Here Is A 'Head Scratcher' For You Ballisticians. Help Me Out!!!

riverwalker76 · August 10, 2011, 11:44 AM

Ok, I recently acquired several thousand .45 ACP of the SMALL PRIMER variety that so many commercial companies are seeming to produce these days.

With the primer being changed from Large Primer, what used to be SAAMI standard, to Small Primer, what I'm seeing a lot of today, what will be the difference in charge data?

It's obvious that with ALL of the standard load data from Lyman, Sierra, Hodgdon, Lee, Speer, Vihtavouri, and Barnes is for a LARGE PRIMER .... what would change if I'm using SMALL Primer .45 ACP brass?

Scimmia · August 10, 2011, 12:01 PM

No change. I seem to remember seeing someone do some testing and the averages came out to ~20 fps difference. If you want to bump the powder a very small amount, you probably could, but most powder measures will vary more than that drop to drop.

dunerjeff · August 10, 2011, 12:25 PM

I just got a 2000K small primer 45ACP brass (so I can just buy one size primer)and I used Mag primers instead of the regular(I backed off .7gr on the powder to start).I will load some up with the regulars once I use up my stash of mags.So far of all the loads I've tried side by side with my old loads (that I have left) I can't notice a difference. They hit in the same group,recoil felt and sounded the same.I'm still testing and hope to get a crono to verify.As long as you get the ones that don't have NT stamped on them,they are not crimped.

Magnum Wheel Man · August 10, 2011, 03:48 PM

personally I'd be concerned about using the small primer cases in extreme cold...

you may not have to shoot in cold weather, but from what I've seen, small primers may not reliably burn the powder in extreme cold... I ( living in MN ) would not use a small primer 45 in a CCW

Scorch · August 10, 2011, 04:03 PM

Same loads, no changes. Just FYI, small standard primers have as much priming compound in them as large primers. If it was supposed to make sense, large primers should have been obsolete by now, but with so many in use it would be hard to change over a whole industry.

dunerjeff · August 10, 2011, 04:16 PM

How does 9mm ,357Sig,40S&W and about forty others with small primers work in cold weather but somehow not 45ACP?Just trying to figure that one out.

Scimmia · August 10, 2011, 04:32 PM

Quote:

personally I'd be concerned about using the small primer cases in extreme cold...

you may not have to shoot in cold weather, but from what I've seen, small primers may not reliably burn the powder in extreme cold... I ( living in MN ) would not use a small primer 45 in a CCW

I don't think large vs small is an issue when talking temperature, but standard vs magnum. If you're shooting in really cold weather, primer manufacturers usually recommend magnum primers.

Magnum Wheel Man · August 10, 2011, 05:20 PM

sorry... believe what you want... BTW... I'm not an expert & don't claim to be

my information came from an artical in a "Handloader Magazine" borrowed from a buddy of mine

IIRC... they tested both pistol & rifle cartridges ( for accuracy ) using both large & small primer pockets & noticed incomplete burning & a bigger spread in chrony results with the small primer pocket loads, in the colder weather... more so than the same cartridges with large primer pockets

Quote:

How does 9mm ,357Sig,40S&W

all of those cartridges are smaller diameter than the 45's... I'd suspect there is a larger portion of the powder not fully exposed to the "fire" of the smaller primer... around the edges & in the back corners

**Unclenick** · August 10, 2011, 07:45 PM

What makes a difference in primers is mainly the amount of empty space they can pressurize and by how much. The benchrest crowd have found, in general, the mildest primers are best for accuracy, but that is under the constraint that the powder fills the case pretty well and the case burns powder pretty efficiently. This is why Lapua produces a version of the .308 Winchester with a small primer pocket that it calls their Palma match ammunition.

This string of photos has a few pairs of small and large primers of the same brand. The small ones produce visibly smaller flames in each case. The idea the amount of priming mix in the two is the same may have been true for some brand at some time, but I do not believe it is generally true, both because of the above linked photos and because Lapua bothers to make the funny .308 case. But if it's important to someone to have an exact answer, I think I can look it up from the drawing numbers for military large and small primers, which I have somewhere.

On the other hand, I wouldn't be too concerned about the small primers not lighting you up in cold weather. Just don't use the slowest or hardest-light-powder and don't use a load that leaves a lot of empty space in the case, because that's when you actually need a magnum primer to get you to adequate start pressure. Stick with stick powders on the fast side of what produces your needed performance and that fill the space under the bullet well, and you'll do fine.

Randy Garrett gets small primer pockets formed in his .45-70 brass for his premium hunting ammunition, and he wouldn't do that if they didn't run well in the cold. The reason he does it is to make it safer to have the heavy recoiling rounds in a tubular magazine where a bullet might tap the primer of the round in front of it, but if it compromised low temperature ignition, he'd find an alternative. But if you're still concerned, call and ask him about his experience with these. He does use actual mil-spec small rifle primers, and those are magnum primers, of the smaller kind.

dunerjeff · August 10, 2011, 09:14 PM

This has sparked an interesting topic,. if there is any noticable better accuracy with either and temperature differences.Tonight after work I went to the range with another 4 test loads(7.4gr Sillouette over 185 JHP Noslers and 185 FP Berry's),2 different guns (PT1911/Kart barrel and XDM 45),Winchester Mag small pistol. Both guns had excellent groups,both were better than my loads with large primers (the XDM wouldn't cycle with the .7gr less powder,not enough oomph)These seemed to be weaker than my normal loads so I'll have to up the powder to my standard 8.1gr. and see if the accuracy stays.

riverwalker76 · August 11, 2011, 09:32 AM

Thanks for all of the replies. I'm finding an increased number of shooters who actually prefer the small primer pocket .45 ACP to the standard large primer pocket.

Thanks again for the replies.

**Unclenick** · August 11, 2011, 11:15 AM

The .45's small powder space has always been subject to primers unseating the bullets before powder gets burning well, so it has always been a good candidate for the change to SP primers. .22 Hornet is another round that has the unseating problem, and it's why Remington 6 1/2's and Federal 205's are often used with it, because performance gets erratic with stronger primers.

I understand, despite complaints about their stiff seating, that the KVB primers (Tula and Wolf) are among the most mild, and have been finding favor among benchrest shooters for that reason.

Ike666 · August 11, 2011, 04:19 PM

Now I see why everyone raved about RWS primers. Any chance they'll start exporting them to the US again?

I've been using BR2s a lot lately - it looks pretty wimpy.

maillemaker · August 11, 2011, 04:53 PM

Funny, I just encountered some of these damn small-hole primers in Blazer .45 ACP brass last night.

Couldn't figure out why they kept jamming up my progressive reloader!

Makes me glad I sort my brass by manufacturer, though. Turns out I only had about 7 of them in all my brass.

I tossed them.

Steve

TXGunNut · August 11, 2011, 10:10 PM

I only have a hundred or so at the moment. Suspect I'll find a few more when I try to reload what I think is LP brass.

When I get enough I'll treat them just like any other .45acp brass. Top Brass, Federal and Blazer look remarkably similar to me. Wouldn't be surprised to learn they come from the same factory.

dunerjeff · August 13, 2011, 07:11 AM

I have about 1000 Federal,850 Blazer,150 Speer spp and there is a definate difference in the primer pocket size. Federal and Speer seat normal but the Blazer I am questioning how many reloading I'll get before the primers are too loose. If Wolf or Tula primers are on the big side I may get some of them for the Blazer brass.

August 10, 2011, 11:44 AM	#1
riverwalker76 Senior Member Join Date: February 13, 2010 Location: Kentucky Posts: 993	Here Is A 'Head Scratcher' For You Ballisticians. Help Me Out!!! Ok, I recently acquired several thousand .45 ACP of the SMALL PRIMER variety that so many commercial companies are seeming to produce these days. With the primer being changed from Large Primer, what used to be SAAMI standard, to Small Primer, what I'm seeing a lot of today, what will be the difference in charge data? It's obvious that with ALL of the standard load data from Lyman, Sierra, Hodgdon, Lee, Speer, Vihtavouri, and Barnes is for a LARGE PRIMER .... what would change if I'm using SMALL Primer .45 ACP brass? __________________ *Admiral Isoroku Yamamoto* - “You cannot invade the mainland United States. There would be a rifle behind each blade of grass.”

August 10, 2011, 03:48 PM	#4
Magnum Wheel Man Senior Member Join Date: July 26, 2006 Location: Southern Minnesota Posts: 9,333	personally I'd be concerned about using the small primer cases in extreme cold... you may not have to shoot in cold weather, but from what I've seen, small primers may not reliably burn the powder in extreme cold... I ( living in MN ) would not use a small primer 45 in a CCW __________________ In life you either make dust or eat dust...

August 10, 2011, 04:03 PM	#5
Scorch Senior Member Join Date: February 13, 2006 Location: Washington state Posts: 15,248	Same loads, no changes. Just FYI, small standard primers have as much priming compound in them as large primers. If it was supposed to make sense, large primers should have been obsolete by now, but with so many in use it would be hard to change over a whole industry. __________________ Never try to educate someone who resists knowledge at all costs. But what do I know? Summit Arms Services

August 10, 2011, 07:45 PM	#9
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	What makes a difference in primers is mainly the amount of empty space they can pressurize and by how much. The benchrest crowd have found, in general, the mildest primers are best for accuracy, but that is under the constraint that the powder fills the case pretty well and the case burns powder pretty efficiently. This is why Lapua produces a version of the .308 Winchester with a small primer pocket that it calls their Palma match ammunition. This string of photos has a few pairs of small and large primers of the same brand. The small ones produce visibly smaller flames in each case. The idea the amount of priming mix in the two is the same may have been true for some brand at some time, but I do not believe it is generally true, both because of the above linked photos and because Lapua bothers to make the funny .308 case. But if it's important to someone to have an exact answer, I think I can look it up from the drawing numbers for military large and small primers, which I have somewhere. On the other hand, I wouldn't be too concerned about the small primers not lighting you up in cold weather. Just don't use the slowest or hardest-light-powder and don't use a load that leaves a lot of empty space in the case, because that's when you actually need a magnum primer to get you to adequate start pressure. Stick with stick powders on the fast side of what produces your needed performance and that fill the space under the bullet well, and you'll do fine. Randy Garrett gets small primer pockets formed in his .45-70 brass for his premium hunting ammunition, and he wouldn't do that if they didn't run well in the cold. The reason he does it is to make it safer to have the heavy recoiling rounds in a tubular magazine where a bullet might tap the primer of the round in front of it, but if it compromised low temperature ignition, he'd find an alternative. But if you're still concerned, call and ask him about his experience with these. He does use actual mil-spec small rifle primers, and those are magnum primers, of the smaller kind. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

August 11, 2011, 09:32 AM	#11
riverwalker76 Senior Member Join Date: February 13, 2010 Location: Kentucky Posts: 993	Thanks for all of the replies. I'm finding an increased number of shooters who actually prefer the small primer pocket .45 ACP to the standard large primer pocket. Thanks again for the replies. __________________ *Admiral Isoroku Yamamoto* - “You cannot invade the mainland United States. There would be a rifle behind each blade of grass.”

August 10, 2011, 12:01 PM	#2
Scimmia Senior Member Join Date: May 19, 2011 Location: Eastern IA Posts: 428	No change. I seem to remember seeing someone do some testing and the averages came out to ~20 fps difference. If you want to bump the powder a very small amount, you probably could, but most powder measures will vary more than that drop to drop.

August 10, 2011, 12:25 PM	#3
dunerjeff Senior Member Join Date: March 31, 2011 Location: central Wisconsin Posts: 440	I just got a 2000K small primer 45ACP brass (so I can just buy one size primer)and I used Mag primers instead of the regular(I backed off .7gr on the powder to start).I will load some up with the regulars once I use up my stash of mags.So far of all the loads I've tried side by side with my old loads (that I have left) I can't notice a difference. They hit in the same group,recoil felt and sounded the same.I'm still testing and hope to get a crono to verify.As long as you get the ones that don't have NT stamped on them,they are not crimped.

August 10, 2011, 04:16 PM	#6
dunerjeff Senior Member Join Date: March 31, 2011 Location: central Wisconsin Posts: 440	How does 9mm ,357Sig,40S&W and about forty others with small primers work in cold weather but somehow not 45ACP?Just trying to figure that one out.

August 10, 2011, 09:14 PM	#10
dunerjeff Senior Member Join Date: March 31, 2011 Location: central Wisconsin Posts: 440	This has sparked an interesting topic,. if there is any noticable better accuracy with either and temperature differences.Tonight after work I went to the range with another 4 test loads(7.4gr Sillouette over 185 JHP Noslers and 185 FP Berry's),2 different guns (PT1911/Kart barrel and XDM 45),Winchester Mag small pistol. Both guns had excellent groups,both were better than my loads with large primers (the XDM wouldn't cycle with the .7gr less powder,not enough oomph)These seemed to be weaker than my normal loads so I'll have to up the powder to my standard 8.1gr. and see if the accuracy stays.

August 11, 2011, 11:15 AM	#12
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	The .45's small powder space has always been subject to primers unseating the bullets before powder gets burning well, so it has always been a good candidate for the change to SP primers. .22 Hornet is another round that has the unseating problem, and it's why Remington 6 1/2's and Federal 205's are often used with it, because performance gets erratic with stronger primers. I understand, despite complaints about their stiff seating, that the KVB primers (Tula and Wolf) are among the most mild, and have been finding favor among benchrest shooters for that reason. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

August 11, 2011, 04:19 PM	#13
Ike666 Senior Member Join Date: October 10, 2009 Location: SW VA Posts: 491	Now I see why everyone raved about RWS primers. Any chance they'll start exporting them to the US again? I've been using BR2s a lot lately - it looks pretty wimpy. __________________ ___________________ "I'm your huckleberry."

August 11, 2011, 04:53 PM	#14
maillemaker Senior Member Join Date: August 30, 2010 Posts: 1,635	Funny, I just encountered some of these damn small-hole primers in Blazer .45 ACP brass last night. Couldn't figure out why they kept jamming up my progressive reloader! Makes me glad I sort my brass by manufacturer, though. Turns out I only had about 7 of them in all my brass. I tossed them. Steve

August 11, 2011, 10:10 PM	#15
TXGunNut Senior Member Join Date: January 16, 2010 Location: If you have to ask... Posts: 2,860	I only have a hundred or so at the moment. Suspect I'll find a few more when I try to reload what I think is LP brass. When I get enough I'll treat them just like any other .45acp brass. Top Brass, Federal and Blazer look remarkably similar to me. Wouldn't be surprised to learn they come from the same factory. __________________ Life Member NRA, TSRA Smokeless powder is a passing fad! -Steve Garbe I hate rude behavior in a man. I won't tolerate it. -Woodrow F. Call Lonesome Dove My favorite recipes start out with a handful of used wheelweights.

August 13, 2011, 07:11 AM	#16
dunerjeff Senior Member Join Date: March 31, 2011 Location: central Wisconsin Posts: 440	I have about 1000 Federal,850 Blazer,150 Speer spp and there is a definate difference in the primer pocket size. Federal and Speer seat normal but the Blazer I am questioning how many reloading I'll get before the primers are too loose. If Wolf or Tula primers are on the big side I may get some of them for the Blazer brass.