My Ruger 77 Mk II VT in .22-250's accuracy has deteriorated since a few months, despite copper fouling control and slow firing. After checking with my Stoney Point OAL gauge, I found that the leade (ogive to lands contact) had eroded 3,3 mm (.12") in only 1300 shots* (= bullet out of case neck !). That's shocking, for it means the bbl. is already gone as it shoots best with bullets seated 0,5 mm (.012") off lands and I can't no longer chase that COL ! I'm thinking of having the bbl. set back and rechambered with a minimum lead + refreshing of crown. Another, more expensive, option would be to rebarrel with a .308 Win Lothar Walther. Any similar experience with the Ruger VT or advise ?

* MAX load of 52 Sierra MK / N 135 / 35.0 (= the rifle's accuracy load)

Have you ckecked every thing esle I just fixed a Ruger like that that was shooting badly. The stocked had cracked on it and it wouldn't hold a zero. The middle action screw hole was drilled at angle. I glass bedded the front and back of the action and fixed tha crack now it is back to shooting. That one was in 243 I put that many rounds through my 22 250 in one p dog trip.

Andre,
Check your scope.
dave

I did check rifle and scope. The problem is I'm no longer able to chase the ogive to lands seating this rifle likes best. Bullet to lands contact would mean a bullet out of the case (the throat set back .12").

What load are you shooting in it? I'm guessing it's a pretty high pressure load to get those kind of results. I had a savage .220 swift that I shot mild loads out of (55 grainers at 3500 fps) and it's lasted forever.

Andre

You can set back the barrel around 12 mm cut a new chamber and still save the barrel should be no problem for a qualified Belgium gunsmith to do this job.

Andre Sorry I answer what you said in the post , it means I agree with you in this solution

Saludos

Daniel

[ 03-04-2003, 12:57: Message edited by: Daniel M ]

Boltman, I'm shooting 52 Sierra MK / N 160 / 35.0. I know it's about a grain above recommended MAX but it shows no sign of overpressure and it's the load my rifle likes best. I also never "cooked" the bbl. which I only use at the range. Original grouping average of .35 MOA (which I was able to maintain by chasing the eroding lands) degraded to a present .75 and I can't no longer maintain the desired COL without having the bullet fall out of the case.

Andre, I'm a big fan of taking large cases and loading them mildly. After shooting a bunch of 3900 fps loads out of my .220 swift I realized the beer bottles I was shooting really didn't know the difference, so I started downloading it. Brass lasts forever, bore erosion is nonexistent. I know the prevailing theory is that a barrel has to heat up badly to erode the bore, but I believe (nothing to back it up with) that extreme pressures will do it as well. At any rate I like mild loads. I'd rather have a 300 win mag shooting a 150 gr bullet at 3050 fps than a 30-06 doing the same. Keeps things simple.

Andre,

I'm not surprised. Even my shihlen barreled 6.5x55 which has never fired a max load has appreciable throat wear after 600 rounds.

I don't think it is necessary to be on or near the lands for top notch non BR accuracy. The most accurate load in my 222rem is a 30gr berger which is nowhere near the lands.

That sounds to be right on in terms of throat erosion 10 thous per thousand rounds. That seems to be my experience on my Target rifles, but barrels are a throw away item on them. You could just change bullets to one with a different ogive that would allow you to have enough bullet in the case. The problem stems from factory chambers having to long a throat to begin with, most target chamber reamers cat a shorter throat so you can load to the lands and have room to "chase the throat" as it wears.

boltman- I think your right on, as pressure and heat are directly related.