284 Winchester neck clearance

[kawsam62s]

Good morning how much neck clearance would a 284 Winchester need? I know my neck clearance is .317 off the reamer print. I had heard a wives tale that said after firing a cartridge you’re supposed to be able to drop a bullet back through the neck, thanks in advance!

 

[Preacher]

Some folks say it needs more clearance than other calibers, I like about .003.
Definitely need to be able to drop a bullet in a fired case or it's to tight in the neck.

 

[Buttstock-TX]

I have explored that recently with a new barrel and got the best results on paper with .004 clearance.

 

[Henryrifle]

@kawsam62s, if you are using Lapua brass then your loaded round neck should be around .313 Assuming unturned brass .004 clearance is generally fine.

If you aren’t experiencing pressure signs, then there is nothing to worry about.

measure a loaded neck and see what you get. I can’t drop a bullet in every fired case from every rifle. If this is a new problem make sure that area of the chamber is clean.

 

[1shot]

.004 total works well in my Shehane.

 

[FeMan]

0.004 is the minimum I load for in my 284.

 

[David Christian]

I target .005 to .007 of total neck clearance.

 

[Laurie]

From the 284 description and tips on the A.S. Main Site 7mm calibre section):

Advanced .284 Win Accuracy Tips
Charles Ballard, reigning 2008 F-Class Champion, is a leading .284 Accuracy guru. His reloading methods, described in his Gun of the Week feature, have produced amazingly good ammo. At 1000 yards, the vertical on his loads is amazingly tight. Over the chronograph he has achieved ES under 7 and SD in the low single digits (see CHRON VIDEO below). Read the article for all Charles’ secrets, but very careful brass prep is key. Pointing bullets using the Whidden Pointing system can also reduce vertical at long range. Chambering can play a role as well. Jerry Tierney, a past NBRSA 1000-yard champion and .284 Win “guru”, has observed that overly tight chamber neck tolerances can cause accuracy problems. Jerry says “some guys who were running minimal neck clearance .284 chambers weren’t getting the accuracy they expected. If you open up the neck to allow more clearance, say .0015-.002″ per side, that seems to solve the problems. I can’t tell you exactly why–maybe it allows a ‘cleaner’ bullet release–but easing the neck clearance has helped many .284 shooters get better results.”

The piece is a bit long in the tooth, but apparently still true. It's worked for me in both 284 and Shehane.

 

[kawsam62s]

Thx everyone
I have .005 of clearance with lapua brass
So that’s not my problem
My last range secession I was trying to find a load for 184 bergers using h4831sc or n160 would not group anything at all so I checked the brass first, last weekend with a different caliber on same platform shot fantastic so that leaves the 284 barrel as the problem ,inspection of the chamber looks worn so I’m going to cut off a inch and rechamber
Hopefully bring the life back!

 

[bulaman]

Good morning how much neck clearance would a 284 Winchester need? I know my neck clearance is .317 off the reamer print. I had heard a wives tale that said after firing a cartridge you’re supposed to be able to drop a bullet back through the neck, thanks in advance!

I am shooting 0.004" (0.002" per side) neck clearance in both straight 284 Win and 284 Shehane.

 

[kawsam62s]

Evening everyone circling back on this thread I did re-cut the chamber and now it shoots very well so success thanks for the help Scott

 

[fkimble@charter.net]

Sounds like you may have had a carbon ring in the throat. Cutting off and rechambering would definitely fix it!

Frank