Iv tried searching the site but had no luck. I load for the 22-250 and 270 and currently use standard cci small rifle primers. What are the differences of standard/Bench Rest/Magnum? I remember reading that you have to lower powder charge weight using non standard primers... All thoughts and ideas and info are greatly appreciated!

Sry type... Im using standard Lg rifle primers...

There is no clear answer to whether so-called "match" primers are better than standard primers. It depends on who you ask.

Some people maintain they see a difference in the finished product (i.e. loaded ammo and its accuracy) depending on whether they use standard or match primers.

Other people (including a bunch of BR shooters) maintain that the difference between standard and match primers is a matter of quality control. Supposedly, the match primers are subject to an additional (or extended?) visual quality control step, ensuring the primers indeed contain primer compound.

I doubt you'll get a definitive answer. It largely remains a matter of belief, whether match primers are worth the additional expense.

"Magnum" primers burn hotter than non-magnum primers. They are intended to ignite large powder columns, though some people also choose to use them for .270 size cases. Personally I find no need to do so, but other people differ - as usual in reloading, there are more ways than one to skin a cat...

If you do choose to use magnum primers, make sure you start loading up from below again. It is probably safe to assume, that the use of a magnum primer will increase pressures, at least that has been my experience in the past.

- mike

quote:

They are intended to ignite large powder columns, though some people also choose to use them for .270 size cases.

Especially with ball powders in lower temperatures.

I just use whatever size primer the load book used for that cartridge.

LWD

From my understanding the Bench Rest primers are weighed to make sure the have the same amount of igniting material in it. Roughly equivalent to weighing every charge of powder rather than relying on your powder through to drop the correct charge every time.

only time i found any difference between BR primers and regular is in the 17 rem where rem 7 1/2 primers work much better

As I understand it, the QC on BR primers is tighter. I've switched between standard and BR primers where everything else was the same and I couldn't see any difference in velocity nor accuracy nor POI BUT when I'm shooting a match, I use BR primers for that warm, fuzzy feeling I get. There is a differende in intensity among the several brands of primers that can affect your accuracy, velocity, etc but you'd have to "trial and error" to find out which one worked best for you.
I've never fooled much with magnum primers except to use them for any cartridge that has a belt. I've hunted in some pretty cold conditions (single diget down to very slightly below zero) and used standard primers and ball powder with no problems.

The biggest difference in "standard", "match", and "magnum" primers is the label and the price. Rarely do they exhibit significantly different performance.

I would not recommend "magnum" primers in either your .22-250 or your .270. It is only when you are using a very large case with large quantities of very slow-burning powder that the "magnum" primers sometimes improve performance.

Similarly, unless you are trying to put five bullets into a single hole in a piece of paper, the difference in "standard" primers and "match" primers is nil.

Primers offered for reloading are amazingly reliable and consistent. I've never found a brand or a type that exhibited any tendancy to do anything other than go "bang" at the proper time and in the proper way. It is rare that you find any significant correlation between the primers used and accuracy or velocity, but it does sometimes happen, so a little experimentation can be useful. The differences in primer performance tend to be greater the smaller the cartridge case.

I've done some unscientific comparisons of magnum and standard primers. Two of these 'what if' tests gave a good sense of the difference. I was trying to find a regulated load for my Chapuis, 9.3. I had a regulated load with standard primers and then decided for some dumb reason that I better have one that used magnum primers. I did the work up and found that the velocities were higher and went higher faster. I stopped before I got a regulation load and salvaged the components. Sometimes even I recognize a bad idea, even when it's mine.
Second test was working up a light cast load for my O/U 8mm using Nambu bullets and small charges of quick burning powder. With standard primers, the groups were terrible. When I switched to magnum primers, groups closed up, not good enough for what I wanted, but much smaller, about 5" at fifty yards. Again velocities were higher, but only slightly so, but in this case they were more consistent, less variation load to load.
I did a comparison of pistol and rifle primers in the 22 hornet and got better accuracy with the pistol primers. Didn't have a chronograph back then, so I don't know what happened to velocities.
My conclusion was that changes in primer required complete load redevelopment, no exceptions. My face isn't pretty, but it's the only one I have.
Bfly

I've used just about every primer ever made.....and have no ability to say (with any confidence interval at all) that there's any difference in any of them.

There have been times I thought I could see a difference.....but statistically it's without proof of any kind!

I have seen high speed photos of primer flashes, and there is quite a bit of difference between brands. I cannot say if this affects external ballistics or not. I haven't done tests, which is the only way to know. I can tell you that I switched from Federal to Winchester primers for my 375 H & H, and it tightened the groups.

I too have read that the difference between standard and match is QC.

I use Federal in nearly all my loads. Why? Because the benchrest boys use nothing else.

Commenting on what Stone Creek touched on;
The only times I've seen noticeable differences in std. vs. magnum primers was in my .358 X .404 IMP.With the std. primers and really slow powders there were a number of click bangs. The same thing but more defined happened using WCC844 and WCC846, both ball powders and not really slow burning.
The Magnum primers corrected the event with slow burning powders but did not 100% correct the problem with the ball powders. Most of the ball powder ignition was OK but now and than you got a slight hang fire.
#34 primer supposedly is designed as a mag. primer. I have used it on everything I load that takes a large rifle primer. Nothing but good results baring ball powders in the .358x.404 IMP. roger

Slightly leftfield question and one for the Quickload users; should I change the ignition pressure variable if using magnum primers and if so does anyone have a ballpark figure of how much by?

quote:

Originally posted by Ghubert:
Slightly leftfield question and one for the Quickload users; should I change the ignition pressure variable if using magnum primers and if so does anyone have a ballpark figure of how much by?

As stated in the QL manual “There is no evidence that ‘magnum’ types cause higher pressures than normal primers.”

All so on page 99 of the QL manual “Ignition behavior, ignition delay and primer mix energy are not taken into consideration in Quickload calculations. The mildest primer sufficient for the given task is assumed.”

“should I change the ignition pressure variable if using magnum primers”. For a primer I wouldn’t. Read page 99 of your manual, it may help you makeup your own mind.

I read once that cci benchrest primers are manufactured by the people who have been manufacturing them the longest, ones with the most experiance on the line.

quote:

Originally posted by midminnesota:
I read once that cci benchrest primers are manufactured by the people who have been manufacturing them the longest, ones with the most experiance on the line.

possibly.....but I'd not buy everything I read on the internet....

quote:

Originally posted by midminnesota:
I read once that cci benchrest primers are manufactured by the people who have been manufacturing them the longest, ones with the most experiance on the line.

I don’t know about CCI but I’ve read that about Federal primers. Not the longest employed people but the most accurate and consistent.

If primer manufacturing was a science there would be published information on them. It’s not a science, it’s an “Art”, much like the master gun flint knappers of 300 years ago. Instead of special little knapping hammers they have eyedroppers today.

I am curious, assuming that what Quick Load says that magnum vs standard do not change pressures, what was I seeing when I was developing the load for the 9.3 double? It was one of the few times that I did any face to face comparison. Temps were similar on the days I did the shooting. Used the same box of bullets, same can of powder, same gun, same chronograph. I will admit to being casual on set up and record keeping. Maybe dumb operator, which I can accept? When I get a little free time, I might run the same test again and be a bit more compulsive about everything.
Thoughts appreciated.
Bfly

I have definitely observed increased pressures when using magnum vs. standard primers. But I have only tried the switch in one or two loads, so this may not qualify as a general rule.

I was surprised to see the statement from QL about no rising pressures with magnum primers. I wonder if they state this, because they can't quantify the phenomenon?

- mike

Black Fly and mho, I’ll expand on the QL quote.

“There is no evidence that ‘magnum’ types cause higher pressures than normal primers. It may happen, but the opposite reaction may also be true. As a rule of thumb: use magnum primers with highly deterrent coated propellants and with spherical propellants which are difficult to ignite”.

I’ll throw this idea out there for you guys to think about:

Primers can effect the velocity + or - without increasing or decreasing chamber pressure, much the same as barrel length can.

Thanks guys. I went back to my notes. The standards were CCI and the magnums were Federals. That could have been the difference as well. This is what happens when you depend on a faulty memory.
Bfly

Yes Virginia, there is a difference between primers. Whether or not you have a rifle capable of utilizing the improved uniformity of a "match or "benchrest" primer is entirely another matter. The idea behind having such primers held to a higher quality standard is increased uniformity. If you are loading for a BR match in which you hope to place 25 to 50 shots within .1 or .2 MOA the difference is worth paying for, if you know how to seat them uniformly. Fireforming the rounds you will use at future matches, or for plinking, or for most hunting applications will be more cost effectively done with standard grade primers.

Magnum primers are best used in loads that the powder manufacturer recommends them in unless you have experimented extensively and found your rifle and powder and bullet and cartridge and application do better with a magnum primer. It may be interesting to note that brass used in short range (up to 300 yards) BR matches (overwhelmingly Norma or Lapua brand) sports a reduced diameter flash hole, the idea being that a milder primer flash produces a less violent ignition which is more conducive to accuracy.. It may also be of interest that a world record 1000 yard record for smallest group was set by a gentleman in Montana not long ago while he was using standard grade primers in his 6 or 6.5 dasher. It may be of further interest that he did not win the event, since a sustained, uniform effort is required to prevail.

I've also read that the BR primers are made with the newest machinery and by the best techs.

I'm not gonna get all twisted up in this but if I switch from a standard to a magnum primer, with everything else being the same, and get a sustained 50fps average increase in velocity, why wouldn't that mean an increase in pressure??

We've had this "pressure and velocity are not related" conversation before but I still don't believe it.

quote:

I'm not gonna get all twisted up in this but if I switch from a standard to a magnum primer, with everything else being the same, and get a sustained 50fps average increase in velocity, why wouldn't that mean an increase in pressure??

It’s a question not a real statement. I’m looking for other people’s thoughts on this.

Take a standard 30-06 with a 180-grain bullet in a 24” barrel. The barrel travel of the bullet from the time the primer is struck and set off to the maximum chamber pressure is 1.75”. That is the highest the pressure gets from the time the primer is struck until the bullet exits the muzzle. In fact the pressure is falling off very rapidly by the time the bullet exits 1.139 ms later. Not all the propellant is turned into expanding gas in the initial explosion, much of it is blown forward with the bullet into the barrel past the 1.75” that marks Pmax and 5% of the propellant escapes the barrel with the bullet. The 5 % that escaped the barrel unburned did not contribute to increasing the bullet’s velocity, in fact it was a drag on the bullet’s velocity.

If we except QL’s statement that primers have no effect on maximum chamber pressure but we see an increase in muzzle velocity when we use a magnum primer in our load, then something else is happening. That “something else” is possibly that more of the propellant is being burnt in the barrel contributing to the increased velocity and energy of the bullet.

The more powder that is burnt in the barrel increases the muzzle pressure not the chamber pressure.

Pressure may reach a maximum sometime after the initial ignition, but it is the start pressure which makes the sudden slap that sets up the barrel vibration that along with the bullet rattling down the tube creates the muzzle whip that we all want to minimize.

Here something to read

http://www.hornady.com/assets/...mance-technology.pdf

I can go along with more of the powder is burnt quicker when using a magnum primer but if more powder is burnt quicker in a smaller area (the bullet hasn't moved very far yet), why isn't the pressure greater?
I have read post where folks were running a close to red line load and switched over to a magnum primer and started getting some pressure signs.

Most of the time I can't seem to tell any difference in shot groups using various primers. I do, however, notice a difference in my .257 Wby Mag. I definitely get the tightest groups using Federal Magnum Match primers. However, to be honest, I've not tried them with many other loads. If I get acceptable groups using Winchester (non-match) primers, then I'm satisfied and don't use the more expensive Federal Match primers.

quote:

I can go along with more of the powder is burnt quicker when using a magnum primer but if more powder is burnt quicker in a smaller area (the bullet hasn't moved very far yet), why isn't the pressure greater?

The pressure is greater but not the chamber pressure. The chamber pressure stays in the neighborhood of 52,409 psi but the muzzle pressure at around 10,324 psi goes + or – depending on the primer.

About primers. I've been reloading for waaaay too many years; but I have found reasons, maybe not why, to use different primers in various situations. But first, if a loading manual says to use; say, a magnum primer with a particular load; you can bet they pretty much know you should ! Having said that, I use a magnum for large doses of stick powder and for large shots of ball powder.Most loading manuals say to do so. I also think in very cold weather, a magnum helps ignition without raising pressures unreasonably; and I've had hang fires using standards in cold temps.I also use Rem. 7 1/2s for hi pressure loads where a small rifle primer is indicated; especially the 17 cals.
I read a great tome on Primers and Pressures by James Calhoon wherein he gives a chart on cup dimensions of primers. It's very informative.I highly recommend it. You will see in the chart why I love the 7 1/2s; they have very thick cups !
I can't address the issue of match vs. standard; but my experience says each load, because each rifle is different, can be positively or negatively effected by primer choice. I follow the books; I can chronograph velocity but I can't accurately measure chamber pressures. Once the primer is blown, or worse, it's a bit late to say I should have stuck with the standard primer the book called for ! I suggest you read everything you can by well respected authors. The loading manuals contain loads of great information, besides loading data. Two books I recommend are : Metallic Cartridge Reloading from DBI books ( see
page 20), and Jim Carmichael's Book Of The Rifle (see page 535 for his comments).Both have been out for a long time , but are still applicable. Hope this helps !
Charles

For what it's worth, I'll relate what I read in an article several years ago concerning a visit by a gun writer to CCI's plant. He reported that they ran QC on each primer line each day, and the product from the line with the least variation that day went into the BR box. The operator who had the most QC "wins" each month won some sort of production award, so there was an incentive to work at primer QC.

It's safe to say that the differences in primers has been covered.

In most all cases for me, I've used a regular large rifle primer in a non-magnum caliber and a mag primer in a "mag" caliber. I load for several 270s and during a load work up in winter of 08-09 I was planning on a wolf hunt. I was told it could be as low as -40 so I used Fed 215M primers in a 270 and it served me well. To date, that load is one of my best ever.

After talking to loaders with decades more experience than me, and with reps at powder companies, I will be loading more 270 ammo with 215M primers using Reloder 22 and H1000 powder, and maybe 7828SSC.

I've got a load book, either Nosler, Speer, or Sierra, where the author introducing the 270 wrote that magnum primers work very well in the 270.