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chaz

Inconsistent Neck Tension.

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Catch

I do give them a bit of room - I have a sinclair runout gauge so I will do a bit of proper testing along the process rather than just measuring the old seated round

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Right - I have had a bit of a play with interesting results

I took my redding match bushing die neck die and shoulder bump/body die & comp shell holder (variable depth) set and tried a few cases

In short I found that where the original runout of the fired case was good - 1 thou or so - the redding combo elegantly sized the cases to give me exactly the should bump and neck runout I was looking for - however any neck thickness imperfections will now be on the inside of the case neck of course

However when the fired case had run out of 4-5 though (I know they should be perfect but they were not) the combo did not correct the misalignment on any occasion !

I then had an idea and went rummaging for an old lee set and found the FL die - it was a bit manky with lube visible inside - an yet it corrected the runnout on all cases ?? - the neck tension would now likely be too much for my tastes however

I am starting to wonder if my shift to redding comp dies (based on the fact that I don't like the fact you can't clean the lee dies, I can't get the decap pins out and an overall sense that they are beautifully designed and poorly built) is achieving anything. Clearly they work for people but I wonder if a combo of a Lee FL die + redding comp shell holders to allow correct 2 thou shoulder bump plus a lee collet neck die would be the way to go. Would work the brass a bit more but the AMP annealer could offset this a little.

I am not invested either way (apart from all the money redding dies :wacko: which I would chalk to experience)

The point is - it is clearly not the press or the shell holders that are the issue - either it is the redding dies - the should bump / body die not doing enough or I may have set them up wrong

Any thoughts??

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All my rifles shoot great so I've no need to do this process.

Not sure how jamming the bullets up the tube affects it.not something I do either.if anything would affect runout that might

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Hobbit - just wondering how much you're trying to size the neck down. If it's a tight bushing, so you're reducing the neck diameter quite a bit over one sizing operation, this can introduce poor concentricity (so I've heard).

If the Lee die is reducing the size of the neck LESS than the Redding bushing ( 0.002" vs 0.008" for example), that might be why you're getting better results with it. Dunno just a thought.

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Another thought, does your Redding neck die have the Expander button/ball still in it? If so, take it out and try again. I've seen / experienced countless problems with the expander button.

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expander mandrel is out - I need to check neck sizing by the Lee FL die

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Taking the expander ball off will give you too much neck tension.i proved that with my forster 6.5x47 benchrest die set 2 thousandths over the expander.6 thousanths with it off.try it yourself and use the one with the least neck tension.forget the runout ;)

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On 17/04/2018 at 5:16 AM, chaz said:

.......

However, the neck tensions were all over the place!

I could really do with some constructive advice here folks....:(

Try an expander mandrel (as opposed to using the expander ball that comes with your FLS die) after running the fired cases through your FLS die with the ball removed. The mandrel will require lube, I find Imperial dry lube adequate although sizing lube is better but then needs to be cleaned out. Look up K&M for a mandrel, a neck turning size will be OK for light tension, although you might want to go smaller.

 

 

 

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3 hours ago, Martin52 said:

Try an expander mandrel (as opposed to using the expander ball that comes with your FLS die) after running the fired cases through your FLS die with the ball removed. The mandrel will require lube, I find Imperial dry lube adequate although sizing lube is better but then needs to be cleaned out. Look up K&M for a mandrel, a neck turning size will be OK for light tension, although you might want to go smaller.

You read my mind Martin. After 3 weeks waiting, for the so called 'Brownells UK' (NOT!) delivered my Sinclair mandrel sizing die arrived. Along with a neck turning mandrel, and dry Sinclair lube. Although, i'm not decided on whether to use the dry lube on the mandrel yet...

Excuse my dumbness, but am i right in thinking the 6.5CM neck turning die will give me 1 thou of a tighter fit than the 2 thou sizing mandrel?

Cheers

Chaz.

Just to add, thanks for all the replies folks, much appreciated...

 

 

 

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4 hours ago, chaz said:

Excuse my dumbness, but am i right in thinking the 6.5CM neck turning die will give me 1 thou of a tighter fit than the 2 thou sizing mandrel?

Yes, the turning mandrel will give you a touch more neck tension. In the case of the 21st Century .204 mandrels I happen to have in front of me for e.g., the turning mandrel is .2015 and the expander is .203 i.e. the turner will give 2.5 thou neck tension, the expander 1 thou.

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23 minutes ago, GT3_richy said:

Yes, the turning mandrel will give you a touch more neck tension. In the case of the 21st Century .204 mandrels I happen to have in front of me for e.g., the turning mandrel is .2015 and the expander is .203 i.e. the turner will give 2.5 thou neck tension, the expander 1 thou.

Cheers Richy. 

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Think of it like this, the larger the mandrel diameter, the less neck tension/bulletgrip there will be.

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Cheers Martin. Got my head round it now..

I believe i've sorted the neck tension issue out, and as a consequence also have less run-out. Albeit, only checking by eye and rolling the finished round on a flat surface. So hardly scientific...

I first decap with a Lee de-capping die. Then FL size my brass with my fixed (non bushing) basic Hornady FL die without the expander ball and decapping rod. I then use a Sinclair neck sizing die, with the neck turning mandrel, giving me 2 thou tension. 

Again, not scientific, but using the Hornady bullet seating die, and my basic single stage Lee press, it feels like the same pressure is needed to seat my bullets. Whereas before, i could definitely feel a variance in the pressure needed to seat the same bullets.

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2 hours ago, jcampbellsmith said:

That's the one JCS. You have to be a little careful as there is an internal larger one. But the one you've put the link to is the right one, (for 6.5CM or lower. Certainly less than .50 cal). I like the fact that the sizing mandrel isn't held in place so solidly like the mk1, which can push the neck out of concentricity. Where the new one has an inner o ring. So as long as you don't screw the top on too tight, the mandrel will enligne itself to the neck. I personally like the 2 thou neck tension, and won't be ordering the 1 thou neck sizing mandrel...

Chaz 

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