Bumping Shoulders Issue

[J E Custom]

Tom

If your chamber is SAAMI spec and the fire formed brass is .002 longer than the SAAMI spec.
that would probably be your Head space (.002 thousandths). so that would be all right just
like it is.

If a reamer is exactly the size of the SAAMi spec. and you have No headspace then the cases
should not increse in length and should still chamber fine.

I guess what I'm saying is that you may not have to move the shoulder at all as long as it
chambers.

And you can use your gauge to see if there is any bolt lug setback after lots of hot loads or
you are getting some brass stretching.

J E CUSTOM

 

[Mikecr]

JE's right.
IMO, Shooters take reloading references/SAAMI this & that too literally.
[John Smith is concerned because his 243Win turned into a 243JohnSmith on firing, and now he can't squish it back into a 243Win, as referenced in a book].
Well, he might not ever, and this is probably not a problem.

When you screwed the die down till it stopped, it was merely stopping at an interference fit up on the body. As you screwed it down & sized further, you squished your brass inward and it took the easiest alternate path -LENGTH. It could get longer because your die was not far enough down to stop it from getting longer. Right near the fullest extent of your adjustment, the shoulders were not only contained, but pushed back.
If this window of needed adjustment isn't working, then you need finer adjustments within it, or get another die which is not so difficult. Better be looking at more than just bumping with the extremes you're describing though.
As mentioned, the competition shellholder set provides very fine adjustment, and discard the o-ring floating for this.

 

[statjunk]

I am thoroughly confused. My understanding is that my chamber is .002 over saami. The bump should be .002 so that puts me back at saami. I'm not saying I want to be at saami specifically. If the brass measured .006 over saami then I'd be bumping it back to .004 over saami. Isn't that what I'm supposed to be doing here?

JE,

Not sure what you mean by I don't need to do anything. I was told that simply neck sizing would lead me to trouble.

Thanks

Tom

 

[tackdriver10]

Statjunk, when you resized the second piece of fire-formed brass, did you notice whether the shellholder was coming in contact with the die? I'm thinking you may be out of stroke and the die may need some material removed from the bottom so that the case can go in farther. I've seen this on more than one occasion. You could always spend more money and purchase the shellholders from Redding that allow you to adjust the height. Usually, .010 or so off the end of the die will fix your problem, if in fact thats whats going on.

Another tip, is when you get ready to adjust your die, (screw it down), take a measurement with your calipers from the top of the die down to the flat spot where it screws in. Adjust, then take another measurement, this will tell you have far you have actually screwed the die down.

No, SAAMI specs aren't the most important factor, but when using your mics, it gives you a reference to go by, and you can set your brass wherever you need it. Its simply for reference.

 

[statjunk]

How likely is it that my problems are being caused by my die?

Do RCBS and Redding dies have a sleeve down at the bottom of the die that moves when it comes into contact with the shell holder?

Thanks

Tom

 

[J E Custom]

I am thoroughly confused. My understanding is that my chamber is .002 over saami. The bump should be .002 so that puts me back at saami. I'm not saying I want to be at saami specifically. If the brass measured .006 over saami then I'd be bumping it back to .004 over saami. Isn't that what I'm supposed to be doing here?

JE,

Not sure what you mean by I don't need to do anything. I was told that simply neck sizing would lead me to trouble.

Thanks

Tom

Before you fire for the first time the brass will be smaller than SAAMI specs. After you fire it is now the size of your chamber (Fire formed) and is the best fit to your chamber and most of the
time it is at the most accurate size. And will have no headspace which is in my opinion the best
for brass and accuracy.

A SAAMI chamber is one that is the exact size of the cartrige specification with "NO" head space.
but most smiths will add .001 or .002 to the overall dimension to aid in loading. different size
brass/cartriges.

If your cartrige/brass is SAAMI spec. after firing then your chamber is not SAAMI spec. or you have no head space. (Head space is based on SAAMI Dimension + the head space dimension

The neck sizing issue is controversial and if not done right it can hurt you but Is the best method
to load consistant loads and to extend the life of your brass.

Remember , the less you work your brass the longer it will last.

Some people full length size every time, and some neck size 3 or 4 times, anneal. and full length
size. It is a personal choice and depends on what the person wants to use it for. (Full length
size for dangerous game and ease of loading, Neck sizing is best for accuracy and long range
hunting where consistency contributes to Accuracy.

The only reason I can see for bumping the shoulder is if you are loading hard/hot and the brass
will not chamber with out a lot of force.

To me the ideal chamber is one that is SAAMI spec. with .0005 to .001 Headspace.

J E CUSTOM

 

[statjunk]

Well I'll be.... I just received the Redding dies in the mail today. Recall I went with the standard die set that includes the FL, Neck and seater die. I was able to bump the shouler back .002 no problem what so ever. Took me about 10 pulls of the ram moving the die in small increments.

I'm really surprised that it was that turn key. Figured it would work better but never believed it would go so easy.

Thanks to all that stuck with me through this. I really appreciate all the time you gave me.

Tom