RAW Rapid What to do with this .177 barrel .?

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Jaxjax

Jaxjax

Member
Oct 17, 2022
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Toledo Wa USA
I have a .177 barrel that mistakenly got the wrong button ran thru it. I'd like to save it but... These are the specs it's at & don't know if worth messing with.
Bore .1695
Groove .1766
Twist 26
No choke & Stainless
It's already fit for a BM RAW . most heavier/longer slugs are way tight. but smaller length slugs & pellets chamber & fire just fine. I have not tried to slow or increase speeds to proper levels for twist & pellet weight yet as I sent it back for the internal measurements listed above. I can get a replacement but I bet I won't get one for a year. If not savable, I'll have him toss it in garbage...lol
 
Jaxjax said:
I have a .177 barrel that mistakenly got the wrong button ran thru it. I'd like to save it but... These are the specs it's at & don't know if worth messing with.
Bore .1695
Groove .1766
Twist 26
No choke & Stainless
It's already fit for a BM RAW . most heavier/longer slugs are way tight. but smaller length slugs & pellets chamber & fire just fine. I have not tried to slow or increase speeds to proper levels for twist & pellet weight yet as I sent it back for the internal measurements listed above. I can get a replacement but I bet I won't get one for a year. If not savable, I'll have him toss it in garbage...lol
Click to expand...
That sounds like a strictly pellet barrel. And trying to fix it would cost you a too much to hopefully work in the end.
 
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Just off the cuff, the twist rate is way too slow for slugs, even for short lightweight ones. But considering it's already machined up and installed, might as well try stuff like the 10gr and 13gr JSB Knockouts.

That said, it might do really well with pellets at distance. Meaning not going squirrely at long range from being overspun, but of course the challenge to achieving accuracy at distance with pellets is the wind.

I'll add that the groove dimension of .1766 gives me pause, because it means the head of most production pellets will be in full contact with both the lands and grooves. In my experience that has not been favorable to accuracy, presumably because the increased bore friction tends to drive up the extreme spread when setting up the hammer strike for the typical "tune to the knee" method. So to compensate you can try increasing the hammer strike to tune it for something closer to the plateau, but that seems to have the consequence of diminishing accuracy due to excess muzzle blast. Just have to try it and see.

Beyond that, I would suggest doing some form of lapping. Preferably a cast lap but at least a bit of fire lapping. Otherwise my guess is mashing .177 projectiles into .170 lands is going to lead up the barrel so fast that it will may be difficult to properly assess the barrel's accuracy potential. Either way, be mindful of the possibility and once you find something that has promise, do a little experimentation with cleaning intervals and/or lubrication.
 
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nervoustrig said:
Just off the cuff, the twist rate is way too slow for slugs, even for short lightweight ones. But considering it's already machined up and installed, might as well try stuff like the 10gr and 13gr JSB Knockouts.

That said, it might do really well with pellets at distance. Meaning not going squirrely at long range from being overspun, but of course the challenge to achieving accuracy at distance with pellets is the wind.

I'll add that the groove dimension of .1766 gives me pause, because it means the head of most production pellets will be in full contact with both the lands and grooves. In my experience that has not been favorable to accuracy, presumably because the increased bore friction tends to drive up the extreme spread when setting up the hammer strike for the typical "tune to the knee" method. So to compensate you can try increasing the hammer strike to tune it for something closer to the plateau, but that seems to have the consequence of diminishing accuracy due to excess muzzle blast. Just have to try it and see.

Beyond that, I would suggest doing some form of lapping. Preferably a cast lap but at least a bit of fire lapping. Otherwise my guess is mashing .177 projectiles into .170 lands is going to lead up the barrel so fast that it will may be difficult to properly assess the barrel's accuracy potential. Either way, be mindful of the possibility and once you find something that has promise, do a little experimentation with cleaning intervals and/or lubrication.
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I would use it to learn lapping /polishing ! Unless you can get your money back as it is out of spec .
 
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The barrel maker has the barrel in hand & did the bore & groove measurements, his solution is just do another barrel but honestly, I don't like his attitude. I had to pay to have this barrel machined to fit RAW,...The barrel maker only will replace barrel & not for my machining costs. I had to refrain from telling him were to stick that barrel..... but there not cheap at 430 for the blanks. so I stayed calm. The bore is a mirror as is right now, & the pellets & slugs I tried actually didn't lead up that bad at all. Accuracy was bad on all slugs I tried but pellets did show some promise even at the the overy fast speed I was shooting at. I might just have it sent back & call it good . I'll maybe try some lapping as suggested. Yeah wind & .177 pellets can test my patience as I shoot .25 & .30 most times.
No refund available. Only another barrel blank done up is his offer to me.
 
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Jaxjax said:
The barrel maker has the barrel in hand & did the bore & groove measurements, his solution is just do another barrel but honestly, I don't like his attitude. I had to pay to have this barrel machined to fit RAW,...The barrel maker only will replace barrel & not for my machining costs. I had to refrain from telling him were to stick that barrel..... but there not cheap at 430 for the blanks. so I stayed calm. The bore is a mirror as is right now, & the pellets & slugs I tried actually didn't lead up that bad at all. Accuracy was bad on all slugs I tried but pellets did show some promise even at the the overy fast speed I was shooting at. I might just have it sent back & call it good . I'll maybe try some lapping as suggested. Yeah wind & .177 pellets can test my patience as I shoot .25 & .30 most times.
No refund available. Only another barrel blank done up is his offer to me.
Click to expand...
Just out of curiosity, how long is your barrel?
 
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This supposed to have been a 3g w/ Bore @ .173 & Groove @ .178
It is definitely not that :ROFLMAO:
PXL_20240910_202429142.PORTRAIT.jpg
 
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I worked a deal out with the barrel maker to ship this outa spec .177 back to me & they start a new barrel that will be supposedly .2200 x .2150 w/ 16 twist @ 28" in SS
My thought is to try a lap a choke in the .177 barrel. Since it's already to tight I could lap maybe 2/3 of barrel from breech end then test & repeat all in small increments. Might not work at all but what the heck anyway, can't hurt what's already broken
 
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