magnum primers ?
- Thread starter rebs
- Start date
25.0 of H335 is close to max, but nothing bad will happen using a magnum primer. Pressure might go up a tick(PSI of 49,300 with a max load of 25.3. A TSX gives 53,000 psi. with less powder.) but not enough to worry about. However, you will most likely see a change in POI and maybe accuracy just by changing the primer.
I once did so experimentation with primers. I would load the same powder and bullet with several different primers and check them for pressure signs and velocity. The only thing I found is that you never know what a different primer will do. I had 1 load that that with 5 different primers had an extreme spread of 5 fps. I had another load that 1 primer showed signs of extreme pressure, and it was a standard and not a mag. primer. Different primers work differently with different powders and from what I saw I would recommend starting low and working up your load every time you change primers, whether going from a standard to a mag, or the reverse, or just another brand.
Marco Califo
New member
Magnum primers are recommended for autoloader rifles to minimize risk of slamfires. I use CCI#41 and Russian 5.56m exclusively for 223. Mostly bolt rifles. You will need to work up with them, but you will NOT see a huge difference. H335 and CFE223 are both ball powders and should actually benefit from the magnum primers with greater consistency.
I dont use CCI #400 anymore because I pierced primers more than I wanted.
I dont use CCI #400 anymore because I pierced primers more than I wanted.
H335 is a spherical powder and per Hodgdon tech support, magnum primers are recommended with all spherical powders as they are coated to slightly retard ignition. I use CCI NATO primers (41 & 34) in my semi autos. They're magnum strength primers with a slightly thicker cup, developed for the military in an effort to help prevent slam fires.
Nosler guy
New member
Magnum primers are usually best to use in a non magnum gun if you're shooting ball powder, which is hard to ignite, and said powder isn't burning completely before the bullet leaves the muzzle. It will up pressure a bit and other than having a powder burn issue it probably won't make performance better. As far as testing multiple primers with the same load and getting extreme pressure signs, you're most likely using brass with different volumes.
http://www.cci-ammunition.com/products/primers/primers.aspx?id=30
Features & Benefits
Mil-spec sensitivity
Initiator mix optimized for ball/spherical propellants
Available in large (No.34) and small (No. 41) rifle
Use the same data as CCI Magnum primers
Military-style semi-automatic rifles
Primer Info and Chart,each primer category is broken down with cup thickness as well as other specifications.
http://www.sksboards.com/smf/?topic=56422.0
I want to slightly correct what I stated in post #13 above. CCI 34 & 41 NATO primers do have a thicker cup than standard primers, but the BR4 and CCI450 primers also have this thicker cup. Where the mil-spec primers do differ from the others is that there is a slightly greater distance between the bottom of the anvil and the primer cup. This is where their resistance to slam fires enters the picture. They won't by any means prevent slam fires, but they can make an out of spec rifle more resistant to them.
Of course, the biggest cause of slam fires is improperly seated primers.
Of course, the biggest cause of slam fires is improperly seated primers.
Catfish has it right. There's no way to know without trying. As QuickLOAD author, Hartmut Broemel points out, there are some scenarios in which a magnum primer can actually lower peak pressure and velocity. Charles Petty, in a 1996 article in Handloader, showed the same 55 grain .224 bullet in a .223 rifle with the same charge of Reloader 10X went 3150 fps to 3300 fps by varying primers, with a magnum bench rest primer responsible for the highest pressure and velocity. So it just depends which primer and powder and bullet combination you choose.
What a magnum primer does that is different from a standard primer is produce a higher volume of gas. That is to better pressurize a larger magnum case in order to have adequate start pressure. Some primers do this with more fuel compound, raising pressure but lowering brissance, thereby producing the gas more slowly. Others just use a larger quantity of their standard priming compound, and those tend to run everything hotter. Some powders, like the older St. Marks Western Canon (WC) series of spherical propellants (H335 is one of them; St. Marks WC844 in bulk form) have heavy deterrent coatings that are hard to ignite. Allan Jones, who worked for CCI, points out CCI reformulated their magnum primers in 1989 specifically to better ignite those old spherical powder formulations. This doesn't necessarily hold for newer spherical powders. More modern deterrent coatings, such as are used on the Ramshot line of powders, do not need that extra ignition effort. Western Powders says standard primers work just fine with the Ramshot line.
The bottom line here is that the proof is in the pudding. Start low and work up to a best accuracy load. Do that with each primer under consideration. Assuming the accuracy of the best loads for each primer at short range (100 yards) is similar, then look at velocity extreme spread for each. Then the primer producing the lowest extreme velocity spread is going to be most accurate at long range.
Dude! You just need to give it a try! All it takes is a telephone or email. I simply called CCI and asked. What they told me was the cup and priming mix and the priming mix quantity in the #41 are identical to their CCI 450 magnum small rifle primer. The difference between the two is the anvil in the #41 is shorter and has a wider angle to its legs, and that's what reduces its sensitivity to military spec levels.
Tcoz,
You're spreading rumors, too. CCI told me directly that the #34 is identical to a CCI 250 in priming mix and cup thickness. Again, the difference is the anvil geometry.
Military specs:
Federal is different. Their GMM205MAR is, they told (email this time) identical to the 205M (not a magnum primer) except the cup is thicker to get to the military spec.
Guys, it doesn't take but a call or email to verify the facts. Let's at least make a little effort to double-check before deciding what to believe and pass along to others. Good information is always best.
What a magnum primer does that is different from a standard primer is produce a higher volume of gas. That is to better pressurize a larger magnum case in order to have adequate start pressure. Some primers do this with more fuel compound, raising pressure but lowering brissance, thereby producing the gas more slowly. Others just use a larger quantity of their standard priming compound, and those tend to run everything hotter. Some powders, like the older St. Marks Western Canon (WC) series of spherical propellants (H335 is one of them; St. Marks WC844 in bulk form) have heavy deterrent coatings that are hard to ignite. Allan Jones, who worked for CCI, points out CCI reformulated their magnum primers in 1989 specifically to better ignite those old spherical powder formulations. This doesn't necessarily hold for newer spherical powders. More modern deterrent coatings, such as are used on the Ramshot line of powders, do not need that extra ignition effort. Western Powders says standard primers work just fine with the Ramshot line.
The bottom line here is that the proof is in the pudding. Start low and work up to a best accuracy load. Do that with each primer under consideration. Assuming the accuracy of the best loads for each primer at short range (100 yards) is similar, then look at velocity extreme spread for each. Then the primer producing the lowest extreme velocity spread is going to be most accurate at long range.
Oley55 said:
Dude! You just need to give it a try! All it takes is a telephone or email. I simply called CCI and asked. What they told me was the cup and priming mix and the priming mix quantity in the #41 are identical to their CCI 450 magnum small rifle primer. The difference between the two is the anvil in the #41 is shorter and has a wider angle to its legs, and that's what reduces its sensitivity to military spec levels.
Tcoz,
You're spreading rumors, too. CCI told me directly that the #34 is identical to a CCI 250 in priming mix and cup thickness. Again, the difference is the anvil geometry.
Military specs:
Federal is different. Their GMM205MAR is, they told (email this time) identical to the 205M (not a magnum primer) except the cup is thicker to get to the military spec.
Guys, it doesn't take but a call or email to verify the facts. Let's at least make a little effort to double-check before deciding what to believe and pass along to others. Good information is always best.
Unclenick, I'm not spreading any rumors. You must have read post #13 but not post #16 where I corrected myself. I said that CCI NATO primers (34 & 41) have a thicker cup than STANDARD primers but that the 450 and BR4 also have the thicker cup. I just didn't mention the 250s. I also said, as you did, that the difference between the NATO primers and magnum primers is the distance between the anvil and the cup is greater.
No rumors there....we said exactly the same thing.
No rumors there....we said exactly the same thing.
Unclenick,
No problem at all. This subject does come up repeatedly, on every forum I read. There always seems to be a lot of confusion and very few people have the correct information. A sticky would be a good idea. I've seen a diagram indicating the various primer dimensions along with a corresponding chart listing these dimensions for various commonly used primers. You've probably seen it as well, but if not, I'd be happy to find it and send it to you to be included in the sticky. PM me if you need it.
No problem at all. This subject does come up repeatedly, on every forum I read. There always seems to be a lot of confusion and very few people have the correct information. A sticky would be a good idea. I've seen a diagram indicating the various primer dimensions along with a corresponding chart listing these dimensions for various commonly used primers. You've probably seen it as well, but if not, I'd be happy to find it and send it to you to be included in the sticky. PM me if you need it.