View Full Version : Problem extracting live round, Ring cut around bullet
It is a brand new upper with an 18" FN barrel, rifle length gas. Barrel is marked "HF MP wylde 1:8". It was purchased as a complete upper.
Zeroing the rifle, it functions fine. Now time to inspect the group so proceed to drop the mag and eject the live round...but can't eject the round, it is stuck. Sometimes muscling the charging handle will get it out, other times need to mortar it.
Examining the round, there is a ring cut around the bullet. Here are a few pics. This is wolf gold. Federal 5.56 and IMI 5.56 were also stuck.
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Before the trip, it was cleaned with a chamber brush.
Is this normal for wylde chambers? Should this upper be returned or is there an easy fix?
I guess I'll be the first to answer that this is not normal, for a Wylde, or any other chamber. There is no easy fix, so it should go back to the manufacturer.
Some very precise chamberings have had indications similar to this. For those, the extraction issue with a live round goes away after some use.
I do not know if that is the case here or not? How many rounds have gone through it? Are there any excess pressure indications on the fired brass?
More than likely though, nobody here will be able to say anything with any certainty without a chamber cast and examining the item first hand.
It can be nice for many to have a snug bore in the throat area on a fresh barrel, but not so nice if it ends up being some other things.
I guess I'll be the first to answer that this is not normal, for a Wylde, or any other chamber. There is no easy fix, so it should go back to the manufacturer.
Before it hurts someone. I'd like to see the base of the IMI brass.
It appears the freebore is too short for the cartridge being fired and the barrel is functioning like a bullet puller when you extract an unfired cartridge.
Are you firing 5.56mm ammunition in a .223 Wylde chamber?
Contact FN. They will want to know about this and can offer advice concerning which ammunition should be fired through that particular barrel. If it is a warrantable issue, they will take care of it.
A general rule of thumb is that you can shoot .223 ammunition through a 5.56mm barrel, but you should not fire 5.56mm ammunition through a .223 barrel.
Yep.
Sure looks like leade is too short.
Should be able to shoot 5.56 or .223 through a Wylde chambered barrel.
Is this a PSA upper? Does barrel have FN logo?
It appears the freebore is too short for the cartridge being fired and the barrel is functioning like a bullet puller when you extract an unfired cartridge.
Are you firing 5.56mm ammunition in a .223 Wylde chamber?
Contact FN. They will want to know about this and can offer advice concerning which ammunition should be fired through that particular barrel. If it is a warrantable issue, they will take care of it.
A general rule of thumb is that you can shoot .223 ammunition through a 5.56mm barrel, but you should not fire 5.56mm ammunition through a .223 barrel.
Don't believe that rule applies with a Wylde chamber
OP - I believe the above folks are correct. DO NOT FIRE that thing until you have it checked out.
If the leade/freebore is insufficient it will cause a spike in chamber pressure that could result in a kaboom.
Repeat - DO NOT FIRE until you have it checked to your satisfaction.
You can google 'signs of overpressure on AR15 brass' and see images of over pressure signs.
Even if you aren't seeing this, it does look as if you are sticking the bullet hard enough that you are beginning to pull the bullet from the case.
Repeat - DO NOT FIRE until you have it checked to your satisfaction.
Seriously.
Some very precise chamberings have had indications similar to this. For those, the extraction issue with a live round goes away after some use.
I do not know if that is the case here or not? How many rounds have gone through it? Are there any excess pressure indications on the fired brass?
More than likely though, nobody here will be able to say anything with any certainty without a chamber cast and examining the item first hand.
It can be nice for many to have a snug bore in the throat area on a fresh barrel, but not so nice if it ends up being some other things.
You're saying that it's not unheard of for an AR barrel's leade to be so tight to allow solid bullet contact, when they're loaded to NATO or SAAMI specs? Throat erosion may eventually eliminate the bullet contact, but I don't consider this a solution. This could have definite impact on chamber pressure, and I suggest that you don't shoot it again until this has been resolved.
It has about 100 rounds through it and it is a PSA upper with a FN logo on the barrel. The spent brass is in a mixed pile with other brass. Not sure if this will give clues to the pressure but I was measuring the velocity. This barrel had wolf gold ~3200fps, IMI193 ~3200fps, and federal xm193f 3250fps. Highest value was a federal xm193f at 3300fps.
It has about 100 rounds through it and it is a PSA upper with a FN logo on the barrel. The spent brass is in a mixed pile with other brass. Not sure if this will give clues to the pressure but I was measuring the velocity. This barrel had wolf gold ~3200fps, IMI193 ~3200fps, and federal xm193f 3250fps. Highest value was a federal xm193f at 3300fps.
Found the problem. Contact PSA and hopefully they will take care of you. I'm crossing my fingers for you.
Found the problem. Contact PSA and hopefully they will take care of you. I'm crossing my fingers for you.
I agree that PSA owns the problem - they are the ones that sourced the barrel from FN.
Don't believe that rule applies with a Wylde chamber
I thought so, but it did not work out for me.
I tried to chamber Federal 5.56mm in a new match rifle with .223 Wylde chamber and the bolt would not go into full battery without using the forward assist. After firing 2,000 rounds of .223 ammunition, throat erosion increased by 0.003" and Federal 5.56mm would chamber easily.
When I replaced the barrel with a new match barrel chambered in .223 Wylde I had the same experience.
Shooting factory ammunition with the projectile touching the rifling can cause high pressure spikes. It can be dangerous and the issue should be addressed without delay.
While this could very well be a problem, it's not always so.
Has anyone examined the fired casings to look for indications of excess peak pressure?
Has anyone examined a chamber cast to some possible prints or defects?
Has anyone examined the chamber with a good borescope? etc..
As an example only, I have made up many good barrels for AR precision/accuracy uses from blanks. With properly sized components for the ammunition within SAAMI and/or NATO spec, the unlocking/extraction/ejection requires much less than mortaring of an unfired chambered cartridge. Many times mass produced factory loads deviated enough to distort those points in some ways enough to cause issues. Sometimes the round not being actually "round" or crimp displacements, etc are enough to do this. I have seen this many times in some of these. There are a few ways around this, but pretty much all of those would require a solution that is a net negative overall for a use that required the precision/accuracy potential to begin with.
It is very possible that this barrel did not meet up to its goal, it is also very possible that the ammunition did not either.
If I was the OP, at a minimum I would look for excess case peak pressure indications first on fired cases, then some other possible match grade ammunition at a minimum to compare to at least for live round ejections after chambering that said round.
I still recommend contacting the manufacturer before firing the rifle further.
While this could very well be a problem, it's not always so.
Has anyone examined the fired casings to look for indications of excess peak pressure?
No. Bolt actions shooters have been using the jam method of setting OAL for years, without a guarantee of over pressure.
Even if the pressure were appropriate in the tested ammo, having rounds requiring to be mortared out of the chamber is a definite problem.
Has anyone examined a chamber cast to some possible prints or defects?
No. but a fired (or even just inserted and removed case) may show if the chamber is rough.
Has anyone examined the chamber with a good borescope? etc..
No. That's beyond what I'd expect any end user to need to do.
As an example only, I have made up many good barrels for AR precision/accuracy uses from blanks. With properly sized components for the ammunition within SAAMI and/or NATO spec, the unlocking/extraction/ejection requires much less than mortaring of an unfired chambered cartridge. Many times mass produced factory loads deviated enough to distort those points in some ways enough to cause issues. Sometimes the round not being actually "round" or crimp displacements, etc are enough to do this. I have seen this many times in some of these. There are a few ways around this, but pretty much all of those would require a solution that is a net negative overall for a use that required the precision/accuracy potential to begin with......and highly likely not something a non-gunsmith should be attempting.
It is very possible that this barrel did not meet up to its goal, it is also very possible that the ammunition did not either.
Does the OP have, or have access to, another rifle with a Wilde chamber, to test this same ammo in a different rifle?
If I was the OP, at a minimum I would look for excess case peak pressure indications first on fired cases, then some other possible match grade ammunition at a minimum to compare to at least for live round ejections after chambering that said round.
Chambering additional types of ammunition is a good idea.
I really don't care to share a more detailed response at this time. An excess of force required to unlock and extract can have many culprits beyond the chamber dimensions.
While I do not disagree about the possible cases cited above, I do see the possibilities of the transfer of information relating to a product ending up in less than positive ways in the end as a possible solution for end use.
I still recommend contacting the manufacturer before firing the rifle further.
I agree. It would be unwise to fire the rifle until at least making contact with the manufacturer and discussing the issue with them.
This sounds like a chamber issue. Contact PSA or whomever slapped it together and allow them to address it.
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