Criterion 300WM Neck Clearance

[brant89]

I'll take a couple thou off as was suggested. Any thoughts on whether this will improve accuracy or not? It currently shoots about 3/4 MOA but is very sensitive to seating depth. I'm not sure if this will have any appreciable impact.

 

[22Kreedmire]

I have a 300wm from them. I believe the reamer spec is .3407 in the neck. Mine is a 300wm match chamber. Throat is a little longer. I can run 215 Berger out a little farther than a saami throat. Let me try find all the spec they gave me and I'll edit this post

 

[brant89]

I have a 300wm from them. I believe the reamer spec is .3407 in the neck. Mine is a 300wm match chamber. Throat is a little longer. I can run 215 Berger out a little farther than a saami throat. Let me try find all the spec they gave me and I'll edit this post

Mine is also the match chamber so it should theoretically be the same reamer.

 

[22Kreedmire]

Mine is also the match chamber so it should theoretically be the same reamer.

 

[22Kreedmire]

Just measured a fired Winchester. .3379"

 

[brant89]

Just measured a fired Winchester. .3379"

So according to this I should have about .005 neck clearance which should be good and your fired WW brass is measuring nearly identical to mine. What kind of groups are you getting with your rifle?

 

[22Kreedmire]

That's .0027 clearance ... total. .00135 per side. Pretty tight. It shoots good. My load of 75.5 h1k and 215 bergers at 2.888ogive shoot cloverleaf at 100 typically. 2870fps

 

[22Kreedmire]

From loaded yeah .0047ish. So bacially .0025 per side. That's plenty. .040 off what I went with. The center group in the first pic. Then a different day I shot it again and came up with the same result. I shot it again last month before we went hunting and shot 2 one ragged hole and 1 off a hair still around .5". Shoots pretty good

 

[MagnumManiac]

I still run turn only necked chambers, but not tight clearance.
I ran into huge pressure issues running a tight clearance in my 338Edge, carbon rings appeared very quick due to this.
Nowadays I run a minimum of .003" clearance but prefer .004".
My best shooting 25-06, have 3 of 'em, has .006" clearance and is a SAAMI chamber. Still baffles me how it shoots so well. It often shoots into the .2'sMoA @ 300yards & 600yrds. Actually shoots better than my Sendero and is a heavy barreled Ruger...go figure. It was a great shooter right out of the box, so I dabbled a little with a Timney trigger set to 1.5lbs, glass and pillar bedded the stock and free floated the barrel. Worked a treat.

Cheers.