Re: Can this thread protector be fixed ?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sbeckman</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kingarmory</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hink</div><div class="ubbcode-body"><span style="font-weight: bold">Thing is....many times, the bore is not concentric to the barrel OD.</span> </div></div>
Sadly, I've seen a few of those as well. Don't know how the manufacturer could botch a barrel up that bad but it happens. Had a Win70 heavy barrel here that was .006" off-center
It isn't very common though </div></div>
Not to derail the thread too badly, but I was trying to think through the manufacturing processes and understand how this happens?
I'm only familiar with one manufacturer of cut rifle barrels so my question is based on that process.
1. Blank is drilled undersize. This can leave the bore off axis, primarily at the muzzle.
2. Bore is reamed to something less than final bore diameter.
So it can still be off center.
3. Barrel is profiled between centers at specified length. This would seem to make the OD concentric with the bore?
4. The bore is finish reamed to final diameter.
5. Rifling is cut.
It would seem that the bore should be pretty concentric at this point?
If the barrel is bent somehow in the profiling process or the hole isn't straight, at the ends at least, the hole would be concentric, no?
Don't know about button rifled barrels but I would think that the profiling would be done after the drilling, reaming, rifling so that the same result would happen?
Something no doubt I'm missing here?
Thanks
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If it was turned between centers the bore would only be concentric at the very ends. After that, cut the barrel anywhere along its length and the bore may not be concentric at the ends any longer. The bore can wonder the entire length of the barrel. Just because it's concentric in one spot doesn’t mean it will be in another.