Problem with Norma brass 243 win.

3

340 in Va

Well-Known Member
Joined
Jan 18, 2018
Messages
104
Location
Millboro Va
I am trying to reload Norma brass, after de-priming, annealing, cleaning in tumbler, lube with Imperial wax, FL size with 2 th bump and wipe wax off the case the brass will go in chamber (bolt striped and no primer). After expanding with mandrel (neck lubed with graphite) the bolt is hard to close. Using RP, Federal and Peterson brass with the same setup I have no problems. what I'm measuring I should not have this problem; any help would be appreciated. This is once fired brass.
 
European brass(CIP Specifications) often has a larger web dia than American brass made to SAAMI specifications, and this is the root of your problem, .4701 vs .4713 or larger.

Just because you bump the shoulder back .002, does not guarantee you that the web dimension has been reduced to fit your chamber.

If you have a micrometer, measure the web dimension just in front of the extractor groove of various brands of brass and get ready for a shock.

For giggles and grins, keep running your full length sizer down in very small increments till bolt can be closed easily on the case, then measure the shoulder set back. In some cases, it is necessary to take off .003 from the top of the shell holder on a bench grinder.
 
VinceMule said:
European brass(CIP Specifications) often has a larger web dia than American brass made to SAAMI specifications, and this is the root of your problem, .4701 vs .4713 or larger.

Just because you bump the shoulder back .002, does not guarantee you that the web dimension has been reduced to fit your chamber.

If you have a micrometer, measure the web dimension just in front of the extractor groove of various brands of brass and get ready for a shock.

For giggles and grins, keep running your full length sizer down in very small increments till bolt can be closed easily on the case, then measure the shoulder set back. In some cases, it is necessary to take off .003 from the top of the shell holder on a bench grinder.
Click to expand...
if the problem occurs after he expands the necks that would be thick neck brass not the .200 line.
load a bullet in the R-P, Peterson and Norma brass and measure the loaded neck dia. and compare to a fired round, you should have .004 clearance between loaded and fired cases.
 
Valid point, Can1010. When the necks are too thick, usually the bolt will not close at all or will be rubbing with the chamber acting as a sizer. Blacken the web and the case neck, then chamber the case. You will see ink rubbed off where it is rubbing.

The web of Winchester brass measures .4666 approx. while the norma measures .469. Then, take into account the full-length sizer dimension. It is not unusual for some European brass to be the same dimension as the full-length sizer, which does not account for brass spring back.
 
can1010 said:
he said that it chambers fine after sizing and the problem only occurs after using the expander mandrel that should eliminate a sizing issue. the other problem is if the brass is too long and hitting the expander mandrel stop and flaring the case mouth could be the only other explanation I can think of.
Click to expand...
Brass was new and fired in this rifle, also trimmed to spec. and does not touch the top of mandrel. I have repeated the sizing process several times on the same 10 pieces of brass, size, check in chamber (it closes with no resistance) run through mandrel and bolt is hard to close. It will be tomorrow before I can work on this. Thanks for the help, everyone. I have been reloading for 50 years and never ran into this problem. If I figure this out, I will report back.
 
VinceMule said:
European brass(CIP Specifications) often has a larger web dia than American brass made to SAAMI specifications, and this is the root of your problem, .4701 vs .4713 or larger.

Just because you bump the shoulder back .002, does not guarantee you that the web dimension has been reduced to fit your chamber.

If you have a micrometer, measure the web dimension just in front of the extractor groove of various brands of brass and get ready for a shock.

For giggles and grins, keep running your full length sizer down in very small increments till bolt can be closed easily on the case, then measure the shoulder set back. In some cases, it is necessary to take off .003 from the top of the shell holder on a bench grinder.
Click to expand...
Will check this tomorrow.
 
Not sure if you have the ability to neck turn a piece of brass, but sacrificing one as an experiment would also answer the question. Worst case, sand it down with a piece of sand paper and see if thay solved the issue (neck only). And if it does, I probably would use that piece of brass again, just a proof of concept on the issue.
If it turns out that the necks are too thick, I'm sure we could help you get them turned down.
 
Check neck diameter at the mouth and at the shoulder with mics after sizing and after expanding. You may have a donut at the base of the neck that is getting pushed to the outside after expanding. If that is the case, then a light neck turn after expanding will remove it. Or, you can inside neck ream after sizing and before expanding.
 
Last edited:
I'm guessing the brass is thick at the neck shoulder junction and when you expand it, the neck shoulder junction gets moved out (like a donut), hampering your ability to chamber.

It may be that your chamber and sizing die don't match exactly and it's impinging at the neck shoulder junction instead of where you measure it.

You could try neck turning a bit at this junction, or sizing slightly more so it closes after the expanding process. It would be like setting up an AI fire forming load.

It's best to ensure you don't have a donut formed, but unlikely on once fired brass.
 
Tiny Tim said:
I'm guessing the brass is thick at the neck shoulder junction and when you expand it, the neck shoulder junction gets moved out (like a donut), hampering your ability to chamber.

It may be that your chamber and sizing die don't match exactly and it's impinging at the neck shoulder junction instead of where you measure it.

You could try neck turning a bit at this junction, or sizing slightly more so it closes after the expanding process. It would be like setting up an AI fire forming load.

It's best to ensure you don't have a donut formed, but unlikely on once fired brass.
Click to expand...

Nailed it!
 

Similar threads

tribb
243 win brass
2 3
Replies
29
Views
2K
catch 22
C
C
Savage Model 11 243 Win. BT Problems
Replies
5
Views
6K
Charles A
C
barleydog
sup with norma 7 mag brass?
2
Replies
17
Views
2K
WildRose
WildRose
W
.243 Win
Replies
5
Views
1K
codym
C
B
.243 win
2 3
Replies
41
Views
8K
dogbuster0006
dogbuster0006

Recent Posts

Top