Mike.

The only two that appear to be upwards in pressure are the H110 load and the Wolf load. There's no telling what the pressure actually is from the appearance of the primers, but the flattened primers on those two usually indicate higher pressures.

The bullet you use will have some bearing on the velocity and pressure you get. The 125 gr Golden Saber tends to shoot faster for me and it seems to develope less pressure, due to the driving band being the only portion that is full bore diameter.

I concur with Paul in his summation about which loads are in the upper range of pressure.

Saying that there are some qualifications.

#1: Which brand of primers were used in all of these loads.
The ones that show no sign of higher pressure might be that way just because the cup material is harder from one brand to the other. This is a proven fact. Federal is by far the softest with, in my experience, CCI being the hardest.
Softer cup material will "flow" at lower pressures. I'm not sure flow is the right word but you get the idea. When the primer looses all of it's natural rounded edge after firing you can be sure that you are nearing maximum pressure. I have taken it one step further only once. I had a Ruger Super Blackhawk once that had milling marks still in the firing pin button. Those marks ended up in my primers once!
The primer on the left looks like it has begun to extrude back into the clearance from the firing pin and bushing. I would stop there with that load, That's just my opinion though.
#2: According to Hodgdon's data with the H110 load you should have gotten between 1881 fps and 1966 fps. If I could make a suggestion. Try that same bullet with SR4756. Make your load to the same velocity and see what the primer looks like. I bet you will be supprised!

I'm not convinced that primers tell you much, or that anything short of tight extraction is much of an indicator of pressure. I have discovered that WLPs give a great indication of relative pressures as you work up a load. Those things tend to flatten more and more as pressures rise. No gauge of actual pressures, though. Even perfs can occur well below what the gun can stand. Seems to me the two best guidelines are published data and the chrono, which generally tells me I've reached the max for a particular gun some time before I reach published max.

Pinymingeo, I think I've seen the reliable pressure changes in WLPs (and maybe even WSPs) you mention here.

The trouble is, I have only used Winchester primers, save for a few explorations some time ago with CCI primers. How do the pressure indicators in Winchester primers compare with other brands?

Jim H.

Gentlemen, thank you for your replies. While waiting, I re-read this thread from the beginning. Took me about 3 hrs… Wow! It's a wealth of information! But I have to say, if I had read this thread before I started reloading - I would have never started. Passions, passions…

Now, in keeping with emerging tradition...

I AM NEITHER TRAINED NOR CERTIFIED BY ANY RECOGNIZED OR NOT RECOGNIZED ENTITY TO DEVELOP LOADS FOR USE IN FIREARMS. MY EQUIPMENT IS NOT COMPLIANT WITH GLP OR GMP STANDARDS. ALL FOREGOING DATA AND ASSERTIONS ARE FICTIONAL AND PROVIDED EXCLUSIVELY FOR ENTERTAIMENT PURPOSES. NO STATEMENT HEREIN OR APPEARANCE THEREOF IS INTENDED AS RECOMMENDATION OR ENDORSMENT OF USE IN FIREARMS OF ANY KIND.

Now, back to the subject matter. I hear loud and clear your warnings about potential overpressure in my 21.5 gr. H110 loads. Thank you, much appreciated. The problem is – it is my favorite load. I’d hate to part with it unless I am convinced there is a problem. And so far I shot in excess of 1000 rounds of this load from GP-100, SP101, 640 and 686 and never had a hint of sticky extraction, blown case or anything at all except flat primers.

So, I took literally Lee’s recommendation to look closely at my primers. Tell me if you think I overdid it

I extracted one of the flat primers from H110 load and filed it open on the side. Here is what I saw.



One doesn’t have to be a metallurgist to see from these images that no amount of internal pressure – large or small - can generate this kind of primer deformation. The inside walls of the primer are perfectly straight and not deformed at all. This leads me to believe that it was external not internal force that caused primer to flow. I can speculate what this external force may be but rather reserve until later time when I get a chance to think more about this.

I realize that I am about to subscribe to heresy in reloading. But looking at this picture I just start thinking that maybe pinky is right…

quote:

Skip: Try that same bullet with SR4756.

Will most certainly do, Skip. This thread is very tempting.

As always, your opinions and critique are much appreciated.

Mike

This message has been edited. Last edited by: rozenbem,

quote:

I AM NEITHER TRAINED NOR CERTIFIED BY ANY RECOGNIZED OR NOT RECOGNIZED ENTITY TO DEVELOP LOADS FOR USE IN FIREARMS. MY EQUIPMENT IS NOT COMPLIANT WITH GLP OR GMP STANDARDS. ALL FOREGOING DATA AND ASSERTIONS ARE FICTIONAL AND PROVIDED EXCLUSIVELY FOR ENTERTAIMENT PURPOSES. NO STATEMENT HEREIN OR APPEARANCE THEREOF IS INTENDED AS RECOMMENDATION OR ENDORSMENT OF USE IN FIREARMS OF ANY KIND. And BTW, I am not an engineer either

You did read the whole thread! And thanks for keeping in the tradition of the thread, more than likely you will become the "fourth disciple"!

quote:

So, I took literally Lee’s recommendation to look closely at my primers. Tell me if you think I overdid it

Yes, but we are going to benefit from it I'm sure.

External pressure, I gotta think about that!

Also, about your H110 loads. I think the primers are fine. I wouldn't change anything especially if they are working in your firearm. The primers aren't excessively deformed by any means. Have you shot them at night? I can only imagine what that would look like!


Chemistry, huh, I feel some good information coming forth real soon! Can't wait!

Mike,

I'm not sure its permissible to surmise the straight wall of the primer cup indicates a lack of abnormality.

If the pressure is exerted equally in all directions, which it is, one portion shouldn't change its shape.

As long as the primer is in the primer pocket, it can only move in one direction, and that's out. It is normally assumed the primer on a revolver unseats the amount of head space present and then is reseated under recoil. While it's unseated, there isn't any external support for the cup, so it can spread somewhat and then the outer most portion doesn't fit back into the primer pocket. That causes it to deform, like what you're seeing (BTW, outstanding pictures!).

quote:

rozenbem;I am not an engineer either

If you want to take me on directly then my E mail is in the Public Profile. I see yours is not. dennis40x

Here's a scan of the primers I used today with 10.0 gr of SR 4756 with a 170 gr 358429 (this load is at least 2.3 gr over the max load published by IMR). There are CCI 500 and Win SP primers, each compared to unfired primers.



They should be somewhere around 1300 fps, but I didn't clock them today out of a 6" Dan Wesson M715.

How did they extract, Paul?

(I loaded up another 100 rounds of THE LOAD today, myself. Gotta keep that .38 Airweight fed! )

They extracted without any problems or stickiness Erich.

That RCBS green lube I'm using sure made a lot of soot and smoke, almost like black powder!

quote:

take me on directly

dennis, don't get your underwear in a knot.

He's having fun with a fun subject and it isn't at anyone's expense.

Chill dude.

quote:

Dan Wesson M715

How many extra barrels do you have for the Dan Wesson, Paul?

Skip,

I just have the 6" for the M715, but I have 3 barrels and 2 shrouds for the M744 stainless .44 Mag I have. The M744 likes 10.5 gr of SR 4756 with a 240 gr LSWC!