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Old 07-25-2012, 09:52   #41
WeeWilly
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Quote:
Originally Posted by alank2 View Post
Hi,

By the way, I got my caliper out and measured the factory chamber dimensions :

case mouth 0.425"
case head 0.434"

I am wondering if a replacement barrel is really what I need, KKM, Storm Lake, etc..

Thanks,

Alan
I only have one 10mm KKM barrel and have never actually measured it. While the ramp cut is a little more shallow than my stock barrels (a little less intrusion into the chamber), the chamber seems as loose at the head as my stock barrels (i.e. you can wiggle the round around quite a bit, less with previously fired brass and its fatter girth ).

I think if a tighter chamber is what you are looking for, maybe a Barsto like Fire Medic has will get you there, not sure the KKM will be a large impriovement, at least judging from my one and only example.
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Old 07-25-2012, 09:58   #42
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Hi,

The other contender (they offer black with QPQ) is Storm Lake. I don't love the side logo however. They said their dimensions are 0.424" case mouth, 0.4281" case head. I am waiting for KKM to respond with my chamber dimension request.

Thanks,

Alan
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Old 07-25-2012, 10:18   #43
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Quote:
Originally Posted by WeeWilly View Post
I only have one 10mm KKM barrel and have never actually measured it. While the ramp cut is a little more shallow than my stock barrels (a little less intrusion into the chamber), the chamber seems as loose at the head as my stock barrels (i.e. you can wiggle the round around quite a bit, less with previously fired brass and its fatter girth ).

I think if a tighter chamber is what you are looking for, maybe a Barsto like Fire Medic has will get you there, not sure the KKM will be a large impriovement, at least judging from my one and only example.
I've owned Federal, KKM and Barsto with Glocks and a custom ramped Fusion 1911 longslide barrel. The tightest of them all have been Barsto and Fusion, both of which fed the BEST of all of them, ironically. Tight doesn't mean poor feeding, and open doesn't guaranteed good feeding. FWIW, my Barsto (both ones I owned) measured .425-.426" and my Fusion measured the same.

I just got a 6" KKM for my G20sf and it also measures .4260-.4265".
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Old 07-25-2012, 10:27   #44
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Quote:
Originally Posted by Fire_Medic View Post
...thanks to Nick for the barrel trade
Thanks to Gabe for the barrel trade, as well! We killed two birds with one stone... the "model of efficiency" ha!! BTW, that Barsto is the best, most accurate, well supported and strongest barrel money can buy. You can bet on that. The case support on the Barsto is unreal. It was the same on my 6" Barsto years back.... Irv Stone definitely knows "what's up"

BTW....

Gabe 2
Nick 0

lol
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Old 07-25-2012, 11:32   #45
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Hi,

I'm looking for super supported so much as I am looking for 100% reliable and still reloadable...

Thanks everyone,

Alan
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Old 07-25-2012, 20:20   #46
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Hi,

Is there a difference between case support at the 6 o'clock position and overall chamber looseness? For example, with a new unsized case in the chamber, it looks like there is maybe between 1/16th to 3/32nd's of exposed case at the 6 o'clock area. I chopped one of my destroyed cases in half and it looks like it is pretty solid about that far in. Would this mean that it has pretty decent support against a blowout even though the overall chamber is oversized and allows the brass to balloon into it?

Just rambling! I ordered the Lee dies and bulge buster kit today just to see how it compares.

Thanks

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Old 07-25-2012, 21:40   #47
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Alan,

Taterhead,

I'm definitely in the minority here on how I determine pressure limits from fired brass measurements. I know most people measure the case expansion along the thin walls of the case, and that does have some merit. The reason I don't measure there is that part of the brass is constrained by the chamber when it expands, and there is almost always a little bit of spring-back after the pressure drops. So the expansion there approaches a diminishing number as you approach maximum pressure. Instead, I measure expansion at the case head, which is around the thick part of the brass web just above the extraction groove. Even though the expansion there is not as large on a moderately loaded round, the brass isn't constrained by the chamber there, so it is free to increase as the pressure goes up. You get a much more linear measurement, especially at max loadings. I also only measure the first loading with Starline brass. After the first firing, you don't really know what the starting dimension of the case head was, and the brass will start work hardening more after each firing.

I'm not saying one method is right and the other is wrong, I just have found that for me, measuring at the case head gives me what I feel is more useful data.
Ah. Got it. That makes sense if you are measuring a different spot. Thanks for clarifying.
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Old 07-25-2012, 21:49   #48
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Most of this stuff is a non issue. The stock chamber is much bigger. If your dies are right, you don't need a pass thru die. ... The problem is in the dies, most likely the sizing ring. The big problem is that the die is scraping down the brass, rather than squeezing it. There is no need for a different barrel, pass-thru die, etc. You may need your sizer die fixed.

FWIW, I size 10 and 40 brass in the same die position w/ no issues.
I completely agree. No need for a pass through die if using the stock barrel. 10 & 40 is resized in the same position. Carbide dies will be turned all the way down to the shell holder and then backed off a hair so that they just barely do not make contact. I really think this is a resizer issue -- IF -- there wasn't an excessive bulge or glocksmile prior to resizing.
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Old 07-25-2012, 21:58   #49
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Hi,

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Originally Posted by Taterhead View Post
-- IF -- there wasn't an excessive bulge or glocksmile prior to resizing.
I'm not sure if there was excessive bulge or not. It was a medium power load. I didn't see the glock smile in them.

Next time I'll measure the fired cases...

Thanks,

Alan
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Last edited by alank2; 07-25-2012 at 21:58..
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Old 07-26-2012, 12:06   #50
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Hi,

Is there a difference between case support at the 6 o'clock position and overall chamber looseness? For example, with a new unsized case in the chamber, it looks like there is maybe between 1/16th to 3/32nd's of exposed case at the 6 o'clock area. I chopped one of my destroyed cases in half and it looks like it is pretty solid about that far in. Would this mean that it has pretty decent support against a blowout even though the overall chamber is oversized and allows the brass to balloon into it?

Just rambling! I ordered the Lee dies and bulge buster kit today just to see how it compares.

Thanks

Alan
Generally when people on GT talk about case support, they are referring to how far the feed ramp intrudes into the chamber.

A tight chamber can have good or bad case support, depending on how the feed ramp is cut, but the loose chamber usually doesn't have great case support.

Whether full casehead support even matters is another story altogether...
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Old 07-26-2012, 13:59   #51
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Hi,

Well...I'm starting to get frustrated and beginning to question the brass...

I loaded up 20 more rounds:
10 of Blue Dot 10gr for 180gr GDHP, CCI 300, 1.250 oal, new starline nickel
10 of Accurate #7 9.6gr for 200gr XTP, CCI 300, 1.250 oal, new starline nickel

Only fired 2 rounds before STOPPING:

The 10 Ring

First round 1116 fps, stopped, picked up case, looked pretty good other than the ballooning which didn't even seem to bad.

Second case 1136 fps, stopped picked up case, noticed the large vertical split in it and decided not to shoot the remaining 18 rounds...

Not a hot load, it chrono'd at 1136 fps, but split nasty. I am really starting to wonder about Starline Nickel brass. I had this happen once a few years ago with Starline Nickel and 38 special - sent the brass to Starline and they said the brass was bad.

What do you guys think??? I gotta go and see if I can polish out the burn mark in my G20 chamber.... :(

Thanks,

Alan
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Last edited by alank2; 07-26-2012 at 14:52..
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Old 07-26-2012, 14:34   #52
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Originally Posted by alank2 View Post
Hi,

Well...I'm starting to get frustrated and beginning to question the brass...

I loaded up 20 more rounds:
10 of Blue Dot 10gr for 180gr GDHP, CCI 300, 1.250 oal, new starline nickel
10 of Accurate #5 9.6gr for 200gr XTP, CCI 300, 1.250 oal, new starline nickel

Only fired 2 rounds before STOPPING:



First round 1116 fps, stopped, picked up case, looked pretty good other than the ballooning which didn't even seem to bad.

Second case 1136 fps, stopped picked up case, noticed the large vertical split in it and decided not to shoot the remaining 18 rounds...

Not a hot load, it chrono'd at 1136 fps, but split nasty. I am really starting to wonder about Starline Nickel brass. I had this happen once a few years ago with Starline Nickel and 38 special - sent the brass to Starline and they said the brass was bad.

What do you guys think??? I gotta go and see if I can polish out the burn mark in my G20 chamber.... :(

Thanks,

Alan
Considering what you've seen so far, the serious case crease during sizing, what appears to be excessive case bulge, and the actual case failure, I would STRONGLY recommend having a VERY close look at your barrel/chamber. Measure it, and check it for cracks, visually, then magnaflux if necessary. Inside and out.

Also, consider the possibility the pressure signs aren't occurring while in the chamber. Try to fit one of the fired cases (before sizing, and not a ruptured case) back into the chamber. It should fit, even if it takes a little force to push it in. Match the orientation it was fired. If it doesn't fit, you have an issue with timing, or the chamber is cracked (expanding during firing).

Bad brass is certainly a possibility (happened to me this year). However, what you are seeing isn't all that can/does happen with a weak alloy and the charges you are using. If the primers are staying in, the pressure isn't great enough to cause the head to fail, and this should also apply to the case wall.
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Old 07-26-2012, 14:45   #53
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Bad piece of brass is always a possibility especially when split long ways like that pictured...

Your Blue Dot load should be Good to go but the Acurate #5 is a little too fast for the heavy 200XTP in my opinion! The same load of Blue Dot would be a better loading for the 200 grain bullet! It is what I use and have gone to 10.5 grains of BD @ 1180-1200 fps from the S&W1006
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Old 07-26-2012, 14:58   #54
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Considering what you've seen so far, the serious case crease during sizing, what appears to be excessive case bulge, and the actual case failure, I would STRONGLY recommend having a VERY close look at your barrel/chamber. Measure it, and check it for cracks, visually, then magnaflux if necessary. Inside and out.
Do you mean for a hairline crack or something? The chamber looks solid (at least to my eye) inside and out.

Quote:
Originally Posted by dm1906 View Post
Try to fit one of the fired cases (before sizing, and not a ruptured case) back into the chamber. It should fit, even if it takes a little force to push it in. Match the orientation it was fired.
It fits and freely rotates. I used the fired case in the picture above.

Quote:
Originally Posted by _The_Shadow View Post
Your Blue Dot load should be Good to go but the Acurate #5 is a little too fast for the heavy 200XTP in my opinion!
You are absolutely right, that was a typo, I am using #7. The BD load is the one that split the case!

When I pinged Starline about my earlier issues with the resize crease they mentioned:

Quote:
From past experience I would say that the radius on the die is not properly blended into the land of the die. Where the radius and the land meet you should not be able to see a sharp corner. This coupled with the fact that you are sizing it down to about .003” below the SAAMI minimum of .420”, and that it is being fired from a Glock are what is causing your problems. We make the brass to a diameter of .421” which works perfectly, so I would try to find a sizing die that is closer to that.
Shouldn't it tolerate going to 0.4165" to 0.417"? 0.420 wouldn't seem to offer much neck tension...

Thanks,

Alan
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Old 07-26-2012, 15:34   #55
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Hi,

By the way, the fired case that didn't rupture measures 0.424" at the case mouth, 0.428" in the middle, and 0.433" at the most ballooned part. It doesn't seem to be bulged on any one particular side or another, it is concentric.

Thanks,

Alan
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Old 07-26-2012, 15:39   #56
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Do you mean for a hairline crack or something? The chamber looks solid (at least to my eye) inside and out.
Yes. That is why I suggest magnaflux. If it were obvious enough to see easily, it would likely be too late (KB!).

Quote:
It fits and freely rotates. I used the fired case in the picture above.
It should fit, and sounds normal. Timing is probably OK, too. If it were overpressure or weak brass, the chamber ramp area should bulge greater, preventing rotation.

Quote:
You are absolutely right, that was a typo, I am using #7. The BD load is the one that split the case!
Whew! I saw that and started digging through load data (then saw you edited it). Your AA7 load is OK, and shouldn't be an issue.

Quote:
When I pinged Starline about my earlier issues with the resize crease they mentioned:

Shouldn't it tolerate going to 0.4165" to 0.417"? 0.420 wouldn't seem to offer much neck tension...

Thanks,

Alan
Starline is correct. Just seating the bullet (.400") will expand the case mouth to .422-.423", minimum. More than enough neck tension.

Even if your die is undersized, you are still blowing up NEW brass, and the brass isn't showing other telltale signs of overpressure. Something is very wrong here, and I think it may be your barrel. Either cracked, or oversize chamber.
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Old 07-26-2012, 16:00   #57
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Hi,

I moved your reply from the other thread to this one...

Here is what they look like after resizing.

The 10 Ring

Thanks,

Alan


alank2


I have a set of Lee dies that are undersized, and they are the EXACT twin to the brass in your picture with the big wide band around the bottom. Also when seating a bullet, I get a really pronouned buldge at the base of the bullet in the brass as well...

Put those dies on the shelf and said "heck with this.." That is a mess looking to happen.

I then talked with RCBS (which is about all I use any way) and they sent me a die .1K under sized and that problem went away, meaning the Lee die was a tad to undersized, and also the RCBS allowed for a better 'base" at the bottom of the die to go a bit further down.

All this will probably be sticks to swallow with folks, but all this taking the huge buldge out, and shooting, and taking it out, and shooting, one day, WILL have a pay day. Like putting ammo in and out of a mag all the time and weakening the spring. One day the place the "buldge was ironed out several times" is going to land at the six 'oclock area in the OEM barrel, and blow !

I promise you !


You can't place that type strain even on brass with out making it weaker in that spot each time.

The pics you have shown above here, withe the reall under sized squeezed down brass with the wide belt at bottom, begins to weaken the brass around the top part of that wide band at the bottom web area, and it 'will crack open'.

I don't know how you got a die so undersized with out ordering it, but that is what makes that band at the bottom, and ALSO will give you a REAL tight friction fit on the bullet and a decent buldge usually at the base of the seated bullet.

I shoot my hottest loads through the Stock G20 barrel, and use the RCBS .1k undersize to iron that out, and fire it 'once more', and then they get loaded down to 'popper' play time stuff. (when in the OEM barrel).

If I want to save brass life a bit, I use the LW barrel in the G20..

Some Guys say they get dozens of loadings, and even more some of them, with their hot loaded OEM barrels. Folks can get away at times for years of doing this and that, but one day..... !


I know a nut case that never checked his oil in his truck, I looked at it one day caused the motor smelled like it was burning... The dipstick was BONE dry . I ask how long it had been since he added/changed oil, he hung his head and said about a year or so.... (older truck btw). Well then it one day freezes up or blows up. Point made.

Point is: "One day." !


So, I also saw on page 3 here I think it was, your split case...

For many years I been shooting 11.0grs BD and 10.7grs BD, and 10.5grs BD With different cast bullets and XTP's and never a problem, at all in the stock OEM Glock barrel in G20/and G29. But again, I only shoot my hottest loads in them 2X, and then their loaded down. Use the AM barrel with ya want a "tad" more case life.


I had a split case (new case) the other day exactly like yours with WW new outta the sack. But was due to 'over pressure' in a load I fired.

The loads you describe are real common around here and else where in 180/200gr loadings in 10mm and They really aren't case spliters. "In this 'case' of yours, (haha) I can't tell ya cause I was not there. maybe a boo boo at the bench a flicker in the powder scale, Got one seated waaaay to short, a bad case.... You may never know.

OR... It may be that extremely squeezed down case (looks like to me at least in the pics on page 1) "bulding pressure", along with some other factors, especially IF you are having a tremendously tight friction fit and then a fairly tight taper crimp, and or if you are also seating a tad to deep, all this plus about one dozen other factors can cause problems.

If it were me, I would at least try another die, say RCBS carbide, and see if that doesn't stop the problem/s. I tell ya man, mine in that Lee, look to the nth degree just like those pictured on page one, and they were bad news...


Good luck !








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Old 07-26-2012, 16:26   #58
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OK amigo, I went in the gun room and ran two OEM fired cases from my G20 through the Lee undersized die..

Here they are:


The 10 Ring


Look familiar ?? haha They look EXACTLY like yours if I would have held the cell phone better i the low light I had the BELT would have been identical ! (pic was not that good)

i tell you, these cased just enough over pressure from such a tight fitting bullet (crazy sounding or not) they gave problems, and man will they roll around inside a stock Glock barrel ! PLUS the belt, as I said, (the magnum belt looking area) is a great place for blow outs.

Yes you can reload your brass from the oem... But get a better die arrangement and watch them "fit" better and work better....



Good luck






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Old 07-26-2012, 16:59   #59
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Hi,

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Even if your die is undersized, you are still blowing up NEW brass, and the brass isn't showing other telltale signs of overpressure. Something is very wrong here, and I think it may be your barrel. Either cracked, or oversize chamber.
Indeed, I would be very surprised that a little bit of undersizing (0.4165 vs 0.420" on NEW brass (0.0035) could be responsible for a case rip, but I suppose it is possible. Wouldn't the brass just expand until it hits the chamber wall and stop?

Quote:
Originally Posted by CanyonMan View Post
All this will probably be sticks to swallow with folks, but all this taking the huge buldge out, and shooting, and taking it out, and shooting, one day, WILL have a pay day. Like putting ammo in and out of a mag all the time and weakening the spring. One day the place the "buldge was ironed out several times" is going to land at the six 'oclock area in the OEM barrel, and blow !

I promise you !

You can't place that type strain even on brass with out making it weaker in that spot each time.
I couldn't agree more and I certainly don't want to remove the bulge or guppy from a piece of brass and keep using it again and again. Still, it sounds like people around here are getting a few reloads at least using the factory barrel with reasonable loads and that is what I am hoping to accomplish before considering an aftermarket barrel.

Quote:
Originally Posted by CanyonMan View Post
The loads you describe are real common around here and else where in 180/200gr loadings in 10mm and They really aren't case spliters. "In this 'case' of yours, (haha) I can't tell ya cause I was not there. maybe a boo boo at the bench a flicker in the powder scale, Got one seated waaaay to short, a bad case.... You may never know.
They were loaded this morning. I am used to powders that meter more uniformly than blue dot, I noticed that it is about +/- 0.1 grains compared to others I use which are a bit more uniform. My usual test is to operate the press in the way I normally would and measure 5 successive chargers, if I am going for 5.1 grains for example, then I want to see 5.1, 10.2, 15.3, 20.4, and finally 20.5. This method should ensure that I am within 0.02 of the charge weight I am going for and I can also see how consistent it is. With Blue dot this morning, it was like 10.0, 20.1, 30.0, 39.9, 50.0. The velocity was right on par with the first round and what I would have expected so I don't think it was an overcharge situation. I also checked each round with calipers and they were all 1.250 to 1.254.

So we have so far:

1. Sizing dies are sizing brass too small at 0.4165 to 0.417" and the vertical split is caused by it being undersized. I still wonder 0.003 is enough to cause a split like this.

2. Barrel issue of some sort. It looks good to me to look at, it really looks solid. The first case is uniformly expanded and fits and can easily rotate...

3. Brass issue. This one I am still wondering about. Especially since this happened to me one time a few years ago with some other Starline Nickel in 38 special. Could the nickel process do something to affect the brass?

Any ideas how I can test or eliminate any of these 3? I want to take baby steps now to figure this out...

One more thing I want to mention in case I didn't above - I have only used NEW cases so far.

Thanks,

Alan
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Old 07-26-2012, 18:19   #60
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Hi,

By the way, the fired case that didn't rupture measures 0.424" at the case mouth, 0.428" in the middle, and 0.433" at the most ballooned part. It doesn't seem to be bulged on any one particular side or another, it is concentric.

Thanks,

Alan
OK, then. I didn't have any similar rounds fired from my G20, with OEM barrel and spring (long time since I've used them), so I fired a couple I had loaded. 180 gr. LTCHC (.401"), 11 gr. BD, new DT brass, CCI 350, 1.260" COL. The components aren't the same, but pressure measurement is the goal, and this should provide that. It's my typical target round. I took a 2L pop bottle with me, filled with water and frozen (2 weeks @ -20°F...very HARD). Had to shoot something, and I was feeling like a snowcone.

Anyhoo.....The measurements....
Mouth = .424"
Middle = .429/.430"
Bulge = .433"
Head = .420"
Snug going back into the barrel, but fits.

For comparison:
Same round through LWD barrel, 24# spring......
Mouth = .423"
Middle = .425"
Bulge = .427"
Head = .420"

Same round through Blackhawk....
Mouth = .423"
Middle = .425"
Bulge (area) = .426"
Head = .420"

After Lee sizer (not BB) = .417" (mouth to bulge area). There was no indication of a "step", or plowing like shown in your pics. Very smooth transition to the .420" web area.

Sound familiar?
Your chamber isn't your problem, unless both of ours are broken, near exactly the same.

Back to square one, sort of.

I hit the bottle about 1.5" from the bottom, and it went through-through (from about 30'). Bottom 1/2 of the bottle/ice entered the upper atmosphere (just followed the case). The remaining upper 1/2 turned to "snow", and remained in the bottle. That was the plan (just flip it over). Damn....Forgot the syrup!
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