Damn

[REDLINE]

REDLINE, Great pictures...There is not much free bore at the end of the chamber in those pictures.  Pictures 1 and 4 look like they have a little more taper in the freebore.  Picture 2 & 3 look like the rifling starts at the end of the chamber with very little taper.

With that short freebore taper you will be using a COAL of 1.2450", so trying 1.2500" may prove to be tight!

As you look inside you can see that the lands are still present at the end of the chamber cut, these should be absent and tapered lands to for the truing cone section. 

The barrels of the Bren Ten pistol's freebore doesn't have any rifiling for 3/4th of an inch...

I'm with ya in noticing the lack of any notable free bore!  It really took me by surprise after taking the first looks at my pics.  Not to mention seeing the same with ii open's pic.  And now this all has me wondering if we're now noticing the missing link on where barrels are differing in instances where we're not really sure why they do in terms of chamber pressure when it doesn't seem there should be a difference.   As in;  How well is this tolerance held between barrels of the same manufactuer?  AND;  How much is it actually differing between different manufacturers?

How does your G29 SLB look by comparison to the posted pics in terms of free bore or lack thereof?  I would also have the same question of other's barrels from other manufacturers.

[Yondering]

Redline, the throat in your chamber is really off center! Pretty poor quality, I would want a refund or replacement. Even Keltec replaced a barrel for me with that problem (in a sub2000 .40 cal); I would've expected better from Storm Lake. Might as well buy a Lone Wolf barrel if that's what you get.

ii open, in your pic we can only see one side of the throat, are the lands present all the way around (throat too narrow) or only on one side (throat cut offset)?

[ii open]

With that short freebore taper you will be using a COAL of 1.2450", so trying 1.2500" may prove to be tight!

As you look inside you can see that the lands are still present at the end of the chamber cut, these should be absent and tapered lands to for the truing cone section. 

The barrels of the Bren Ten pistol's freebore doesn't have any rifiling for 3/4th of an inch...

1.245 still does not clear, but @ 1.240 its all good.  Looking at the rifling, it does not go to the end of the chamber, lands also look tapered.

[ii open]

Yondering this is the best I can do(using iPhone)

[REDLINE]

Redline, the throat in your chamber is really off center!

I don't believe the chamber is off center at all.  At the same time I don't know if it is or isn't.  Keep in mind that the pics peering through the barrel are not centered, therefore giving an optical illusion to anyone assuming they are in relation to the chamber seeming off center.  The other pics aren't all good enough to judge from each other if the chamber is off center or not.

[Yondering]

Redline, the throat in your chamber is really off center!

I don't believe the chamber is off center at all.  At the same time I don't know if it is or isn't.  Keep in mind that the pics peering through the barrel are not centered, therefore giving an optical illusion to anyone assuming they are in relation to the chamber seeming off center.  The other pics aren't all good enough to judge from each other if the chamber is off center or not.

I said the throat is off center from the bore. The freebore area between the chamber and rifling. It is obvious from the pictures that it's cut off center; the rifling lands run all the way to the chamber on one side, but are machined away on the other side. That is not acceptable for best accuracy, and will probably cause leading with cast bullets too.

Usually the chamber and throat are cut with the same reamer, so that would indicate the chamber is probably offset from the bore too, but you can't tell that from your pics.

[Yondering]

Yondering this is the best I can do(using iPhone)

The throat in that one looks off center from the bore too (offset towards 1:30-ish in the picture), but not as bad as Redline's. See how the lands run all the way to the chamber at about 7:00-8:00? Directly opposite, at about 1:30, it looks like the lands are machined away, and there is a faint line visible where the throat ends and the rifling begins.

If it was cut correctly, the end of the chamber would transition to a short smooth freebore area, with no rifling visible. This area can be straight or slightly tapered, depending on the application. After that freebore, the lands in the rifling should taper up to full height, evenly all around the bore. The area containing the freebore and tapered lands is called the "throat"; it is the transition between chamber and rifling, and is important that it's straight and concentric! Look in your factory Glock barrels, you won't likely find any that are cut offset like these Storm Lake barrels.

[REDLINE]

I said the throat is off center from the bore.

Got it.  My bad for not understanding the first time.  When time allows I'll see if I can get some better pics of the throat for more detail all the way around.  I do see what you're saying though in regard to the current pics.

[REDLINE]

Yondering this is the best I can do(using iPhone)

The throat in that one looks off center from the bore too (offset towards 1:30-ish in the picture), but not as bad as Redline's. See how the lands run all the way to the chamber at about 7:00-8:00? Directly opposite, at about 1:30, it looks like the lands are machined away, and there is a faint line visible where the throat ends and the rifling begins.

If it was cut correctly, the end of the chamber would transition to a short smooth freebore area, with no rifling visible. This area can be straight or slightly tapered, depending on the application. After that freebore, the lands in the rifling should taper up to full height, evenly all around the bore. The area containing the freebore and tapered lands is called the "throat"; it is the transition between chamber and rifling, and is important that it's straight and concentric! Look in your factory Glock barrels, you won't likely find any that are cut offset like these Storm Lake barrels.

Are you saying all that based on the sole pic in reply #18?  If so, I'm trying to figure out how you could make any judgement at all in regard to the throat at the 1:30 position.  Not trying to be argumentative, and maybe I'm just blind, but just saying.

[Yondering]

Yondering this is the best I can do(using iPhone)

The throat in that one looks off center from the bore too (offset towards 1:30-ish in the picture), but not as bad as Redline's. See how the lands run all the way to the chamber at about 7:00-8:00? Directly opposite, at about 1:30, it looks like the lands are machined away, and there is a faint line visible where the throat ends and the rifling begins.

If it was cut correctly, the end of the chamber would transition to a short smooth freebore area, with no rifling visible. This area can be straight or slightly tapered, depending on the application. After that freebore, the lands in the rifling should taper up to full height, evenly all around the bore. The area containing the freebore and tapered lands is called the "throat"; it is the transition between chamber and rifling, and is important that it's straight and concentric! Look in your factory Glock barrels, you won't likely find any that are cut offset like these Storm Lake barrels.

Are you saying all that based on the sole pic in reply #18?  If so, I'm trying to figure out how you could make any judgement at all in regard to the throat at the 1:30 position.  Not trying to be argumentative, and maybe I'm just blind, but just saying.

I'm basing that on both of the pictures ii open posted.

Possibly even more interesting is that your barrel and ii open's are both cut offset in the same direction, up and to the right, 1:00-2:00 direction. That may be caused by SL's tooling setup for the reaming operation. They most likely aren't using a piloted reamer (if they are, the pilot is too small), and don't have the reamer aligned with the bore well enough.

Your last and second to last pictures in reply #9 show the offset throat quite clearly. (I also see the barrel was upside down for those pictures.) Rifling all the way to the chamber in the upper right, and freebore on the lower left.

[sqlbullet]

Redline, I agree with Yondering about your barrel.  Looks like the throat is not uniform.

But, if you are happy with how it shoots, that doesn't matter at all.  All the measuring, investigating, etc are efforts to quantify how a gun will shoot without shooting it.

There are plenty of guys out there with guns that are out of spec that shoot just fine.  No sense to become unhappy about some spec when you are happy with how it shoots.

ii open, on the other hand, clearly has an issue.  If the gun won't chamber factory ammo, it is due a ride back to Storm Lake.

[The_Shadow]

What I was pointing out is the small amount of rifling/lands appear to be present below the tapered part, the lands should be cleaned down to equal that which was removed by the rifle broaching tool(FREEBORE).  Have a look at this diagram which could explain some issues...