Case neck tension?

Ken

Ken

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Hi,

I have been reloading a bit for my 300 wsm and have noticed when seating the bullets there seems to be quite a differance in feel from one round to the next. (By that I mean the amount of effort required to seat the bullet as felt on the press handle)

I believe this is why I cant get a real consistant shooting load for this gun. I have not had this problem with any of the other calibers I reload for, any ideas or solutions?

Thanks in advance.
 
yep, chamfered the mouths.

I bought the brass new and have a couple firings on them, this has been an issue right from the start. I even colapsed a shoulder on one of the first loads

thanks for your help
 
Ken,

I recommend cleaning the inside of your case necks with a motorized steel bore brush. It's also a good idea to sort your brass by how many times it has been reloaded, and I prefer to use Bushing type FL dies. They're made by Redding, Forster and now RCBS. Bushing dies provide the "exact" neck tension that you need, and you can forget about using the neck expander button (good deal). When ordinary NK or FL dies are used, the tension is correct ONLY if your neck thickness is a specific thickness (and it rarely is).

If your brass is clean, and you still feel different seating pressure, and if your necks are "properly" chamfered, then you're feeling the difference in the brass hardness. There's less working of the brass when you don't use your expander button, and your necks won't harden as quickly.

- Innovative
 
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Bushing dies can only give you 'exact' neck tension if the case necks are all the same thickness which is accomplished by turning the necks. I don't think switching to bushing dies will change anything in this case.

Your problem might be from varying neck thickness or it might be from varying hardness of the case necks.

Annealing may cure the second problem, sorting or case neck turning might help the first problem.

A new lot of brass might be worth trying too.
 
Ken said:
Please excuse my ignorance but what exactly is a bushing die and how does it differ?
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It's a more advanced die used for precision reloading. It has interchangable neck sizing bushings of specific diameters that squeeze the neck down a known amount, but requires brass with very uniform neck thicknesses. This usually means necks that have been machined to a uniform thickness.

You can vary the neck tension by using different bushings. The neck is just sized down, there is no expander ball used. This results in less working of the brass.

I wouldn't worry about them right now.
 
what neck sizer are you using? next time you size the brass measure the inside diameter and group them together in the same sizes. if you still get the fliers and the neck tension is the same no use spending $$ on stuff you don't need.
 
Ken said:
so, I need a neck turner then? or anneal? or both
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Neck turning shouldn't be necessary just to achieve reasonably consistant neck tension. I think I would try annealing or just buy another batch of brass.

How many cases are we talking about here? Can you sort out the ones with high seating force and keep them in seperate groups?

Someone earlier mentioned keeping track of firings. I think you mentioned that these cases were bought new and have only been fired a couple of times. If some of these cases have been fired several more times than the others it may just be a case of work hardening of the necks but I don't think you've reloaded these enough times for this to be the problem.

It is unusual for the neck tension to vary so much that you can feel it on the press handle. My feeling is that you've gotten 'hold of a crappy batch of brass. Annealing may cure it, I wouldn't invest the time in neck turning yet.

You should be able to achieve good results using standard dies, newish brass and not much else.
 
50 rounds, one bag. I have kept track of firings and It doesnt seem to be related to that, right from the start even when it was new I noticed it.

I'll give annealing a shot first, then new brass I guess.

Thanks for your help guys
 
So I annealed and loaded a bunch of cases tonight and the bullets all seated nicely, I can't wait to range test them
 
Ken said:
Hi,

I have been reloading a bit for my 300 wsm and have noticed when seating the bullets there seems to be quite a difference in feel from one round to the next. (By that I mean the amount of effort required to seat the bullet as felt on the press handle)

I believe this is why I cant get a real consistant shooting load for this gun. I have not had this problem with any of the other calibers I reload for, any ideas or solutions?

Thanks in advance.
Click to expand...

Try another bullet, I have been reloading for quite awhile now. I have never noticed accuracy to fall away because of neck tension. The 300 WSM I had was a little more finicky than the 300 Winchester.
 
I had the same problem with Winchester brass. Not just with the 300WSM either.

Unless the brass is new, I reanneal every time I reload.

I also clean the inside of the necks and lube them before sizeing.

Same as you found out, no more trouble. Still a few accuracy problems but at least I know it isn't the case neck tension.
 
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