Gunsmithing Question on bevel in chamber

[BigBrother]

My terminology could be way off here, just a warning

I was having some jamming problems with my Rem 700 with a DBM- rounds would get jammed in the action after not much forward motion of the bolt. I took it to a reputable local smith and he showed me the problem after some inspection - a small bevel, which usually exists right before the throat, didn't in my case, so the lip of the brass right before the bullet was catching on a tiny "ledge" before the round was being fully chambered. He beveled it a bit and it should be good to go.

I've been curious though- is that a common omission? Seems weird to me that a barrel at a mass production facility would be missing a key step in its production process.

Erg?

 

[border_reiver]

Re: Question on bevel in chamber

there's usually a slight chamfer at the forward of the neck, perhaps the brass was flowing into a void, something that didn't form correctly..how did he 'fix' it?

 

[BigBrother]

Re: Question on bevel in chamber

Chamfer was the right word, thank you. Rigged something that allowed him to add a slight chamfer without tearing the whole thing apart. Don't know more than that.

 

[border_reiver]

Re: Question on bevel in chamber

did he drop some headspace gauges in as well?

 

[BigBrother]

Re: Question on bevel in chamber

Ask yourself: does it really sound like I would know the answer to that question?

All I know is he was able to duplicate the problem I was having, showed me a few of the cases impacted at the lip, which corresponded pretty much dead on with the problems I was having. Did his thing, it cycles much smoother now in general (he also polished the feed ramp, and adjusted the seating of the DBM slightly). Other than that, don't know.

I was just curious about the chamfer, and whether stock barrels (not Rem custom or anything) usually have them.

 

[border_reiver]

Re: Question on bevel in chamber

I'm sure he did and apparently the case shoulder fits the chamber, but just an FYI for future reference, if a cartridge doesn't go in as planned always have headspace checked first. If one thing's wrong in the chamber, so might be somethin' else.

 

[BigBrother]

Re: Question on bevel in chamber

Ok, cool. I appreciate it.

Now, back to that original question.. experiences out there?

 

[eddieharren]

Re: Question on bevel in chamber

I don't believe the original poster was referring to the neck of the chamber. I believe he was referring to the very rear portion of the barrel shank or tenon. Sometimes a sharp edge will hang up on the mouth of the case, even when a bullet is seated, and prevent the cartridge from entering the chamber. A very slight bevel usually eliminates the problem. No need to worry about headspace issues as thes has no bearing on headspace.

 

[Hateca]

Re: Question on bevel in chamber

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DocEd</div><div class="ubbcode-body">I don't believe the original poster was referring to the neck of the chamber. I believe he was referring to the very rear portion of the barrel shank or tenon. Sometimes a sharp edge will hang up on the mouth of the case, even when a bullet is seated, and prevent the cartridge from entering the chamber. A very slight bevel usually eliminates the problem. No need to worry about headspace issues as thes has no bearing on headspace. </div></div>

I agree with this. The original poster said "jammed in the action after not much forward motion of the bolt". If this is the case the round never made it into the chamber.

He is talking about the edge around the bolt nose recesses or the mouth of the chamber.

 

[BigBrother]

Re: Question on bevel in chamber

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DocEd</div><div class="ubbcode-body">I don't believe the original poster was referring to the neck of the chamber. I believe he was referring to the very rear portion of the barrel shank or tenon. Sometimes a sharp edge will hang up on the mouth of the case, even when a bullet is seated, and prevent the cartridge from entering the chamber. A very slight bevel usually eliminates the problem. No need to worry about headspace issues as thes has no bearing on headspace. </div></div>

Yeah, I believe this was it.

So, once again, back to the original question - in your experience with them, is this a relatively common occurrence with Rem factory barrels or did I get a franken tube?

 

[BigBrother]

Re: Question on bevel in chamber

Alright, just talked with the smith again, got it explained more fully.

The spot in question, by the way, was the chamber mouth.

Turns out there *was* in fact a bit of a chamfer- not a total omission -just not what was necessary to support the fast cycling I was doing.

Anyway, thanks all for your help,
BB