High pressure signs...or not?


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seektruth
May 1, 2008, 10:29 PM
Guys, I need some expert advice on how to proceed with some 45acp loads. I loaded and tested these months ago, but just now I'm getting some time to mess with the 45acp handloads again. The loads were as follows:

230 gr Rainier plated round nose
Wolf primers
4.0 gr Titegroup

I shot some out of my Taurus PT1911. I thought I may be over safe pressure with these loads because the primers are flattening some. There is still some of the rounded shoulder left, but they definitely look flatter than they should. Upon further inspection, I found that the primers seem to be slightly protruding from the case, whereas they were flush or slightly below when loaded.

Considering the symptoms, I now believe that this isn't a case of being over pressure at all. The minimum load for Titegroup with 230 gr fmj is 4.4 gr, and the recommendations I found said to decrease by 10% for lead or plated bullets. So that's why I started with 4.0 gr. It seems to me that this is actually such a light load that the primers are pushing out slightly and flattening a bit as a result. Thoughts?

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Steve C
May 1, 2008, 11:21 PM
Flat looking primers is also a sign of low pressure. There's no point in looking for pressure signs in the .45 acp as its a low pressure cartridge and you'd be well over 2x allowable pressure before you'd notice any of the typical primer pressures signs.

Hodgdon lists a 4.0gr start load with a 230gr LRN on the on-line load data so your load is right on.

seektruth
May 1, 2008, 11:23 PM
Steve...that's exactly what I was thinking, but I wasn't sure. I'm just not that experienced with this stuff and want to verify that my load is safe. Thanks!

The Bushmaster
May 1, 2008, 11:52 PM
Flattened primers are not a sign of over pressure. If you see soot around the primer or a cratered or punched primer you might be looking at too much pressure, but flattened primers? No....That is a normal function of the primer to back out a bit when the primer is set off (head space) and be slamed back against the breach and flattened when reseated by the powder charge going off...

hoptob
May 2, 2008, 01:59 AM
+1

Here is a what primers look like in some factory and handloads.

http://i247.photobucket.com/albums/gg160/hoptob/Primers.jpg

Mike

seektruth
May 2, 2008, 08:23 AM
Those pictures posted by Mike show what I'm seeing. The Wolf example looks exactly like mine do. I shot some factory ammo and didn't see the same thing, so between that and the advice of some uninformed 'experts' I thought I had a problem.

I had a couple different local guys look at these cases with the flattened primers and they said 'high pressure', citing the flattened primers as the evidence. They've been handloading for years and I thought they knew what they were talking about. But it didn't make sense to me...now I know. Thanks guys.

rcmodel
May 2, 2008, 01:05 PM
I'd try the same load with American primers and see what they look like.

Who knows what Wolf primers are supposed to look like!
They may be much softer (or thinner) then American primers.

rcmodel

hoptob
May 2, 2008, 06:01 PM
RC,

I've been using Wolf small pistol primers for awhile. They behave very similarly to WSP.

Mike

SlamFire1
May 2, 2008, 07:58 PM
Man, oh man, primers are hard to read. I think it is better to read tea leaves than primers, you are just as likely to predict the future, and you get a good cup of tea.

For a low pressure pistol like a 45ACP, the pressure limit is really the dynamics of your pistol. The cartridge is fairly low pressure to begin with, you can, if you are crazy, blow the unsupported web of the cartridge, but it takes one heck of an overload to pierce or blow 45ACP primers.

Let me explain the dynamics of your pistol. Semi Auto pistols are designed to work with certain pressure ammo which pushes the slide back at a certain speed.

If the ammo is too low of pressure, well Duh, the round won't eject.

If the ammo is too high of pressure, that slide goes back too darn fast and bashes the heck out of your frame. I had a Colt that had a factory defect, the dwell was too short and the slide recoiled too fast. That peened the frame out in 3000 rounds. (Colt replaced the frame but did not fix the barrel/slide misalignment. Wilson Arms had to fix that. )

So, if your cases eject like a rocket trying to get into orbit, if your frame shows signs of peening, your ammo is too hot.

I like to keep my 230 bullets just at 800 fps in a M1911. So I use a chronograph and measure the velocity. I recommend you do the same. You can always chronograph factory ammo and compare.

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