I also have 1 tikka 223 that is firm to close on a go gauge. It has several hundred rounds of factory and reloads with no problems. Just pmc ammo was a little hard to close. I have 2 other tikka 223 and they dont have the short headspace.
Failure to Fire Tikka 223
- Thread starter rugger7622
- Start date
Interesting thread.. I've had the exact same problem.
Tikka T3x Varmint with LC brass and CCI 450 primers.
I've gone through the same process to trouble shoot that the OP has. I measure head to datum distance on a dozen pieces of brass, I know they're within 3 thou of the maximum that I can use in this rifle.
I mark that measurement on each case. Go to the range, come back with 2 that won't fire at all in this rifle. I re-check the head to datum measurement on those 2 cases when I get home, and it IS definitely shorter than when they were initially loaded..
I check firing pin protrusion, right at 55 thou from the bolt face. I take the bolt apart, clean it thoroughly, lube it with either G96 gun treatment spray or even with lighter fluid. No change. Firing pin spring is good, it's given me no problems with any other case and primer combination, or with 450's in any other case for that matter.
I use an RCBS hand primer, after removing the primer pocket crimp with a Lyman cutting tool, not swaging it, and then using a Lyman uniformer tool. The primers go in fairly easily, and they're definitely seated.
So, LC brass. Looking carefully at the cases, I can see that the shoulder is not well defined, does not come to a sharp corner where it transitions into the body of the case.
I anneal all my brass. The only thing I can think of is that the brass is slightly "domed" in the shoulder area, and the extra force required to ignite the harder 450 primer is pushing that "dome" backwards into a straight line before the primer ignites. If the brass wasn't annealed, it might not be a problem, either.
It's a bizarre situation. If you'd told me that the firing pin can dent the primer without setting it off, enough to push the shoulder back, I'd say you should seek professional help.
The other common factor is the Tikka. Maybe their firing pin springs are on the weak side of what they should be.
In any case, I saw the title of this thread, read it, and said, "Well, I'll be damned.. it's not just me!"
My solution was to not use the LC brass, I only had less than a hundred of them anyway.
Lapua, Federal, PMC, IVI, everything else works fine in this rifle. Just not LC. It's too bad, it's good quality brass. Certainly better than Federal or PMC.
Tikka T3x Varmint with LC brass and CCI 450 primers.
I've gone through the same process to trouble shoot that the OP has. I measure head to datum distance on a dozen pieces of brass, I know they're within 3 thou of the maximum that I can use in this rifle.
I mark that measurement on each case. Go to the range, come back with 2 that won't fire at all in this rifle. I re-check the head to datum measurement on those 2 cases when I get home, and it IS definitely shorter than when they were initially loaded..
I check firing pin protrusion, right at 55 thou from the bolt face. I take the bolt apart, clean it thoroughly, lube it with either G96 gun treatment spray or even with lighter fluid. No change. Firing pin spring is good, it's given me no problems with any other case and primer combination, or with 450's in any other case for that matter.
I use an RCBS hand primer, after removing the primer pocket crimp with a Lyman cutting tool, not swaging it, and then using a Lyman uniformer tool. The primers go in fairly easily, and they're definitely seated.
So, LC brass. Looking carefully at the cases, I can see that the shoulder is not well defined, does not come to a sharp corner where it transitions into the body of the case.
I anneal all my brass. The only thing I can think of is that the brass is slightly "domed" in the shoulder area, and the extra force required to ignite the harder 450 primer is pushing that "dome" backwards into a straight line before the primer ignites. If the brass wasn't annealed, it might not be a problem, either.
It's a bizarre situation. If you'd told me that the firing pin can dent the primer without setting it off, enough to push the shoulder back, I'd say you should seek professional help.
The other common factor is the Tikka. Maybe their firing pin springs are on the weak side of what they should be.
In any case, I saw the title of this thread, read it, and said, "Well, I'll be damned.. it's not just me!"
My solution was to not use the LC brass, I only had less than a hundred of them anyway.
Lapua, Federal, PMC, IVI, everything else works fine in this rifle. Just not LC. It's too bad, it's good quality brass. Certainly better than Federal or PMC.
rugger7622
Silver $$ Contributor
I don’t know, nor have I ever seen it and there are at least two more people on this thread that has seen it.
Buttstock-TX
Silver $$ Contributor
I have a Tikka T3X Superlight on the way now and hope to pick it up next week. I'm planning to use the large amount of LC brass that I have on hand to load for it. I'm glad this was posted in case I run into similar issues. I am also very happy to hear of the accuracy you are getting with 77's.
What you are seeing reminds me of when I had a batch of new undersized PRVI brass for a 9.3x62 chamber. Most rounds would fire with one primer strike, but about 3 in 10 did not. Most of the "did nots" eventually did with two or three strikes. I seem to recall I did have one of those 3rd strikes pierce upon firing though...
Once the brass was fired, all was well from then on.
What you are seeing reminds me of when I had a batch of new undersized PRVI brass for a 9.3x62 chamber. Most rounds would fire with one primer strike, but about 3 in 10 did not. Most of the "did nots" eventually did with two or three strikes. I seem to recall I did have one of those 3rd strikes pierce upon firing though...
Once the brass was fired, all was well from then on.
Do we know if the brass is over annealed? Smells like the brass is sized short and we might be moving the radius at the shoulder neck junction. It does feel like something is a little off. Starline doesn't typically size the same as other brass.
rugger7622
Silver $$ Contributor
Yes,
All my resized brass shoulders are within .005 of each other when loaded, checked by a whidden gauge as well as a comparator. On the whidden gauge my resized brass, all of it, is within .005 of Sammi 0. I load the brass, shoot the brass, I have 2 FTF, I recock, those two fire, when I get home I remeasure those two pieces and the shoulders now measure -.007. My other 28 pieces of fired brass measure essentially the same as when I started
I don't have that measurement. I've always tried twice to fire a FTF.
I don't have this measurement.
Only FTF cases, all other show essential no shoulder growth - even after 3 firings
Nosler Factory Unfired = 1.4595
Nosler Fired = 1.4560
LC Sized = 1.4590
LC Fired = 1.4580, 1.4590, 1.4590, 1.4580: Avg = 1.4585
LC FTF = 1.4555, 1.4510: Avg = 1.4533
Starline Sized = 1.4585, 1.4575, 1.4575: Avg = 1.4578
Starline Fired = 1.4595, 1.4600, 1.4585: Avg = 1.4593
Starline Unfired = I don't have any to measure, but I have 100 coming this week.
I can try that for my next outing. All my resized matches what's above.
I see this logic, but my LC brass is sized right at Saami zero and pretty close to my Nosler factory load. I did try Win SRP and had a couple failures as well. I have some Federal Match I could try.
This current 3 firings has not been sized, just neck sized.
I've got another 100 SL ordered as well as 100 pieces of Lapua
I did try Win SRP, but will load up 20 with Federal, for my next outing
I really appreciate your detailed response and suggestions.
Hmm.. we seem to have lost somebody?
No matter. One thing to consider is where your case shoulder datum gauge is touching the shoulder.
I started with a Hornady comparator set, and they supply a .330" insert for the 223.
If you read their general instructions for which insert to use, they say this:
Determining the proper bushing diameter: If you add the neck diameter and the shoulder diameter and divide that number by two, use the bushing closest to that number.
This should put you in the middle of the shoulder, ideally. The .330" bushing sits high on the shoulder, well above the middle.
After reading another thread on the forum a couple of years ago, and having the FTF problem with Lake City brass, I made a smaller insert, hole size is .306" in the new one. It sits very close to the center of the shoulder.
The measurement to the datum, while not exactly subjective, depends heavily on having the exact same size insert as anyone else you are sharing information with. Otherwise it's irrelevant. Same thing with measurements to the bullet ogive.
I don't know if the OP has made any measurements to determine the largest case to datum size that his rifle will accept?
For instance, in my Tikka the bolt is hard to close on any cases that exceed 1.491" from base to a .306" datum. Remember, that's not a standard .330" datum, but it IS in the middle of the shoulder on a 223 case.
I size my cases to be no shorter than 1.488" to that .306 shoulder datum. So, if you wanted to call that a bump, you could do that. But remember, all I'm doing when I full length size my brass is to squeeze the body and the neck to a standard dimension. The shoulder moves ahead as a result but it's restricted by the shoulder in the die, so it can't be any longer than 1.488".
It doesn't really get bumped at all, unless it's initially longer than that.
It's unlikely to be, since there's some spring back after firing, and my empty fired brass will always re-chamber fairly easily in the rifle.
People talk about "bumping the shoulder" 2 thou on fired cases.
In reality, what you want to get is 2 thou difference between your sized cases and ones that barely fit in the rifle.
My experience with the LC brass was that the shoulders weren't straight and well defined, but a bit rounded. Maybe a result of the chamber they were initially fired in, maybe they were like that when new.
Someone mentioned brass being over-annealed and a loose fit in the chamber. Mine ARE annealed each time, but I don't think they're too soft. If the whole shoulder is touching the chamber, I think they'd be fine.
Everything else I load works fine, I just had this problem with LC.
My point was that if that small rounded surface was all that was touching the front of the chamber, it wouldn't take nearly as much force to push it back as it would if the entire shoulder was bearing on the front of the chamber.
A hard primer and a reduced bearing surface might give you the right conditions for the shoulder to get pushed back as the firing pin hits the primer.
Something to talk about at the very least.
No matter. One thing to consider is where your case shoulder datum gauge is touching the shoulder.
I started with a Hornady comparator set, and they supply a .330" insert for the 223.
If you read their general instructions for which insert to use, they say this:
Determining the proper bushing diameter: If you add the neck diameter and the shoulder diameter and divide that number by two, use the bushing closest to that number.
This should put you in the middle of the shoulder, ideally. The .330" bushing sits high on the shoulder, well above the middle.
After reading another thread on the forum a couple of years ago, and having the FTF problem with Lake City brass, I made a smaller insert, hole size is .306" in the new one. It sits very close to the center of the shoulder.
The measurement to the datum, while not exactly subjective, depends heavily on having the exact same size insert as anyone else you are sharing information with. Otherwise it's irrelevant. Same thing with measurements to the bullet ogive.
I don't know if the OP has made any measurements to determine the largest case to datum size that his rifle will accept?
For instance, in my Tikka the bolt is hard to close on any cases that exceed 1.491" from base to a .306" datum. Remember, that's not a standard .330" datum, but it IS in the middle of the shoulder on a 223 case.
I size my cases to be no shorter than 1.488" to that .306 shoulder datum. So, if you wanted to call that a bump, you could do that. But remember, all I'm doing when I full length size my brass is to squeeze the body and the neck to a standard dimension. The shoulder moves ahead as a result but it's restricted by the shoulder in the die, so it can't be any longer than 1.488".
It doesn't really get bumped at all, unless it's initially longer than that.
It's unlikely to be, since there's some spring back after firing, and my empty fired brass will always re-chamber fairly easily in the rifle.
People talk about "bumping the shoulder" 2 thou on fired cases.
In reality, what you want to get is 2 thou difference between your sized cases and ones that barely fit in the rifle.
My experience with the LC brass was that the shoulders weren't straight and well defined, but a bit rounded. Maybe a result of the chamber they were initially fired in, maybe they were like that when new.
Someone mentioned brass being over-annealed and a loose fit in the chamber. Mine ARE annealed each time, but I don't think they're too soft. If the whole shoulder is touching the chamber, I think they'd be fine.
Everything else I load works fine, I just had this problem with LC.
My point was that if that small rounded surface was all that was touching the front of the chamber, it wouldn't take nearly as much force to push it back as it would if the entire shoulder was bearing on the front of the chamber.
A hard primer and a reduced bearing surface might give you the right conditions for the shoulder to get pushed back as the firing pin hits the primer.
Something to talk about at the very least.
dellet
Gold $$ Contributor
Please stop using SAAMI 0 and +/- SAAMI 0. These are not measurements and have no meaning.
If it takes “a lot of force” to close the bolt on a go gauge, it’s a problem and can damage the gauge and or chamber and is no help in diagnosing the problem.
Some things to check.
What is the base to shoulder measurement after chambering, without pulling the trigger?
The measurements of fired brass shows it shrinking as often as it’s growing. The only ways this happens is if the brass is longer than the chamber to begin with and is getting crushed, or it is a very low pressure load. Enough pressure to expand the case, but not stretch it.
The case head clearance if set up properly, with a minimum chamber and minimum cartridge would only be .004”. We already know your chamber is short because, to get it to close on a go gauge, it took “a lot of force”. This is confirmed by your fired brass numbers. They are still minimum cartridge or shorter.
You say the primers are seated with .006” crush, maybe you are maybe you aren’t.
If just the cup measures .113”, you might be ok. If you’re measuring the cup to the anvil, then they are under size.
Here’s where understanding crush come in. The anvil sticks up out of the primer cup, generally .0010”. If you seat the primer to when the anvil touches the primer pocket, when you feel touch, you need to seat the primer another .0010” just to fully seat the anvil in the cup. To get .006” crush, you need to go that much further. That’s a lot of crush, at least for me. So if your seating to where the anvil touches, where you fist feel touch, and then seat another .006”. The primer is not fully seated and will cause exactly what if happening.
As for why only on LC brass, best guess is that the bottom of the primer pocket is shaped different compounding the problem. Creating a different feel.
The other wild card is some people say you can have ignition problems by over crushing a primer. That seating the anvil against the cup is a problem. Never experienced that but it’s something to consider.
One last thought is that you checked primer protrusion. Did you check recess?
The firing pin is spring driven. You have basically set up your chamber and cartridge to “0” headspace. If the clearance between the firing pin and the primer is 0 or minimal, there is a chance it’s not building enough speed to set off the primer. If the primers in the none LC brass sit deeper, it may be your cause.
If it takes “a lot of force” to close the bolt on a go gauge, it’s a problem and can damage the gauge and or chamber and is no help in diagnosing the problem.
Some things to check.
What is the base to shoulder measurement after chambering, without pulling the trigger?
The measurements of fired brass shows it shrinking as often as it’s growing. The only ways this happens is if the brass is longer than the chamber to begin with and is getting crushed, or it is a very low pressure load. Enough pressure to expand the case, but not stretch it.
The case head clearance if set up properly, with a minimum chamber and minimum cartridge would only be .004”. We already know your chamber is short because, to get it to close on a go gauge, it took “a lot of force”. This is confirmed by your fired brass numbers. They are still minimum cartridge or shorter.
You say the primers are seated with .006” crush, maybe you are maybe you aren’t.
If just the cup measures .113”, you might be ok. If you’re measuring the cup to the anvil, then they are under size.
Here’s where understanding crush come in. The anvil sticks up out of the primer cup, generally .0010”. If you seat the primer to when the anvil touches the primer pocket, when you feel touch, you need to seat the primer another .0010” just to fully seat the anvil in the cup. To get .006” crush, you need to go that much further. That’s a lot of crush, at least for me. So if your seating to where the anvil touches, where you fist feel touch, and then seat another .006”. The primer is not fully seated and will cause exactly what if happening.
As for why only on LC brass, best guess is that the bottom of the primer pocket is shaped different compounding the problem. Creating a different feel.
The other wild card is some people say you can have ignition problems by over crushing a primer. That seating the anvil against the cup is a problem. Never experienced that but it’s something to consider.
One last thought is that you checked primer protrusion. Did you check recess?
The firing pin is spring driven. You have basically set up your chamber and cartridge to “0” headspace. If the clearance between the firing pin and the primer is 0 or minimal, there is a chance it’s not building enough speed to set off the primer. If the primers in the none LC brass sit deeper, it may be your cause.
DShortt
Gold $$ Contributor
I suspect you found the issue right here.
I personally use a #8 insert out of the Hornady BULLET comparator set (.302" dia in my particular kit) because I also had problems using the A330 comparator insert from the Hornady HEADSPACE Comparator kit (.338" dia in my particular kit).
As you mentioned, the A330 insert was too close to the shoulder/case wall transition and I had problems getting accurate measurements.
Yes, I know. SAAMI specifies .330". I'm not sure why they did that. Doesn't matter, it's above my 'pay grade'. Meanwhile, I'll continue to use a comparator insert closer to the midway point between the neck and case wall on the shoulder and be happy.
DShortt
Gold $$ Contributor
OK, so how does the firing pin/spring have enough energy to change the cartridge base to datum measurement by .007", but not enough energy to set off the primer?
That .007" difference has STILL not been explained.
Unless, simply chambering the brass is making that much difference.
I don't think the OP has tested that yet unless I missed it. Hard to believe, but maybe..... And even then there should be no room for the case to move when the firing pin strikes the primer.
I really wish I could sit down next to the OP and have the measurements demonstrated. Something doesn't make sense.
Maybe his primers are seated .007" above the case head and then seated by the firing pin fall and he's not catching that? No telling at this point.
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dellet
Gold $$ Contributor
I think the .007” is a false flag. If you look at his numbers the case is basically a crush fit or 0 space. Either that or there is no powder in the case to make it fill out the chamber. The brass is not growing, even shrinks when it did fire. I think the answer will likely be it’s getting crushed chambering. But again, thats never been checked. But I don’t think that’s the failure to fire, regardless. Never happens on any other brass that is the same length.
I really think the primers aren’t seated correctly. Possibly due to a slightly different shape, or if bought once fired, the crimp wasn’t removed correctly. If the primers were swaged, were the pockets uniformed. If the rounded corners were cut out, in only one brand, the pokets would measure the same but primers set to the same depth would have no support at the edge where needed. Back to my original post. You can’t hammer on a primer hard enough to set the shoulder back and not set off the primer.
Lots of focus on headspace. He doesn’t have any. That won’t cause a light strike on a primer. Even if there is .007” space after chambering, that’s not near enough to cause a light strike.
rugger7622
Silver $$ Contributor
I feel like I have explained this, but I'm not doing a good job of it. I measured the shoulders in a comparator as well as a whidden chamber gauge and all of all the brass after sizing, are within .0005 of each other. The brass that fires has basically zero should difference when measured. The FTF brass is .007 shorter than when I measured, it's been recocked and fired.
All the brass chambers easily, including the eventual FTF brass. Easy to close the bolt.
No, I'm at .005-.006 crush, every primer on these 30 were measured before powder loading. I know it doesn't make sense and it doesn't make sense to me.
My guess and it's always been my guess based on my measurements the crimp in LC and the rounding of the LC brass pockets, maybe CC450's and their hardness are leading to the issue.
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rugger7622
Silver $$ Contributor
Great post thank you. You are correct, I'm using a 330 comparator and I had the suspicion of inconsistent shoulder landing point when this 1st started and moved to the Whidden gauge to try to eliminate it. I still use the whidden guage when loading along side a comparator. As far as the primer seating, I've been using the CCI data of primer pocket cup height of .113, which in my mind would seat the cup and crush the anvil, regardless of the anvil distance.
Does this thought make sense? I've had the FTF issue with primers not crushed and with primers crushed. I thought the gap with no crushing could be the issue so I moved to a hand primer and can feel the crush as well as I've measured it.
DShortt
Gold $$ Contributor
The thing is, I'd like someone to explain how only FTF brass measures. 007" shorter after it fires on a second attempt.
The only explanation I can conceive is your measurements are off to begin with at the .330" datum line.
Where exactly did you get the LC brass from? Maybe something strange is going on and some of it was run through a .223AI die or similar?
rugger7622
Silver $$ Contributor
Would it make sense to have my smith pull the barrel and reset the headspace to easily close on a go gauge? I've had several people suggest that and several say it's not the issue. Again, the barrel shoots great. It would rule out a variable but could lead to others?
DShortt
Gold $$ Contributor
I'd leave it alone and not use the LC brass in this rifle long before I did that.
Something is off with the LC brass, evidenced by the fact that Starline brass causes no problems.
rugger7622
Silver $$ Contributor
My hunch is that it's the combination of spring pressure hitting the primer and not going off and the second firing of the bolt and the spring pressure, but this is the 1st time I've had to troubleshoot an issue like this.
After the 1st occurrence, I started measuring the FTF brass and every piece has should set back much greater than fired brass in this barrel.
rugger7622
Silver $$ Contributor
I have more starline brass coming and I'll get some virgin measurements as well as 100 pieces of Lapua brass........so I can really throw in another variable!!!!
DShortt
Gold $$ Contributor
OK, well at this point I'd say something is off with the shoulder angle of SOME of the LC brass.
rugger7622
Silver $$ Contributor
I can get behind this could be a contributor/cause.
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