primer question
- Thread starter rebs
- Start date
They're not the exact same size, but are intended to fit in the same primer pockets. That can happen because the manufacturers have a tolerance range for primers and primer pockets, both. I know Remington's old spec was for a diameter of 0.2100-0.2115" for large primer diameter, and 0.2090±0.0004" for large primer pocket diameter. Winchester's is probably similar.
If you look at CCI's standard primer description they boast "easier to seat than ever before", so they've reduced the diameter slightly or added a chamfer maybe. Bottom line, they won't feel the same going in as they used to.
If you look at CCI's standard primer description they boast "easier to seat than ever before", so they've reduced the diameter slightly or added a chamfer maybe. Bottom line, they won't feel the same going in as they used to.
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There are a lot of details that you need to pay attention to when handloading. This is not one of them. Different brands of primers are interchangeable in size and one will not loosen the primer pocket over another. If anything the primer pocket would swage down a primer if it were slightly oversize. No primer is going to expand a case head by being seated into it.
Jim Watson
New member
Agreed, the primer will more likely be sized down than the pocket in the solid casehead expanded.
This is not so in shotshells. There is more variability in battery cup primers and if you use a large one once, the steel cup expanding the brass and plastic of the shell, you must stick with it. There were even people cramming 209 primers into 57 hulls as the old small Remingtons got scarce.
This is not so in shotshells. There is more variability in battery cup primers and if you use a large one once, the steel cup expanding the brass and plastic of the shell, you must stick with it. There were even people cramming 209 primers into 57 hulls as the old small Remingtons got scarce.
As the specification I cited shows, primers are intentionally wider than primer pockets to get a snug press fit to form a good seal. They are usually brass (albeit nickel plated much of the time) same as the case, and they rely on the fact case heads are thicker than primer cup walls to insure the cup is what gives way in when press them together. The brass head gives very little, except, as mentioned, with shotshells, for which the brass in the head is much thinner than in common centerfire cartridge cases. The bottom line is that changing primer brands typically has no effect on a modern centerfire cartridge within the useful life of the case.
Most manufacturers follow the SAAMI suggestions for component dimensions, including primers and primer pockets. While there will be very little variation in the pockets and primers there is still manufacturing tolerances. It's silly to argue that one primer is bigger than another unless one measures the components from several different lots of manufacture...
Stick with Nick_C_S' first post.
Stick with Nick_C_S' first post.
I don't think there's any SAMMI spec for primer pockets or primer cups. None appear in any of SAAMI's drawings nor other standards shown in their documents. I've searched the universe and find no specs. Cup dimensions are sometimes listed, but that of pocket is hard to find.
Will-j,
CCI used to be terrible. My Dillon Square Deal could not seat them completely more than about half the time in .45 Auto. CCI got better after their early 90's production line revamp. Wolf and Tula still are that way. It's caused by burrs on the edges of the cups. Per my quote from CCI, they have now done something on their new line that went up a couple of years ago to make seating even easier. I can no longer tell the difference on the Square Deal.
mikld,
Bart's right. There's no SAAMI standard covering primer or primer pocket dimensions to be found. SAMMI leaves every dimension you can't measure on the outside of a finished cartridge case up to the manufacturer. That includes all the inside dimensions, case capacity, etc. By contrast, the military specs the primer pocket, flash hole, thickness of the head from outside back end to the inside, and wall thickness at a couple of points as well as hardness at key locations on a cross-section (though the hardness is just advisory as they only care if it ultimately holds up during testing), and their testing is far more extensive, typically involving thousands of round, like their primer qualification testing does, where SAAMI just asks for a 10 round test in their standard.
If you look at Rev. A (not B, which has different numbers with NOBIH specs rather than Olin specs for some primers) of McDonnel Douglas Report A0514 Olin and Remington specs for a small rifle primer truly are not identical except for primer pocket and flash hole diameter (though the FL spec is given differently by them, with Olin giving it as a critical maximum dimension with unilateral minus dimension and Remington as a standard plus and minus dimension. This has changed since the report revision in 1976, but it nonetheless shows how much difference there was in their thinking at the time. Since SAAMI was founded in 1926, this would not be happening if there were a SAAMI standard for it.
CCI used to be terrible. My Dillon Square Deal could not seat them completely more than about half the time in .45 Auto. CCI got better after their early 90's production line revamp. Wolf and Tula still are that way. It's caused by burrs on the edges of the cups. Per my quote from CCI, they have now done something on their new line that went up a couple of years ago to make seating even easier. I can no longer tell the difference on the Square Deal.
mikld,
Bart's right. There's no SAAMI standard covering primer or primer pocket dimensions to be found. SAMMI leaves every dimension you can't measure on the outside of a finished cartridge case up to the manufacturer. That includes all the inside dimensions, case capacity, etc. By contrast, the military specs the primer pocket, flash hole, thickness of the head from outside back end to the inside, and wall thickness at a couple of points as well as hardness at key locations on a cross-section (though the hardness is just advisory as they only care if it ultimately holds up during testing), and their testing is far more extensive, typically involving thousands of round, like their primer qualification testing does, where SAAMI just asks for a 10 round test in their standard.
If you look at Rev. A (not B, which has different numbers with NOBIH specs rather than Olin specs for some primers) of McDonnel Douglas Report A0514 Olin and Remington specs for a small rifle primer truly are not identical except for primer pocket and flash hole diameter (though the FL spec is given differently by them, with Olin giving it as a critical maximum dimension with unilateral minus dimension and Remington as a standard plus and minus dimension. This has changed since the report revision in 1976, but it nonetheless shows how much difference there was in their thinking at the time. Since SAAMI was founded in 1926, this would not be happening if there were a SAAMI standard for it.
Code:
SR Primer: Olin Remington
Height: 0.111-0.119" 0.115-0.122"
Diameter: 0.1748-0.1756" 0.1746-0.1751"
SR Pocket Olin Remington
Depth: 0.113±0.001" 0.116±0.001"
Diameter: 0.1740±0.0005" 0.1740±0.0005"
FH/vent: 0.080-0.010" 0.075-±0.005"I years gone by, 70's-80's, CCI pistol primers were hard to seat, often "crumpling" when seating. I used Winchester and Federal whenever I could find them. I still have a partial box of CCI Large Pistol Magnum primers from that era that were put away and forgotten. I am using them up now in heavy .45 Colt loads (H110) and they are still just as hard to seat.
Some folks might disagree, but if you give me my druthers I want Federal and Remington. CCI's late production is a LOT better that their earlier stuff though, and often are the only primers available, and Winchester large rifle primers are doing a lot of blowing out at the edge of the primer.
As far as changing the size of the pocket, even the crumpling primers didn't do anything to the pocket.
Some folks might disagree, but if you give me my druthers I want Federal and Remington. CCI's late production is a LOT better that their earlier stuff though, and often are the only primers available, and Winchester large rifle primers are doing a lot of blowing out at the edge of the primer.
As far as changing the size of the pocket, even the crumpling primers didn't do anything to the pocket.
Winchester had complaints at one point about inadequate sensitivity in their rifle primers, so they dropped the nickel plating and maybe thinned the cups a little. Now they have complaints about slamfires and blow outs. No doubt the thinner cups will be the easiest to squeeze into a pocket.
CCI Primers
U NICK... Appreciate you clearing things up for me. Bought a couple thousand each size of CCIs waaay back when.(late'70s-early'80s) and got cramps in my thumbs from priming. Ended up breaking my Lee Auto-Prime handle/lever and slitting the inside of my thumb.
After calming down, I called Lee to fuss them out, only to be asked what primers I was using. Was told by Lee that CCIs were at fault and thought Lee was just shirking responsibility for poor quality in their product. Bought a HORNADY set-up and......same damn trouble with priming.
Went out and bought a Buuunnch more assorted brands and ....no trouble setting the primers with any other make. Most of the CCIs are still sitting in the corner, dusting up.
Now that I know the problem, I think I will dust them off, chamfer some primer pockets in some cases, and see if they will seat easier. After all, they did give good accuracy and low SDs/ESs.
WILL.
U NICK... Appreciate you clearing things up for me. Bought a couple thousand each size of CCIs waaay back when.(late'70s-early'80s) and got cramps in my thumbs from priming. Ended up breaking my Lee Auto-Prime handle/lever and slitting the inside of my thumb.
After calming down, I called Lee to fuss them out, only to be asked what primers I was using. Was told by Lee that CCIs were at fault and thought Lee was just shirking responsibility for poor quality in their product. Bought a HORNADY set-up and......same damn trouble with priming.
Went out and bought a Buuunnch more assorted brands and ....no trouble setting the primers with any other make. Most of the CCIs are still sitting in the corner, dusting up.
Now that I know the problem, I think I will dust them off, chamfer some primer pockets in some cases, and see if they will seat easier. After all, they did give good accuracy and low SDs/ESs.
WILL.