5R rifling

DJ Fergus

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Dec 25, 2015
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First let me say that, I have no concern whatsoever that this would have any significant effects on accuracy. Just stating some observations. I have some older 5R bartleins that I've borescoped in the past. They looked pretty much like I expected them to with the ramps from the lands into the grooves being equal. I have a newer bartlein that I borescoped a couple of nights ago. I noticed that the ramp on one side of the lands was longer with less angle. Not exactly, but similar to what a shilen ratchet land & groove might look like or similar to a Broughton canted land.

Have any of you fellows borescoped & noticed anything similar on a bartlein?
 

DJ Fergus

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Dec 25, 2015
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I might send them an email just to see what they say. I'm not really concerned about it just curious.
 

DJ Fergus

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This is bartleins response.

"It could be more shadow that’s making it look that way, please remember we're only talking about .0035" in height that we're looking at, basically a human hair.
I can assure you it's not like a Ratchet, I owned one years ago and have inspected several and they are only half a land, triangle shaped with no top.
We do grind our cutters with angle on both sides but sometimes the trailing side is shallower on 6.5 fast twist. Broughton's also are very different being a Button process, 5R is very difficult to pull without a large amount of twist variation which is why their shape is different than traditional 5R."



I think what I'm seeing may be due to: "We do grind our cutters with angle on both sides but sometimes the trailing side is shallower on 6.5 fast twist. "

Anyway, no worries about the barrel. Bore finish looks really nice.
 
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