Nik0251
Nik0251
20 posts
Joined September 2014

Primer seating

When loading small primers in pistol or rifle the primer doesn't always seat unless I give the case a quarter turn or so then it slides right in, original primer bar 25 yrs. old on 550b.
LDBennett
LDBennett
2 posts
Joined July 2009

RE: Primer seating

If the center bolt that hold the shell plate is no tight enough you could have this problem. If that is OK then the primer punch is adjustable. i think the manual twill you how.

LDBennett
dahermit
dahermit
17 posts
Joined October 2007

RE: Primer seating

I am having the same problem with Winchester small pistol primers in 38 spl. I normally use Federal primers, but they are scarce and I have had to switch to Winchesters. My manual, version 7.6 does not show how to seat the primers deeper (they are not going all the way to the bottom of the primer pocket) other than to "make sure the shell plate is right side up..." and "...shell plate is too loose...". My shell plate is right-side up (number 2 showing), and I screw the shell plate bolt all the way in until the shell plate will not turn, and then back the bolt out a slight amount (about 3-5 degrees) until it turns...however, if it turns freely, the primers are not bottomed in the pocket. It I snug the shell plate bolt any tighter, it will move through the first two stations freely, but bind on the second two, indicating to me that the inner surface of the index sprocket is not square with the mating collar on the shell plate bolt...my 550b is around 25 years old with at least 20,000 round through it. As for "adjusting the primer seating depth", the primer punch has a recess where the set screw holds it, so I do not see how the depth can be adjusted. So, how can I seat the primers to the bottom of the primer pockets or do I need a new index sprocket?
Pampurrs
Pampurrs
42 posts
Joined September 2016

RE: Primer seating

Dahermit,

FYI, I use Winchester primers and have loaded thousands of rounds of 38spl, 357 mag, and 9mm with no seating problems. My point is, the problem is not with the Winchester primers, but more likely something with the machine itself.

Pam
dahermit
dahermit
17 posts
Joined October 2007

RE: Primer seating

I agree...it is not the fault of the Winchester primers. I can get them to seat to the bottom of the primer pocket using a Lee hand priming tool, just no longer with my 550b.

Dillon, do you have any input?
dahermit
dahermit
17 posts
Joined October 2007

RE: Primer seating

Mystery solved. This A.M. I did a lot of investigating and measuring. Everything was within normal specs. There was no appreciable wear on the parts that could cause primers to seat too shallow. I concluded that there must be an obstruction. Looking up from below, I found that one of the countersunk flat head screws that hold the Roller Bracket Shell Platform in place had worked its way out a few turns. The design of the 550b is that when the Primer Slide is in the forward position (and the ram is lowered to seat the primer, the screw head contacts the the top of the Primer Slide (if the screw is backed out), effectively stopping the ram from coming all the way down to seat the primer to its full depth.
I am back to reloading, no new parts needed.