2500 rounds of 75 ELD Match through a 223 and ZERO throat erosion??

[DellaDog]

Can this be possible?

For the first 2000 rounds (24” MullerWorks) the barrel easily shot .25” I never chased the lands because every time I checked, the measurement was within a couple thousands from the first measurement.

But now it wont hold under .75” with identical load.

Tried Berger 85.5s and they will hold under 1/2”. Berger 70 VLDs will shoot 1/2”. Got me thinking.

Is it possible somethings not right and I’m not hitting the lands when I measure the 75s and they’ve gone to shit because I’m way off the lands?

Can a barrel be fed a steady diet of 24.1 grains of 4895 and 75 ELDMs and have ZERO throat erosion?

Thanks for any input.

 

[whatsupdoc]

Not even remotely possible.

 

[DellaDog]

While I agree it defies all logic, I've carefully measured and remeasured using the Hornady gauge, and it measure 1.885, damn near exactly what the measurement was over 2000 rounds ago. I even jammed the damned bullet in there till it stuck hard, and the measurement was still within a couple thousandths.

Made me think, maybe I'm hitting something hard, like a carbon ring, so I scoped it. No ring (besides, I measured new at 1.885)

Maybe its hanging up just at the neck where the fire cracking in the pics? The pics run from the neck up trough the barrel. Not exactly pretty, but nowhere near as fire cracked as the last 6.5 I replaced.
(I ordered some foam wipe out patch-out to better attack the copper)

Stumped and confused.

 

[702lineman]

I went through the same shit. It is the bullets!!! A friend of mind also did it and there was another thread on the exact same issue a couple weeks ago.

I even spun up a new barrel for mine!! Still shot hornady like shit. So I measured some of the bullets in the new lot I had and BINGO. .035 difference bto!!! My friend had a lot that the diameter was undersized pretty badly. I tried the 85.5 bergers and bugholes.