Tight neck

[jsthntn247]

Does not enough neck clearance usually cause any other problems than pressure issues. Not sure what reamer was used on my 260ai but I can't seem to get a load worked up for it. I was checking brass dimensions last night and noticed that a bullet could not be forced into the neck of a fired round.

 

[jonbearman]

In my opinion and others .003-.004 should do it.You have almost zero clearance and is kinda dangerous.I would do a cleanup cut plus .001 extra and see what you have then. It will cause horizontal like it did in my no turn neck that turned out to be a disaster.I had to trim .004 off my brass total to get it to shoot.All is well know.

 

[Immike]

Absolutely agree, it won't shoot until you have enough release.

 

[Shynloco]

I've read and been told that AT A MINIMUM, you need a healthy .001 clearance. Personally, I'd be looking for .002 (or more). You could cause yourself some serious headaches with no clearance at all.

 

[lpreddick]

being unable to force a bullet into a fired case is not unusual in tight neck chambers. if a bullet falls into such a case the chamber neck may be quite large and the brass will be worked a lot. .001 clearance is probably very safe. my new 6 BR has the pt&g .2704 neck and loaded neck are .269! "everybody" was shooting this combo, so i did and the gun is a laser. the quickest way to know the diameter of the neck is to measure a fired neck after wiping off residue and add .0005(brass springback). then meaure a loaded neck at the pressure ring and subtract...anything .001+ is felt to be safe.

 

[LCazador]

You need .002" clearance at least. That's only .001" neck thickness. Without proper clearance pressure is going to be all over the place like a yoyo and translates into some pretty poor accuracy. Check you chamber length too and make sure you're at least .005" under that length. Besides poor accuracy and inconsistent velocity, improper clearance is also going to take it's toll on your brass, lost time in prepping and cost of replacing it! Hopefully you're cleaning that dreaded chamber ring on each cleaning, as that will cause even less clearance at the mouth.

 

[jsthntn247]

In my opinion and others .003-.004 should do it.You have almost zero clearance and is kinda dangerous.I would do a cleanup cut plus .001 extra and see what you have then. It will cause horizontal like it did in my no turn neck that turned out to be a disaster.I had to trim .004 off my brass total to get it to shoot.All is well know.

Ha, that's the answer I was hoping for, I'm getting horizontal stringing and havn't been able to get rid of it. Looks like I'm going to turn the neck .001 per side and see if that changes anyting.

 

[CatShooter]

Does not enough neck clearance usually cause any other problems than pressure issues. Not sure what reamer was used on my 260ai but I can't seem to get a load worked up for it. I was checking brass dimensions last night and noticed that a bullet could not be forced into the neck of a fired round.

I have several rifles in which bullets will not drop into the fired neck.

Before you turn necks, do your self a big favor and do a chamber cast of the neck with cerrosafe:

http://www.brownells.com/gunsmith-tools-supplies/barrel-blanks-tools/barrel-chamfering-accessories/cerrosafe-chamber-casting-alloy-prod384.aspx )

... all you need in thee neck is 2 or 3 thou larger than loaded case neck.... which might not except bullets after firing. If you DO not have enough clearance, you will know how much to turn.

Without doing a cast, you are just cutting up necks in the dark.