Subtle Sdb Problem On Last Primer

[Gavin Melville]

Hi,

I recently sold my SDB and the new owner has had endless trouble -- I never had any. The remaining problem is that the last primer tilts as it drops into the cup, and normally gets crushed. I have tried or checked:

1. Everthing is clean.

2. The blue tip is new, and the correct size.

3. The press is mounted well.

4. The top adjustment screw is set correctly (looking down the tube shows it to be centered.

5. When the primer mechanism is out of the press it always feeds single primers OK.

6. When it won't feed the tilted primer always damages the lips on the end of the blue tube tip.

7. It has loaded 10's of thousands of rounds without any problems (for me).

8. If you insert primers one at a time 1 out of 2 will fail to feed.

9 I have added a 200g projectile onto the end of the primer rod and this has dropped the failure rate from 100% to 50%.

10. When you have the handle fully down and the primer has not fed a small tap on the end of the primer rob always makes the last primer feed.

The only thing I noticed was that as the primer sled moves out it drops slightly at the outer end -- maybe 1mm at most just as it reaches full extension. This is aided by the spring below it. The Delrin guides are not worn -- this seems to be the channel it runs in being slightly to wide, but not worn. I have tried adjusting the top adjustment screw for both the correct setting, and one where the sled is leaning back slightly, and neither works well. All other primers feed Ok. When looking down the primer tube the cup is centered front to back (in the direction the adjustment screw operates) but is very slightly off sideways. There is of course no sideways adjustment -- this is done by two small bumps in the casting. The sideways error would be 0.1mm at most. The primers tend to be hung up in a front to rear plane.

Returning it to Dillon is not an option in New Zealand....

I would appreciate any bright ideas -- I think the new owner is starting to think I sold the press because it didn't work anymore.

TIA,

Gavin Melville

gavin.melville@acclipse.co.nz

[dillon]

First, be sure the primer seating cup and punch are fully seated into the primer slide. Using dial calipers, measure from the underside of the primer slide to the top of the primer cup. This should measure 1.410", +/-.003" tolerance.

HOw the priming system works is that the colored plastic magazine tip should almost rest on top of the white plastic primer retaining pin. The primer is at an angle, resting on the tapered end of this pin. The slide goes back, pushes on the flat end of the pin, allowing one primer to drop into the cup. If the cup is too tall,

it hits the side of the primer instead of sliding underneath it.

The primer slide rocks slightly when all the way underneath a primer, but this shouldn't cause any problems.

[Gavin Melville]

First, be sure the primer seating cup and punch are fully seated into the primer slide. Using dial calipers, measure from the underside of the primer slide to the top of the primer cup. This should measure 1.410", +/-.003" tolerance.

I will check this.

HOw the priming system works is that the colored plastic magazine tip should almost rest on top of the white plastic primer retaining pin. The primer is at an angle, resting on the tapered end of this pin. The slide goes back, pushes on the flat end of the pin, allowing one primer to drop into the cup. If the cup is too tall,

it hits the side of the primer instead of sliding underneath it.

I have found that some of the blue primer tube tips have a small circular "bump" on them which protudes down enough to touch the white pin -- I have removed this.  The primer mechanism does work as explained here on all but the last primer.  I will setup the press so I can remove the priming assembly when it jams and see if the primer is always in the same plane when it jams -- from approx 6 attempts last night  it is dropping at the front edge ie. nearest the shellplate.  The primer cup is certainly not too tall, but may be slightly short.

The primer slide rocks slightly when all the way underneath a primer, but this shouldn't cause any problems.

<{POST_SNAPBACK}>

[Bill Nesbitt]

I never use the last primer in the tube. I have one of the plastic followers from the primer warning device and watch it. I reload the primer tube with 2 or 3 primers left. No problems that way.

Bill Nesbitt

[Bronson7]

Hi,

I recently sold my SDB and the new owner has had endless trouble -- I never had any.  The remaining problem is that the last primer tilts as it drops into the cup, and normally gets crushed.  I have tried or checked:

1.  Everthing is clean.

2.  The blue tip is new, and the correct size.

3.  The press is mounted well.

4.  The top adjustment screw is set correctly (looking down the tube shows it to be centered.

5.  When the primer mechanism is out of the press it always feeds single primers OK.

6.  When it won't feed the tilted primer always damages the lips on the end of the blue tube tip.

7.  It has loaded 10's of thousands of rounds without any problems (for me).

8.  If you insert primers one at a time 1 out of 2 will fail to feed.

9  I have added a 200g projectile onto the end of the primer rod and this has dropped the failure rate from 100% to 50%.

10.  When you have the handle fully down and the primer has not fed a small tap on the end of the primer rob always makes the last primer feed.

The only thing I noticed was that as the primer sled moves out it drops slightly at the outer end -- maybe 1mm at most just as it reaches full extension.  This is aided by the spring below it.  The Delrin guides are not worn -- this seems to be the channel it runs in being slightly to wide, but not worn.  I have tried adjusting the top adjustment screw for both the correct setting, and one where the sled is leaning back slightly, and neither works well.  All other primers feed Ok.  When looking down the primer tube the cup is centered front to back (in the direction the adjustment screw operates) but is very slightly off sideways.  There is of course no sideways adjustment -- this is done by two small bumps in the casting.  The sideways error would be 0.1mm at most.  The primers tend to be hung up in a front to rear plane.

Returning it to Dillon is not an option in New Zealand....

I would appreciate any bright ideas -- I think the new owner is starting to think I sold the press because it didn't work anymore.

TIA,

Gavin Melville

gavin.melville@acclipse.co.nz

<{POST_SNAPBACK}>

Hey Gavin, I'm just thinking out loud here but maybe if you add an empty case (45 ACP, I think) to the top of the follower rod it may feed the last primer. Only thing I can think of is the added weight when you have primers in the tube is ensuring a positive feed and the reliability goes away when that weight is removed. Hey, just an idea that won't hurt, easy to do.

Bronson7

[dillon]

For problems in dropping the last primer, it often requires a very slight adjustment

on the upper set screw #13961a. This screw is the internal stop, controlling how far back the primer cup comes underneath the primer magazine tip. The cup should come back just beyond being centered under the magazine tip. large primers, by virtue of having a much larger radius at the bottom edge of the primer cup, will feed as long as this adjustment is kinda close. Small primers, having a smaller, sharper radius at the bottom of the primer cup, require a more exact alignment to feed the last primer, as there isn't any appreciable weight on it to force it around the corner. Make teeny tiny adjustments on this set screw, on the order of 1/16th to 1/8th of a turn at a time. never adjust it more than 1/4 turn in total.