Fire Lapping?

[kleven626]

Me again,
Just got off the range and notice something. After 10-15 shots my pattern opens up from 3/4" to 5". My first 3-4 shots will be 3/4'' and 4-8 will be 1-1 1/2 and after that 3-5''. This is all at 300yds. After 20-25 shots I go home in discuss and clean, load some more and head out and the second verse is the same as the first.
The only thing I can think of is that the barrel is fouling out. I run Butchs Bore Brite and have cleaned with JB's.
I shoot a Remington SPS .308 tactical. 20'' barrel.

My load is 4x.7 of varget, 155 lapua scenars and brass. loaded into the lands .001-2.

Like I said earlier my first 3-4 shots I can cover with a penny at 300yds after that EEEERRRR.

I was thinking a treatment of Tubbs Final Finish?

Thoughts?

 

[cmillard]

you can't expect the world from the factory remington barrels. sounds like you need to get yourself an arbor press and some wilson dies etc so you can load at the range. while loading, that would be a perfect time for some hoppe's to sit in your bore.

 

[kleven626]

Explain?

 

[rocketron]

do you leave the barrel cool down?

Ron

 

[whiskey08]

I was said the other day that I thought varget leaves alot of fouling because I noticed that my accuracy dropped out at 40 rds.

Id bring it down to 100yds just to eliminate most of the weather conditions. Then id start shooting till my accuracy is gone. Then id clean the barrel on the spot if your accuracy comes back you know for certain what it is.

Id look at lapping with some 600 grit and 1000 grit compound before i fire lapped. Id think youd get better results and it would be easier for you to control the lapping, you can also feel any rough spots on the barrel as your doing it. My buddy does is it on his remington rifles, afterwards the barrels clean much easier, and he doesnt loose accuracy.

 

[Longtrain]

Somethings not right.

Does your barrel shoot well after being cleaned or does it need a few fouling shots to settle in?

Have you discounted scope, mount issues? All tight? Can you try another scope to remove that variable? Are all bedding screws tight to spec?

If those ring out ok, clean and shoot, hopefully getting your predictable results, as soon as your accuracy drops off, clean again and see if you accuracy returns.

I have fire lapped using Tubb's stuff on a Savage barrel, it worked as far as smoothing the barrel, accuracy was good before and after. The main reason I lapped was to make cleaning easier, eventually I replaced the barrel.

You don't say if you shoot competitively, if you do, you need accuracy for at least 80 rounds, hopefully more, so your barrel going south at 25 isn't acceptable in my book.

So IMO, if you can't improve your results, try Tubb's stuff, if it doesn't work replace the barrel with a decent one, it will save you so much pain.

Good luck

Tony
Longtrain

 

[Quackaddict]

I don't buy the "Varget is Dirty" explanation, I use an almost identical load of Varget and 155 scenars in my savage 308 and it shoots that load as long as I can pull the trigger without doing something stupid. At 100 yds it groups in the .4's and .5's, and I clean maybe every 200 rnds.

Maybe I just got lucky but I don't even get that much change from my Ruger pencil barrel in 270 win.

How fast are you shooting? I would suspect heat before needing to clean.

 

[bheadboy]

I dont think loads are the problem, something is moving after the gun heats up, what is the bedding, free float, the rem recoil lug needs to completely beded so it will not move on recoil and often the factory setup is not good in this

also i would back off aboutg 1/2 gr on the loads.

Bob

 

[kleven626]

My speed is 2770fps. I have warne rings and a 20moa picatinty rail. I thought the heat thing to. Thats why I would shot 10-15 and go down and look at targets. By the time I get back the barrel would be cool. Shoot 10 more and the groups would be just as bad or a little worse. Everything is tight. Like I said it shoots good for the first 10 but after that...

 

[gme]

.001-.002 in to the lands?
Gary Eliseo

 

[bshaw]

I'd would think bedding also. I have a Rem 700 .308 SPS varmint on a Bell & Carlson stock with the barrel free floated. It still has the factory barrel with 3750 rounds down the tube. I fire lapped it after 200 rounds, it tightened up my groups somewhat but it really made cleaning simple. I clean the barrel well after around 200-300 rounds and never have any copper problems. I do run a patch down it with Kroil after shooting but only to knock out the big stuff. My load is 44.5 g Varget 175g SMK at 2734 fps it will hold MOA from 100 - 1000 yds if I do my part. You can try the Tubbs it can't hurt, but I would look for barrel contact with your stock

 

[tyler 56]

i had the same thing to say as bshaw i have a rem 700 sps varmint bull barrel with factory stock the more i shot even with cool down period i had wild groups when i got a bell and carlson stock my groups stayed consistant at 1/4" moa at 100. i dont think its the varget fouling but i could be wrong. hope i helped