When to set back a 6x47 lapua?

ultramagmed

ultramagmed

JKM
All,

I recently built a 6x47 Lapua, I've only had it done for a couple of months but, I have already fired nearly 700 rounds through it (just can't quit shoot'n the damn thing). It currently shoots in the mid .2's to low .3's. Should I wait till accuracy starts falling off or should I be more pro-active and set it back before that happens? I'm shooting 40.0 grs. of IMR 4350 under 107 SMK's, with CCI BR-4's making the spark. They're going 3209 fps. out of a Krieger 8 twist 30" tube. Any and all opinions appreciated.

Thanks in advance,
Med.
 
Well since no one else and commented here's my HO. First, I do not shoot a 6x47 but I nave worn out a few 6/284 barrels. By the time they went south, about 650 rounds or so, the first 4"-5" of the barrel were toast. But, that was varminting. When a varminting barrel starts spitting out an occasional shot shooting at pigs at 600, did the wind get me, did I misread the distance?? While this same spit shot happening at 600 in competition, they call that a DQ. And, in most varminting applications that is full case, wide open loadings.

This is not really a good comparison but you get the idea. The idea being in a powder heavy cartridge like that, the barrel probably is done for when you start doubting it. In the 600 yard benchrest game you probably aren't going for maximum velocity. Matter of fact, many 600 yard competition shooters, even with that extra case capacity, are still only clocking about 2950 fps or so.
 
Thanks Jerry,

I don't have a bore scope which is what I'm assuming you inspected your bore with. I know Jackie Schmidt sets his barrels back frequently, I just don't know what interval he uses. I am shooting the upper load window with this cartridge according to my ladder test. The gun still shoots good but, we're not shooting BR out here either. I would just like to get the most bang for my buck out of this tube so to speak.

Thanks again,
Med.
 
I would say since you only have 700 rounds down her, your should still be good, this is based on my past history using a case very similar (holds 49.7g of H2O). I don't shoot a 6x47 but I do have a 6mm-250 30 degree improved and have had a few barrels on it now. Side by side to a 6XC case, mine is a hair bigger and I now use Norma 6XC brass since it so close to my case. I use 37.5g H4350 and 105g bullets back then at 3070 fps and my first barrel spit out 3799 rounds in FClass comp (Gaillard 1:8 barrel) and it went from 1/4 moa the prior 2+15 (only a few X's off the then US Record at 800 yds) to "hard to hit the black" (44") at 1000 yds after a poor 900 yd too - 2+15's. Bore scoped, she was cooked for a good 8" and alligator cracked for about 4" more. Turned that one into a brass fire forming barrel. The next one, a Krieger 1:8, I took to 1686 rounds and 4" burnt out at this point, throat totally gone. Turned into the 6BR and this barrel is still shooting great with 474 rounds since changing it over. The new Krieger barrels (got 2 this time) which has had nothing but 115g DTAC and RL17 thru her and is doing really good (cleaned the 1000, just need more X's) at 1217 rounds but I have not looked down the pipe one that one yet and the 2nd one is still new, only broke in, like maybe 200 rounds tops. And guess what, if you look down the winning barrel at the next match, I would bet you and it's owner would say it is toast and I would bet he would not be winning anymore for awhile due to lost faith! The rifle will tell you when it is time if your shooting targets. Yes, the throat is probably gone by now or at least washing out at the 6 but if she is still shooting, who cares. If it bothers you, then do it, faith in your setup means alot too. You could shoot a post chamber and an after re-chamber target, but I bet your not going to gain much if any at 700 rounds. Heck, some barrel need that many just to start shooting really well IMO. Hope this helps ya' and let us know what you do and how it went.
 
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Thanks Keith,

I hate to be so persistent but, I'm preparing for my first match this September (tactical 3 gun) and a lot rides on the long range bolt gun portion. I know it's a long way off but, I want to be shooting the best that I can and considering the wait that is involved for barrels these days I don't know if I'll have a new one by then (hell I just lucked onto the one I've got). I am confident in my abilities and the existing chamber will make it an easy set back. Maybe I'll give it a few more rounds and then set it back; as I stated above the gun still shoots well. I actually just re-added and I'm right at 555 rds. as we speak but, I definitely don't want to lose faith in my or the guns' potential. I do appreciate you taking the time to reply and I will give an update on the results when I decide to do the set back.

Thanks again.
Med.
 
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