45 acp large vs small primer question

[Jim Watson]

Depending on the powder I got from 25 to 40 fps less with .45 Small.
That wouldn't matter much in factory equivalent loads but if you are loading light target ammo, you could get malfunctions or fail to make power factor. But since that would be with reduced loads, you could make it up with a little heavier powder charge or a small pistol magnum primer.

 

[ballman6711]

Took me about 5-10 mins to figure out WTH was going on one time. Took my priming tool apart and everything before realizing the brass had a large pocket - DA.

I did this recently as well, really had me scratching my head.

About the only way I can sort them is to use a lee pocket cleaner on the large end and do it that way.

I also do this when I see one I'm not sure about. Works really well IMO.

chris

 

[lordpaxman]

Does the size of the primer affect your recipe for a round?

My recipes start from published data. Does the published data you use specify the primer mfg or size you must use? And I don’t mean what the published data shows for testing.
I did run chrono tests out of an abundance of caution on .45s with CCI 300, WLP, and CCI 500 and didn’t find any statistically significant differences.

 

[CQB45ACP]

My recipes start from published data. Does the published data you use specify the primer mfg or size you must use? And I don’t mean what the published data shows for testing.
I did run chrono tests out of an abundance of caution on .45s with CCI 300, WLP, and CCI 500 and didn’t find any statistically significant differences.

You're the first to mention this in the context of published data. It made me curious so I looked at my handy dandy 45acp published load data notebook.

It includes Alliant, Western/Accurate, Hodgdon, Speer, Lyman, and a couple others with top of page cutoff.

None specify small primers to the extent one can tell

For all but Lyman, either Fed 150 or CCI 300 are specified by brand and numeral.

Lyman only identifies by brand—Fed or CCI—but not numeral nor size.

(Some mention of 1911s having issues with SP? FWIW, none of my four can tell the difference.)

 

[Bill_in_TR]

You're lucky that you planned ahead. I've heard from many 1911 shooters who are growing concerned because LPP are so much harder to find...many are down to their last 5k

For newer reloaders who don't have a large stash set aside, SPP case make it easier to build up stocks


I wouldn't think you'd have much difficulty, but I think you'd agree that it does take more pressure.

That additional pressure could easily be enough to make a shooter have to convert from a hand primer to a bench priming toll...due to their hands tire sooner. It could also increase the chance that a reloader loading on a manual progressive might be more likely to have a high primer...which they hopefully catch when case gauging

I noticed you didn't address my third point of SPP requiring a lighter strike to ignite...in essence, making them more reliable.

I should likely add the disclaimer that I'm not bias against LPP...I have 10K+ Federal on hand for use in my Starline brass. I'm just making the case that there are valid reasons for SPP .45ACP...beside the fact that it would be more production efficient for manufacturers convert all their production to SPP

I did say that all your points were valid so I wasn't questioning your third point. Although truthfully I don't recall ever having an FTF with the large primers. None of what you said was wrong. It is just that in my situation I haven't seen any problems with LPP in practice. Maybe if I live long enough I will be forced to changeover but I'm a pretty olde pharte.

 

[ballman6711]

I recently did a test of LPP vs. SPP in 45acp, and what I found was that my SPP wouldn't cycle my 1911 consistently.

(Some mention of 1911s having issues with SP? FWIW, none of my four can tell the difference.)

That was me. I call this a light target load, but Speers online data doe's show it at near max, although it is at or below pretty much every one else's data.

chris

 

[GeoDudeFlorida]

My recipes start from published data. Does the published data you use specify the primer mfg or size you must use? And I don’t mean what the published data shows for testing.
I did run chrono tests out of an abundance of caution on .45s with CCI 300, WLP, and CCI 500 and didn’t find any statistically significant differences.

I have yet to find a definitive, authoritative document stating clearly that the brisance and ejecta are significantly different between Standard LP and Standard SP. Those are the factors determining how effective the primer is.

Large pistol primers have larger cross sectional area for the primer to strike and still connect with the anvil. That’s about the only difference.

But I’ll be happy to read a white paper which proves otherwise.

 

[LV Gun]

I load both LP and SP in 45 Auto / Auto Rimmed and shoot both, honestly I can’t tell any difference. I now just shoot SP in 45 auto and LP in 45 Auto Rimmed if they made Auto Rimmed in SP I would switch them out.

 

[hdwhit]

I have used both large and small primer 45 ACP brass. I load them the same, 8.5 grains of Blue Dot and a 185 grain JHP bullet. The large primer loads tend to register an average of about 20 fps faster than the small primer loads on my chronograph. I take that to mean there really isn't much of a difference.

I tend to prefer small primer 45 brass since many reloaders who are set up for large primer brass will just give me small primer brass to get rid of it. So, now, probably 80% of my brass is small primer.

 

[.45Coltguy]

Along with some others here, I have and load both small and large primered .45 acp brass. Cannot tell any significant difference really. My load is is 5.4gr Universal under a 230gr coated RN. These are just plinkers, but, chronographed some; hardly any difference in MV or POI. They don't bother me at all.

 

[dartor]

I haven't loaded any small primer 45 but I am setting some brass aside. I still have 8k LPP from about 2001 ($75.00/5000) I'm working through. It may be a while before I load any with SPP.

 

[The Happy Kaboomer]

I throw all my 45acp small primered brass in the brass recycle bucket.