7mm RM chambering help

[11B2CV]

Long time lurker with a challenge;

I am recently loading for a Remington 7mm RM PSS I bought a year ago, and I have ran into a problem with loads. I cannot get full length sized rounds to chamber in this rifle! Details;

1. Two different dies, RCBS and Redding, neither of which work. Both dies size to specifications (neck, head diameter, etc) via caliper as sort forth in Hornady, Sierra, and Nosler manuals.

2. Cases which do not "fit" the PSS slide into my Savage 111 smooth as silk.

3. Chamber was polished out by local reputable gunsmith.

4. Out of the bag Winchester brass, with no prep what so ever, chambers great (that really confuses me)

Am I missing the obvious?

 

[Michael Eichele]

Sounds to me like you have excessive runout (crocked necks). This will cause this. If your Savage has more clearance than your 700, they will chamber easy. If your 700 is somewhat tight, the crocked necks and also bullets will cause MAJOR resistance. That is why new cases go in so easy.

The minute you touch those cases with an expander ball, youre hosed! You will need to throw away the expander ball and turn your necks down to where when you run them trhough the full case sizer, the necks are sized for .002-.004" neck tension. If your dies are too tight in the necks for this, you will need a body die and then neck size with a Redding type S and the right bushing.

Hope that helps!

Good luck!

Been that, done there!! /ubbthreads/images/graemlins/laugh.gif

 

[keithcandler]

The die is not screwed down far enough...

Sometimes the press has to "Cam" over on the full length sizing operation. Many people make the mistake of screwing down the die until it touches the shell holder with out a piece of brass in the press. Then when they put a piece of brass in the shell holder and actually size the brass, they see a gap inbetween the shell holder and the bottom of the die, which I think is not your problem.

Good luck!

 

[CatShooter]

Some information you didn't give...

1 - Do the fired cases go back into the chamber?

2 - Do the FL sized cases (empty) go back into the chamber?

If both DO go back into the chamber, then do the following.

Measure the neck OD of a new round, and measure the OD of a reloaded round and see if there is a difference.

And (God I hate to say this), are you using the right Dia bullets? (It HAS been know to happen, even to experenced loaders).

The thing that is fishy is that you say you have used TWO FL dies, and the cases are not chambering.

You do NOT need to neck turn the cases if they orginally went into the chamber.

.

 

[CatShooter]

[ QUOTE ]
Sounds to me like you have excessive runout (crocked necks).

[/ QUOTE ]

Whatsa "Crocked neck"... My kid brother has been crocked a few times, but it didn't effect his neck /ubbthreads/images/graemlins/wink.gif

[ QUOTE ]
You will need to throw away the expander ball and turn your necks down to where when you run them trhough the full case sizer, the necks are sized for .002-.004" neck tension. If your dies are too tight in the necks for this, you will need a body die and then neck size with a Redding type S and the right bushing.

[/ QUOTE ]

That's a lotta unnecessary work. For a tight neck bench or match rifle, OK...
... but for a factory chamber?? If the chamber needs that much work, the gun is a problem and needs to go back to Big Green!

.

 

[Michael Eichele]

What is a lot of work is trying to get straight brass with an expander ball in the die.

 

[Michael Eichele]

So I missed the second o in crooked. Never miss spelled before?

 

[11B2CV]

Thanks for the ideas!

However, I think I did overlook the obvious...

I am mixing fired brass from two different rifles, and although I am full length resizing, could not the Savage "blow out" the case in the shoulder or head dimension that the die cannot resize, but is out of spec with the PSS?

 

[Buckmastr]

I have an abolt that won't take full length resized brass from my RCBS dies even though those same shells fit other 7 mm mags no problem. I tryed to keep the brass separate between guns but eventually broke down and bought the RCBS small base die set and problem solved, the newly sized shells fit in every gun including mine. I've heard other people with similar problems around the 7 mm mag. I'm not sure about brass life with the small base set but it hasn't been an issue yet.

 

[11B2CV]

Forgive my ignorance but I haven't heard of a "small brass" set..... I'll give it a look!

Again, this is a great forum. I am a long time lurker, but I have picked up quite a bit of info from the wiser ones here IE; Bailey, Meichele, Fiftydriver, etc....