Please help me figure this STW out

[abrian]

Just finished building a new STW, im in a huge time crunch for a coveted Oregon antelope hunt in 10 days. I'm having trouble figuring out what the deal is and hoping someone can see something I'm not.

Rig: Remington 700 7mm STW with Pacnor 26" barrel 1:9 twist, Vais brake, McMillan Game scout stock, Jewell trigger, Nightforce NXS 5-22, Nightforce rings and rail.

The best powder/ammo combo is 73gr H4831 with Barnes 168gr LRX

PROBLEM: at 100 yards I can shoot 4 out of 5 rounds 1/2 MOA, but 1 out of 5 is always a flier at least 2 inches off the group. All velocities are close to each other. Barrel is clean each time I shoot a new 5 set. No rhyme or reason on which shot is the flier either.

ATTEMPTED FIXES: different powders(retumbo, h1000, & RL22), charges, bullets, different shooter, different rest, fowled barrel, factory ammo, checked tightness of rings and bases, checked action screws, barrel is bedded and floated, no over-pressure signs.

Am I missing something obvious? I can't seem to shoot a group without having an unexplained flier. I didn't spend the time and money to build this thing to have to worry about a flier. Again I'm in a time crunch to use this thing in 10 days, yes I have other options, but I want to figure this gun out.

Thoughts?
(I also posted this question in the STW threads)

 

[abrian]

Also, so far each round has been fired through brand new Remington brass with CCI Mag rifle primers

 

[winmagman]

Try tinkering with your OAL, sometimes .005 or.010 longer or shorter can tighten things up considerably.

Chris

 

[MudRunner2005]

I would ty a different powder like IMR 7828 SSC. 4831 is a really fast burning powder.

Also, try adjusting the OAL like was suggested.

Also, I have found H1000 and Reloder 22 to not be as stable as they say they are.

 

[idaho elk hunter]

First check your bedding especially around your recoil lug. Second free float the barrel. if it is a heavy contour barrel put a small pressure point at the very end of the stock. Third check the action bolts to see if they are torqued correctly. Changing powder or bullet seating depth is not going to cure the problem. It is within the firearm. The fourth remedy will definitely cure it if the above recommendations do not work. Send it to JE Custom.

 

[abrian]

Action bolts are tight. Barrel is free floated up to approx. 3" in front of the recoil lug. its a #4 contour. The only thing that is making me wonder now is, McMillan screwed up the barrel channel on the stock. So I had to have a smith inlet a little more so it wouldn't rub. The next time I shoot I am going to check to make sure its still free floating.

question: should I have it free floated all the way to the lug?

Thanks for the replies so far.

 

[idaho elk hunter]

Do not free float all the way to the lug! 3 inches might be a little extreme but it is not your problem. Back in the day we used to bed the whole length of the barrel! Some of those shot VERY good.
On a #4 contour you should put a pressure point at the beginning of the forend of the stock up against the barrel. It does not take much. A little will do. To see if this will cure or help the problem you can take poster board and fold it into the barrel channel till it contacts the barrel and applies a slight upward pressure on the barrel. Go to the range and do a 5 shot group in 3 minutes. If it doesn't work then its easily removable.

Free floating a barrel so a "cardboard box" can fit between the barrel and stock is a waste of time. Check it with a standard envelope that you would mail a letter in. Check to see if there is any resistance in the channel by sliding back and fourth. That is plenty enough clearance.

 

[abrian]

I will try the pressure point. I don't have a huge free float gap, just enough so I can snake a dollar bill betweent the stock and barrel

 

[idaho elk hunter]

The dollar bill method is also a good way of measurement. Many times we focus on the firearm and its working components "within" the firearm operating system. This is the mistake I am making here in my recommendations.

Check out the scope mounts, Scope base, Scope rings and make sure of the alignment, Lap if needed. See if the scope is shifting. Are you shooting the third shot in a hot barrel? The problem your experiencing could be external of the firearm.

Shoot 2 rounds and check the COAL of the 3rd round. If the neck tension is not appropriate, then the third round due to recoil could be shifting the bullet in the cased. This is pretty far fetched. But it could happen.

This is all anyone could on their own. If all of this does not fix it then I will resort back to my earlier recommendation of JE Custom.

 

[ShootnMathews]

Is the flyer always in the same location?? I have one rifle that as I was loadworking it always had one flyer in the same location. I shorted the seating depth slightly and the flyer moved 180 degrees of the last location. I split the difference between the two depths and now she shoots sub 1/2"@ 200

 

[ddgo]

You might have your firing pin checked to see if its straight. One of the first things we check on a rebuild. If its not tight bedded you can also check for deflection in the bedding. If its tight bedded I don't know if you can check for deflection. Anything more than .002 deflection is a problem
Ddgo

 

[Barrelnut]

Is the flyer always in the vertical or horizontal plane?

 

[RT2506]

It could be as simple as the NEW CASES. Neck or part size in a FL die some cases and just bump the shoulder and give your best load a try. I had a new 700 Rem 7 mag about drive me out of my mind trying to get it to shoot well all the time using NEW cases. When I ran out of new cases I part sized them just bumping the shoulder and it seemed not to matter what bullet I tried with a case full of AA3100 it would shoot bug holes.

 

[abrian]

Is the flyer always in the vertical or horizontal plane?

Vertical plane