Shoulder Bumping Help Needed

[MRc00per]

Hey Everyone,

Newbie here asking a newbie question. I've only reloaded with fresh brass until now. I cleaned 200 pieces of 300 win mag brass (gunwerks brass) via SS media and a tumbler which turned out great. I measured all 200 pieces with a sinclair shoulder bump comparator and found my longest peice was 2.2095. I removed my firing pin and placed the brass in which closed pretty easy to my surprise. I placed an unfired round I had left over and did notice that it closed minutely easier.

Using the redding competition die and competition shell holders I started with the longest one (.010) lubed the case and resized. I placed it in the rifle and no difference, I measured it and it actually got longer, now measuring to 2.2105. I went as far down as the .004 holder and it's still 2.2105.

Not really sure what to do at this point.
The die is set up properly, with the shell holder touching the die with cam over.

I read some brass doesn't necessarily expand entirely after only firing once. And the handle does close easily. I would not have thought it needed to get resized If I didn't compare it to a live round but when I say it's a minute difference I mean minute. I have to do it several times to notice a difference.

My thoughts are 1, they need to be fired once more to be fully fire formed. 2, I need to shave the die (i would really like this to not be the answer) or 3, I'm retarded and I'm doing something wrong

 

[Supersubes]

All that’s happening is your brass shoulder isn’t touching your die shoulder yet. The body is being squeezed down radially, which elongates the case. Like squeezing a tube of toothpaste in the middle.

As you’ve read, the case may not be fully expanding.

No need to shave the die yet. You still have the .002 shell holder to try, then a standard shell holder. If you need more, hone a standard shell holder down, not the die.

What kind of rifle?

 

[FLIGHT762]

Use a regular shell holder first to see if you get some shoulder movement down. Turn your die in & resize with a standard shell holder until you get a good cam over reading of 2.207" or so or at least down to 2.209". Your Competition shell holders aren't sizing down enough. The reason you're getting the 2.210" is you're bottoming out in the +.004".

You should see some shorter bump with a regular shell holder. You can then use the competition shell holders if you're bumping too much with a regular shell holder.

 

[MRc00per]

So I took your advice and went and got a regular shell holder. It finally bumped down but only went down to 2.209 however it feels good so I'm going to give this a shot. Thank you for your advice. I'm shooting a savage stealth evolution with a rebarreled 28in criterion bull barrel

 

[FLIGHT762]

You might have a very snug chamber. If you ever get to annealing the brass, you'll need the Competition shell holders so you don't over bump. After annealing, the brass is soft and it may bump back further than you want.

 

[spife7980]

You wont need competition holders, you can do everything with a regular $5 shell holder that you can do with the $50 competition shell holders by simply adjusting your die.

When you dont size down enough to bump the shoulder the base of the die is still getting squeezed, squeezing there on the base inside the contained die pushes the brass to the only place that it can go and thats expanding forward up towards the shoulders. Thats why your brass grew. Its like when you roll/squeeze a playdough snake, it will get skinnier and longer.

Turn the die in/down a tad more to reduce the space between the die body and the shell holder and you will eventually eliminate any empty space and the shoulders will push back.

I would test that piece of brass that grew .001 on you. If it chambers then your brass still has room to grow, if it were fully expanded and the shoulders then got pushed forward in the die from only sizing the base of the case then it would have grown beyond the chamber limits and you would have trouble closing the bolt on it.

 

[buffybuster]

Chances are your brass is NOT fully fireformed to your chamber. Belted magnums headspace on the belt and not the shoulder. As a result the shoulder dimension is not closely maintained and can vary from chamber to chamber. If your fired brass will chamber without resistance, then I would neck size or partially resize the neck, load and shoot. Then remeasure your should datum. It may take a few firings to get the case to fully expand to the chamber. When you no longer see case shoulder growth and/or the brass chambered with resistance, set your shoulder bump from there.

 

[MtnCreek]

^Agree.

Does the 2.2105 chamber? If so, I’d dive with that die / shell holder setup and remeasure after firing.

 

[308pirate]

You wont need competition holders, you can do everything with a regular $5 shell holder that you can do with the $50 competition shell holders by simply adjusting your die.

When you dont size down enough to bump the shoulder the base of the die is still getting squeezed, squeezing there on the base inside the contained die pushes the brass to the only place that it can go and thats expanding forward up towards the shoulders. Thats why your brass grew. Its like when you roll/squeeze a playdough snake, it will get skinnier and longer.

Turn the die in/down a tad more to reduce the space between the die body and the shell holder and you will eventually eliminate any empty space and the shoulders will push back.

I would test that piece of brass that grew .001 on you. If it chambers then your brass still has room to grow, if it were fully expanded and the shoulders then got pushed forward in the die from only sizing the base of the case then it would have grown beyond the chamber limits and you would have trouble closing the bolt on it.

This is the right answer.

Using shell holders to control shoulder bump is just...……..not smart

 

[MtnCreek]

@308pirate It can be useful in some situations. I use a redding comp shellholder set to control headspace between multiple rifles using the same sizer and no die adjustments needed when setting up.

 

[Deleted member 10043]

Instead of shaving the die what is wrong with shaving the case holder. I did that not too long ago with a similar problem. Also, this is what happens when people demand to pay more for a sizing die.

 

[Steel head]

I just chuck up my case holders in my handy dandy case holder adjusting tool.