How will changing primer brands affect a developed load?

Alleycat

Alleycat

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Hey Folks,
So with lots of help from this forum I've been having a ball reloading .243, .300 Sav, .375 Win etc etc
When I started buying components for some reason i only bought 300 cci 200 primers and guess what? I ran out of primers and now can only get WLR primers.
What I would like to know is how much affect does simply changing primer brand have on a load? Pressure, accuracy etc? Must one start all over in working up from start load?

Cheers
A
 
I contacted CCI and they stated as long as the primers are regular and not magnum, your load should stay the same. Winchester is supposed to be the hottest of the regular primers and I have swapped the CCI in the same load with the same results, so I wouldn't worry. Magnums you need to back off about 3 %.
 
Great thanks for the reply. I didn't think it would make much difference but figured I'd ask.
I havent tried magnum primers yet but have seen them recomended fairly often particularly when H-414/W760 is being used.
 
Magnum primers might give better results and I use them for ball powders, when over 50 grains and with any powder that is considered "slow" which is generally over 50 grains.
None of the cartridges you are loading for would use more than 50 grains so stick with the large rifle primers.
While working up a load once using both CCI and Federal magnum primers, the end result was obtained was the same powder weight.
 
I recently swapped from CCI LRP's to WIN LRP's for the same reason (ran out, couldn't find locally). I used exactly the same load data and have exactly the same accuracy (about 3/4" @ 100yds).
If the accuracy wasn't the same I would probably do load development again but only +/- 2% from the previous most accurate load, not the full range.
I don't load anywhere near the max so that isn't a concern for me. I'm generally around the starting loads with best accuracy.
 
Which cartridge where you loading for? I ask because I recently switched one of my .45-70 loads from CCI200 to FGMM magnum primers and saw a big difference. I had worked up to a max of 54.0 grs H4198 under a 350 Hornady RN with CCI200s. @ 54.0 MV was 2104 and 2103 fps for the 2 rds fired. The only pressure sign was it slightly popped the lever open. I decided upon 52.0 grs which gave a hair under 2000 fps and zero pressure signs. When I switched to the Fed match magnum primers I loaded 50 thru 52 grs to test. 50 grs ran 2078 fps and had very faint cratering of the primer. I shot 1 more @ 51 grs and got 2110 fps and noticeable cratering and popped lever. That's a higher MV with 3 grs less and everything else identical. I did not fire the 51.5 - 52 gr loads. That's why I'd like to hear what you're loading for because it seems to matter when switching between mag and non-mag primers. I've always been suspect of guys saying "ah its fine, it makes no difference". If I had followed that and loaded my usual load with mag primers, pressure would be dangerously high.

horseman2 said:
Magnum primers might give better results and I use them for ball powders, when over 50 grains and with any powder that is considered "slow" which is generally over 50 grains.
None of the cartridges you are loading for would use more than 50 grains so stick with the large rifle primers.
While working up a load once using both CCI and Federal magnum primers, the end result was obtained was the same powder weight.
Click to expand...
 
Metallic cartridges are very tolerant of slight pressure variations like those that would result from changing primers. My only concern would be if you were already at max load and then switched to a hotter primer.

Where a primer change can have a dramatic effect is in shot shell reloading because shot shells don't have the structural integrity of metallic cases. Then I would be extremely cautious in changing primers. For metallic cases, however, you should be gtg.
 
Handloading magazine did a test using a pressure barrel a few years ago on this very topic. End result was that up to 10,000 psi difference was possible in a cartridge by just changing the primer. So ................. swapping primers may not show any difference in performance or it could generate enough excess pressure to ruin your day.

In any case I personally would not change brands without knocking the load down a bit and working back up. All of my rifles are worth more than the cost of a half-dozen cartridges used for testing.
 
'Boo said:
Handloading magazine did a test using a pressure barrel a few years ago on this very topic. End result was that up to 10,000 psi difference was possible in a cartridge by just changing the primer. So ................. swapping primers may not show any difference in performance or it could generate enough excess pressure to ruin your day.

In any case I personally would not change brands without knocking the load down a bit and working back up. All of my rifles are worth more than the cost of a half-dozen cartridges used for testing.
Click to expand...

You only reported a small portion of that test.

The same test did mention that the pressures became extreme and even inconsistent with magnum primers, with certain powders, usually faster types, case capacity and of course how close to maximum the loads were.

I personally use magnum primers with all of my handloads. I do this because I get a lot less issues with velocity and pressure inconsistency under different temperatures etc.

Common sense is needed when hand loading. When you change out any component, you need to WORK UP A SAFE/ACCURATE load. Being married to a loading manual is OK but there are often better methods. They cater to everyone. They watch their backsides very carefully as well.

When you change out anything, even if it's a new can of powder or a different lot of primers or bullets, BE CAREFUL.

There are a lot of variances between different lots of primers and powders. With bullets, jacket material will change with availability to the producer. Again, BE CAREFUL.

My loads have all been modified for magnum primers. The only cartridges I don't load magnum primers into are pistol cartridges. That is because I've never noticed any real differences in performance with magnum primers in the small cases.
 
primers come in cases of 5,000. buy several cases and then buy more when you finish the first case.

When you are out of primers, you are out of loading. Primers, unlike gold, never go down in value....
 
Random swapping of primers in a max., or a near to max, load ... is a bad idea, IMO.
Primers, they do affect M.A.P., and especially the appearance of the primers face will vary after firing. For those who look to primer appearance first and only for their judgement of relative pressure, one must be aware that a primer face can look very different, one brand to another, at the same actual firing pressure/vel..
A hard CCI will not look the same as a soft Fed. will, at equal firing pressures. The cup's metalurgy is different, & they will look different.

Eg:
My pet 6.5x55.
This one is a LR laser, most often a sub 1/2 MOA type of a laser(if, I'm on the game that day). It gets shot from +30c to -30c temps., and is loaded with RL22, which is a temp sensetive powder. To stay on the node, I need a winter load, and a summer load. That higher vel. node, it is not very wide, about 1 grain worth of powder to stay in it, top to bottom. Best accuracy is up near max. pressure.
Winter load is primed Fed. GM215M.
Summer load = CCI BR2.
That primer change alone is worth 1.5 grains of powder, according to the chrono.
Ends up, with summer load .3gr's less powder than winter when the chrono returns to center node = 2675fps.

Primer face appearance is very different between the two. One would swear the GM215M's were much higher pressure ... but no, they are very close to the same. Chrono and targets don't lie.
 
I was running 77gr of rl-22 with cc250 primers and .308 cal 208gr amax's in my .300wm. Excellent load. Ran out of primers and was forced to switch to Winchester.
Being cautious I dropped the starting charge right down to 69 and started all over again. At 74 grains i burst a primer cup, gas cut my bolt face and pee'd me off. Didn't see any signs of over pressure and I'm so far below my proven charge that I chalked that up to a defective cup. One more shot... Burst also. What the hell she's already ruined, one more... Burst too. This is winter time, 3'c.
So there we are 3 grains under and popping primers just from a simple change in brands.

I order up a new bolt head, get lucky that the headspace is fn'eer bang on. Load up another batch starting at 69 and go shooting.... Burst a primer at 72gr. It's a bit warmer, early spring, think it was about 13'c that day. Whatever, it's just the slightest nick so I decide I'll settle at 71 as it was satisfactory. I shoot a few dozen times through spring, temps rise and then I popped a primer at 71gr. Think it was 19-21'c

Now we are popping cups with win primers at a full 6 grains under my previous cci load. I forget the exact numbers but I believe the win primers loads never got within 200fps of the cci load.

One more bolt head ordered up, this time had to adjust headspace so I ordered up the wrenches.
Had to drop the load to 69 grains. 8 grains below the original load!!

I found more cci primers, the win primers might find themselves in a fire or maybe some reduced loads for girls and children to practice with.

Now I must say that I have heard there was a bad lot of primers that came out of Winchester. So I don't know if the brand itself is garbage or if I just found myself a box from that lot. Either way cci has t let me down through about 5k rounds of .300wm, 10mm, and .223. They work and I'm sticking with them.
 
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Ganderite said:
primers come in cases of 5,000. buy several cases and then buy more when you finish the first case.

When you are out of primers, you are out of loading. Primers, unlike gold, never go down in value....
Click to expand...

That's what i should have done. Not sure what the heck i was thinking. Pretty sure i walked away with my measley 300 primers thinking "oh this is lots".....green horn!
 
"...only bought..." It can take that many for load developement. Buy 'em by the thousand.
"...Must one start all over in working up from start load?..." You should as you have a different load by using a different primer. However, a great deal depends on the load. Close to max loads can get ugly with a different primer. Mid-range loads, not so much. Still best to do it.
"...contacted CCI and they stated..." They'll also tell you you must use their "milspec" primers for a battle rifle. Those are nothing more than a marketing gimmick.
 
Viking, BR2 primers are very close to magnum primers. I really notice very little difference between the two.

In my 6.5x55, I have two basic loads that I use. Summer load with 140 grain bullets over H4831 and Winter load consisting of 95 grain bullets over H414 SL10, appx W760, all with CCI 250 primers.

These are relatively slow powders and behave better with magnum primers.
 
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Viking, BR2 primers are very close to magnum primers. I really notice very little difference between the two.
Click to expand...

Yeah bearhunter, the variable seems to be more in the BR2's primer cup's harder metallurgy, than in any major difference in absolute brisance compared to GM215M's. That's been noticed in many other cals. that I load for.

My summer to winter 6.5x55 load adjustment, it varies only in primer switch and .3 grain less of R22 powder. Same everything else. What is in common, both versions of this load are right up there pressure wise.
When first tuning in, back early days, in order to get back down into node if still using the 215's in the heat, it took a 1.7gr. reduction.
For a while, it was a wee bit confusing to look at CCI primer appearance, when the hard facts of correct vel., and being back on the accurate node, were staring me in the face.

Other 6.5 shooting friends have had similar experience. Maybe, it's one of those headscratcher anomolies specific to this particular cal./load?.

Bit of a pita, for sure, but no other combo I've tried is as accurate, so ... so be it. Worth the trouble. :D
:cheers:
 
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