.035 throat erosion in 450 rounds

[K redden]

Checked my new dasher after 450 rounds, to find .035 of erosion. I'm consirned about this ,because my 6br has moved half this much in 1500 rounds. Here is the specs on the dasher. Krieger 1-8 twist , 32.3 grains varget, 105 amax . This barrel was broken in correctly with very little copper fouling. It has not had a brush in the bore and gets cleaned with wipe-out. It also seems hard to keep my load in tune now.
Any info appreciated on this. Thanks K Redden

 

[JCardenas]

Pm in bound

 

[Dusty Stevens]

May be your reamer design. Did you spec your reamer or get one off the shelf?

 

[chkunz]

What do you think your tolerance is on your ability to measure throat erosion?

 

[mac86951]

Likewise, what is the erosion on the last 100 rounds vs. the first 100?

We would assume that it has eroded in a linear fashion, but it may not be. I'd check it again at another 100-200 rounds.

-Mac

 

[K redden]

I'm going to start watching the erosion closer over the next 100 rounds. I believe it wore a little bit more in the last 100 rounds. It kind of snuck up on me with fire forming, load testing and finally getting a load tuned, just to chase the lands. I fell good on the measurement on this, as Dan Dowling cut me a critter out of a barrel stub for these purposes. Thanks for the info K Redden

 

[r bose]

Same sort of question asked by someone shooting a 6x47 couple days ago. He had 90 thou erosion in 1000 rounds.

My 6xc, (this is my first "6") has eroded 120 thou in 1267 rounds. Seems to me that if you push any "6" over 3K FPS (and some go way faster than that) they are gonna go quickly. I was very surprised at first. I'd only shot 223 and 308 before and never saw this kind of barrel wear.

 

[mikecr]

I wonder if part of it is just the throat angle reshaping and allowing your bullet ogives deeper penetration.
For instance, many use 1.5deg throat to begin, and this in no way matches bullet ogives.
So if it just wears a tiny bit, the bullet could be seated further out(as a step change) to stop against it again.
With this, I would think the 'erosion' observed would level off -until actual erosion -which will really take off.

 

[racesnake]

Mr. Redden....do you have access to a borescope? It would be interesting to know what the bore looks like.

 

[GrocMax]

I wonder if part of it is just the throat angle reshaping and allowing your bullet ogives deeper penetration.
For instance, many use 1.5deg throat to begin, and this in no way matches bullet ogives.
So if it just wears a tiny bit, the bullet could be seated further out(as a step change) to stop against it again.
With this, I would think the 'erosion' observed would level off -until actual erosion -which will really take off.

I wonder about the value of the shallow angle myself. .006" land height 1.5 deg leade its a .229" long ramp. We're going to measure 'erosion' by seating depth to touch the lands, .035" in this case is really not much wear geometrically.