Getting these to funtion

[Sieger]

Originally Posted by farinacci56

First I gotta say the amount of information here is amazing and thanks. I am trying to get a couple of guns to function and hope you can help. One is a 1929 DWM police gun, a 4" P0-8 the second is a 1917 LP- 08, both all matched, good shape both of them. The magazines are brand new mec gars. I was told a medium slow powder is best for these so I using 5.5 4756 with a 124 grain round nose hardcast bullet - brand Hunter's Supply seated to 1.173 oal. They function well most of the time, but I get an intermittent failure to feed where the loaded round ends up with the bullet ending up missing the chamber and pointing in the direction of the ejection port. I have Goetz and Sturgess' book ( another treasure) and according to them this jam is an indication that the toggle and breechblock are not travelling back all the way rearward and creating the failure to feed with the loaded round pointed in the direction of the ejection port. The holdopen works about 80% of the time and the jam as described is about 10 -20% of the time. I am tempted to load a bit hotter, but my Lyman manual says 5.5 of 4756 is the max for this bullet weight and I hate to go hotter with guns of this age. They shoot so well that I'll love to get them to work for the combat matches we have. any ideas would be much appreciated- regards MC

PS Don't think I am limpwristing them

Hi,

Here we go.

Please read my Sticky, in this section, on How to Determine Proper OAL for a new bullet type you are reloading.

I've visited Hunter's site and judging from the bullet they are selling, this could be your problem. Lead round nose bullets of this design often catch on the magazine release, on the inside of the magazine, while climbing up the magazine wall. This split second delay is just enough to cause the malfunction. For more sure of a function, I'd get the pistol functioning properly on FMJ bullets first; then I'd moved to lead.

By the way "they" say a 9mm won't shoot lead accurately. Ha!!!! For perfect function, both Lyman and RCBS make excellent truncated cone moulds for the 9mm. They are both around 120 grain moulds, depending upon the type of lead you are using. At 29mm OAL, these are accurate bullets, particularly the RCBS configuration!!!

SR 4756 is an outstanding powder for the 9mm Luger cartridge, giving both excellent accuracy and power, but, unfortunately, it has been discontinued. The best powder on the market, right now, for 9mm Luger FMJ shooting, for both power and accuracy, is Power Pistol.

Your 5.5 grain load is my personal accuracy load for a 124 grain FMJ bullet with SR 4756. How accurate? Eight in the X ring at 25 yards, pistol held over a sand bag. For lead bullets, it's AA5 at just about the same load. How accurate? Eight in the X ring at 25 yards!

Drop your load down to about 5.0 grains and work up 1/10 of a grain at a time until your hold-open works every time. Also, check for the most accurate group in this range. If your hold-open won't work in this range, there may be a problem with your hold-open spring, the hold-open itself or your magazines.

With any of the above loads, your pistol is firing full power loads, not under powered ones, so we can eliminate that theory. The jam you are describing can occur with either an underpowered load or an overpowered one. This often causes confusion for inexperienced Lugersmiths.

Are your lead bullets' noses jamming themselves into the extracter groove? If so, either your OAL is wrong or your bullets' are not compatible with Luger feeding.


The best two powders for the LP-08 are 3N38 and Blue Dot. How accurate? Three touching at 25 yards, consistently.

I hope this helps!


Sieger