New build does not shoot. Need some help.

[Metzger]

Well I had put together my first "custom" rifle together. It seems to shoot really inconsistently.

300WM .050 FB 3.6 Match chamber 3B contour, Defiance anti, Mesa Precision altitude stock, Hawkins BDL, Wyatt MBE-3, Tigger tech.

Action screws 65in lbs
Scope 20 in lbs and 45 in lbs to picatinny Checked twice and re installed.

The "break in"

Remove oil from barrel then shoot
Shoot 2 clean copper and carbon, bore scope to make sure. used 150GR reduced recoil
Shoot 4 clean copper and carbon, bore scope to make sure.

Ammo used

180SST superformance
180Gr Winchester super X
200Gr Hornady ELD-X

Shot off a bipod and bag

Weather semi calm wind 3-4mph L to R 40* in the AM to 60* by noon

Confirmation took my 6.5CM and shot a sub 1/2moa group

Barrel temps low

Findings:

Before shooting trigger was touching BDL made clearance

BDL and wyatt mag box was rubbing BDL removed then shot the second to final group of a one hole with Winchester super X let cool and shot the final group of the day with Winchester Super X

 

[Jud96]

If the bottom metal is binding with the box magazine then that's causing your accuracy issues. If it was professionally bedded I would have thought that would have been checked, but mistakes happen. I would contact the gunsmith that bedded it and see what they can do for you.

 

[tobnpr]

Build yourself, or use a smith?
Is it glass bedded?
The action should be bedded in this stock, it's not a drop-in bedding block type.
Mesa even notes this in their description of the stock, they state:
"Paint is removed from receiver area for proper glass bedding and to save time from sanding."

 

[Metzger]

Build yourself, or use a smith?
The action should be bedded in this stock, it's not a drop-in bedding block type.

I had a "reputable" smith do the bedding and the barrel manufacture chamber and install barrel.

 

[Boe]

I would be looking at the Factory ammunition, Its very difficult to diagnose accuracy issues with inconsistent ammunition. If you or a friend are able to reload you'll most likely find your groups will tighten up. If not , you can at least start to look at other issues with the rifle as being the cause. I've seen alot of factory ammo throw a couple together then the rest all over the paper.
Richard Hilts
Hilts Accuracy Custom Rifles
www.hiltscustomrifles.com

 

[tobnpr]

^^^
This as well.
I see three of the 200's at around an inch- expecting better than that from factory ammo other than perhaps FGMM and Black Hills isn't realistic. Even then, handloads rule.

I'll add, that an ultralight, .300 Win Mag is not an easy rifle to shoot with bench-like precision, and I would venture to say most shooters can't do it as accurately as say, your .260. Perhaps you can- but recoil flinch/faulty trigger control is often subtle and you may not realize you're even doing it.

 

[Metzger]

^^^
This as well.
I see three of the 200's at around an inch- expecting better than that from factory ammo other than perhaps FGMM and Black Hills isn't realistic. Even then, handloads rule.

I'll add, that an ultralight, .300 Win Mag is not an easy rifle to shoot with bench-like precision, and I would venture to say most shooters can't do it as accurately as say, your .260. Perhaps you can- but recoil flinch/faulty trigger control is often subtle and you may not realize you're even doing it.

I have blackhills 200ELDX in my stash figured id try Hornady as they are all hard to find. I have had other light 300WMs this one is by far the best in terms of recoil control with just a brake.

 

[mtang45]

Barrel manufacturers do on occasion turn out a bad barrel. Had a new build about 15 years ago that started out its life just like this. No consistency, it was maddening. Tried everything from a reloading standpoint, different bullet types/weight, different powders, brass, seating depths etc. It never got any better. Finally had it re-barreled and presto, all better.

 

[MagMan]

What scope? Did you bed your rail?

 

[Jakeweb09]

I'd definitely try some handloads before saying bad barrel but it's possible. Seems like the bottom metal is your biggest culprit. Make sure mag box has some wiggle to it and isn't tight I've had that mess with a gun of mine before

 

[Lou270]

I had a similar issue with custom 300. Did all kinds of stuff with loading and factory ammo and even had the action milled so I could get closer to lands (it was built on a mauser 98). Then I noticed the cerakote was chipping by the bolt. Relieved it and shoots 180 accubonds very well now. This was put together by a reputable (pretty well known) smith, at least on other foruns. Good luck. Could be something small like that

Lou

 

[JAYgs8163]

I have this same stock also with a Hawkins bottom metal. We had some accuracy issues also. Ended up working the stock around the bottom metal and bedded the bottom metal also. Problem solved. Shoots sub 1/2 MOA now. Good luck.

 

[nksmfamjp]

What is different 6 to 7?

 

[Metzger]

What is different 6 to 7?

nothing changed