Will magnum primers change group size?

[littlephil]

Howdy all, I worked up some loads for my 45 colt, and settled on 15gr of 2400. This load gave me the best group, and it's also the start load for the "tier 2" loads that I found. I worked up to 17gr, but anywhere above 15, I also had a bunch of unburned powder. I have very little if any with the 15gr load. So my question is, would it be possible that running mag primers would give me any better groups with the bigger charges, or should I just stick with the load that works now?
Btw, I'm shooting a 275gr bullet, and running CCI primers. This load will just be mostly for deer, and maybe black bear or hogs if I ever get the chance.
Thanks for any help.

[Six Pack]

You never know until you try, Phil. If it doesn't shrink your groups, it may marginally increase your velocity.....it may do neither or it may do both. Watch for pressure.

[axis223]

it did for me in 223rem out of a bolt gun. I shot the same loads with cci400 and cci450mag primers and groups shrunk. your results may vary.

[Slamfire]

If you can see a point of impact change in a handgun, then it is real. If you don't, it may or may not be there, but your hold may not be good enough to reveal it one way or another.

[buck460XVR]

A while back in one of my reloading mags there was an article about the use of mag primers with 2400. Seems Alliant advises against it and the general consensus is because magnum primers produce erratic ignition with 2400, thus widening group sizes. Still you won't know till you try. I would try a firmer crimp with the heavier loads with the hopes that would help some with complete ignition.

[9x45]

Magnum primers will generate more velocity, it may or may not change group size. I've run both regular and magnum for hot 9mm's and have noticed any difference to 40 yards.

[littlephil]

Well, after reading the replies so far, I checked into it with a Google search. It seems that the general consensus is, that when 2400 is used in large volume cases like 44 mag and 45 colt, it's not a good idea to use mag primers. There were various reasons stated, not all of which were stated in the same article or thread at once though. I may do another work up with a little more crimp once I get more bullets and primers. I'm using a Lee fcd to crimp into the crimp groove on the bullets, but I used about 3/4 turn instead of the full turn recommended for a heavy crimp. (Buckled a 357 case slightly when I tried a full turn before, been leery since)
I guess for now I'll just stick with the 15gr load with regular primers. If I start to run low on 2400, I've got plenty of red dot which was a close second in accuracy with 7gr. I just wish I had a chrony to see what kind of fps I'm getting.
Thanks for all the help y'all, I'm new to the ol' colt, but I already love it!

[WIL TERRY]

LET IT BE NOTED : The manufacturer of 2400 rifle propellent do NOT recommend the use of so-called Magnum primers. ANY standard primer is easily up to the task of proper ignition in any cartridge with the proper propellent charge.
And so it goes...

[Shimpy]

A while back in one of my reloading mags there was an article about the use of mag primers with 2400. Seems Alliant advises against it and the general consensus is because magnum primers produce erratic ignition with 2400, thus widening group sizes.

For years I used in 44 mag 21.5 grains of 2400 with CCI large pistol mag primers and 245 gr keith hardcast bullet. Excellent load and accuracy.

[Hunter Customs]

I've loaded 2400 for years in 357mag, 44mag and 45 Colt never found a need for a magnum primer in any of them.

I've loaded more different loads for 45 Colt then any other handgun cartridge that I load for, to date my favorite load is 12grs of HS6 topped off with a 270gr WFN cast bullet.

From a 5.5 inch barrel Ruger I'm getting a little over 1100 FPS with this load, it's one heck of a Whitetail load.

Best Regards
Bob Hunter

[littlephil]

Thanks for the info fellas, I also reload 38/357 and I use 2400 for 357. The load I use is ignited by a mag primer, can't remember now which manual I used, but it called for mags. That was also all my lgs had when I started collecting components. I haven't had any problems with those loads so far, but I've only got the two handguns that I reload for currently so I don't have much experience with different calibers yet.

[Hook686]

I load .357 magnum using Alliant 2400 powder also. A few years ago I noticed that Alliant show magnum primers, where previously they showed standard primers. I inquired about the change. The response I received was essentially that that was what they had on the shelf the day they did the testing. Figure .1 to .2 grains of powder going from standard to magnum primers is my thought on the matter. Will that improve accuracy ? I like the answer above ... maybe yes, maybe no. Good luck. Be sure to post your findings.

[Mozella]

Yes, they will change group size. In the case of my .223 F/TR rifle ammo, magnum primers increase groups size.

In the case of my 6mm BR F-Open rifle ammo, they decrease group size.

Of course, your equipment/ammo may react differently.

You gotta' experiment.

[TimSr]

Alliant does not recommend magnum primers for their pistol powders. Nor do the caution against using them. Just basically saying they are not necessary.

Primers fall, under "fine tuning". They may make larger groups, smaller groups, or no change. The only way to answer that question is to try them.

While Alliant says they are not "necessary", some uses report better results with some of the slower powders, and 2400 is among them. Your mileage may vary, but there is no danger in finding out.

[buck460XVR]

Alliant does not recommend magnum primers for their pistol powders. Nor do the caution against using them. Just basically saying they are not necessary.

Yesterday, they told me almost nuttin'. Had some time, thought I'd e-mail them on their "ask the experts!" contact site. Basically got a generic answer that sounded like something off a cheat sheet saying "Buck, Alliant and Speer do not list magnum primers with 2400, but other sources do. Always follow load recipes exactly." When I replied again, that all I wanted was some info as to whether or not they recommend them, advised against them, or could give any info on advantages or disadvantages of using magnum primers with 2400, again, I got another generic reply that mirrored the first, other than they claimed it was the bullet that determined whether or not a magnum primer should be used. But no info of what kind of bullet. So much for asking the experts.

[TimSr]

LOL! I could have predicted that, Buck. Ask them if you can use their data for Speer Bullets with Sierra bullets, and you'll get the same response. In other words: "These are the specific component combinations we tested, and if you wish to substitute any of the components, we have no comment."

[littlephil]

Thanks again for the info!
I'll probably end up trying some mag primers in the future, but for now at least, I'm gonna focus on trying to stock up on components that I know work well. (Never know when one might need em)
If (when) I get around to trying out some different components, especially primers, I'll be sure and post my results.
Also I can't say I'm surprised by the responses one can get from manufacturers when asking about using different components. It's sad that in this day and age, the companies are so afraid of a lawsuit, that they can't give you any data beyond what's published.
Thanks again for all the replies and info, that's why I love this forum!

[T. O'Heir]

It's a very decided 'maybe'. A magnum primer might increase pressures. It will not increase velocity.
Magnum primers are about the powder used. Not the cartridge.
2400 doesn't require magnum primers and Alliant doesn't say to use 'em. Other sources, like Hodgdon, are suggesting magnum primers for magnum named cartridges for some daft reason. They'll say use 'em for .357's but not .38's with the same powder. Something ain't right in Hodgdonland.
Note the note with the cross.
http://www.cci-ammunition.com/produc...imer_chart.htm

[rclark]

It [magnum] will not increase velocity.

Yes it does ... Most time I've used them. While only 25fps or so in most cases, it is still any increase in velocity (and corresponding increase in pressure). I've done several back to back tests over a chronograph. In a handgun any deviation in velocity is going to affect where the bullet hits on target. That's a given. But the 'how much'/'can you notice' is something else! The longer the distance the more you see the divergence of course.

For example with CCI primers:

Longshot in .44Mag 240g bullet:
10.0g Standard 1099 Magnum 1148
10.5g Standard 1143 Magnum 1189

2400 in .44Spec 240g bullet:
15.0g 2400 Standard 1104 Magnum 1151 WLP 1076
In this case the ES was 115 for Magnum and only 54 for Standard, WLP was 81. Got to watch that too besides the velocity change!

TB in .44Special 240g Bullet:
5.2g Standard 756 Magnum 765

HS-6 .45 Colt 255g SWC
13.0g Standard 1100 Magnum 1139
In this case the Magnum primer had a slightly better ES (62 vs 52) but really not enough to matter.

And the list goes on....

[pete2]

Littlephil.

To answer your question, magnum primers may change group size. Even changing brands of primers may change group size.

[buck460XVR]

Originally posted by TimSr:

LOL! I could have predicted that, Buck.

The funny thing to me was the link was for Ask the Experts! and I got a response that was almost certainly copied word for word from a reference, handed out to the so called experts, to limit liability. The "bullet determines whether or not you use a magnum primer" statement led me to believe the only thing "expert" was the title of the link.

Along with Gun Forums, Google and other sources of info, I've generally found that most manufacturers websites are good place to glean info. Some are better than others. To say I was disappointed with the responses I got from Alliant is a given, but like you, it was similar to what I expected, considering the sue happy world we live in today. Still, I really expected some form of response besides, "always follow load recipes and do not deviate from listed components".

[Rimfire5]

I tested large rifle and magnum primers in my .30-06 in the cold.

The magnum primers added 12 fps to the muzzle velocity and actually did improve accuracy slightly with 175 grain bullets.
The SD was slightly lower as well.
The temperatures were hovering around 30 deg. F.
I attributed the improvement to a more aggressive initial powder ignition in the cold temperatures.

[Unclenick]

Charles Petty had an article in Handloader in 2006 where a magnum primer, as compared to a mild primer (the mild primer was a Federal 205, but I've forgotten what the magnum was) increased velocity 4.8% (223 Rem, 55 grain V-max, 24 grains RE 10X, 3150 fps raised to 3300 fps). But you don't get that kind of predictability all around. QuickLOAD's author, Hartmut Broemel points out in the program's user manual that there are circumstances under which it makes no difference to use a magnum primer and some under which it can actually lower velocity and pressure, as when unseating a bullet prematurely before a slow powder gets burning well. It's a complicated interaction and testing gives you the only sure answer with your components in your chamber. Just back your powder down about 5% when making a primer change, then use a chronograph to help you adjust the load to get the same velocity you had with the original load before the primer change. You will then be pretty close to the same pressure as long as it's the same powder, case, bullet and bullet seating depth being tested in the same gun.

The main difference a magnum primer makes is it generates a larger volume of gas to provide better starting pressure in a larger volume magnum case. There are other subtle differences in some cases, such as CCI's magnum primer formulation change in 1989 to help ignite the St. Marks spherical propellants better (especially their Western Cannon series of rifle propellants that are sold as Hodgdon and Winchester rifle spherical propellants with different names). They can adjust flame duration and temperature as well as starting pressure and spark showers via primer formulation.

This article describes more about it.