Hello All:

       I recently loaded some 32-40 cases with 12, 13, and 14 grains of 4759 behind 169 grain plain based bullets.  I got many severe overloads.  Two blew a hole through the primer and many were very cratered.

      I thought that I was loading very accurate loads.  I was using a Jones powder measure after I confirmed the weights of the powder charges with a scale.   

     My question is this: can 4759 "hang up' in a powder measure to cause severe overloads?  To prevent this from happening, I will weigh each load when I charge the case.

     I can not guess how much pressure I must have had generated with "mild" loads and lead bullets.  I have never had such high pressures in my life!   

      The rifle was a Winchester 1885 and the primers were large rifle.  The bullets were seated a small amount off of the rifling.

       Any suggestions about powder hanging up in a powder or other things that I could have done wrong?

                           Stay well my friends,

                           Zeke

I would assume if powder hung up in the measure, then you'd also have squib loads adjacent to the load that was extremely hot. Did you notice any light loads when firing these?
I always use a "story stick" when making up loads with powders that take very light charges. I simply put a wood dowel in the neck of the case and make a mark at the mouth with a felt pen. I charge all my cases, and then drop the dowel into each case to see how the mark lines up. Any that are off get put on the scale to check the charge.
I'd probably would have stopped at the first one that showed excess pressure, and taken them home to pull bullets and check them all.

How about an oversize firing pin hole and/or a too long firing pin?  I have seen "holey" primers and flowing primers in several old SS especially Sharps.  These are not a pressure sign as in a modern narrow diameter firing pin hole with a tight fitting firing pin where 50K  pressure or more can cause a flattened primer that flows or cups around the rounded firing pin--IMH.  For example,  my original Sharps-Borchardt in 45/70 primers flow back into the firing pin hole with 20K pressure loads, while my Sharps Borchardt in 22 Lovell with a sleeved firing pin hole and modern smaller diameter firing pin never show what you are calling excess pressure signs.  Maybe look into having the firing pin hole sleeved?

Yup!  I dump the charge into the pan for the scale and if it looks light then I push a wire up into the measure to dislodge the granules. 4759 is not very user friendly in my Redding.

As someone else asked did you also have some "Squib" loads?
All the loads you listed should have been okay. I shoot 15.5 Grs of 4759 behind a 195 Gr bullet in a number of M1885 32-40s. My bullets are soft, 25/1 Lead/tin and are Breach seated. Have never had a problem. My procedure when loading is to throw the charge and set the cases in a cartridge block and then before putting in the Cork wad I use to contain the powder stand up over the block with a very bright light and look straight down into EACH and Every case at the powder level. The results you have described I am sure would have been obvious overloads. I have tested myself more than a few times with this procedure and I always have found the excessive loads. I have used this procedure for 32-40, 33-40, and 38-55 calibers. The next issue, are you sure you have 4759? Try throwing a load of 40 Grs weighed into your shells. You should not be able to get 40 Grs of 4759 in a 32-40 cartridge. 4759 is a bulky powder. One of the reasons I like it is because it you can not throw a double with 4759 in most of the Schuetzen calibers.  If you are getting bridging of the Powder which has been known to happen with 4759 I got some advise years ago. Get a small Needle Rat Tail file and file the drop tube out of round kind of oblong in one direction this makes bridging very difficult if not impossible. Also inspect your Firing Pin tip condition. I have found over the years a few Hiwall firing pin tips that were used with Black Powder loads where the Tip had eroded to a nearly sharp point. I always caught the condition but I am sure I would have had pierced primers if I had shot those rifles with smokeless loads. HTH Regards FITZ.

    The primers were Winchester Standard Large Rifle.

      I have been loading rifle, pistol and shotgun since 1956.  I thought that I had my ducks in a row with this rifle but perhaps I made a huge mistake.

     I went back to my loading room and went through all of my equipment and procedures and I can not find anything that I did incorrectly.  I will load some shells with great care to perhaps determine where I  made an error or errors.

      The 4759 looks like it would flow through a measure very well. 

     Perhaps I have reached an age or mental condition where I am no longer confident  to reload.

                      Thanks for the replies,

                      Zeke

A couple of things. Yes 4759 will and does bridge and will give inconsistent loads. It is one of the reasons that I recommend 4227 for the 32-40 and 38-55. If you have an old Belding and Mull measure they do a much better job with 4759 than most measures. If not weigh your charges. 
One other thing that just popped into my head, does your scale measure grains and grams? Many electronic scales do. If you accidently had it set on grams that would explain a sever overload. 

40 Rod

If one is serious about consistent charges then I think the best route is to 
throw light and use a dribbler to make to weight. Even better is to make/buy
one of the electronic dribblers that senses zero on the scale. 

Of course, one must always remember: " the difference between theory and practice is much greater than theory would predict".  IOW Murphy and his cousins are alive and well. 

I've only been loading since 1952 ... and I think i still have 'most' of my head.