I went down the striker spring strength rabbit hole. I set up with a very accurate scale and measured all my bolt guns striker spring pressure in pounds. Remingtons, winchesters, Browning, tikka. I found that the tikkas were the lowest. My half dozen tikkas were all the same except this one 223 bolt was 2 pounds less than the rest. That included one that had seen at the time over 3000 rounds and was still fine. Bad batch of springs I assume.
Tikka sells the spring on an assembled firing pin assembly only.
I bought the kit(2 actually to make shipping worthwile) with a oem strength spring and a 10% plus power spring. Built jaws to take the spring off the bolt for the vise at work.
Tried all 4 springs and all were weaker than what a good oem should be. Keep in mind these are/were stainless steel springs. Emailed the dealer here in canada. They put me in contact with the manufacturer in Australia. Honestly didn't look like they tested things properly, they sent me new springs from Australia. Twice. All weaker than oem as per my testing. Never even shot them just on the scale.
Then he says we will give up trying to make a stainless spring, and will make music wire springs. He send me some of those. While disassembling the firing pin assembly for the 25th time the little collar that is part of the retension system seized half way off the pin while the vise was opening. We bent the pin trying to get it off. I think it was one of the after marked collars that came with the kit, and not the oem. It did go on and off a bunch of times before this, trying every spring they sent me(it was always at least half a dozen)
So I went ahead and bought a new firing pin assembly. I never got to try his music wire springs. This new assembly had the same spring strength on the scale as all my other tikka bolts.
So back to the brass and primers. Cci primers are among the harder ones to set off priming compound wise. 450s have a thick tough cup. Lake city brass is very thin in the neck shoulder area. Also very soft. Borderline over annealed. This combo just deadens the firing pin fall. It will litterly push the shoulder back a measurable amount with a few misfires.
I took a fired piece of remington brass and lake city and dryfired/misfired on each 10 times. The lake city comes out looking like 222 brass. The shoulder on other brass will move also but nowhere near as far.
The fix? A federal 205 primers. Never another issue in 100s of rounds. The thin soft brass in a firearm with lower end striker power needs an easier to set off primer simple as that.
The whole time this was going on I also shot a load with lapua brass through this gun. Thicker necks/shoulders. The same 450 primers. Never an issue even with the spring that was down 2 pounds in strength.
The issue is a combination of thin soft brass, hard to set of primers and a firearm with just enough striker strength to keep your bolt lift smooth.
