NECK SIZING

Get or give advice on equipment, reloading and other technical issues.

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twotwothree
Posts: 18
Joined: Thu Jan 05, 2017 5:00 pm

Re: NECK SIZING

#31 Postby twotwothree » Tue Jan 02, 2018 9:29 pm

michaeljp65 wrote:What sort of rifle is it? Tikka 243 or 308 or similar? I don't think its rifle related, seldom is if reloading yourself. In regards to the ring around the case head. Get a paper clip and straighten it out with a small hook at one end. Run this hook down the side of the case till you hit the bottom. If you do not feel anything near that mark around the bottom, don't worry about the marks. I have some cases now that have a ring around the base and I'm not at all worried, it may have come from the die.
Hard to lift bolt and hard to extract It sounds like you are not setting the headspace correctly. You need a headspace gauge a set of verniers to measure your fired case headspace and set your sizing die to match, and a good quality FL/bushing die. Once you have these tools it will all seem very easy to get right.

Rifle is a t3 in 6.5x55 brought new removed the barrel and had a lilja barrel fitted and the reamer came from jgs in the us. I will try the paper clip method tomorrow. It has accured to me that a 6.5x55 and a 308 do not share the same shell holder i wonder if this is a problem as I am lead to believe I need a 308 bolt face. I have a 308 in the safe i might have a look

bruce moulds
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Joined: Sun Jun 19, 2005 4:07 pm

Re: NECK SIZING

#32 Postby bruce moulds » Wed Jan 03, 2018 5:49 am

here is where i would put my money if you are not overloading.
when you shoulder bump, brass has to go somehere.
if the body of the case is not supported, the case body can expand as the shoulder pushes back.
the tapered nature of the 6.5x55 will sow this faster than say a 308.
to successfully shoulder bump, the case walls must be supported, and a min fls die is the way to do it.
then the moving brass can only move forward, and must be trimmed off.
there are die manufacturers that can produce such a die for your chamber if you send then 3 twice fired cases.
a min fls die will not move much more brass forward than a neck die, hardly requiring any trimming, and therefore not causing cases seperations.
the tapered cases can almost have another type of headspace on the tapered walls.
keep safe,
bruce.
"SUCH IS LIFE" Edward Kelly 11 nov 1880
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pjifl
Posts: 578
Joined: Fri Jun 17, 2005 12:15 pm
Location: Innisfail, Far North QLD.

Re: NECK SIZING

#33 Postby pjifl » Wed Jan 03, 2018 7:19 am

It is very difficult giving advice without being able to see details. Easy to go off on a tangent or miss things.
I never considered that case head separation was part of this discussion because the brass is almost new and heavy loads were suggested by some past ladder testing.
Good brass will take a few oversizings and stretchings before case head separation rears its head. But best to treat those expensive cases correctly.

Overloading by itself will never produce case head separation as long as cases are sized correctly. Gross overloading will induce case head flow and failure but that is another issue.

Overloading by itself can produce a wider base and also a wider belt slightly above the base.

If the actual base is expanding the overload is close or beyond safe limits. Certainly, your brass will not last long. One can usually accept a very slight base increase after a 1 or 2 firings but if it keeps increasing after that you are most definitely into unsafe loads.

The main way to produce case head separation is to over resize the shoulder back too far. I do not think that Accurate Shooter article explained this very well at all. There is a danger that when cases are a tight fit, people think they have to resize (bump) the length more and thus produce excessive headspace without realizing it. Firing and resizing like this a few times will produce case head separation before long. Actual case head separation looks fearsome and usually occurs on extraction. It has the potential to be very dangerous but in practice the separated case head actually seals well with modern cases but that is no excuse.

The sharpened bent wire trick is incredibly effective and should be on every reloader's bench. You do not have to use it every time and once good reloading practice has been achieved it will monitor the state of the case where it may separate extremely well with occasional use. I suspect newcomers are hypnotized by fancy tools and do not take a bit of bent wire seriously.

The other almost essential tool is some gauge which facilitates measuring the base to shoulder length before and after resizing. It can be nothing more than a short bush or spacer placed over the neck in conjunction with a dial caliper. Best shaped to the shoulder angle but at a pinch a lot of common items will tell you invaluable info. You are simply looking for a slight change in length before and after resizing or bumping. Fancy commercial ones are available but do not rule out other simple ones at least as a temporary solution. Monitoring this dimension outside a chamber is just so easy and reliable. Trying to do it within a chamber introduces other factors which can fool you into over sizing.

Sorry if these comments may seem a bit too simple and basic. As I said, It is difficult to give advice in isolation.

Peter Smith.


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