Federal brass???

[Driller54]

Hello guys!!
Had some federal brass Layin around already once fired in another gun both rem model 700's in 7mmrm. Shooting vld's and loaded 168grn Bergers in them doin the ladder step for finding bullet seating depth. While loading the longest coal for the round as suggested for using hunting vld's and the long ones chambered fine. Not even thinkin about it I took my 5 minute drive to the range. Shot the longest rounds fine. Picked up the shorter coal and to my surprise the shorter rounds would not chamber and for the life of me I can't figure out why I got back home and mic the brass again and all the measurements are as specified in my manual so I could use some help in the mean time I'm gonna go with some Winchester brass and see what happens as Winchester brass has never given me this problem and can't figure out why a bullet seated further away from the lands will not chamber???

 

[7stw]

Without a doubt I would say that the case's geometry is off. If a round is shorter than another, and will not close, the case dimensions are certainly off. This does happen , especially with belted mags, when it was fired in another gun first. Most of the time, full length resizing corrects this. ( unless the dies are backed off). Check the upper outer shoulder angle. You may find a little kink there, that will do it. 7STWlightbulb

 

[rscott5028]

Look for a slight bulge just ahead of the belt.

 

[Driller54]

7stw I do have my fl sizer die back off a dimes thickness with the press handle all the way down. I have little experience in reloading but gotta start somewhere ya know? I did this I'm sure you know why to try to keep from working my brass in hopes of just neck sizing... If you got a minute maybe you could explain about both styles of sizing for me and which would be better for me?? Thanks guys

 

[boomtube]

"7stw I do have my fl sizer die back off a dimes thickness with the press handle all the way down."

There's your problem and it has nothing to do with OAL or the brand of the brass - you are neither FL sizing nor neck sizing. With your present incomplete sizing you're squeezing the case body enough to push the shoulders too far forward for the 'sized' cases to chamber. As a noob, forget neck sizing, just concentrate on making ammo that works until you get a LOT more experience. Most cases fail with neck splits so neck sizing has very little or no effect on case life anyway.

Just screw your sizer die down in small increments - like 1/16th turn - until your resized cases chamber easily. Lock your sizer there and complete your reloading.

 

[Driller54]

Boomtube. I was reloading for this cartridge before and was having issues with my bullets not seating firmly in the neck i could and did pull the bullets with my fingers although very accurate i didn't feel safe as this is hunting ammunition. So maybe you could explained in "noob" terms how to set up my rcbs sizer die and decaping pin?.... Like I said I re mic'd the brass when I got back to the house and maybe you could explain how it got past me?

 

[Driller54]

Also boomtube why would other brass from the same batch done the exact same way chamber and a handful won't?

 

[7stw]

7stw I do have my fl sizer die back off a dimes thickness with the press handle all the way down. I have little experience in reloading but gotta start somewhere ya know? I did this I'm sure you know why to try to keep from working my brass in hopes of just neck sizing... If you got a minute maybe you could explain about both styles of sizing for me and which would be better for me?? Thanks guys

For the most part, full length is your best bet. Belted mag cases are fussy to set up for with the intent of backing off to gain case life, etc. I have 3 ,7 mags, and I full length resize for all three, however, I do occasionally neck size only, with once fired brass if I want to do some target work. The one thing about neck sizing only, is that after a few firings, you must full length resize, or your brass will grow TOO long, or tall, then you will crush the shoulder when you do full length resize. REMEMBER, a belted mag headspaces on the belt, not the shoulder. Stick with F/L resizing for now, as you evolve, pick up a neck sizer, and experiment. Good record keeping is a must! AIM SMALL, MISS SMALLlightbulbgun) 7STW

 

[Driller54]

Ok well I've noticed that when I measure the brass before I even run it in the die it actually needs nothing. All measurements are within book specs so it seems. Can you explain from what points to measure etc. With fl sizing what am I actually sizing? Am I trying to bump the shoulder back? How to i run it up far enough to size the mouth to firmly hold the bullet and do my headspace correct?

 

[Driller54]

I'm just tryin to get some accurate ammo to shoot here boss?

 

[boomtube]

Why do things vary? They just do, due to too many variables to write in a web post. A handloader learns to deal with variations as he finds them, reloading is not a 'one adjustment fits all' thing.

Your present 'dime gap' sizer adjustment only insures the shoulders won't be sized correctly. FL sizing ajusts all dimensions of a case if it's done correctly. I suspect you've read about 'partial" FL sizing without understanding what it means; if we jam a case as far into a sizer as we possibly can we can set the shoulders further back than is neccessary and that produces unneeded case stretching during firing. The ideal is to set the sizer so the shoulder gets moved back to the fired location and no more, that provides ammo that will chamber but not stretch when fired.

The grip on a bullet is determined by the diameter of the expander ball and hardness of the neck brass. There is no simple way to adjust for it but, if it's so bad you can pull bullets by hand, you may need a smaller expander. Hard brass springs back more after expanding than soft brass. Federal tends to be a little softer than others and that means it will last longer before splitting but it's a trade off for other things.

 

[Driller54]

I'm thinkin I got somewhat of a handle on fl resizing... So what is neck sizing even if I don't pick up the practice but rather to learn?

 

[7stw]

I'm thinkin I got somewhat of a handle on fl resizing... So what is neck sizing even if I don't pick up the practice but rather to learn?

Neck sizing is nothing more or less than is implied. When you get a neck size die only, it does not contact the body, or shoulder at all. It simply squeezes the neck in on the up stroke, and expands the inner neck to spec on the down stroke. It does not change the body contour at all due to lack of contact. On your F/L dies, you need to insure that you have them set properly. They need to be set so that the press moderately cams over on the shell holder when you are at the top of the stroke. This insures body, neck, and shoulder dimensions are back to original. Remember, belted mags headspace on the belt, not the shoulder. If you run it with a gap, the shoulder will contact the chamber wall. When you realize this, you will readjust the die, and that will crush the shoulder on the brass, then it is junk. I would recommend that you set your dies to FULL LENGTH , let them alone. Later on, you can try neck sizing, on every other resize. For now keep it simple. AIM SMALL, MISS SMALLlightbulb 7STW.

 

[backwoods83]

Belted cartridges only headspace off the belt on the first firing, I can get 5-6 neck sizings after initial fireform before the shoulder needs a slight bump. With belted mag cases the innovative tach dies are the best. Don't let anyone tell you crap about belted mags being inaccurate and outdated, they hold lots of records to this day and will continue to be extremely accurate. You need to do a little more reading and maybe get someone you know local to give you pointers. I don't care how much I get bashed fl sizing every time is not the best way.