Help Diagnosing Misfires

[T-shooter]

Your primers look normal. Here are some pictures I took from an AR. I put a titanium firing pin in since the pin is free floating and hits the primers when a round is chambered. The titanium made a much smaller indentation than the stock steel pin.Never had a misfire with it. The bottom right is a fired round with a slightly flattened (Federal) primer. The .020" headspace issue sounds like the problem.

 

[fyrewall]

Your links showing dud rounds had normal primer indents??? What caused the excessive head-space of the dud rounds? When you expanded the necks of the ADI brass was there any chance the shoulders were set back or was this expansion done just to remove normal dings and neck dents. All the fail to fire that I have had, caused by excessive head space, had shallow firing pin hits. A spring loaded ejector would push a short loaded round forward into the chamber so the firing would not hit it deeply - your links do not show that. I have never seen new factory brass that had grossly excessive head-space.

Your VLD bullets are jammed.

My assumption is that your weapon is a bolt action vs AR type.

I am confused.

 

[Webster]

I had a similar problem with new unfired LC brass. Turns out the shoulders were too short. Try it without expanding the necks prior to loading the new brass.

No real opinion on this but when I fire form 6BR cases to 6BRX I have 0.100" space between the case shoulder and the chamber shoulder. The primers always go off? Must be because I jam about 5 thou. The case head is against the bolt face.

 

[Richard Coody]

No real opinion on this but when I fire form 6BR cases to 6BRX I have 0.100" space between the case shoulder and the chamber shoulder. The primers always go off? Must be because I jam about 5 thou. The case head is against the bolt face.

that is why you jam when fireforming. one of the many fireforming techniques

primers should be seated by feel not to some arbitrary depth. with a good priming tool you can feel when it bottoms out then call it good.

new brass is always short. i don't recommend setting a die up for bumping the shoulder until the brass is fully fireformed. usually about 3 firings. until then just set the die up to size the neck.

reloading your fired brass without any shoulder bump and seating the primers by feel should correct your problem. if not then it is time to look elsewhere

 

[Iowa Fox]

Start with verifying re-chambered headspace against your brass length. New brass is often way short of spec, you need to know where it sits in your chamber once you close & lock bolt, otherwise everything else you check will have no relevance to the problem.

My thoughts exactly. Think base to datum. Measure one of the pieces of fired brass, a piece of re-sized brass, and a piece of new brass. On the piece of fired brass knock the old primer out before you re-sized to measure it so the primer doesn't give you a false reading.

 

[6MMsteve]

if your fireforming you need to jam the bullets with good amount of neck tension, you did say you have a new barrel jam them about 40 to 80 thou with good neck tension and they will shoot, or your firing pin needs to be adjusted for fired length

 

[onelastshot]

I'd purchase a box of factory ammo and shoot it. In short, if it shoots fine you know the problem is your reload if it doesn't then you've got to look at your firing pin and firearm. Simple process of elimination.

 

[JSH]

I am no authority but will throw in here. There is a lot over thinking on things we do.
The primer anvil needs to be in contact with the bottom of the primer pocket, plain and simple.
Buddy uniformed a bunch of virgin Lapua cases years back. He proceeded to seat all of them at a uniform depth, no idea where he came up with the number.
Well, he did square up the pockets and uniform them, BUT, he also made them enough deeper that he had all kinds of issues. Things were tried, money was spent, hair was pulled, dogs were kicked, this went on for close to a year. It was also a cause of pierced primers, which in turn he took as high pressure, which led to thinking it was short throated.
It snow balled and got way out of hand, over a simple problem.

If fire forming brass and the chamber is so much over parent case size, as mentioned jamming a bullet in the throat holds the case back against the bolt face, in order for the shoulder to move rather than the web. This does raise pressures for sure.

Another way I have formed is to put a false shoulder. Neck up one size, then back down just enough for the bolt to close. Then you can seat bullets off the lands of you so desire.

If the extractor is all that is holding the case, there can be enough spring that you get odd hits.

The one picture of several I looked at the OP posted, looks like a good solid hit to me. Almost deep enough that a double strike maybe?

 

[savagedasher]

I have found that most misfires are a product of
Bad head space Too much
Improper primer seating
Or a weak fireing pin spring
Larry

 

[dkhunt14]

I'd purchase a box of factory ammo and shoot it. In short, if it shoots fine you know the problem is your reload if it doesn't then you've got to look at your firing pin and firearm. Simple process of elimination.

I don't know of any factory ammo loaded with BR4 primers. The BR4 primers are harder and thicker cupped. It takes everything to be right to make them go bang. Matt

 

[dkhunt14]

Your links showing dud rounds had normal primer indents??? What caused the excessive head-space of the dud rounds? When you expanded the necks of the ADI brass was there any chance the shoulders were set back or was this expansion done just to remove normal dings and neck dents. All the fail to fire that I have had, caused by excessive head space, had shallow firing pin hits. A spring loaded ejector would push a short loaded round forward into the chamber so the firing would not hit it deeply - your links do not show that. I have never seen new factory brass that had grossly excessive head-space.

Your VLD bullets are jammed.

My assumption is that your weapon is a bolt action vs AR type.

I am confused.

Lots of factory brass is .010 or more short. Matt

 

[6MMsteve]

I am no authority but will throw in here. There is a lot over thinking on things we do.
The primer anvil needs to be in contact with the bottom of the primer pocket, plain and simple.
Buddy uniformed a bunch of virgin Lapua cases years back. He proceeded to seat all of them at a uniform depth, no idea where he came up with the number.
Well, he did square up the pockets and uniform them, BUT, he also made them enough deeper that he had all kinds of issues. Things were tried, money was spent, hair was pulled, dogs were kicked, this went on for close to a year. It was also a cause of pierced primers, which in turn he took as high pressure, which led to thinking it was short throated.
It snow balled and got way out of hand, over a simple problem.

If fire forming brass and the chamber is so much over parent case size, as mentioned jamming a bullet in the throat holds the case back against the bolt face, in order for the shoulder to move rather than the web. This does raise pressures for sure.

Another way I have formed is to put a false shoulder. Neck up one size, then back down just enough for the bolt to close. Then you can seat bullets off the lands of you so desire.

If the extractor is all that is holding the case, there can be enough spring that you get odd hits.

The one picture of several I looked at the OP posted, looks like a good solid hit to me. Almost deep enough that a double strike maybe?

false shoulder is imho the best way to fireform, I'm fireformin right now and my 7mm stem took a coo coo, so trying to form 260ai has been a headache without false shoulder but I still have a club

 

[mikecr]

Webster, 2thou crush means primer just bottomed to pocket +2thou further (preload). It is recommended by manufacturers, and the K&M provides for this with actual measure.

Another thing that can cause misfires, and it also gives plenty of primer indent (like pictures), is a firing pin slipping in it's cocking piece.

 

[Homerange]

Thanks all for the help so far.

Tikka action - stock firing pin. Is there an easy way to measure protrusion of the firing pin? Currently thinking I'll measure the gap to the bolt face and deduct the gap to the firing pin from the front of the lugs.

Tikka action is the issue.

My sons one while quite new had the same problem. We had it sent to the NZ Tikka distributor for their in-house gunsmith to look at.
When they attempted to bill us for just a bolt strip and clean we told them to stick their bill where the sun don't shine.

This was a few month old rifle, bolt never stripped so the only grunge in it will have been factory lubricants.

Give it a good clean with solvents and brushes to ensure you get any grunge loosened.

 

[WyleWD]

The OP isn't alone in this concern about BR4 primers. We have a pair of Stolle Pandas in 6br that we're getting FTF at about 4 out of 10 will not go off. Federal, Winchester, and Rem 7 1/2 all work fine. Headspace is fine, previously fired brass, bullets into the lands by ten thousandths.WD

 

[fyrewall]

Possibly, there is an excessive amount of over think here. I would imagine ADI would be embarrassed to have made a batch (lot) of brass having excessive head space that it would not reliably work in all standard chambers. This might get into 5.56X45 vs. .223 chamber issues but cartridge head space should be the same.

Suppose that the USA military, tasked with never ending deployment, had a lot of ammo that was not reliable for any of a number of reasons, excessive head space included, the DOD, US Congress, and military families would be all over Lake City. Making military ammo is serious business and that is why inspectors go over the stuff.

My next project is to rework a large batch of new Lake City 5.54X45 (complete with circle enclosing cross, LC 15, first rate) into .20 Practical - I have done 1000's of rounds using all sorts of new and once fired brass - Winchester, Remington, PPU, Lapua, Nosler, LC, PMC, without any problems. Quick and easy with total confidence in all components used - brass, powder, bullets, and primers. I would guess ADI brass would have similar standards as my LC brass. CCI would also be mortified to hear about any FTF over like .001 percent.

I see much conflicting info regarding the problem.

 

[scyzer]

Possibly, there is an excessive amount of over think here. I would imagine ADI would be embarrassed to have made a batch (lot) of brass having excessive head space that it would not reliably work in all standard chambers. This might get into 5.56X45 vs. .223 chamber issues but cartridge head space should be the same.

Suppose that the USA military, tasked with never ending deployment, had a lot of ammo that was not reliable for any of a number of reasons, excessive head space included, the DOD, US Congress, and military families would be all over Lake City. Making military ammo is serious business and that is why inspectors go over the stuff.

My next project is to rework a large batch of new Lake City 5.54X45 (complete with circle enclosing cross, LC 15, first rate) into .20 Practical - I have done 1000's of rounds using all sorts of new and once fired brass - Winchester, Remington, PPU, Lapua, Nosler, LC, PMC, without any problems. Quick and easy with total confidence in all components used - brass, powder, bullets, and primers. I would guess ADI brass would have similar standards as my LC brass. CCI would also be mortified to hear about any FTF over like .001 percent.

I see much conflicting info regarding the problem.

One other thought I had was whether those -20 thou relative headspace measurements could have simply been a product of the misfire itself. I've gone back to my lot of brass and have failed to find anything remotely close to those two rounds (I regret throwing the other misfires in the range FTF bin now).

Is there any chance the firing pin strike itself was enough to move the shoulders back that much? And with the lack of detonation, the lack of brass expansion left it at that relative headspace?

 

[BenPerfected]

Maybe some of the primers got wet. Try a new box and a different lot of primers.

 

[fyrewall]

.020 is a hefty set back. I am looking at my calipers now and can see lots of daylight at .020. I don't think a firing pin strike would ever set back or shorten brass that much, .223 & 5.54X45 Nato cases are tough and made to handle semi auto & full auto bolt smashing, often with dirty chambers. The folks at ADI would be confident that they made good brass. Keep stuff clean and use common sense and seat primers so the anvils touch and F/L size to correct head space and you should not have any problems.

Checking for wet primers is total common sense. Any chance that shipment or storage in the steamy tropics could have affected them ? It is a long distance between Lewiston ID and Australia.

Can kangaroos be seen hopping around mall parking lots down there ?

 

[TheOtherZilla]

I don't recall seeing this posted and it's a long shot, BUT: have you pulled a bullet or two and looked to see if there is actually powder in there? Just sayin as I seem to load a cartridge sans powder every once in a while..