Normal throat erosion?

[bailey1474]

Last night I decided to load a few more shells for my .243. I already had all the case prep done so all I had to do was throw some powder and plug the case w/a 105 gr Amax.

While I was letting my Lyman DPS warm up, I decided to use my Stoney Point OAL gauge to make sure my old seating depth was still OK. What I found concerns me a bit.

A few months before, when I worked up this load, 2.285" OAL w/the SP gauge was .020" into the lands. Last night I got consecutive consistant readings of 2.290" to the lands!!!!
I then adjusted my seating depth to 2.310", so it would still be .020" in.

I had noticed the rifle was not shooting as well and I was getting much higher ESs and SDs than I used to. This was part of the reason I checked it. Is this normal to see this much erosion after 500 or so rounds?

Thanks for the info,
B.J.

 

[ss7mm]

Seems like a lot of errosion for that amount of shots, but anything is possible.

One question I would have is, are you using the same bullet you used in your original measurements?

When I set up a case for use with my Stoney Point OAL gage I use a bullet of the exact type and style that I will be firing and then that bullet stays with the gage. There could possibly be slight variations in the measured oal of different bullets so if you set a bullet aside and keep it with the gage then you will be measuring each time with the same bullet and don't have to worry about any variations.

 

[bailey1474]

[ QUOTE ]
When I set up a case for use with my Stoney Point OAL gage I use a bullet of the exact type and style that I will be firing and then that bullet stays with the gage. There could possibly be slight variations in the measured oal of different bullets so if you set a bullet aside and keep it with the gage then you will be measuring each time with the same bullet and don't have to worry about any variations.

[/ QUOTE ]

That is exactly what I did. I used the same bullet for both measurements.

I can't say that I've ever shot a rifle this much, so this is all new to me!! I've shot more in the last year than I did in my first 26 yrs of life /ubbthreads/images/graemlins/shocked.gif.

 

[nowler]

by my poor math, you have had 25thou errosion over 500rounds? is that right?

depending on what kind of barrel it is, you can get 10 - 15 thou erosion over the first 100rounds through a new barrel under normal conditions, this being the case, you've had another 10-15 thou over 400 shots? nothing unusual here.

given that a lot of shooters pull barrels at 100thou of erosion, seems like you are in the normal acceptable barrel life to me. somebody will maybe correct me kindly if i am wrong. i wouldn't be worrying about it if i was you though.

 

[bailey1474]

It is just a factory Savage and probably has around 800-1000 rounds through it now. It was just 500 since I last checked the throat. I have never shot a rifle as much as I have this one and have sure never checked the throat length. I was just curious if this was on par w/what everyone else was seeing in their bbls.

I'm not too worried about it. That 105 Amax will be able to chase the lands for quite awhile. Besides, when it's shot out, that just means I have an excuse to get a new one!!!