Why Magnum primers?

[hm2 clark]

So, do the factory Hornady loads use magnum primers?

[Tedward]

So, do the factory Hornady loads use magnum primers?

Thanks, got it...

[XcountryRider]

Anyone load a large rifle magnum Primer in a fire formed 7.62X39 case?

[pburr]

Thousands and thousands of rounds in Service Rifle practice and matches and I have never experienced a slam fire or piercing! I use FGMM primers in my match rounds. I certainly dont doubt it can happen, but this is one reason I think the use of Titanium firing pins is worth the extra $$. All of my Match rifles use them, including my Grendel. Only my M4/SBR's have the M-16 type firing pins plus 5.56mm NATO chambers.

[LR1955]

Guys:

I have had two slam fires with 5.56 AR-15's and one with an M-14. Slam fires occur with the bolt locked so it won't damage the rifle. Slam fires can be caused by not seating primers deeply enough, using primers that are too soft, and or mechanical issues with the firing pins for an M-14 and firing pins and bolt face wear with AR's. They will not destroy a rifle but can be very dangerous because the thing goes off when the bolt locks and not when you want it to go off.

Out of battery firings will damage the rifle but it won't do what is seen in those pictures. I have had one out of battery firing and it was with a Grendel. Luckily for me, I was doing off hand practice so was single loading it and I control the muzzle when loading so it went off and the bullet went down range, the floor plate of the magazine blew out, the bolt got destroyed and the bolt and carrier jammed in the receiver. I experienced no physical injury. I had people I trust look at the rifle and question me about my loading techniques, primers, etc and we do not know why it had an out of battery firing.

What you guys see in those pictures is due to a handloader thinking he can get away with an extra couple of grains over a max load with a bullet that is too heavy. You won't shear off and fragment stocks with a out of battery firing or a slam fire. You will destroy the rifle when your loading techniques create a situation where the bullet becomes a bore obstruction as in the picture of the camouflaged M-14 in the gun case. Note in that picture the split barrel? The bullet became a bore obstruction.

It is not uncommon for competitive shooters to hot load, overload, and otherwise do things that are risky in order to make an extra point or score an extra X. Overload enough and just like any other mechanical piece of equipment, the frame will fail. My bet is that the guys who blew up their rifles in those pictures were grossly overcharging or even mistakenly used the wrong powder. Unfortunately, the most likely situation was they deliberately overcharged, thinking it would give them a winning edge.

LR1955

[bwaites]

Or that they had a squib load during rapid fire and had a bore obstruction

[babaganoush]

What you guys see in those pictures is due to a handloader thinking he can get away with an extra couple of grains over a max load with a bullet that is too heavy. You won't shear off and fragment stocks with a out of battery firing or a slam fire.
LR1955

Thanks for clearing this up. I have seen one KB due to Head spacing issues, and another due to improper hand loads. Both were ugly, and they resembled a couple of the pictures just posted.

While I have not personally experienced or witnessed a confirmed a slam fire event, it just seems to me that by the very nature of the mechanics involved, the bolt would just about have to be in lockup before the SF would occur.

David

[LR1955]

Or that they had a squib load during rapid fire and had a bore obstruction

Bill:

Could be but less likely than a overload.

If a guy had a squib load, it is more likely the bullet would leave the barrel than stick in the barrel. And with squib loads, it is unlikely that the bolt would unlock or cycle far enough to strip a fresh round. If there was no powder, the bullet would lodge in the barrel but the bolt would not unlock. I have rarely seen bullets go far enough into a barrel from a primer that a loaded cartridge could chamber behind the lodged bullet but that isn't always the case. I do know that a primer won't push a bullet through a rifle or carbine length barrel. Or a pistol barrel that is more than about two inches long. And, squib loads make a weird noise and have a weird recoil that an experienced shooter will recognize instantly, no matter how much adrenaline is pumping or how focused he or she is.

Why do I know these things? Not only have I witnessed them happening, I have had numerous experiences with squib loads and lodged bullets in barrels myself. Rifle, pistol, and revolver. Thus my total distrust for any progressive press made, no matter how many safety features they have built into them. Pistol is one thing. You know it and get the wooden dowel and hammer out. Rifle is a huge PITA because you will probably ruin a cleaning rod hammering the bullet out. If I load rifle on a progressive, I visually inspect every loaded cartridge to ensure the primer is seated under the rim and then I weigh each cartridge to check that each is charged with sufficient powder. Makes the time saved using a progressive somewhat minimal but at least I know the cartridge is safe.

I am sure you must have had more than one squib load or no powder load to contend with as you shoot IPSC stuff. It is the nature of the beast when using progressive presses and making a thousand rounds in a morning.

I think if there is anything a new handloader can take from this is that they will experience a squib load and a load that has no powder at all at some time in their shooting career. No matter how careful you are, it will eventually happen. It may even be a factory load or a commercial reload. It will happen so if you fire a shot and hear a pop or a noise that isn't right, stop and check to ensure the bullet left the barrel. This is one reason why experienced handloaders rarely recommend a new reloader start with a progressive press.

LR55

[LR1955]

Thanks for clearing this up. I have seen one KB due to Head spacing issues, and another due to improper hand loads. Both were ugly, and they resembled a couple of the pictures just posted.

While I have not personally experienced or witnessed a confirmed a slam fire event, it just seems to me that by the very nature of the mechanics involved, the bolt would just about have to be in lockup before the SF would occur.

David

Dave:

Yes, the bolt locks up in slam fire. In the early days of using AR-15's in High Power and when shooting off hand, you would see some shooters load by putting the barrel on their shooting stool muzzle pointed down (through the stool and at the ground). They would rotate the rifle around so the ejection port faces them and drop a round down the chamber -- then let the bolt slam shut. He, he, he.

You know it. Bang -- right through the stool and into the ground. This was in the early days when guys didn't realize that AR's were sensitive to how hard the bolt slams shut and or didn't know about hard or thin primer cups. It was convenient because of the design of the AR-15 and it caused slam fires. Today you will still see guys drop the bullet in with the barrel on the shooting stool but they won't let the bolt go until the barrel is pointed down range and in most cases, at the target itself.

I have never seen a slam fire with a military M-16 or M-4 series using military ammo. Or a issued 1911 or M-9 firing issued ammo. I have seen squib loads with service ammo but it was extremely rare. I have seen M-4's give up the ghost and even an old Haskins 50 cal that had just been hydrofluxed and deemed 'safe' blow the barrel apart on the first round fired out of it.

LR1955

[Nukes]

Not to mention a good face.
One should also be careful using WSR primers. There is a higher incidence of slam fires with the new WSR primers. Apparently the new copper tinted primers are a lot softer than the older chrome colored ones.

Interesting that the current (9th) edition Hornady Reloading Manual uses WSR primers for the 6.5 Grendel information.

Other than a general statement recommending magnum primers for magnum cartridges, the Berger Reloading Manual 1st Edition does not specify primers for any of their loads.

Thousands and thousands of rounds in Service Rifle practice and matches and I have never experienced a slam fire or piercing! I use FGMM primers in my match rounds. I certainly dont doubt it can happen, but this is one reason I think the use of Titanium firing pins is worth the extra $$. All of my Match rifles use them, including my Grendel. Only my M4/SBR's have the M-16 type firing pins plus 5.56mm NATO chambers.

Like pburr, despite many thousands of competition and practice rounds, I have never had nor even seen a slam fire—excepting open bolt MGs
;-)

Though I am aware of the claims for faster lock times and fewer (no?) slam fires, are these just theoretical reasons? mere marketing so that we buy $50 firing pins? or is there actual data supporting the accuracy and safety claims?

[Nukes]

We recommend using CCI M41 Primers in all loads for the 5.56 but not for the 223. Using a Magnum Primer with load data designed for non-magnum primers is good way to get a medical bill or at the least a Gunsmith bill. The M41 is a Milspec primer and has a harder primer cup to prevent slamfires and a hotter primer charge to help with cold weather ignition. Having discussed this with Bill at AA and CCI, we have come to the conclusion that the CCI 41 primer is basically the same primer charge as a CCI 450. I have used both in our 6.5 Grendel loads. Have not had any issues with either, except for some rifles with match trigger in which the hammer springs were lighted to decrease trigger pull. Then the Hammer didn't have sufficient energy to ignite the harder M41 Primers. We have since gone to all CCI 450 Primers. One item we did learn is that using Federal primers had a tendency to "empty mags real fast". So they are a no GO!!. Another experience lesson - Always use M41 or M34 Milspec primers in 308 based AR's and compensate for the magnum charge by reducing the charge weight by 10% and working back up from there. (I can tell you how to do that in a gas rifle but that is a another subject!) The firing pins are heavier and they will slamfire a lot easier! Just got done diagnosing that issue with a 243 Win AR we built recently. The 308s didn't have the problem, but the loads we have developed for the 243 did, due to using Benchrest CCI primers. We are working on a firing pin fix to correct the problem.

Is anyone using milspec primers and experiencing failures to ignite in their bolt guns?

[stokesrj]

I've personally seen four or five slam fires and in each case it was a CCI400 or Win SR primer. Remington even warns not to use their small rifle primer in AR's right on the box. Almost every year at the national matches at the command, "with one round load" at the start of the standing slow fire event, a round goes down range from a slam fire. It is usually a combination of things, thin walled primer, round inserted all the way into the chamber, and possibly a high primer. They all add up and even then it is a .01% issue. I've also seen blanking and pierced primers when folks run out of small rifle magnum primers and move to CCI400's especially. That is simply because they are on the edge and the ticker cup of the small rifle magnum primer was strong enough to withstand it and the small rifle primer is not.
I've never seen this issue in a 6.5 Grendel, these were all .223s.
Bob

[glocker21]

We recommend using CCI M41 Primers in all loads for the 5.56 but not for the 223. Using a Magnum Primer with load data designed for non-magnum primers is good way to get a medical bill or at the least a Gunsmith bill. The M41 is a Milspec primer and has a harder primer cup to prevent slamfires and a hotter primer charge to help with cold weather ignition. Having discussed this with Bill at AA and CCI, we have come to the conclusion that the CCI 41 primer is basically the same primer charge as a CCI 450. I have used both in our 6.5 Grendel loads. Have not had any issues with either, except for some rifles with match trigger in which the hammer springs were lighted to decrease trigger pull. Then the Hammer didn't have sufficient energy to ignite the harder M41 Primers. We have since gone to all CCI 450 Primers. One item we did learn is that using Federal primers had a tendency to "empty mags real fast". So they are a no GO!!. Another experience lesson - Always use M41 or M34 Milspec primers in 308 based AR's and compensate for the magnum charge by reducing the charge weight by 10% and working back up from there. (I can tell you how to do that in a gas rifle but that is a another subject!) The firing pins are heavier and they will slamfire a lot easier! Just got done diagnosing that issue with a 243 Win AR we built recently. The 308s didn't have the problem, but the loads we have developed for the 243 did, due to using Benchrest CCI primers. We are working on a firing pin fix to correct the problem.

Great info! I have recently started using CCI450 primers as my stock of CCI41 hae been depleted. I have been using 123gr SST but have recently been toying with 140gr bullets in my 12" Grendel. Any thoughts on 450 with 140gr bullets and 8208xbr?

[1Shot]

Only slam fire I have ever had was with the M1 Garand many years ago when I first got one and started hand loading for. It doubled once and then with the next clip it tripled. Experienced M1 person at range stopped me and before I could tell him what primer I was using he said I bet you are using Federal primers. Sure enough I was using Federal. 210 Match. He as well as others in the high power game have told me that the only primer that they have seen slam fire that was seated correctly has been Federal. Federal now makes a AR specific small rifle primer. Only slam fire I have ever witnessed with an AR was when a fellow was trying to use Remington 6 1/2. I have used many Remington 7 1/2 with no problems. As I said I have never had any problems with any primer except Federal. On Jonny's Loading Bench on YouTube he did a primer comparison video using just one load and there was a difference in what primer was used but not that much with some. Now that was with ONE load. If you change the load things might be difference. Go to YouTube and check this out. I used CCI 450 with all my Grendel loads because that is what I started working with and what I found my loads with.

[Mesa1978]

Factory Hornady with the brass colored primers have cratered and ruptured in my Grendels. Handloads with the CCI 450s never have had an issue with the same bullet weights as factory.