My Reloaded Steel-case Went KABOOM

[bj139]

For the sake of clarity, I would add to the bold portion of the above that the only "shallower" component of the Grendel chamber is in the throat, where the compound throat constricts into a "forcing cone" prior to the lands. The Grendel throat diameter is also larger than that of the 264 LBC (.300" vs .295"). The rest of the chamber dimensions (everything back from the neck) are identical.

The rear of the cartridge protrudes from the chamber an extra .011".
It has to in order to fit into the deeper .136 bolt face versus a .125 boltface.

[rabiddawg]

I thought the .011 was to allow use of the 6.5 Grendel extractor?

[NugginFutz]

The rear of the cartridge protrudes from the chamber an extra .011".
It has to in order to fit into the deeper .136 bolt face versus a .125 boltface.

Not to take issue with you, BJ, but the 264 LBC, as designed and sold by Les Baer as the 264 LBC-AR, uses the same bolt as the Grendel / Beowulf marketed by AA. i.e. with the .136" bolt face depth. Further, both of my BHW 264 LBC barrels use the .136" bolt face. BHW has since discontinued headspacing the chambers for the .136" bolts and now uses the .125" bolts.

As far as headspacing is concerned, yes, the use of the .136" bolt will mean that the base of the case will protrude an extra 11 thousandths than if your chamber was headspaced for the .125" bolt. In spite of this, you cannot say unequivocally the the Grendel is headspaced any differently (shallower or deeper) than a 264 LBC. That depends entirely on the individual barrel manufacturer, and not on the design, per se.

And, finally, at the risk of further muddying the waters, it is noteworthy to say that both SAAMI specification Grendel chambers and 264 LBC chambers have been head spaced for both the .125" and the .136" bolts.

[IceAxe]

Not to take issue with you, BJ, but the 264 LBC, as designed and sold by Les Baer as the 264 LBC-AR, uses the same bolt as the Grendel / Beowulf marketed by AA. i.e. with the .136" bolt face depth. Further, both of my BHW 264 LBC barrels use the .136" bolt face. BHW has since discontinued headspacing the chambers for the .136" bolts and now uses the .125" bolts.

As far as headspacing is concerned, yes, the use of the .136" bolt will mean that the base of the case will protrude an extra 11 thousandths than if your chamber was headspaced for the .125" bolt. In spite of this, you cannot say unequivocally the the Grendel is headspaced any differently (shallower or deeper) than a 264 LBC. That depends entirely on the individual barrel manufacturer, and not on the design, per se.

And, finally, at the risk of further muddying the waters, it is noteworthy to say that both SAAMI specification Grendel chambers and 264 LBC chambers have been head spaced for both the .125" and the .136" bolts.

Wouldn't it be more accurate to say all .136" bolts have an additional .011" non support over a barrel chambered for a .0125" bolt. If a .136" bolt was used on a barrel chambered for .125" bolt you would have the same amount of un-support as a barrel chambered for the .136 (.011") with an additional .011" case stretch?

[NugginFutz]

Wouldn't it be more accurate to say all .136" bolts have an additional .011" non support over a barrel chambered for a .0125" bolt. If a .136" bolt was used on a barrel chambered for .125" bolt you would have the same amount of un-support as a barrel chambered for the .136 (.011") with an additional .011" case stretch?

Not necessarily. While you could make a case for the first part of the statement, I would take issue since the second part (.136" bolt used in a chamber cut for a .125" bolt) essentially results in extreme headspace and the creation of a distorted case. It is at this point where the two configurations become incompatible due to brass which will now fire only in this non-standard configuration. Not what I would call a desirable outcome.

[sneaky one]

Steel cases were Not Meant To Be Reloaded dude, OP should know this. This is bad info to pass along to the younger crowd...…..

[NugginFutz]

Steel cases were Not Meant To Be Reloaded dude, OP should know this. This is bad info to pass along to the younger crowd...…..

You are correct. I’ve been attempting to dispel some misconceptions about the chambers - not dispense advice on how to reload steel cases. I don’t believe the op was implying that steel should be reloaded, and my comments were specifically directed toward brass.

[Sticks]

Steel cases were Not Meant To Be Reloaded dude, OP should know this. This is bad info to pass along to the younger crowd...…..

This was also an attempt at Moscow Match.

[bj139]

Not to take issue with you, BJ, but the 264 LBC, as designed and sold by Les Baer as the 264 LBC-AR, uses the same bolt as the Grendel / Beowulf marketed by AA. i.e. with the .136" bolt face depth. Further, both of my BHW 264 LBC barrels use the .136" bolt face. BHW has since discontinued headspacing the chambers for the .136" bolts and now uses the .125" bolts.

As far as headspacing is concerned, yes, the use of the .136" bolt will mean that the base of the case will protrude an extra 11 thousandths than if your chamber was headspaced for the .125" bolt. In spite of this, you cannot say unequivocally the the Grendel is headspaced any differently (shallower or deeper) than a 264 LBC. That depends entirely on the individual barrel manufacturer, and not on the design, per se.

And, finally, at the risk of further muddying the waters, it is noteworthy to say that both SAAMI specification Grendel chambers and 264 LBC chambers have been head spaced for both the .125" and the .136" bolts.

I didn't know the 264LBC was chambered to use .136 bolts as well as .125 bolts. I learned something.
BHW does specify 6.5Grendel for .136 bolts and 264LBC for .125 bolts.

At the risk of muddying the waters with facts, I decided to measure a Grendel case.
At .136, I see that NONE of the sidewall of the case is unsupported. I should have done this before commenting.

NEVER MIND.
Roseanne Rosanadana

[NugginFutz]

I didn't know the 264LBC was chambered to use .136 bolts as well as .125 bolts. I learned something.
BHW does specify 6.5Grendel for .136 bolts and 264LBC for .125 bolts.

At the risk of muddying the waters with facts, I decided to measure a Grendel case.
At .136, I see that NONE of the sidewall of the case is unsupported. I should have done this before commenting.

NEVER MIND.
Roseanne Rosanadana

Hmm... I wasn't aware that BHW (now Columbia Arms) was still in the 6.5 Grendel game (IIRC, they'd done a one time batch of barrels). I'd last heard that they'd gone back to just the 264 LBC, and only with the .125" bolt.

But enough of this thread-jacking...

[grayfox]

This was also an attempt at Moscow Match.

heh-heh... more like Russian roulette if you ask me... but I repeat myself.

[Onebigelf]

Roger -- I kind of thought this would happen. Still, I don't think it is the issue at all. Here is why.

I have pulled thousands of rounds of Lake City ball ammo. The absolute worse for pulling bullets was M-855 (5.56 Ball). Between the tar and the crimp, some of that stuff was almost impossible to pull using a bench mounted bullet puller. I have had to crush the bullet in the puller die then hammer the press handle with a wooden mallet for about one of twenty rounds. A kinetic puller would break before one of those bullets came out. I have even had to go as far as seating those bullets a bit deeper to break the tar and crimp seal and then pull them. Even then, some of them needed a huge amount of force.

That said, have also shot thousand of rounds of them and witnessed hundreds of thousands of rounds of them being fired and have never seen a problem due to the crimp or tar. I seriously doubt the problem was the tightness of the neck.

Finding out why becomes pure speculation after the fact because so many parts have been damaged. About the only thing that is pretty much certain is that something set off the primer before the bolt went into battery.

LR55

I have reloaded many rounds of Wolf and Tula ammo with better bullets of the same weight and the original powder charge and primer. The biggest problem I have in doing so is pulling the original projectile, which ranges from modest tension to damn near impossible to remove. The tension on the new projectile is, by comparison, much lighter and seems no different from what I have experienced pulling brass factory ammo. I would look elsewhere for the problem, but that said - yeah, you can't blame Wolf when you modified the ammo, and you can't blame the gun when you fired modified ammo. One of the things I would lean toward, I run mine through a sizing die with the decapping pin removed before seating the new projectile. Pulling the bullet when they are as tight as the factory ammo is has a tendency to stretch the shoulder forward and lengthen the case. My guess, your ammo was out of spec for headspace.

John

[rickt300]

I still do the Moscow match thing but I toss the cases that are especially hard to pull the original bullets from. I also change the powder charge at the same time, But after seeing this I may stop doing it.

[Frontier Gear]

Okay so call me ignorant, but I have never heard of "Moscow match" before. My assumption was that it was an attempt to make Russian ammo into match grade ammo, so I Googled it just to see. That was a mistake... Most of the results were for football (soccer), but the top result informed me that my true love was waiting for me in Russia.

[bj139]

Okay so call me ignorant, but I have never heard of "Moscow match" before. My assumption was that it was an attempt to make Russian ammo into match grade ammo, so I Googled it just to see. That was a mistake... Most of the results were for football (soccer), but the top result informed me that my true love was waiting for me in Russia.

Go for it.