45 ACP primer sizes

[sfl_gunner]

I'm planning to start loading some 45 ACP soon. My only question before I start is about the primers to use. I've seen comments about there being both small pistol and large pistol primers in 45. Are there specific brands that use one size or the other? What difference will the primers make for loads?

Which size primer is better? Why?I have plenty of both so supply isn't the issue.

 

[Englishmn]

The only problem is when you have both and get one of the opposite mixed in on a progressive press. It either jams up or spills powder everywhere.
Otherwise use what you have. Large primer 45acp is still more common around here. Blazer is typically small primer.

 

[Blue68f100]

The large primer will deliver about 20-25 fps more over a small primer. So unless your loading max it does not matter. If your loading on a AP you have to presort for primer size to keep things running smooth. For to days primer condition it will probably be easier finding SP over LP. I shoot reduced BE loads in my 1911's, so it does not matter. Large was what the cartridge was designed for originally. SP came out with the low toxic primers for indoor range use to limit lead exposure.

 

[9mmepiphany]

Blazer,Federal and Speer all offer .45ACP cases utilizing SPP. SPP are going to be the future standard for .45ACP. LPP aren't really needed to get reliable ignition.

The nice thing about loading SPP .45ACP cases is that SPP are usually easier to find.

When loading/priming on a progressive press, you can feel the lack of resistance if a LPP case sneaks into your SPP run...this should be a sign to stop and remove the LPP case . In the reversed situation (SPP case in LPP run), you're going to smash/distort the LPP.

I've also found SPP easier to ignite than LPP...so more leeway in a competition tuned pistol

 

[Hartkopf]

And in lean times, SRP could be used in place of SPP. With the LPP cases, LRP can not be used. (Unless you do lots of tweaking and even then they will be harder to ignite and not worth the effort)

 

[243winxb]

What difference will the primers make for loads?

https://www.starlinebrass.com/articles/small-pistol-primers-vs-large-pistol-primers/

large primers give more velocity

A test on accuracy would be more interesting to me & more important then velocity. Machine rest test needed.

I have not tested it. I am staying with WLP.

 

[jmorris]

For year Winchester NT was the only ones I came across. Lots of them these days.

A test on accuracy would be more interesting to me & more important then velocity. Machine rest test needed.

I’ve got one, however, besides primer size there are also cases out there with different diameter flash holes, all of the changes make differences but they are also depend on the rest of the combination you are using.

Small primers are easier to light off than large, so I have used them in revolvers because they allow for a better trigger pull before they start to become unreliable.

Main thing is a large primer won’t go into a small hole and humans are not perfect, so I have made devices that sort them for me. This one probes the pocket after being deprimed and culls SPP brass from the machine before the priming station.



This one is stand alone and deprimes the brass then sorts by pocket size.

 

[lightman]

I have limited experience shooting small primer brass but I have seen very little difference between small primers and large primers. Slightly less velocity, 10-20 FPS and no noticeable difference in accuracy.

As some of the others have said, mixed sizes can be a pain if loading on a progressive loader if they are not sorted. Theres nothing different about loading them except for primer size.

I would suggest loading what you have and to expect no problems.

 

[mdi]

When the small primed 45 Auto brass started showing up I did my own tests (some reloaders became real upset, emotional about the idiots that used small pistol primers on their old friend, mostly progressive press users). I bought some (100?) small primed 45 ACP brass and loaded them with CCI small pistol primers. I already had many 45 ACPs with CCI large pistol primers. Identical loads in both (Bullseye under 230 gr FMJ). Same guns, Ruger P90 and RIA 1911, fired over my chrony and found not enough difference to make a difference. Large primed loads may have been a bit faster but the difference could be explained by normal shot to shot variation.

I inspect every case before reloading and tossing a small primed case into a container takes about 1/10 second. I can see the difference between small and large primer pockets so it's no big deal for me...

 

[dh1633pm]

I am of the opinion that SPP and LPP for a single caliber is a curse. It just adds to the sorting that you have to load. I would say stick with one or the other and not both.

 

[Dudedog]

As mentioned earlier LP is a little faster, my tests showed LP are about 20fps faster than SP.
Either will work just fine, if I was buying brass I would try to get SP as they are easier to find right now.
It is kind of nice to have both that way if you can find primers in either size you are good to go.
As a side note I find them much easier to sort (LP vs SP) one they have been deprimed.

 

[.45Coltguy]

Just mail me your .45 acp cases using spp's. I load both and see no real differences at all.I run a single stage press and have plenty of time to sort.
Retirement has it's virtues.

 

[Ks5shooter]

Sort and standardize.

 

[Slamfire]

I have had greater variations in velocity due to temperature, and different barrels, than I saw with WLP versus WSP primers

Rock Island Arsenal GI M1911 5" barrel

230 FMJ 7.8 grs AA#5 Lot DM WLP OAL 1.265" taper crimp 0.469" mixed cases
13-Sep-18 T = 82 °F

Ave Vel = 815.4 fps
Std Dev = 18.02
ES = 68.22
High = = 847.6
Low = 779.4
Number rounds = 28


230 RMR FMJ 7.8 grs AA#5 Lot DM small primer brass WSP OAL 1.265" , mostly Blazer brass
taper crimp 0.469"

10-Jun-20 T = 91 °F

Ave Vel = 805.6
Std Dev = 12.56
ES = 39.38
High = = 822.4
Low = 783
N = 16

small pistol 45 ACP goes bang and where it was aimed.











Might be better to start off with small primer brass as no matter how diligent you are, after collecting your fired brass at the range, a small primer case will make its way into the can. I pick up my fired 45 brass in the area, and there have been times the case under the visitors chair was not mine. And it was small primer, and I was shooting large primer. Even if, as I have tried, inspecting all the case bottoms, the size difference between small pistol and large pistol is not glaring enough to always see the small pistol primer case.

This is a real problem when using a progressive as I have had a number of times when resistance to priming on my Dillion 550B revealed a small primer case over a large primer. The danger is, primers do ignite when compressed. There are enough pictures on the web showing the damage that happens when this happens. Including in hand primers!

I have a can of small primer range pickup brass, and I don't shoot small primer the same day I shoot large primer. Too risky when collecting. Trying to insert a small pistol primer in a large pistol primer case is a nothing burger. It feels too easy, and the primer falls out anyway.

I really wish ammunition manufacturer's had not introduced small primer 45 ACP brass, as I have ammo cans of large pistol. Small primer brass is just a risk to me, luckily no kaboom's during repriming yet! But never say never. This is literally playing with fire. This is another example of Corporate Externalities.

 

[The Happy Kaboomer]

I am of the opinion that SPP and LPP for a single caliber is a curse. It just adds to the sorting that you have to load. I would say stick with one or the other and not both.

Yep. Any SPP 45 acp brass I get goes into the scrap bucket.

 

[FROGO207]

Due to lack of LPP in the recent past I am saving my LPP for use in 45 LC and 44 MAG loading. Now using small primer 45 ACP brass so I can use SPP or SRP as I have many more of those stored away. Hopefully the primers will all come back in stock before I run critically low on everything.

 

[hdwhit]

I've said it before and I'll say it again; I prefer small primer 45 ACP brass.

* Small primer 45 ACP brass is often cheaper.
* SPPs work just as well as Large Primers.
* Every other pistol cartridge I load uses SPPs.
* I find no difference in overall performance.

 

[AJC1]

Get the brass that you have or see primers for. I haven't seen lpp in stores in 2 years. Spp are available quite regularly. I collect it all but shoot spp currently for the above reason.

 

[highlander 5]

I have a good supply of 45 acp in SP/LP so I don't worry about supply. All the brass are in MTM cases with a label denoting small or large primer.

 

[sfl_gunner]

I have a ton of mixed brass. I guess I have a winter project this year.