mil-spec primers or not?

[Ronald Pickett]

I reload for my mini14 and have satisfactory results. But after problems with my M1A I was warned about using non-military ammo in it due to slam-fire. I bought mil-spec primers for it since I want to work up loads for deer hunting with it. The action of the Mini14 looks the same as the M1A, so the question is should I be using mil-spec primers for the Mini14 also? I have fired many rounds through it with factory ammo (.223) and rounds I've reloaded with Win small rifle primers with no problems yet. Another related question is, when I reload for a Bushmaster AR, should I use mil-spec primers? Are the Mini14 and the Bushmaster AR subject to slam-fire?

 

[kingmt]

Subjected to definitely. I only use the Wolf & Tula primers. I have heard stories about federal primers tho.

 

[Ronald Pickett]

Subjected to definitely. I only use the Wolf & Tula primers. I have heard stories about federal primers tho.

Thank you. I don't know of Wolf or Tula primers. I've also heard that Federal primers are soft so I will definitely stay away from them. I have some but will only use them in my bolt guns. I saw some cci mil-spec primers that I will buy for the auto-loaders. I'm going to look in the Mini14 manual and see if there is any warning about not using mil-spec ammo. Springfield sent me a warning AFTER my gun blew up, though I'm sure it was not a slam-fire.

 

[JO JO]

for what it is worth I reload all my 223/5.56 with cci 450 and have used rem 7 1/2 in the past never an issue yet ,

 

[Bartojc]

I reload for my mini14 and have satisfactory results. But after problems with my M1A I was warned about using non-military ammo in it due to slam-fire. I bought mil-spec primers for it since I want to work up loads for deer hunting with it. The action of the Mini14 looks the same as the M1A, so the question is should I be using mil-spec primers for the Mini14 also? I have fired many rounds through it with factory ammo (.223) and rounds I've reloaded with Win small rifle primers with no problems yet. Another related question is, when I reload for a Bushmaster AR, should I use mil-spec primers? Are the Mini14 and the Bushmaster AR subject to slam-fire?

Every AR has a floating firing pin as you know, so should you use a mil-spec primer ? Most loading books and the like will suggest mil-spec primers for AR rifles. Only you can answer that question for you. Ideally yes you should. Do people get away with using standard small rifle primers ? Yes. Are some primers harder than others ? Yes. You will hear of many people shooting thousands of rounds with standard primers. Just be sure you know what can happen, and be aware.

FWIW I have used standard small rifle primers in .223 for my AR, CCI brand to be specific. I have experienced one slam fire. Was it because of the primer being too soft or was it a primer a little high, maybe a crimp not fully removed and slight primer damage ? No one will know for sure.

-Jeff

 

[Walkalong]

Tula/Wolf make primers intended for 5.56/.223 in semi autos. (I bought Wolf in quantity before the craziness) So does CCI ( Their #41 primer). Federal came out with some recently as well.

http://www.midwayusa.com/product/1301170074/cci-small-rifle-military-primers-41

http://www.midwayusa.com/product/95...gold-medal-ar-match-grade-small-rifle-primers

https://www.powdervalleyinc.com/

The old silver Winchester small rifle primers worked well, but the new brass colored ones are softer. I have used Fed 205s with success, but they are not generally recommended.

The biggest thing is to make dang sure they are seated below flush!

Welcome to THR

 

[hdwhit]

...should I be using mil-spec primers for the Mini14 also?

I have loaded thousands of rounds of .223 for my Mini-14 over the last 30+ years using regular CCI, Winchester and Remington primers. I use an RCBS hand priming tool and take care to make sure they are fully seated. I have never had a slam-fire or any other malfunction related to the primer.

I can't say anything about Federal primers because the places I have bought primers over the years didn't stock Federal.

Are the Mini14 and the Bushmaster AR subject to slam-fire?

Theoretically, any rifle - particularly those with a floating firing pin - can slam-fire.

Wikipedia has a good article addressing the subject of slam-fire: https://en.wikipedia.org/wiki/Slamfire The term's common use is defined in the article, "When the face of the bolt hits the head of the chamber ... inertia causes the firing pin to continue forward until it is stopped on the primer of the round. Sometimes this inertial force is sufficient to set off the primer..." Most modern fiearms incorproate features in their design to ensure the firing pin cannot reach the primer until the bolt is fully closed. The Mini-14 (and the M-1 Carbine), has a bar machined into the receiver that engages with a lug at the back of the firing pin and will not let the firing pin move forward until the bolt is closed. Any momentum from the bolt's forward motion is likely to be fully expended pushing against that bar so the interia remaining after the bolt had gone into battery and the way cleared for the firing pin to move forward will almost certainly be too little to ignite the primer. A slam-fire in that case would still be potentially dangeous since it occurs when the shooter is not ready for it and may not have control of the rifle, but it is unlikely to be catastrophic.

A greater concern is out-of-battery firing of a round when the primer is struck not by the floating firing pin but by the bolt face before the bolt is fully closed. This is potentially catastrophic and in my opinion the best way to address it is good reloading practice in which primers are set fully into the primer pocket so that they are just slighly below the head of the case and thus are not called upon to absorb the impact of the bolt stripping the round from the magazine and ramming it into the chamber.

 

[wally]

I have experienced one slam fire. Was it because of the primer being too soft or was it a primer a little high, maybe a crimp not fully removed and slight primer damage ? No one will know for sure.

Or was it a "bump fire"?

I don't do a lot of rifle reloading, but when I did over 20 years ago, I used CCI or Remington small rifle and large rifle primers for .223 (AR & Mini14) and .308 (M1A, HK91) and never had an issue. I don't recall ever seeing "milspec" primers in the stores or catalogs, or any mention of using them in the reloading manuals of the time.

Was a real need for these discovered? or are these a liability lawyer / marketing department inspired product?


Just before I hit "post" I decided to dust off my old reloading manuals from back then.

Speer #11 (Third Printing 1988) has no mention of any special primers for 5.56 (CCI 400,450) or .308 or 30-06 (CCI 200,250) loads .

Speer #12 (First Printing June 1994, about the time I stopped reloading rifle rounds) still lists only 400, 450 primers for .223/5.56NATO loads. But it does recommend primer No. 34 for "military style semi-automatic" rifles in .308 and 30-06 loads.

Hornady Fourth Edition (Second Printing 1991) only mentions Remington 7-1/2 for .223 and Federal 210 for .308 & .30-06.

I'm not saying don't use "milspec" primers, if you are just getting started and are loading for semi-autos why not just start there (unless they are way over-priced or unobtainable), but if I had appropriate primers on hand I'd certainly try them first when working up my loads and only "load two" and be alert for problems with slam fires.

 

[Ronald Pickett]

Or was it a "bump fire"?

I don't do a lot of rifle reloading, but when I did over 20 years ago, I used CCI or Remington small rifle and large rifle primers for .223 (AR & Mini14) and .308 (M1A, HK91) and never had an issue. I don't recall ever seeing "milspec" primers in the stores or catalogs, or any mention of using them in the reloading manuals of the time.

Was a real need for these discovered? or are these a liability lawyer / marketing department inspired product?


Just before I hit "post" I decided to dust off my old reloading manuals from back then.

Speer #11 (Third Printing 1988) has no mention of any special primers for 5.56 (CCI 400,450) or .308 or 30-06 (CCI 200,250) loads .

Speer #12 (First Printing June 1994, about the time I stopped reloading rifle rounds) still lists only 400, 450 primers for .223/5.56NATO loads. But it does recommend primer No. 34 for "military style semi-automatic" rifles in .308 and 30-06 loads.

Hornady Fourth Edition (Second Printing 1991) only mentions Remington 7-1/2 for .223 and Federal 210 for .308 & .30-06.

I'm not saying don't use "milspec" primers, if you are just getting started and are loading for semi-autos why not just start there (unless they are way over-priced or unobtainable), but if I had appropriate primers on hand I'd certainly try them first when working up my loads and only "load two" and be alert for problems with slam fires.

You're right, these primers do not call themselves mil-spec, but the ones I bought are #34 CCI and says they are for 7.62 ammo on the box. The person who recommended them called them mil-spec. Thank you for your info. My M1A blew back and out the bottom of the magazine hole in the middle of a mag. The base of the case was split as if it went off while not completely into the chamber. Only the one round went off- the one I pulled the trigger on. It was a factory .308 Wolf brass round, not one of my reloads. Springfield repaired the rifle, and blamed it on me, saying it was from the ammo I used. They said they were suspending the warranty on the rifle. When they sent it back, enclosed was a warning about slam-fire and only using mil-spec ammo.

 

[ArchAngelCD]

Can you use standard primers? Of course you can. Should you? I would not. When there were no mil-spec primers available you had no choice. Now that they are available why not be sure you are safe? Will your gun blow up without them, probably not but why take a chance.

When loading for a semi-auto rifle (M1 Garand and AR15) I use these primers in this order.
CCI #34 or #41 primers, CCI Magnum primers, Rem 7 1/2 in the AR and then standard CCI primers. I have used Winchester primers at times too without incident.

Only you can decide how much risk you are willing to take. I choose to use the more resistant primers just in case.

 

[Sunray]

"...Mil-spec primers..." As in CCI #34 or #41 primers? Those are nothing more than magnum primers. Brilliant marketing plan, but they're still just magnum primers. Absolutely no need for 'em in any semi-auto. Magnum primers are about the powder used and nothing else.
"...using non-military ammo in it due to slam-fire..." Using reloaded ammo in an M1A voids the warrantee. Slam fires are caused by incorrectly loaded ammo, usually high primers, not the rifle.
"...the Mini-14 looks the same as..." And that's as far as it goes. No need for magnum primers in it either.

 

[ArchAngelCD]

"...Mil-spec primers..." As in CCI #34 or #41 primers? Those are nothing more than magnum primers. Brilliant marketing plan, but they're still just magnum primers. Absolutely no need for 'em in any semi-auto. Magnum primers are about the powder used and nothing else.
"...using non-military ammo in it due to slam-fire..." Using reloaded ammo in an M1A voids the warrantee. Slam fires are caused by incorrectly loaded ammo, usually high primers, not the rifle.
"...the Mini-14 looks the same as..." And that's as far as it goes. No need for magnum primers in it either.

Not true... Yes they are magnum strength primers but they also are more resistant to impact. Your information is incorrect.

 

[kingmt]

I have never had a slam for in an AR but they do get nice little dimples from the firing pin striking them. I have had 22LR slam fire. The primer is in the correct position on both.

I don't think it's a matter of how soft the cup as but more how sensitive the compound is.

 

[Reloadron]

"...Mil-spec primers..." As in CCI #34 or #41 primers? Those are nothing more than magnum primers. Brilliant marketing plan, but they're still just magnum primers. Absolutely no need for 'em in any semi-auto. Magnum primers are about the powder used and nothing else.
"...using non-military ammo in it due to slam-fire..." Using reloaded ammo in an M1A voids the warrantee. Slam fires are caused by incorrectly loaded ammo, usually high primers, not the rifle.
"...the Mini-14 looks the same as..." And that's as far as it goes. No need for magnum primers in it either.

I will disagree here. While they are in fact a magnum primer there is a little more to it. From our friends at CCI:

Small rifle primers
#41......................................Mil. Spec. primer, thick cup, magnum primer charge, angle of anvil change.
BR4.....................................thick cup, standard anvil and standard priming mix held to a tighter tolerance.

Justin M./Technical Service Rep.
2299 Snake River Ave.
Lewiston, ID 83501
Alliant/Blazer/CCI/Speer
(800)379-1732

The same is true for the #34 primers. So while it is true that they are a magnum primer charge there are several other differences so we can't say that a CCI #41 small rifle primer is the same as a CCI 450 small rifle magnum or that a CCI #34 is the same as a CCI 250 large rifle magnum. The differences extend beyond standard and magnum. CCI is very good about taking phone calls and answering emails with questions. When we have a primer related question it is best to just call or email CCI. They are more than happy to answer any technical questions about their products.

As to their use? Like many here I was rolling my own long before CCI introduced their Military Small Rifle or Large Rifle primers with NATO sensitivity. I have tried the #34 and #41 primers with some very good results, especially the #41 flavor. That said I haven't a clue how many rounds I loaded for M1 Garand, M1A, AR-15 and other floating firing pin rifles without a mishap. Rumor control always had it that the Federal primers were more sensitive but anyone who has looked at the NRA Master Po M1 Garand load data sees they use Federal primers. In conclusion I figure since the #34 and #41 primers have worked well for me I use them when I have them. I don't worry about it if I don't have them. I see them as a "nice to have" and not a absolute must have necessity.

Ron

 

[NeuseRvrRat]

You can always count on Ron to bring some facts and logic to the discussion.

 

[Blue68f100]

I've had one slam fire in my 458 SOCOM. This gun gets you attention when it goes off, not likely to miss it. This round use the LPM CCI #350. This is the recommend primer for this cartridge and I continue to use it. For my other AR's I use #41 or Rem 7 1/2. I was getting pierced primers with the Rem 6 1/2 so I no longer use them. I get better groups using the #41 over all. I do have some loads that prefer the rem 7 1/2.

Slam fires do happen, on rare occasions. Just use safe gun handling when you drop the bolt on one.. You never know when this will happen.

 

[Reloadron]

I've had one slam fire in my 458 SOCOM. This gun gets you attention when it goes off, not likely to miss it. This round use the LPM CCI #350. This is the recommend primer for this cartridge and I continue to use it. For my other AR's I use #41 or Rem 7 1/2. I was getting pierced primers with the Rem 6 1/2 so I no longer use them. I get better groups using the #41 over all. I do have some loads that prefer the rem 7 1/2.

Slam fires do happen, on rare occasions. Just use safe gun handling when you drop the bolt on one.. You never know when this will happen.

Yeah, the Remington 6 1/2 primer is not a good choice for the higher pressure small rifle rounds. Remington makes it a point to mention:

Warning:

• Remington does not recommend this primer for use in the 17 Remington, 222 Remington, 223 Remington, 204 Ruger, 17 Remington Fireball. Use the 7-1/2 Small Rifle Bench Rest primer in these cartridges.

• This 6-1/2 Small Rifle primer is primarily designed for use in the 22 Hornet.

My understanding is the cup is thinner than the heavier primer like the Remington 7 1/2.

While I have never had a slam fire I did witness one once. The rifle was a PolyTechnics M14 clone and it happened during a match. The shooter was OK with scratches and cuts but the rifle was toast. The general consensus was a slamfire. When shooting any of my rifles with a free floating firing pin I avoid situations which could contribute to a possible slam fire. I figure the fact that I have not experienced a slamfire does not mean I am doing something right, rather that to date I have been fortunate.

Note to Self: Ron, you are out of CCI #34 primers. Next HAZMAT order make sure to include some.

Ron

 

[ants]

Yes. But...

I keep wondering about the TENS OF MILLIONS of AR15 rifles since the 1970's that only get commercial factory ammo, which don't have milspec primers. Why aren't they all blowing up and slam firing? Surely there would be more than the few on YouTube and the anecdotes you hear on Al Gore's Internet.

Using milspec primers in rifles with floating firing pin is good conservative and safe advice for those of us who wish to be extra safe and conservative. Maybe it's not a bad idea to minimize disaster to such a small margin that it just never happens to you. Sounds like reasonable advice to me. It's all personal choice. If you wish to be extra safe, there are extra things you can do. It is good to have a choice.



Just for kicks, 8 years ago when there was a post-Obama run on primers and they were hard to find, I decided to do an experiment. I took a box of 1000 small pistol primers and loaded max loads of H335 in mixed 223 and 5.56 brass. Yes, that was small Pistol. Not small rifle. I inspected for dimples in the primer cups, and there were a few. No different than rifle primers. All pistol primers fired perfectly, not a hint of a problem. So I did it 4 more times for a total of 5,000 rounds. Not a hint of a problem. If the dangers are ubiquitous, you would think there would be at least a tiny hint of a problem in 5,000 rounds, at least once. 5,000 rounds is not lock solid conclusive, but it is interesting evidence. The potential problems may be smaller than Al Gore's Internet tells us.


Can slam fire occur? Theoretically it might, especially in a marginal rifle with marginal ammunition. Keep your rifle tip-top shape and load your ammunition correctly, you minimize the "might" to such a tiny margin that it just never happens to you.

 

[243winxb]

Are the Mini14 and the Bushmaster AR subject to slam-fire?

Beware of parts guns and non-factory trigger.

Load, chamber rounds from the magazine. It slows the bolt speed.

Don't put a round in the chamber, then let the bolt slam on it.

 

[macgrumpy]

You're right, these primers do not call themselves mil-spec, but the ones I bought are #34 CCI and says they are for 7.62 ammo on the box. The person who recommended them called them mil-spec. Thank you for your info. My M1A blew back and out the bottom of the magazine hole in the middle of a mag. The base of the case was split as if it went off while not completely into the chamber. Only the one round went off- the one I pulled the trigger on. It was a factory .308 Wolf brass round, not one of my reloads. Springfield repaired the rifle, and blamed it on me, saying it was from the ammo I used. They said they were suspending the warranty on the rifle. When they sent it back, enclosed was a warning about slam-fire and only using mil-spec ammo.

By definition this is not a slam fire, it's an out-of-battery ignition of the cartridge. A slam-fire happens when the cartridge goes off as the bolt closes without the shooter attempting to squeeze the trigger. If the bolt popped open when you squeezed the trigger then the problem was either a failure of the locking lugs or the ammo being too hot. Springfield has had bolt lugs fail due to improper hardening and Wolf ammo being what it is doesn't impress me, but without testing and more information who knows what made your rifle fail. I can say though, that it wasn't a slam-fire.

 

[wally]

Ronald Pickett said: ↑
You're right, these primers do not call themselves mil-spec, but the ones I bought are #34 CCI and says they are for 7.62 ammo on the box. The person who recommended them called them mil-spec. Thank you for your info. My M1A blew back and out the bottom of the magazine hole in the middle of a mag. The base of the case was split as if it went off while not completely into the chamber. Only the one round went off- the one I pulled the trigger on. It was a factory .308 Wolf brass round, not one of my reloads. Springfield repaired the rifle, and blamed it on me, saying it was from the ammo I used. They said they were suspending the warranty on the rifle. When they sent it back, enclosed was a warning about slam-fire and only using mil-spec ammo.

By definition this is not a slam fire, it's an out-of-battery ignition of the cartridge. A slam-fire happens when the cartridge goes off as the bolt closes without the shooter attempting to squeeze the trigger. If the bolt popped open when you squeezed the trigger then the problem was either a failure of the locking lugs or the ammo being too hot. Springfield has had bolt lugs fail due to improper hardening and Wolf ammo being what it is doesn't impress me, but without testing and more information who knows what made your rifle fail. I can say though, that it wasn't a slam-fire.

My thoughts exactly when I first read this, but I wasn't sure I fully understood what the OP was saying.

 

[firewrench044]

Slam fires are a reality!!
I have had one ( M1 Garand (3006 )) no damage done (bolt must have been mostly closed )
I have seen many others that destroyed the rifle
They are not common but do happen, and anything I can do to avoid another one I will do

Your bolt on the Mini14 also has a free floating firing pin so the possibility is there
If it was me I would use the Mil. spec. primers in that gun
I do in my Garands (6) and AR15s (4 )

 

[Rule3]

Yes. But...

I keep wondering about the TENS OF MILLIONS of AR15 rifles since the 1970's that only get commercial factory ammo, which don't have milspec primers. Why aren't they all blowing up and slam firing? Surely there would be more than the few on YouTube and the anecdotes you hear on Al Gore's Internet.

Using milspec primers in rifles with floating firing pin is good conservative and safe advice for those of us who wish to be extra safe and conservative. Maybe it's not a bad idea to minimize disaster to such a small margin that it just never happens to you. Sounds like reasonable advice to me. It's all personal choice. If you wish to be extra safe, there are extra things you can do. It is good to have a choice.



Just for kicks, 8 years ago when there was a post-Obama run on primers and they were hard to find, I decided to do an experiment. I took a box of 1000 small pistol primers and loaded max loads of H335 in mixed 223 and 5.56 brass. Yes, that was small Pistol. Not small rifle. I inspected for dimples in the primer cups, and there were a few. No different than rifle primers. All pistol primers fired perfectly, not a hint of a problem. So I did it 4 more times for a total of 5,000 rounds. Not a hint of a problem. If the dangers are ubiquitous, you would think there would be at least a tiny hint of a problem in 5,000 rounds, at least once. 5,000 rounds is not lock solid conclusive, but it is interesting evidence. The potential problems may be smaller than Al Gore's Internet tells us.


Can slam fire occur? Theoretically it might, especially in a marginal rifle with marginal ammunition. Keep your rifle tip-top shape and load your ammunition correctly, you minimize the "might" to such a tiny margin that it just never happens to you.

Pretty much sums up my thoughts.

Again (as in other threads) my manuals and Hodgdon online call for regular small rifle primers. What did we do before the 41 primers where advertised and MARKETED?

The Mini 14 chambered for 5.56 is also OK to shoot regular marked 223 Rem ammo

So if you were to buy say Hornady, Winchester marked 223 ammo, what primers do they have in them??

https://ruger-docs.s3.amazonaws.com/_manuals/mini.pdf

http://www.hornady.com/store/223-Rem/

 

[Blue68f100]

It wasn't till recently that the mfg started adding service rifles in their load books. So up till then all data was for a bolt gun. Bolts guns it does not matter as long as they do not pierce. I would suspect any ammo that you buy that has the NATO stamp use a mil spec primers.

 

[Reloadron]

It wasn't till recently that the mfg started adding service rifles in their load books. So up till then all data was for a bolt gun. Bolts guns it does not matter as long as they do not pierce. I would suspect any ammo that you buy that has the NATO stamp use a mil spec primers.

Blue, I don't know that I would say the all the data was for bolt guns, I figure the load data likely more focused on the cartridge specifications and hunting rifles should be able to handle the pressures developed by those loads. That would include bolt guns as well as hunting type auto-loaders, lever guns, pump actions and other common actions. Mil-Specification primers are just primers which meet a military specification, for example MIL-P-46610E(MU) which I believe was mentioned earlier in this thread. The Mil-Spec calls out the conditions the primer needs to meet and that is about it. They do cover the test methods which while not exciting material is somewhat interesting.

Even the service rifle loading data called out in for example the Hornady 9th Edition call out CCI 400 or CCI 450 primers for the .223 Remington and they call out Winchester WLR for the .308 Winchester Service Rifle Loads. My guess, and just a guess is that any US manufactured ammunition meeting NATO specifications for service rifle would need primers that comply to the Mil-P specification. Before the introduction of the Mil-Spec primer to the reloading or hand loading community we used standard and magnum primers. Slamfires can and do happen and while we can take all sorts of precautions to avoid them that does not mean we will be spared.

(OFF Topic) Blue, so may I assume a Blue Ford F100 is in your garage? There is what I believe a Green and White 1968 F100 for sale locally. I want to think it is an F-100 anyway. Sweet truck! </ OFF Topic>

Ron