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Posted: 4/8/2021 6:33:26 PM EDT
I had an slr107cr that I sent to a very reputable smith to get cut after I sbr'd it. He calls me today after he cut the barrel and explains that while the muzzle of the barrel was perfectly centered, the place where he made the cut was off center.
Anyone see this before?  Attached File Attached FileHe is sending it back to me but I'm worried about how it will shoot. How will tbis impact accuracy and what if I want to put a suppressor on it like a wolverine? |
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Posted: 4/8/2021 6:45:07 PM EDT
[#1]
I can't speak for anyone else, but that would piss me off.
I don't think it will affect accuracy much, once sighted in, but...  If you build what you want, with that barrel, are you going to be able to just forget about it? edit: Can you tell how I feel? |
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Posted: 4/8/2021 6:48:29 PM EDT
[#2]
Not uncommon, especially with hammer forged barrels.
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Posted: 4/8/2021 6:54:55 PM EDT
[#3]
Quote HistoryQuoted: I can't speak for anyone else, but that would piss me off. I don't think it will affect accuracy much, once sighted in, but... If you build what you want, with that barrel, are you going to be able to just forget about it? edit: Can you tell how I feel? As long as the accuracy is ok and I can mount my can on it, I really don't care. If anything, it would drive me to find a 107ur and make a suchka. |
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Posted: 4/8/2021 6:56:10 PM EDT
[#4]
Quote HistoryQuoted: Not uncommon, especially with hammer forged barrels. This one is and thats what we figured. Uneven pressure during the hammer forging... The question is how will it shoot? |
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Posted: 4/8/2021 7:07:43 PM EDT
[#5]
That bore in the barrel is NOT in straight line relative to the outside of the barrel. The bore is cut by something long and skinny and relatively weak (or the barrel is formed around something similar). The outside is cut by a lathe and the barrel itself is larger and stronger.
The only part (concentricity-wise) that affects accuracy is which direction the bore is facing at the point that the bullet exits. Think of a bent barrel like a krummlauf. Only the exit affects the direction its' headed. Same is true if the bore isn't in line with the barrel. I've heard that boring/rifling starts at the muzzle end just to make sure that it's concentric. Plus I think the rifling might be creating an optical illusion that isn't helping. |
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Posted: 4/8/2021 7:28:09 PM EDT
[#6]
Quote HistoryQuoted: That bore in the barrel is NOT in straight line relative to the outside of the barrel. The bore is cut by something long and skinny and relatively weak (or the barrel is formed around something similar). The outside is cut by a lathe and the barrel itself is larger and stronger. The only part (concentricity-wise) that affects accuracy is which direction the bore is facing at the point that the bullet exits. Think of a bent barrel like a krummlauf. Only the exit affects the direction its' headed. Same is true if the bore isn't in line with the barrel. I've heard that boring/rifling starts at the muzzle end just to make sure that it's concentric. Plus I think the rifling might be creating an optical illusion that isn't helping. That makes sense! |
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Posted: 4/8/2021 11:24:26 PM EDT
[#7]
Is there a burr in the bore on the thick side? The direction of the saw cut will leave a burr on the out direction. Look like it was cut on a band saw. The saw direction lines up with the thick side in your pictures (either in or out).
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Posted: 4/9/2021 8:04:56 AM EDT
[#8]
Quote HistoryQuoted: Is there a burr in the bore on the thick side? The direction of the saw cut will leave a burr on the out direction. Look like it was cut on a band saw. The saw direction lines up with the thick side in your pictures (either in or out). I'll have to see when I get the rifle back with the parts. It might be a bur on the part, but I know that the barrel side would be cleaned up and crowned appropriately. |
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Posted: 4/9/2021 9:34:57 AM EDT
[#9]
In Bulgaria baffle strike you.
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Posted: 4/9/2021 6:31:20 PM EDT
[#10]
Quote HistoryQuoted: In Bulgaria baffle strike you. I'll check it before I fire the first round. I have a 30 cal rod on order. |
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Posted: 4/9/2021 9:10:24 PM EDT
[#11]
I have a Remington .22 that I cut the barrel down. Where I cut it the bore looked a little more off center than yours. For the record it shoots fine.
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Posted: 4/10/2021 12:14:33 AM EDT
[#12]
That sucks
I have a Walther G22 (terrible gun, I bought it when I was 19) where the bore is very noticeably off center at the muzzle. Seems ironic since when sold in Europe it was available with a Walther suppressor so you would assume they were making decent quality barrels with concentric bore and threading. Mine had the threads turned down, maybe that was the reason why. I was too young to notice it for years. |
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Posted: 4/10/2021 3:14:47 PM EDT
[#13]
Quote HistoryQuoted: That bore in the barrel is NOT in straight line relative to the outside of the barrel. The bore is cut by something long and skinny and relatively weak (or the barrel is formed around something similar). The outside is cut by a lathe and the barrel itself is larger and stronger. The only part (concentricity-wise) that affects accuracy is which direction the bore is facing at the point that the bullet exits. Think of a bent barrel like a krummlauf. Only the exit affects the direction its' headed. Same is true if the bore isn't in line with the barrel. I've heard that boring/rifling starts at the muzzle end just to make sure that it's concentric. Plus I think the rifling might be creating an optical illusion that isn't helping. This. Spot-on. |
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Posted: 4/28/2021 10:56:38 PM EDT
[#14]
Back in the kit build days this was a common find on FAL barrels people cut down from 21" to 18". It's probably a lot more common than we realize.
While I'm sure there are others, HK is the only barrel maker I know of who has straightness measuring/testing equipment. |
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Posted: 4/29/2021 9:47:41 AM EDT
[#15]
This is not unexpected and not the fault of your gunsmith. I cut down an AMD barrel and encountered the same thing. It's not a problem unless you plan to put a suppressor on it, and even then it may not be a problem if your smith knows what to do.
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Posted: 4/29/2021 11:20:51 AM EDT
[#16]
Actually that barrel is not that bad. I have seen much worse.
Take a 24" barrel and cut it in half......most likely, it will be off center way more than that. Tony |
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Posted: 4/30/2021 1:29:47 PM EDT
[#17]
Quote HistoryQuoted: Actually that barrel is not that bad. I have seen much worse. Take a 24" barrel and cut it in half......most likely, it will be off center way more than that. Tony I just got a 30 cal rod and checked it against my muzzle device and it looked pretty good. Im going to try to shoot it this weekend. I'll check again once the wolverine gets approved and update the thread... |
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