small primer/large primer does it make a difference in a 45ACP cartridge

[Jim Curlee]

Just curios if you guy's think there is any difference between a small primer, and a large primer, other than fitting them to the correct case?

Jim

[Earlwb]

I would say no. But it is annoying when you are reloading though, if you got the cases mixed up.
But when I checked the large primer offers a little more velocity than the small primers do. soif you are using max power reloads mixing these primers up could result in overpressure situations.
reference https://www.starlinebrass.com/articles/small-pistol-primers-vs-large-pistol-primers/

[44MAG#1]

Difference? What degree of difference? What amount of difference?
It would be WRONG to say there is NO difference since there can be differences in different lots of the same primer. What if you compared a "hot" lot of small primers to a "mild" lot of a large primer? Vise versa? To many variables to make a definite summation. Would some powders due to burn rate show more variables?
Who knows? I have chronoed some loads with both and the differences were smaller than one would get if one changed "lots " of the same powder or changed "lots" of the same primer.
I don't worry about it. There will be some that will have thousands of dollars of equipment and own more firearms than the United States Army and will give more answers to you.
Just telling what I found which in ballistic testing is an ever changing thing.
Remember ever changing no matter who gives the information.
Even the well know labs such as Hornady, speer, Nosler and Sierra.

[memtb]

My immediate response would be no.....except with the possible mix-up when reloading. With the small capacity of the 45 ACP case, I can’t envision the “need” for a large primer.....the small should provide “more than enough” energy to get proper ignition! There may be a small difference in pressures with max or near max loads....but, I suspect that it would be pretty insignificant! JMO memtb

[PrestoColumbus]

it's got to do with lead in the air. This thread has a good write up on it

https://castboolits.gunloads.com/showthread.php?149905-The-story-behind-small-primers-in-45-ACP

[Wis Tom]

I have chono both, with the same powder, and can't seem to see a whole lot of difference. In this day and age, it's what you have the most of, in terms of small and large pistol primers, and cases.

[Tatume]

Just curious, so I loaded some of each and tested for accuracy. Used 4.2 gr Bullseye and 200 gr Zero SWC in both. No difference.

Some of my 1911s fit the category of curios and relics, but most are modern.

[dannyd]

Not for what I load use both work fine.

[Mk42gunner]

The only way I can see it making any difference is if your gun has way off center firing pin strikes. If you do have a gun like that, it needs some serious Armorer/ Gunsmith attention anyway.

Robert

[bruce drake]

I separate all SP primed 45ACP brass that I might get at the range when I clean the range of brass others leave behind and they get reformed and re-necked into 400 Corbon and 38-45ACP cases while LP primed cases get tossed into the 45ACP brass bin. This way, the higher pressure cartridges get the SP brass for longer case life while the run of the mill 45ACP brass gets the LP cases.

[ioon44]

I load both SP and LP in .45ACP. I have developed a habit of looking at the head stamp every time I put a case in my 550 just in case I missed one when sorting out the cases.

One interesting thing is when chrono graphing .45 ACP using WSPM and WLP primers the WSPM gives me a ES of 10 to 20 and the WLP gives me a ES of around 60 using the same powder and bullets, both loads have good accuracy.

[wv109323]

Not much ballistic difference between the two just the physical size difference.

[Ed_Shot]

I've had SP and LP 45 ACP with identical load over my chrony. The chrony sees little difference and the target sees no difference. I seperate and hoard my SP brass for a rainy day.

[practical_man]

I’ve used both. Both work fine in my self loading pistols. No significant difference in accuracy or velocity when using the same quantity of the same powder (BE, Clays, or 231)

In my 45 acp revolver, small primers give me fits. The DA trigger on that revolver is right at 6.5 pounds. It sets off all large primers with monotonous regularity. Small primers have the occasional misfire with the light hammer fall. All strikes are dead center of primer.

I suspect there is some difference in the amount of deflection and deformation due to different bending moments for given primer diameter. It only shows up the revolver tuned for racing.

[USSR]

Uh, you'll probably have better luck finding large pistol primers than you will small pistol primers.;)

Don

[bimus]

Some time back I bought some Blazer aluminum cases and some boxes where small primers and some where large primers . I bought some Buffalo Bore 45-70 and they where small rifle .

[Battis]

Today, I went to the range with 50 or so .45 ACP rounds with small pistol primers, and a light powder charge. Accuracy was the same, but I had several stovepipes. Never happened with the large pistol primers.
I'm thinking it was the light loads. I'll try again with more ba-booom.

[Rodfac]

No difference in my chrono'd tests. Accuracy and velocity virtually the same. But saving small primered .45 cases was/is a royal PITA. I use the few that I have for field plinking purposes where I'm sure to lose a goodly proportion of them. YMMv, Rod