Any Issues Ever Discovered with Small Pistol Primers in .45acp?

[jmorris]

They should have shown the shot count and the extreme spreads and standard deviations.

I collected some data on the 3 different styles of Winchester cases back around 2002, when SPP 45 acp first started hitting the dirt around here.



My sample size of different loads was too small to draw any conclusions but the large flash hole had the smallest es/sd of them all. Couldn't tell the difference between any of them at the ranges I was shooting.

 

[CoalCrackerAl]

When im sorting brass. The small primer ones go in their own bins. I have run into small in 10mm too. Also in 243 or 6.5CM. I forget what one it was.

 

[gudaki]

Zero issues with me.

 

[FROGO207]

Had a coworker I showed how to reload shortly before the pandemic. Helped him set up his bench. All of his handgun ammo was SPP. Then his son obtained a 45 ACP about a year or so later. They could not find any LPP so I gifted him 500 SPP 45 ACP brass. I have been saving the SPP brass as a hedge against no LPP availability. Still have a couple K of them left if needed.

 

[Slamfire]

I collected some data on the 3 different styles of Winchester cases back around 2002, when SPP 45 acp first started hitting the dirt around here.

View attachment 1203236

My sample size of different loads was too small to draw any conclusions but the large flash hole had the smallest es/sd of them all. Couldn't tell the difference between any of them at the ranges I was shooting.

I assume the big hole in the center belongs to a Large Pistol Primer. Even in a picture, it is hard to eyeball sort SP from LP.

I assume the amount of primer cake in a SP is less than that in a large primer. Seems to make sense. In terms of primer performance there are a number of characteristics that take instrumentation to measure. The time from hit to ignition, the time to peak energy release, the amount of energy created, also the amount of matter ejected is hugely important. Glass has been used as a frictionator, and hot glass (may be a plasma) impacting gunpowder is just great for gunpowder ignition. The flame temperature, peak flame, and the duration of flame, are all important. All we have is a chronograph, and that won't measure any of the things happening in a primer.

While the influence of the primer alone is small compared with other variables, but there will be things that are just due to different primers, and there will be things due to variance within primer lots. And we can't measure to the thousandths with our wooden rulers, so we make guesses as to what is going on.

I have met rifle shooters I respect who tell me they get more consistent results with small rifle primers. They also have had misfires with small rifle primers in 308 Win cases, in cold weather!

 

[9mmepiphany]

I have met rifle shooters I respect who tell me they get more consistent results with small rifle primers.

I seem to remember a very popular benchrest cartridge was the .22/6mm PPC from the early 70s with much of it's superior accuracy attributed to it's use of SRP

 

[jmorris]

All we have is a chronograph, and that won't measure any of the things happening in a primer.

While the influence of the primer alone is small compared with other variables, but there will be things that are just due to different primers, and there will be things due to variance within primer lots. And we can't measure to the thousandths with our wooden rulers, so we make guesses as to what is going on.

I think, for me, I don't have any 45 ACP's that show me different results on target with different primers. So it doesn't make any difference to me what primer I use.

That said, I also do have rifles/loads that do their best with a specific primer and I note that. For example the only thing I use Remington 6 1/2's in is 22 Hornet but the difference between them and all of the others I have was evident in observation of the targets, despite me not having he equipment to quantify the different properties among the different primers alone.

 

[lightman]

In my limited use I have seen very little difference in performance or reliability between small and marge primers. I prefer large primers just because ...................! I can see the utility of small primers if you didn't have a supply of the hard to find large primers.

 

[Jimster]

I think it’s kinda stupid to have two different sizes for such a popular historic cartridge. Who in the world thought that would be a good idea? Guess I’m old and opinionated. LPP for me just because it seems right.

 

[rperyam]

None

 

[Jim Watson]

I got 25-40 fps less in .45 Auto with small pistol than large pistol, depending on powder. A small pistol magnum or small rifle will pick that back up if you don't want to change the powder charge. Nothing obvious on target.

 

[9mmepiphany]

I think it’s kinda stupid to have two different sizes for such a popular historic cartridge.

You're right, that's why they are attempting to standardize on the SPP

Who in the world thought that would be a good idea?

Only the folks clinging to LPP cases.

The savings are substantial for the manufacturers to not have to produce/buy LPP

 

[jmorris]

I think it’s kinda stupid to have two different sizes for such a popular historic cartridge. Who in the world thought that would be a good idea?

The first I remember were CCI Blazer Non Reloadable aluminum cased 45 ACP around 2000-02, the Winchester Non Toxic came out that used SPP and is reloadable.

I suppose you could reload the aluminum cases too, know a guy that ruined a Kart barrel in about 2 months of using them.

 

[Jimster]

Jeeze. I feel like I’m always on the wrong side of opinions. Oh well, to each his own.

 

[wanderinwalker]

I'm just here because I sought out .45 ACP ammo with SP cases when I got my Colt Competition Model, specifically to avoid having to buy yet another primer size. Granted, I was already loading with Large Rifle, Small Rifle and Small Pistol, so having Large Pistol would've just completed the set, but still. Anyway, no issues with reliability using SP cases. I've read some arguments that a LPP might give a larger margin for the firing pin hit to be off-center, though to my way of thinking a strike that's so far off center it misses a small primer is a gun issue to be rectified.

Fast forward to the pandemic, and I was gifted a few hundred Large Pistol primers from a friend who had stopped reloading. So of course I now have 2 buckets of .45 brass and have the option of using whichever pistol primers I can put my hands on.

 

[9mmepiphany]

I've read some arguments that a LPP might give a larger margin for the firing pin hit to be off-center, though to my way of thinking a strike that's so far off center it misses a small primer is a gun issue to be rectified.

Yes, that rationalization never held water for me either. If your firing pin is hitting off-center, you should immediately have it corrected

 

[hdwhit]

Other than sorting cases, no problems.

I have loaded and shot .45 ACP LPP brass, but since everything else I load for handgun is SPP, I gave preference to .45 ACP SPP brass.

Having shot SPP and LPP loads across the same chronograph and noticed only minor differences, I would say that primer size matters most when you're sorting the brass and seating the primer.

 

[Barmcd]

I just save the SPP brass for the time when I can't get LPP. I'll still be able to shoot 45 ACP.

 

[StrykerByte.45]

I never noticed a difference even using magnums. Apparently SRP can be used also.