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Posted: 2/7/2011 7:40:22 AM EDT
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I'm having some major inconsistencies with my 9mm cartridge OAL.
I'm shooting for an OAL of 1.165". I'm getting them coming off the press anywhere from 1.154" to 1.176". Any ideas? I'm using a Hornady LNL AP press and Lee dies. (Yes I know this is longer than normal 9mm. This is a major power factor 9mm load for USPSA, hence the long OAL) |
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Sounds like the ogive of your bullet doesn't match the shape of your seater plug. The ogives vary slightly and contact the seater at a different spot, thus altering your OAL.
I'm experiencing the same thing with Berry's 124gr HP and RCBS dies. My OAL varies by .015". Posted Via AR15.Com Mobile |
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Quoted: Sounds like the ogive of your bullet doesn't match the shape of your seater plug. The ogives vary slightly and contact the seater at a different spot, thus altering your OAL. I'm experiencing the same thing with Berry's 124gr HP and RCBS dies. My OAL varies by .015". Posted Via AR15.Com Mobile RCBS will make a custom seater plug for about $21, shipping included. I just got two a couple of weeks ago...made a big difference. |
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Quoted: Quoted: Sounds like the ogive of your bullet doesn't match the shape of your seater plug. The ogives vary slightly and contact the seater at a different spot, thus altering your OAL. I'm experiencing the same thing with Berry's 124gr HP and RCBS dies. My OAL varies by .015". Posted Via AR15.Com Mobile RCBS will make a custom seater plug for about $21, shipping included. I just got two a couple of weeks ago...made a big difference. I remember seeing you post about it. I'm not sure it's worth it on my end because I'm switching bullets after I get the rest of these loaded up (just 50 more to go). The HP's are nice, but for putting holes in paper, 115gr RN is plenty. Thanks for the idea though 
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| Ditch the Lee seating die. It was the single biggest contributor to my lack of consistent OAL on my own 9mm loads (major & minor). The seating plug adjusting knob tended to unscrew itself as I loaded so that the rounds would grow from first to last round loaded. I only noticed it when rounds would not chamber because the bullet was hitting the rifling before fully chambering. |
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As tempting as it is to let the dogs loose....
Suggestion; actually two. If you have no faith In your Lee dies toss them in trash can now and get a set of real dies.. LEE is all I use and I don't have issues. You could remove all of your dies. Take handfull of brass, measure.. keep only the longest and shortest. Now set your expander die to barely bell shortest piece. Then insert longest piece in shell holder and confirm you still have full top dead center stroke of ram. Now install the rest of your dies per LEE's instructions and make a run. Posted Via AR15.Com Mobile |
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Quoted:
Ok, other than dumping my lee dies is there a fix to this? I was going good there for while and all of a sudden it started walking. If the seater plug is walking out you probably need a new o-ring in there with a tighter fit. If the die is backing out you can actually put an O-ring around the die under the locking ring if you're not using the lee locking rings which already have the o-ring in place. DOC |
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I'm pretty sure there's an O-ring inside of the die that holds the seater stem from moving around. I would try and match it up at the hardware store, with the same size or maybe a little thicker. Clean out the die with alcohol and put the new O-ring in without any oil or anything. Maybe the a fresh O-ring will hold things in place better. I'm not guaranteeing anything, but it'd be a cheap thing to try.
ETA: DOC beat me by a minute with a similar response! |
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Quoted:
Ok, other than dumping my lee dies is there a fix to this? I was going good there for while and all of a sudden it started walking. Sounds to me that these guys have you squared away. Something is obviously working itself loose if they were consistent, but now they're varying. Posted Via AR15.Com Mobile |
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Quoted:
Since you fellows have seamingly narrowed the problem down to variations in the amount of belling are any of you willing to admit that you need to start trimming to a uniform length that is within spec? I load right around 20k rounds of handgun ammunition per year. I absolutely will not trim handgun brass. |
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Quoted:
Quoted:
Since you fellows have seamingly narrowed the problem down to variations in the amount of belling are any of you willing to admit that you need to start trimming to a uniform length that is within spec? I load right around 20k rounds of handgun ammunition per year. I absolutely will not trim handgun brass. I don't trim handgun brass. I load for bullseye and service pistol. My loading is accurate at 50 yards with no trimming needed. |
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