I just shot over pressure reloads in my .45acp


May 26, 2006, 09:04 PM
For reasons of stupidity, I just shot exactly 5 230gr. LRN through my SW1911 that were powered with 4.7-4.9gr of clays.
I collected the cases, and while the the primers werent overly flattened, I did notice a very slight bulging at the base of the spent brass.
I proceded to shoot 100 reloads of 3.6-3.8gr of clays pushing the same bullet.
I will inspect the barrel and breechface
The pistol took it all without a hiccup.

Anyone who can calculate these things tell me what kind of pressures and velocity I was running?

I know I was stupid as heck, but other than that; did I possibly cause any unseen damage?

Im hoping that since the primers werent all flattened, and looked ok, that Im probably ok.


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Ohen Cepel
May 26, 2006, 09:07 PM
I think you'll be fine. If the cases weren't too tore up 5 rds shouldn't be an issue.

May 27, 2006, 07:27 AM
You didn't do any damage to a quality gun, and especially with lead bullet loads.

When data first came out for Clays in 45 the max listed for 230 FMJ was 4.7 grains. I shot literally THOUSANDS of them without a hitch, and so did a bunch of guys I know and shoot with. We did not have much if any primer flattening. The max listed now is 4.0, and according to Hodgdon there have been no changes to Clays other than normal lot to lot variations. They would not tell me WHY they pulled the max charge back when I asked, but my guess it is to guard against pressure spikes from setback and not because the original loadings were over normal 45 acp pressures. I don't have any proof, that is just an opinion.

4.7 with a fmj is going to make a LOT more pressure than 4.7 with a LRN.

If I were you I wouldn't worry about it for a second.

Dave P
May 27, 2006, 07:53 AM
Quickload says you were at 22425 PSI (saami is 21000) and velocity is around 850 fps.

3.8 grains get you 720 fps, and just making Major (165 pf).


May 27, 2006, 09:04 PM
thanks guys; It looks like I need almost 4.0 gr to make major;
3.8 was getting me 680-ish fps.

Paul "Fitz" Jones
May 31, 2006, 01:01 AM
I heard many years ago from the general of my state National Guard that when the Browning .45auto was being tested for approval for the USA army that General Thompson wanted to know what it would take to ruin the pistol and he found that it took 10 grains of pistol powder (Bullseye)? to do the trick spectacularly. And the pistol became our 1911.

June 5, 2006, 08:22 PM
In Hatchers Notebook, pp 184-185, he reports that it took
"took 12 grains of Bullseye instead of the normal 4.6 grains" to blow up a 1911. These tests were done in 1932 when the metals of the 1911 were not (I've read) as good as those of WWII.

I would expect that a good brand modern 1911 would exceed that. I have once or twice in my early days of reloading double charged one or two and all it did was kick real good...aside from making me pee in my pants.:D

And I'm fond of Bullseye for 38 and 45 acp. Also like plain Clays and its also a bit more bulky and easier to see in the 45 case while reloading.

June 6, 2006, 12:14 AM
Please excuse the thread hijack, but is there any way to compute a chamber-pressure estimate from charge and projectile by hand? Or figure estimated max charges from bullet weight, space for powder and chamber pressure?

(What I'm thinking: bigger, heavier projectiles with as much charge download as necessary to stay right at the OAL and 21,000PSI limits.)

June 6, 2006, 03:15 PM
Diamondback6: Dave P in this thread mentions "Quickload says you were at 22425 PSI (saami is 21000) and velocity is around 850 fps". For years there have been some programs for calculating pressues in rifles and also devices that actually measure your pressure. I would not trust my life to my calculations. I stick to published loads and never load to max. The only times I have not is when there is no loading available data for a cartridge.

Back to .45's
I once years ago fired what I now know were over pressure loads in GI .45 that I purchased from the NRA (actually the old DCM) back in 1963. Six grains of unique behind a deeply seated 255 grain colt revolver bullet.

The gun became looser. I believe that steel on the orginal .45s were softer than what people use to today. It use to be that people only fired light target loads in the cup gold so they would not loosen up. It takes a lot to blow up a .45 assuming the gun does not fire until it is fully locked to the front.

June 6, 2006, 03:20 PM
i wish i had the money and facilities to do some testing like that. i'd really love to do a high-speed film of a 1911 shooting >10g of bullseye/clays/etc

June 6, 2006, 06:22 PM
Hi all,

Just to provide a little information on .45 ACP loadings.

Ammo loaded to approximately 25% above industry standard was once used to proof 1911 pistols, and seat the locking lugs...so 6 grains of Unique probably won't hurt anything unless there's a specific problem with locking lug
engagement and/or headspace to start with. I've used 250-grain bullets and
a charge of Unique very close to...and actually a bit above...the one that you mentioned in order to seat and finish equalizing the lugs on fitted barrels. I don't recommend it unless the barrel is correctly fitted, and only enough rounds to finish seating the lugs for the final .0005-.001 inch.

June 7, 2006, 01:17 PM
The more I read on various reloading forums, the more I see why published reloading data has been backed off. There seem to be a increasing numbers of people in eternal pursuit of cramming that last tenth of a grain of powder in. When dealing with a powder like Clays, that's a dangerous game. I have a 1911 barrel from a friend's Colt Series 70 with a nice bulge about halfway down the barrel after an adventure with some Bullseye. He was going to throw it away, so I asked for it, and it hangs right in front of me on the pegboard in back of my reloading bench. I see it often enough to remind me.

Look at a comparative powder burning rate chart, like the one on Hodgdon's site, and you'll see that Clays is VERY fast. Any fast-burning powder can spike with a tenth-grain change when approaching max loads, depending on all the usual variables: case, primer, bullet seating depth /setback, ambient temperature, etc. Even some not-quite-so-fast burning powders have been known to do this. If one is going to operate close to that "edge," then the variations in the powder measure being used had best be EXACTLY known, or every single charge weighed by hand.

Not only are more moderate loads easier on the gun, but have been demonstrated in many cases to be more accurate.

June 9, 2006, 03:49 AM

There is no way to preceisely know the presure without a gauge on the barrel. If you read the SPECs, SAMMI and others use a reference barrel. Presumably, the barrel manufactures do too.

Using only the velocity of the bullet through a chronograph is an estimate at best.

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