Throat erosion in my 20BR

[jimmy1937]

I have shot about 350 round in my 20BR so far. Measured throat erosion last eve. , about 25 thousands. My load has been 30.5 grains varget using 39 grain blitz kings. Measured velocity at 3850-3900. Is this amount of throat erosion normal wear in the 20BR. Thanks Jim

 

[topwater225]

Good question.....I don't have the answer, but I have roughly that many rounds or more down mine. Shot it today and still shoots small bug holes. My load is 29.5 RL 15 and 55 grain Bergers.

 

[LCazador]

It all depends on how fast you shot those shots, but that sounds about right. The 20BR is a barrel burner, a lot of powder vs. the bore size. That is one of the reasons I shoot the VarTarg. The 20 BR was initially started for benchrest "group" shooting, ie; smaller bullet, smaller group. That thought never really took over the 6PPC's reign. What weight bullet are you shooting?

 

[fdshuster]

"The 20BR is a barrel burner". Yup ! And a 17BR would be even worse. Reduce the bore diameter, but keep the same case powder capacity and the results speak for themselves. The cost of high performance.

I had a 22BR for several years and the barrel life was a little better than the 22-250 that it replaced. I used approx. 26 grs. of powder in the 22BR versus approx. 36 in the 22-250.

 

[DogBuster]

Had one...its been rechambered to 20/222

waiting for it back sooon from P-N....9 twist/3 groove...

Had 1100 rds out....they were to X/section the chamber for me....

 

[TimP]

Some of what you are thinking is erosion may just be the reamer fuzz smoothed out. I had a .243 Win that after 200 rounds my seating depth changed by .030. Checked it with a bore scope and the throat looked fine. That barrel lasted 1200 rounds and was fire cracked pretty good by 500. The price you pay for an overbore cartridge.

 

[fdshuster]

Tim: I had 3, 243 Winchester chambered barrels. A factory Remington, a Douglas chrome moly & a Shilen stainless. All firing was single shot, slow fire with moderate loads, and they were all toast & ready for the scrap pile at an average of 1400 rounds fired, so your 1200 is close to what I got.

I began to see some serious firecracking also at between 400 & 500 rounds fired.