Federal primers more sensitive?

[2ndAmendmentNut]

Are Federal primers significantly more sensitive then other brands of primers? The reason I ask is because both on this forum and others I have read about people preferring to use Federal primer in their tweaked double-action revolvers as though the weaker springs would have trouble reliably firing “harder” primers like CCI and Winchester. Also my Lee hand priming tool has a specific warning against the use of Federal primers.

[Rocky Raab]

Yes, they are. Federal uses the "basic" formulation of priming compound, as opposed to the "common" formulation, primarily because it is more sensitive and thus easier to set off.

That's an advantage for guns with weak mainsprings or light hammers, but is also a disadvantage because the primers are also more susceptible to mass detonation. That is why they are spaced farther apart in their containers, and why some priming tool makers warn against their use in tube- or tray-type tools.

[anachronism]

Tell them they're fat & ugly. If they cry, they're sensitive. Seriously, the only way to find out what works best in your case is to try it. I personally have no use for any firearm that requires such specialized selection in components. They need to work every time, not just when Federal primers are available.

[44mag1]

I only use federal primers in my glock 20 and they always go bang, cant say that about cci and winchester primers.

[StarMetal]

Yes, they are. Federal uses the "basic" formulation of priming compound, as opposed to the "common" formulation, primarily because it is more sensitive and thus easier to set off.

That's an advantage for guns with weak mainsprings or light hammers, but is also a disadvantage because the primers are also more susceptible to mass detonation. That is why they are spaced farther apart in their containers, and why some priming tool makers warn against their use in tube- or tray-type tools.

I'm not buying that. Here's what the primer engineers have to say about it: Occasionally a person has a bad experience with a dropped cartridge invokes the theory of primer pr-stressing. They are moving a civil engineering concept and practice to a technology where it does not apply. The theory is that the act of seating a primer stresses the priming mix to the point where it's chemistry is on the ragged edge of gross instability. Not so. Where this true, every cartridge dropped, regardless of how it lands, would discharge. Come on-thousands of cartridges get dropped each year, and few actually activate. The real story is that Boxer primers leave the factory with the anvil higher than it would be when seated in a cartridge case. Seating so the anvil legs touch the bottom of the procket lets the anvil tip penetrate into the pellet of mix. The nearly universal recommendation of having the primer cup bottom 0.003 to 0.005 inch below flush with the case head exists to set the proper amount of priming mix between teh cup and the anvil tip. This critical distance is known as the bridge thickness. Establishing the optimum thickness through proper seating means the primer meets sensitivity specifications, but does not create chemical instability.

That after the primer is seated and is more sensitive. I believe Federal chose their packaging to "insure" safety. I remember when primers came in the little trays that just had slots and the primers were up on their edges touches the primers to it's side.

Joe

[BruceB]

For once, I'm gonna differ with friend Joe.

We have an S&W 642 (Airlite 2" .38 Special, double-action only) which went back to the factory for some work. While it was there, they did a trigger job at no charge.

Before it was sent to S&W, it ignited all primers of whatever manufacture very reliably. After the trigger job, which is VERY nice, it will ONLY fire Federal primers. Because the trigger is so nice, I just buy Federal 129 Hydra-Shoks for the 'carry' load. I keep around 100 rounds of this factory stuff on hand, and test-fire a few every once in a while just to be sure that the current ammo in the gun will work if needed. I also bought a few thousand Federal Gold Medal Match primers for .38 practice loads. The little revolver works perfectly with these loads, and I now load only Federal primers for all our .38 Special loads.

Based on this one, single example, I have to say that Federals are indeed more sensitive than other primers, at least in the Small Pistol size.

[StarMetal]

For once, I'm gonna differ with friend Joe.

We have an S&W 642 (Airlite 2" .38 Special, double-action only) which went back to the factory for some work. While it was there, they did a trigger job at no charge.

Before it was sent to S&W, it ignited all primers of whatever manufacture very reliably. After the trigger job, which is VERY nice, it will ONLY fire Federal primers. Because the trigger is so nice, I just buy Federal 129 Hydra-Shoks for the 'carry' load. I keep around 100 rounds of this factory stuff on hand, and test-fire a few every once in a while just to be sure that the current ammo in the gun will work if needed. I also bought a few thousand Federal Gold Medal Match primers for .38 practice loads. The little revolver works perfectly with these loads, and I now load only Federal primers for all our .38 Special loads.

Based on this one, single example, I have to say that Federals are indeed more sensitive than other primers, at least in the Small Pistol size.

Hi Bruce,

No problem disagreeing. I wonder though how much of that could be the primer cups on Federals may be really really soft? Dang, just when you think you have all the equipment you need, I need a Rockwell machine.

Joe

[NoDakJak]

I certainly agree with Bruce B and note that Winchester SP primers seem to be more sensitive then the CCI primers that have given me so many problems. My Model 60 S&W was tuned for handloads using Alcan primers and when they ran out I went back to my old standby, CCI. That batch of primers must have been designed for use in submachine guns as they were certainly too hard for my model 60 even after replacing the springs with new factory springs. It is now 100% reliable with both Federal and Winchester primers. I have tried a couple thousand Remington SP primers with no problems but they don't seem to be commonly available in my area. I haven't used any CCI SP primers for almost fifteen years so don't know how they are now. Perhaps I should buy a brick and give them another test. I hope that this information helps someone. Neil

[imashooter2]

Both of my game guns, a 686 and a 625 have 7 pound DA pulls. Both are 100% reliable when shooting Federals, they are 70% at best with Winchester and even worse with CCI. I've never used any other brands, but a friend has used Wolf in his lightened 625 with results similar to using Winchester.

I don't know if the reason is softer cups or different chemistry, but I know the end result is real. Federal pistol primers are more sensitive than the competition.

[Firebird]

I believe Federal chose their packaging to "insure" safety. I remember when primers came in the little trays that just had slots and the primers were up on their edges touches the primers to it's side.

Joe

My understanding is that Federal changed to it's current wide space packaging after a delivery driver managed to set off a case of primers by dropping another package on top, crushing the primers.

[Hip's Ax]

I am mostly a rifle target shooter and primer sensitivity is an often discussed topic. Semi auto's like the M1, M1A and AR-15 have a floating firing pin that "taps" the primer everytime the action strips and chambers a round. For this reason it is said by many (actually most) not to use Federal primers in these type rifles due to an increased risk of slam fire.

So yes, I believe that Federal primers are easier to set off than other brands.

By the same argument the CCI mil spec primers (#34 and #41) are the least sensitive.

[HeavyMetal]

I haven't shot a match in a long time but, back in the day, I remember every gunsmith that built a PPC gun told the customeer the gun was "set up" for Federal primers.

This allowed them to give the lightest DA trigger with the most reliability.

Primer purchase for me has always been dictated by what was on the shelf. I will pick federal first and then Winchester. I have used CCI and constantly seemed to have Trouble with size on the darn things. I do have some CCI's in my small stash of primers but they are regulated to Back up Status behind the 4000 corrosive military ptrimers I got in trade a couple of years ago!

The hardest primer I have ever fired have been the remington's!

[Rocky Raab]

It has nothing to do with dropped cartridges or "pre-stressed" compound. The chemical formula Federal uses is more sensitive to begin with. The basic chemical (so called because its pH value is more base than acid) is simply easier to initiate than the common (more acidic) formula.

The shipping containers are designed so that if one primer does go off for any reason, the ones around it will not also detonate. One way to do that is to separate the primers a bit. That's what Federal does. If they all touched or nearly touched - as CCI, Rem, WW and other primers with the "common" formula are packaged - the greater sensitivity of the Federal primers would lead to mass detonation. As happened in that shipping incident and at least once in Lee Auto-Prime tools.

It's that (ahem) basic.

[jhrosier]

...Primer purchase for me has always been dictated by what was on the shelf. ....
Forward in time, to the present....
I have a couple of revolvers that need the standard weight mainspring re-installed.
Federal primers have been unavailable around here for a while and a couple of my guns only work single action with the harder primers.

I've been told that the current production CCI primers are not as hard as the ones from twenty years ago, but they are still harder than Federals.

Jack

[StarMetal]

I am mostly a rifle target shooter and primer sensitivity is an often discussed topic. Semi auto's like the M1, M1A and AR-15 have a floating firing pin that "taps" the primer everytime the action strips and chambers a round. For this reason it is said by many (actually most) not to use Federal primers in these type rifles due to an increased risk of slam fire.

So yes, I believe that Federal primers are easier to set off than other brands.

By the same argument the CCI mil spec primers (#34 and #41) are the least sensitive.

That's a classic example of a harder or thick primer cup difference. Has nothing to do with sensitivity.

I'll tell you a rifle that's bad for slam fire and that's the MAS 49/56. It has a floating firing pin like an SKS. In fact the action is very much like an SKS except it's a gas impingement system instead of gas piston. I can make the rifle full auto with large piston primers!!! I have not got it to slam fire with various brand of large rifle primers.

I'll do a test with it and the AR 15 when I get some Federal large rifle and small rifle primers.

Joe

[Rocky Raab]

It's BOTH cup toughness and compound sensitivity. Those two factors are either compensating or additive in a given primer. If you combine a thin/soft cup with a more sensitive priming compound, you get a primer that will go off if you stare at it too hard (that's a jest, of course). That's how Federal primers are made. But combine a hard/thick cup and a less sensitive compound and you have a primer you have to really whack to make it work. The latter is how those "mil-spec" CCI primers are made.

Neither is good or bad; they're just designed for different uses.

[Throckmorton]

I can guarntee you that my tuned Blackhawk knows the difference between CCI's and anything else...it will not reliably fire them,and also doesn't care for Winchester primers.
I use Federals when I can get them,Reminton's seem to work fine,3rd choice is Winchester.
IT's not a self defense gun,btw,it's a cas gun,so it doesn't 'have' to be 1000 percent reliable,btw.

[StarMetal]

Gentlemen,

I was working on my lawn tractor this evening and I got a late phone call from Federal. I had called them earlier with some primer questions. I got a call back, like I said, from a primer tech first name Gary. I gave him the general run down of the forum post here and here's what he said. He said first and foremost primers have a sensitivity specification they must meet set by SAAMI, same organization that sets cartridge specs. He said that all primers must fall in that specification and he assured me that if they did not they not only didn't get shipped, they were destroyed. With that said he said he sincerely doubts that any sensitivity could be distinguished between primer brands. He went on to say that if a firearm would only set Federals off that was a primer cup hardness/thickness factor..or...seating depth issue...or...the varying differences between brands in cup height. He said Federal does use a different primer compound from the other brands, isn't the lead one mentioned above, and is no more sensitive then others. One interesting thing he said, that I asked, was the government hasn't been on them one iota about cleaning up pollutants from primers, although they do have a clean shooting primer intended for indoor shooting. I asked if he knew Allen Jones that writes for Shooting Times and he said very well. He said he's one sharp cookie and has been in this business about as long as anyone and you could take his primer notes to the bank. Some of the primer information I stated was picked up from Mr. Jones. One of them was that you can't write a book on various brand primer performance because they change to often and to fast. Final note was on the Federal primer packaging. That was mandated from the DOT, nothing to do with sensitivity. He did say they all wonder when Remington was going to catch up with packaging. He said if Federal primers were so sensitive, why does Federal use the same primers in loading their ammunition that is specifically aimed at semi-auto rifles.

Joe

[2ndAmendmentNut]

Thank you StarMetal, very informative.

[Rocky Raab]

Some of that is a bit different from other information I have - also directly from federal, mind you - but mine isn't quite as fresh as yours.

While all primers fall within the sensitivity range specified by SAAMI, I'll go with the field experiences of many, many people and opine that Federals are much closer to the "more sensitive" end of that range than some other primers.

And the shipping requirements are indeed set by DOT, but to pass the DOT-described tests, more sensitive primers would have to be packaged farther apart than less sensitive ones. Federals are packaged the farthest apart of any I've seen. So that also contributes to the idea that they are indeed a bit more "touchy."

Not disagreeing with either you, Joe, or with Gary at Federal. But there are several ways to interpret a "fact" without contradicting it.

[StarMetal]

Some of that is a bit different from other information I have - also directly from federal, mind you - but mine isn't quite as fresh as yours.

While all primers fall within the sensitivity range specified by SAAMI, I'll go with the field experiences of many, many people and opine that Federals are much closer to the "more sensitive" end of that range than some other primers.

And the shipping requirements are indeed set by DOT, but to pass the DOT-described tests, more sensitive primers would have to be packaged farther apart than less sensitive ones. Federals are packaged the farthest apart of any I've seen. So that also contributes to the idea that they are indeed a bit more "touchy."

Not disagreeing with either you, Joe, or with Gary at Federal. But there are several ways to interpret a "fact" without contradicting it.

Gary did say Federal primers could be a wee bit more sensitive then other brands, depending where the other brand set their specs. Here's what I think. I think Federal may be a wee bit more sensitive and coupled with a softer cup...adds up to a primer that seems more sensitive. To prove it is by far more sensitive would require testing equipment that test the primer cake compound separate from the cup and anvil. Then I'll believe it.

Gary was in total disagreement with the packaging and of hand primers or auto presses not using Federal primers. Like Allen Jones said primer companies change their primers often. What was hard or sensitive yesterday might not be today. Like I said, I seat my primers properly with a hand primer and I've never had a slamfire to date in any semi auto rifles I have. The MAS 49/56 is notorious for this and in fact on the French Board there is a mod to put a spring on the firing pin. I can make my MAS full auto by using large pistol primers and load the first one with a large rifle primer. Charge the rifle with the large rifle primered cartridge and then rock and roll.

Next time I get a pack of Federal small rifle primers I'll load a dummy round for my AR15 and I'll repeatably chamber it over and over and I'll bet you it never fires.

Joe

[JeffinNZ]

My Lee Autoprime instructs say not to use Federal primers in the device which is fine as I don't use Federal primers anyways.

[BruceB]

Folks, it doesn't matter what semantic meaning you give to the word "sensitivity".

The fact is that, for the purposes of the individual handloader, the relative sensitivity of the priming compound, or the hardness and thickness of the cup, does not matter one bit.

What DOES matter is the way the final, assembled primer reacts to outside influences. Whether the reaction is influenced by thinner cups, thicker cups, less compound, more compound, or a different compound is irrelevant to the handloading consumer.

As a consumer of many thousands of primers, due to personal experience, I have for years treated Federals as MORE SENSITIVE than any other common brand available to me. My guns have agreed with me, and I will continue to treat them in this way. My 642 and other .38s will continue to dine only on Federals, and my autoloading rifles will never see a primer of this brand.

On my bench, in my guns, and in my opinion, Federals ARE more sensitive. Why they're more sensitive, I neither know nor care. They are very good primers, too!

[9.3X62AL]

Good summation, Bruce. Your experience is consistent with my own. The only Federal primer on my bench is their hottest one, the #215 LRM. They are difficult to find around here, as are Remingtons--even before the hoarders started their black helicopter-inspired nonsense. CCI and Winchester are the most easily located, and (wouldn't ya know it) those brands predominate on my bench. Funny how that works.