Loading problem Question!!??

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74man

74man

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I was loading 124 gr 9mm Flat Point today and I couldn't get a set col. I would set the die at 1.120 and measure one case, then the next one would come out at 1.110 and then again the next one would be 1.115 without adjusting anything at all. What am I doing wrong? I have an RCBS Carbide set. I screw the die down until it touches the ram and back it off about 2 turns. Then I set the first round to a col of 1.120 and I would use that completed round to set my crimp. I would back off the Seater Stem and screw the die down to a light crimp, then screw the seater stem down until it just touched the bullet and I would adjust from there but for some reason my setting would change with every cartridge, what could cause this to happen. I am confused. Help???
 
I have never had this trouble before, once my col is set it usually stays that way. I tried to use both stems, flat point and round point but both did the same. I would load one and set it at 1.120, load another and the col would be 1.110 without adjusting the stem. This is what I don't understand. Could the crimp be set too much? The cases aren't bulging or colapsing like too much crimp would cause them do. I will try again tomorrow and see if there is any change
 
74man said:
I have never had this trouble before, once my col is set it usually stays that way. I tried to use both stems, flat point and round point but both did the same. I would load one and set it at 1.120, load another and the col would be 1.110.
Click to expand...
Are you saying you loaded THIS exact bullet using the exact same dies on the exact same press and had less than 10-thousandths variation?
 
What 124gr FP are you using? Mixed HS brass can have different neck tension and case length that can affect seating and crimping. Check your dies’ lock ring and seating stem lock nut to make sure they’re not loose. Clean your seating stems to make sure there’s no buildup. With mixed HS range brass I see variations as well, a bit less than +/- .010” but still some variation. Good luck.
 
Even with my sorted brass I have no idea of the times each piece has been fired.
Op, are you sure yours seating the bullets straight? If you seat them a little crooked that will add friction to the bullet and could cause a little distortion which will change the OAL of the finished round compared to the next one.
I have all sorted brass but I have no idea how many times each one has been fired.
I can still get usually .003-.006" on my sorted brass in my progressive presses with 9mm.
I have actually distorted bullets on some hard to size brass with even sorted brass, I could see a ring on the nose of the bullet and the OAL was way off compared to the others. Time for that one to go in the recycle bucket.
With 9mm I sort headstamps to get a closer case capacity from case to case.

But, I pick the hard to resize cases out while resizing to get a "more consistent over all neck tension" when loading a batch of sorted cases.
That makes for a more consistent OAL over all.
 
I have almost exactly the same problem. I made 40-170 TC Lee PC cast bullet testloads using Winchester brass. My dies are RCBS carbide dies and I'm suing my Rockchucker. And I wanted to load this bullet with the same powder charge and was seating the bullet at 1.088 (where the slide would just close minus .002"), 1.080", 1.070", 1.060", and 1.050" OAL. I seat my bullets before crimping them. The seater is flat. I seat carefully screwing in the seating stem until I get the correct OAL and then tighten everything up snug because I adjust the stem again slightly. OAL varies +/- .002" or so. I've loaded them slow, pumped the handle, turned the case and seated a little, loaded six at a time, and I still get variation. I finally decided that if the variation is around the OAL I want, the difference will show.
 
if you have a 30 or 27 caliber comparator, measure your loads and see if your ogive is consistent. that is the important part.

luck,

murf
 
You loading on a progressive? Because this will totally happen if you have one die touching the shell plate with too much tension, and the rest aren't. You'll get flex, and on every cycle when all the stations aren't full you'll get a different COL on the case being seated. Also, if you don't have your shell plate tightened down enough, you'll get this. If you're on a single stage, you've got something else going on. In the case of a single stage my guess would be since you're seating and crimping in the same step, you have different lengths of brass...and the crimp is preventing the bullet from seating correctly on the brass that is excessively long, and vice versa. You could try seating in one step, then crimping everything in another step.
 
Lots of good answers, but here's my troubleshooting process; clean seating die, inspect components (a burr or ding on the case head can skew OAL), measure and inspect/compare bullets (length and ogive can differ, noses can differ w/dings, burrs, etc.), make sure die is high enough so crimp is not interfering, and inspect press and shell holder (a bit of grit on the shell holder can cause variations). If these don't help consistent OAL, I then put everything away and go have a cup of coffee and watch TV. Start from scratch another day...
 
Remove the seating stem from the die. Get a hand full of projectiles and one my one place them in the stem and measure. Are they all measuring the same length? Doubt it.

I once ran into this with a box of Xtreme bullets. Had a second box so I tried those and the problem disappeared.
 
Here is what I did!! I stopped reloading until this morning, set my col and did all the bullets the same col. Then I crimped all the ones that I got the right col. All did well and came out correct. I then loaded some MRM 115 gr. Round Nose and set my col and crimp at the same time, like I usually do and they all came out the same, within a few thousandths. I then loaded some MRM 124gr HP's and they all came out the same, within a few thousandth's. I still don't know why the MRM 124 gr. Flat Point's wouldn't work with the same process. What I ended up doing on the FP's, was setting the length and then doing the crimp separately and they all worked that way. I measured about 10 of the Flat Points and the all measured the same length and Diameter. I am stumped but I don't have anymore Flat Points to load so I am good to go. I still have about 150 each RMR 115 gr. RN, about the same RMR HP's in 124gr and about 300 each 147 RN to load. Then I can finish my 40S&W cases (all Nickel cases), about another 800 each.
 
74man said:
What I ended up doing on the FP's, was setting the length and then doing the crimp separately and they all worked that way. I measured about 10 of the Flat Points and the all measured the same length and Diameter. I am stumped but I don't have anymore Flat Points to load so I am good to go.
Click to expand...
Given that statement, I’d conclude that somehow the crimp during the seat/crimp step was altering the COL. Whether that’s uneven case lengths or just a seating stem not being optimal for the flat point or some other combination. I’d be tempted to modify a seating stem specifically for that FP. If you ever figure it out, let us know?
 
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