Knife edge chamfer

ChewyChewbacca

ChewyChewbacca

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Not sure what to do here.
I bought some “new” Lapua brass from a gent here and when I received them although they were unfired they weren’t what I call new. The inside chamfer had been done enough that the case has a knife edge on them. I can feel a ridge on the outside and when I take it so it’s smooth off the case now has a ragged edge to it.
I have found that Lapua brass is somewhere in the middle of min/max for case length so I trimmed one and when took the ridge off inside and out I still had the knife edge.
So the question to the experienced loaders here is: Is it going to make a difference one way or the the other in my load development accuracy wise using these cases?
I’m shooting from a bolt gun and not crimping.
 
Mystic Precision said:
Shoot, don't worry about it. Brass will lengthen with use and this issue will be removed in time.

Enjoy

Jerry
Click to expand...


Thanks Jerry. I just didn’t want to go through all the load development if it was going to make a difference on the accuracy. I measured some of the brass and the length is all over place. I’ll go through it all and trim it to the same length and start from there.
 
ChewyChewbacca said:
Not sure what to do here.
I bought some “new” Lapua brass from a gent here and when I received them although they were unfired they weren’t what I call new. The inside chamfer had been done enough that the case has a knife edge on them. I can feel a ridge on the outside and when I take it so it’s smooth off the case now has a ragged edge to it.
I have found that Lapua brass is somewhere in the middle of min/max for case length so I trimmed one and when took the ridge off inside and out I still had the knife edge.
So the question to the experienced loaders here is: Is it going to make a difference one way or the the other in my load development accuracy wise using these cases?
I’m shooting from a bolt gun and not crimping.
Click to expand...

I use a CNC Burr to chamfer the inside of my case necks on the Lapua Brass when trimming to OAL. Perfectly fine to do so.

Things it will do: Regrow and thicken in time. Ease bullet seating, As long as the cut is square, keep the bullet runout to a minimum as it eases the projectile in.

I have done this in my 204 and 6.5. Works great. No detriment to accuracy or brass life. Since it helps start the bullet gently into the neck, there is less neck runout after seating.

But be careful, that edge can be mighty sharp. I started this when I switched to bushings in my dies. Love the results.
 
Got Juice? said:
I use a CNC Burr to chamfer the inside of my case necks on the Lapua Brass when trimming to OAL. Perfectly fine to do so.

Things it will do: Regrow and thicken in time. Ease bullet seating, As long as the cut is square, keep the bullet runout to a minimum as it eases the projectile in.

I have done this in my 204 and 6.5. Works great. No detriment to accuracy or brass life. Since it helps start the bullet gently into the neck, there is less neck runout after seating.

But be careful, that edge can be mighty sharp. I started this when I switched to bushings in my dies. Love the results.
Click to expand...

Interesting.
Was always under the impression that when the case was run into the sizer die the thin edge would tend to chip.
I found that some of the brass had a ridge on the outside from being pushed out from when the inside bevel was made and when I took it off as gently as I could with the chamfer tool it left a serrated edge on the case lip. I did a couple and left the others be. You say that you use a bushing die which I don’t have so it’s going to be interesting to go through a cycle with this brass to see the results.
 
ChewyChewbacca said:
Interesting.
Was always under the impression that when the case was run into the sizer die the thin edge would tend to chip.
I found that some of the brass had a ridge on the outside from being pushed out from when the inside bevel was made and when I took it off as gently as I could with the chamfer tool it left a serrated edge on the case lip. I did a couple and left the others be. You say that you use a bushing die which I don’t have so it’s going to be interesting to go through a cycle with this brass to see the results.
Click to expand...

One thing I am not doing thus far is annealing my necks. This was an experiment of sorts to see if it would be a good substitute, and what the results would be.

So far. So good. The leading thin edge of the chamfer I agree with you seems to conform to the neck after seating. Good thing? Bad? For me I am inconclusive. But so far, some brass has 10 loadings on it, and is in good useable condition.

Some more experienced reloaders might call this practice bad or not necessary, and that is quite all right. The more I learn about reloading, and learning from others, and some trial and error, I can conclude that you never know what works until you try. And sometimes it is good to try methods that are not conventional to see what (if any) changes it makes
 
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