Small primer vs large primer same case.
- Thread starter Waterboy3313
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JFrank
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I may be thinking of 223, I’m not a big fan of either cartridge but the ones I have seen were LRP.
Varminterror
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A lot of higher volume reloaders who use progressive presses hate the small primer pocket pistol brass, because it requires an extra step of sorting to avoid choking the press by trying to shove a large pistol primer up the keister of a small primer pocket piece of brass. Whether those folks use mixed range pick-up brass, OR use dedicated headstamp, sorted brass, getting an errant piece of small pistol pocket brass in the mix will choke the press and interrupt production. Not what we want at all, and for many of us doing so, that sorting step defies the philosophy of shooting high volume, mixed pickup brass, so it's a rather frustrating opportunity.
entropy
Member
Ok, Show Me's admonition aside, you doubled down on this, so I will respond with his user name: Show me.
Unless it's some ComBloc made 5.56, it will have small primers by STANAG.
OP
OP
Waterboy3313
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Makes sense I'm not super high volume shooter and tubs of brass sorted by headstamp. I also have certain headstamps I won't use.
Varminterror
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The only "large primer" 223/5.56 are Berdan primed brass. Berdan primers are very close in size (0.21") to Large Rifle primers, but of course, nobody reloads Berdan primed brass. Not REALLY a large rifle primer, but visually close enough.
All boxer primed commercial 223rem and mil-spec 5.56x45 brass use small rifle primers.
Varminterror
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Is your question wondering more about rifle brass, or pistol brass? I think the ideas behind each are a little different, and of course, the consequences for the reloader using either LRP vs. SRP vs. the reloader using either LPP vs. SPP are a bit different as well.
JFrank
Member
I’ll stand corrected gents.
Thank you..
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OP
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Waterboy3313
Member
My focus is primarily for pistol use. I do load small primer 6.5 creedmoor. I only use alpha small primer brass. I bought it when I started loading for the creedmoor. I also don't shoot it all that often and single stage when loading it. I believe I am pushing it to near max published load data.
Varminterror
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If you were willing to do the legwork, you could likely source all of your brass for free, as many loaders/shooters will give away small pistol pocket 45's for free, or trade 2:1 in your favor for large pocket brass... That is, assuming you were willing to be the guy committed to the small pocket batch.
I just pitch small pocket brass into a bucket, then when the bucket looks full enough to make a decent batch of several hundred rounds, I load them up. It's not so complicated to shoot small or large, it's just a pain in the butt when the wrong size weasels its way into your progressive press (or autofeed priming press).
JFrank
Member
I must be brain locked on a different cartridge, at my age I must admit to an occasional mental error.
Carl N. Brown
Member
Supposedly some .45 ACP ammo went from LPP to SPP because the non-toxic indoor-range-safe environment-friendly primers were only available in small primer size. That was a surprise discovery when I sorted through my range brass pickups awhile back.
I know exactly where it came from and I assume you do too.
Charlie98
Member
I think it was Federal who started that... SPP .45 brass used to have NT in the headstamp, to denote Non-Toxic. It was an easy way to pick out the SPP brass.
When I set myself up with components small primers were just starting to be seen in a couple calibers where large primers were the norm. I didn't plan for this so all small primers pocket brass that should be large primers pocket gets bagged, tagged and set aside just in case I need it in the future. I don't have a lot of these odd balls as I have tried to rein in my brass scrounging obsession.
I picked up an ammunition box worth of small primer brass in the 45 ACP. It is not dangerous when I find a large primer 45 ACP in the bin when I am loading small primer brass. Typically I notice powder spillage in the bin, then fish around to find the large primer case without a primer.
It is scary when a small primer case appears above a large primer, when loading large primer brass. It is always a case I picked up at the range with my fired large primer brass. Might have been a case under the bench, out in front, or well behind, and was there before I started picking up my fired cases. And when picking up a hundred or more cases, I don't examine the base of each one, they just go into a bin. I have heard of enough primer explosions on progressive presses that I am actually worried about having one. In theory I should "feel" the resistance, but in practice, the difference in feel between tight pockets and a large primer being crammed into a small primer pocket is slight at the beginning of seating.
This data is on different days, which makes conclusions suspect, but I believe it takes more powder to get the same velocity out of a small primer case.
Rock Island Arsenal GI M1911 RIA 5" barrel
230 FMJ 7.8 grs AA#5 Lot DM WLP OAL 1.265" taper crimp 0.469"
13-Sep-18 T = 82 °F
Ave Vel =815.4
Std Dev =18.02
ES =68.22
High = 847.6
Low =779.4
N =28
230 RMR FMJ 7.8 grs AA#5 Lot DM small primer brass WSP OAL 1.265"
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
It is scary when a small primer case appears above a large primer, when loading large primer brass. It is always a case I picked up at the range with my fired large primer brass. Might have been a case under the bench, out in front, or well behind, and was there before I started picking up my fired cases. And when picking up a hundred or more cases, I don't examine the base of each one, they just go into a bin. I have heard of enough primer explosions on progressive presses that I am actually worried about having one. In theory I should "feel" the resistance, but in practice, the difference in feel between tight pockets and a large primer being crammed into a small primer pocket is slight at the beginning of seating.
This data is on different days, which makes conclusions suspect, but I believe it takes more powder to get the same velocity out of a small primer case.
Rock Island Arsenal GI M1911 RIA 5" barrel
230 FMJ 7.8 grs AA#5 Lot DM WLP OAL 1.265" taper crimp 0.469"
13-Sep-18 T = 82 °F
Ave Vel =815.4
Std Dev =18.02
ES =68.22
High = 847.6
Low =779.4
N =28
230 RMR FMJ 7.8 grs AA#5 Lot DM small primer brass WSP OAL 1.265"
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
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thump_rrr
Member
For those worried about low temperatures and small primers.
This target was shot at -20°C or -4°F.
I didn’t have a chronograph out that day but they were starting loads for 6.5 Creedmoor.
H4350 and BR-4 primers under 140gr ELD-M’s.
This target was shot at -20°C or -4°F.
I didn’t have a chronograph out that day but they were starting loads for 6.5 Creedmoor.
H4350 and BR-4 primers under 140gr ELD-M’s.
jmorris
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Yeah that will crash average speed. My older mark 1 eyeballs would miss one every now and again. I added a SPP culler to my 45 acp press that didn't load them but did take them out of the line up before getting to the priming station.
Small primer pocket culler.
www.youtube.com
ballman6711
Member
My 45acp primer test: https://www.thehighroad.org/index.php?threads/45acp-primer-test-part-three.927284/
It is a lengthy three part test, and for those that don't want to read it I'll sum it up.
All primers tested (spp, lpp, and srp) went bang. Accuracy wasn't noticeably different at 15 yards or so, but accuracy wasn't a primary concern. Ejection varied with small primers vs. large primers. No chronograph data since I don't have one.
My conclusion was that spp were a bit weaker than lpp, and may need another tenth or two of powder for consistent ejection and complete powder burn.
chris
It is a lengthy three part test, and for those that don't want to read it I'll sum it up.
All primers tested (spp, lpp, and srp) went bang. Accuracy wasn't noticeably different at 15 yards or so, but accuracy wasn't a primary concern. Ejection varied with small primers vs. large primers. No chronograph data since I don't have one.
My conclusion was that spp were a bit weaker than lpp, and may need another tenth or two of powder for consistent ejection and complete powder burn.
chris
1976B.L.Johns.
Member
You'd have learned the hard way trying to put the wrong primer in one.....
I think he meant flash hole, not primer pocket.
