Throat erosion at 600 rds???

[DT400]

2014 Savage 12FV 22-250 varmint barrel, barrel is not stainless.
So this gun likes to shoot dirty so I don't clean the gun for 100+ rds usually.
So I am now cleaning the barrel real well getting all of the copper out.
This gun has always shot very accurately and it isn't much off form normal.
While scoping the barrel I found the first 2" or so of the barrel (throat area) has surface cracking pretty good. The steel looks like a dried out clay lake bed where it has all cracked up in various shapes.
I use this gun for prairie dog shooting and will usually get through 50-70rds during a shoot over a 6 or 7 hr time frame. The barrel gets warm but I don't let it get too hot to touch.
This barrel has around 600-700 or so rounds through it. I roll my own and shoot IMR4064 at 34.0 grns which gives 3660 fps with Nosler Varmageddon 55gr pills.
I intentionally keep the fps down since the 22-250 is known to be such a barrel burner and I want to keep the barrel as long as possible. It just seems that 600-700 rds is too soon to have this sort of issue.
The rest of the barrel looks great...other than tool marks form the rifling process.
I have a couple SAKO's (30-06 and .308) from the late 60's that look brand new in the throat area. I understand the 22-250 could be hotter in the throat but this seems excessive.....Is it?
Question is is this of a concern? I am obviously concerned that is why I am asking. I have not sent a query off to Savage yet but will.
Wanted to get your alls opinion on this.

Thanks

Darrell

[gbflyer]

Only a concern if it no longer shoots well in my opinion. I personally think that borescopes are a confidence trick invented by barrel makers. [emoji1]

[schnyd112]

Gotta agree with above. If it shoots, it shoots. The one takeaway could be there is no reason to load down, your barrel is consumable. May as well use it up before it goes bad.

I had a swift with close to 3000 rounds that was still a 3/4" gun before I rebarreled. I had no qualms going over 4000 with 50 g vmax, but it was fed a steady diet of 37.6 g 4064 and 55 vmax and smk's at 3850-3900 (tel:3850-3900).

[thatguyshm]

I picked up a bore scope as well, ran it down my 257 Weatherby. It shoots great but I have the same style of cracking for the first five inches or so. I just laughed about it. You pay to play my friend. I don't even have 400 down the barrel. But I will continue to shoot the rifle until it long longer groups and then I'll send it out for another barrel. The scope shows you visuals of your barrel but I still plan on going by feel with all my rifles.

[LoneWolf]

This is pretty much the standard for bottle neck cartridges. Pushing a lot of heat through a small hole (overbore). It's a trade off, you shoot it till accuracy becomes unacceptable, re-barrel, and start the process over. I'm on my 4th 6mm barrel in 2 years shooting it in Practical Precision matches. I expect to change barrels between 1400-2000 every time. Accuracy standard is 1/2 MOA or better for match shooting. Beyond that it gets sold off at a deep discount or becomes a practice barrel.

[DT400]

Thanks all.
I agree that if the barrel is still accurate that there is no need to replace it.
It still is capable of less than .25 MOA (actual shots at 200 yds can be .5" if I do my part)
It just seemed like it was a bad batch of barrels for it to heat check so soon.
I REALLY like to shoot this gun and was heartbroken when I saw the damage.

Darrell