I finally set up my Dillon 450 and after adjusting everything and testing repeatedly to make sure everything was good to go I started cranking out some .40S&W. After 10 rounds I went to check the rounds I had finished and found while half of them were at the 1.125" OAL I set it for the other 5 where around 1.190" OAL. I pulled the bullets and ran them through again, same result. I know that a little deviation between rounds is normal but that is quite a variation. What could be causing this and what can I do to fix it?
Change of OAL while loading on a Dillon 450
- Thread starter 300inline6
- Start date
Are you using separate dies for seating and crimping? there is a chance if some of your cases are a bit longer they might put a bit of extra pressure on the locking ring to loosen them if they are not tightened securely. make sure you've got the proper bullet seating punch and tighten the locking nut on top of the die after setting the bullet seating depth. also tighten the locking collar on the seating die after setting for crimp/no crimp( if you have separate seating/crimp stations). other than that the only thing I can think of is a loose plate on the press(the one that the cases run on,not the shell plate), or you have a lot of crud running around under the cases on that same plate.
I'm using separate dies for seating and crimping. They are the Dillon .40/10mm die set. I searched the web and found that some people fill all four stations with cases to simulate a load on the press in case there is any flex in the plates and adjust the dies that way. So I filled the stations up and readjusted the seating die and double checked the the rest and readjusted the shellplate and ran another 15 rounds though. This time 10 were right where I wanted them at 1.125OAL and 5 were long sitting at 1.136OAL, WTF? I even ran them through the seating die again and they still came out the same length. The cases are all the same head stamp and the same length.
paperslayer
Regular
- Location
- Chilliwack
seating dies do not push on the tip of the bullet, they push on the rounded side. You likely have an issue with the consistency of the bullets, not the press or dies. use a comparator or a a re-sized upside down case and measure off the ogive and see if you have the same difference.
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So I gave the resized upside down case a try and the difference was about the same as when I measured OAL before. So I pulled them all( getting real good at using my bullet puller, lol) and grabbed another ten cases and reset my dies and ran them through. This time I still had 4 that were long. I'm going to phone Dillon tomorrow and see if they have any ideas.
After getting a busy signal 5 times and then being on hold for twenty minutes I finally got through to someone at Dillon( I can only imagine how busy they have been recently!!) and explained what was happening. He said that the variations I've been seeing isn't that bad and i shouldn't be to worried and is most likely caused by many factors like case thickness, bullet shape, press flex, etc, etc. He explained that if they can be loaded into the mags(they can) and that they chamber fine in my barrels(they do) that everything is good to go.
I guess I might be stressing over nothing. What do you guys think?
I guess I might be stressing over nothing. What do you guys think?
yeah, I guess the big picture says it really isn't a biggie. I never measured all my loaded rounds once I set my dies. Once I got my dies set I gave a check after 5 rounds,then I measured again after 10,and after every 100. I never encountered any variation. My press is the older 450, it doesn't have the tool head setup of the 550,maybe the press has a very slight bit of excess freeplay between the press frame and toolhead. I guess the variation you are getting isn't causing any function problems in your firearms, so forget about it and enjoy shooting...factory ammo isn't perfect either. btw my powder charging usually varies +/- .1 grain and I could care less,it makes no difference to my pistol. benchrest shooters would consider it pure blasphemy,but I'd rather shoot than get all bent over the little stuff.
