Dillon PM "Drift"

I typically reload 45ACP in batches of about 400 rounds. During the loading of a batch a week or so ago I kept seeing "drift" from the Powder Measure of +-0.3 grains either side of the nominal 3.8 of N310. I checked everything several times, nothing obvious. That batch of ammo was hopeless - in a very tight gun the variation in energy led to frequent FTE's and other failures - luckily that was just training ammo.

Today I decided to up the charge to 4.0 grains to ensure that even with a slightly light drop the rounds should all have enough "oomph" to reliably cycle the gun. After just a few strokes I found that the PTU was not flaring the cases enough to easily place the bullets and also saw a big range in drop weights again - fortunately before actually producing complete rounds. Then the problem literally hit me between the eyes when the Powder Measure detached itself from the station and jumped into my face!

Some time ago when I was using one 650 with several different tool heads and PM's I decided to switch to the 3D printed QD plastic powder measure clamps. It had slowly worked through the plastic and the PM was able to "ride" up on the PTU causing inconsistent drops. Then it finally gave up completely. Ho hum!

Replaced it with the OEM aluminum clamp and buttoned everything back up securely - end of problem. I now have dedicated press/tool head/PM for each of my primary recipes and so I no longer need the QD feature anyway!

Live and learn!

“Then the problem literally hit me between the eyes when the Powder Measure detached itself from the station and jumped into my face!”

PICTURES OR IT DIDNT HAPPEN! Lol 


I’d pay good money if you’d been wearing a GoPro. Sorry but it just sounds ridiculously hilarious. 


 Hope you didn’t get hurt.  

The only damage was to my pride!

Will test the ammo tomorrow - no doubt it will be a touch sharper than I like - but as long as they all cycle the gun I shall be happy. Then I can wind it back to my regular recipe!

I use an aluminum QD for the powder measures on my 550. Got them for $25 each on EBay

So a few thoughts on light loads. My gun maintains the same accuracy over a 0.3 grain spread. When I load I load targeting the higher side of that target, as a bit lighter won’t be detriment to function if for some reason it throws a bit light. In my case my gun shoot really well from 3.9-4.1 bullseye with a 185 projectile so in my case I do have some safety factor if the powder throw or lot is a bit higher in velocity. End of the day good scores can be shot with warmer ammo, most of the loads we shoot are very light per caliber. Though end of day do what ever you can in your power to make sure your projectiles clear your barrel, gunsmiths work too hard to ruin their work threw carelessness.

Chris, yes, your points are valid. In my case this whole "light load" problem only arose cause I got some new guns which were EXTREMELY tight and my stash of consistent, but on the light side, reloads were just not suitable. I shot all of those using my old wadgun, which is still quite accurate, but much looser.

I have put a lot of stronger rounds through the new guns and can now try to home back in on a "short line" or training recipe. Then everything was confounded by the PM QD glitch. Only now can I get things back to normal. 

Point taken about squibs - I am VERY careful about those!

Roy, Agree it is a very specific thing to to loading procedure and the gun being used. However it is a good caution for those with less experience. Light loads may offer an advantage but they also can have potential for problems (both small and potentially large) in the right conditions if care is not observed.Matches are more fun when no one has alibis.

https://www.ebay.com/itm/Quick-Disconnect-for-Dillon-Precision-Reloading-Powder-Measure-/143343838197?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=711-127632-2357-0

Certainly a better option to getting hit in the head with a pm, lol.

Bob