equipment& tecknical

[mongrel284]

Hi all. New member here. Please forgive me for the dumb question here in this space. 7X284 project to neck turn or no neck turn this is the question

[AlanF]

Welcome to ozfclass.com. I used to neck turn with my 6.5-284 then went with a no turn neck with the 7mm and have no regrets. The Lapua 6.5-284 brass isn't perfect in terms of neck uniformity, but I don't believe its worth turning them in our game. There are other things you can do which give a better return on the time spent in my opinion. The short range BR fellas shooting in the 0s with 6PPCs maybe. I know of a few other 284 shooters who have stopped neck turning also. Opinions will vary on this of course. Without very thorough testing, its difficult to know what to attribute performance improvements to. I just base it on a general impression that velocity variation and bullet runout is no worse with unturned necks.

[mongrel284]

Thanks Allan. There seems to be so many different ways of doing things it can do ones head in. Maybe with everyone's experimenting I thought a patten might be happening.

[DenisA]

Alan, if you don't neck turn your necked up Lapua brass, I guess you must be reaming out the donuts or using hybrids?
My experience has been that the donuts that form in un-turned, necked up 6.5-284 Lapua brass, interferes with deep seated VLD's after aboout 3 firings in no turn chambers. Even with 2/3 only neck sizing. They will stop a bullet from dropping into a fired case.

I wish they were all as simple as a 6BR to prep.

[plumbs7]

I'm by no means a top shot so to speak!
But I wouldn't bother with a tight neck! I run a no turn neck chamber , all be it .308.

What I do is semi neck turn . Meaning I tidy up the neck and leave about 20% of the dull brass behind. As taking to much away could be dangerous and defeats the purpose !

Bullet runout is more important and also cleaning the necks with a scorchbrite seems to help!

Just my opinion , but I think one can fall into the trap of not keeping it simple ( stupid ).
A brilliant wind reader is worth a lot more 6's than x's . A t least that is one skill I'm always trying to prove on . Not sure if u ever master it!

Regards Graham.

[AlanF]

Alan, if you don't neck turn your necked up Lapua brass, I guess you must be reaming out the donuts or using hybrids?
My experience has been that the donuts that form in un-turned, necked up 6.5-284 Lapua brass, interferes with deep seated VLD's after aboout 3 firings in no turn chambers. Even with 2/3 only neck sizing. They will stop a bullet from dropping into a fired case.

I wish they were all as simple as a 6BR to prep.

Denis,

I have never had issues with the 180 VLDs and donuts - this could be helped by the fact that my reamer has more free bore than most (0.239") and also I size not much more than halfway down the neck.

Rgds,
Alan

[mongrel284]

If running a no turn neck on a 7x284. What would be the best clearance to have on your chamber at the start. As I heard that .0003. plus loaded, is better the a tighter clearance. And a very light neck tension. Thought please

[Brad Y]

I run a .318nk and do as Alan does sizing the top portion of the neck. I have used an inside neck reamer to cut out the donut as well but it does re form a little. Doesnt seem to make a difference cutting it out or not but do one or the other not half and half. My reamer has a slightly shorter freebore (0.220")

[shooter mcreid]

I thought it was 0.003" or 3 thousanths of an inch clearance between a loaded round and you neck chamber. you may have typed one to many zeros.
correct me if I'm wrong.

[AlanF]

My reamer has a 0.317" neck, and loaded rounds (no turn) measure 0.313", so that leaves 0.004" total clearance (0.002" each side). That seems to be a good compromise which doesn't overwork the brass, and is unlikely to be affected by carbon buildup, neck thickness variations etc. which may result in pressure spikes.

[Matt P]

I believe the bigger calibers require more clearance even in a turn chamber, I use 3.5 to 4 thou clearance on my rifles.
Matt P

[Brad Y]

Agreed Matt. I run 2-3 on a dasher, 4 on a 260 improved and about 5 on the shehane.

[AlanF]

Matt, Brad,

I presume by clearance of 0.004" you mean 0.002" each side?

Alan

[Brad Y]

That is what I am talking about Alan, yes.

[mongrel284]

Thanks guys. For your input .