New Primers

[boxs]

I've loaded a over a thousand rounds using Winchester WSP Primers in 9mm. I experimented (starting low-working up) with various loads and have some favorites. My question is- if I change nothing but primer brands do I need to start over? I have a chance to buy some CCI.
TIA
Boxs

[SMSgt]

I load with whatever primers are available at the LGS (but don't use the Russian stuff, CCI being my preferred). I've never changed my loads nor have ever seen any detectable change in performance, etc. at the range or in the field. (Don't use a chrony.)

Having said that, I don't load max loads. If I were, I'd drop the powder load slightly to be sure. Max loads have never proven as accurate as a lessor level and just make more noise with more powder burned. But that's just my opinion.

Loading loads for match? Then you would need to verify your load with a different primer.

[jepp2]

If I were in your position, one major point would be how hot are your current loads? If they were mid-range loads, I would make that switch and not worry at all. If they are super hot, I would back off at least 0.1 gr and check for signs of pressure. Secondary is what powder you are using. A mid burn rate powder I would not worry about, a super fast powder like TG, I would approach more cautiously.

If you have access to a chrono, it is a very simple exercise. Just another reason why it helps to run your loads across a chronograph. If you were changing powder lots, I put it much higher on the need to back off some with the next loads than switching brands on the same type of primer.

[flintsghost]

Primers can make a tremendous difference in performance on rifle loads. I usually load for max accuracy and find that my rifles perform best on max or near max loads. As such I find that Winchester and Federal Match primers give the most consistent burn. On pistols, I'm not sure that there is as much of a difference. While I use Win Large pistol a lot and a few loads have Rem Small pistol and my best 357 mag load uses CCI small magnums. But I don't mix or match primers at all. They all have slight differences in my opinion. The effects of primers on chamber pressure cannot be measured with a chronograph. One can only estimate based on velocity changes.

[Rule3]

Technically, the correct answer is yes. You should. Anytime you change anything in the mix(recipe) it is a whole different load.

That being said, I do not think most people do. The load data in manuals have a specific bullet, powder and primer. Chances are you may not have that particular primer or even that exact brand of bullet.

As SMSGT said if you are not at max loads you will not ever know for general range shooting handgun ammo. Benchrest shooters probably would.

I don't

[robertrwalsh]

You will, at least in theory, get some minor variation from primer brand to primer brand. Unless you are pumping all your rounds out over a chronograph, or at right at the edge of the pressure envelope, it is nothing to worry about.

[boxs]

Thanks for all the replies. All my loads are mid range, I'm just putting holes in paper, no need for hot loads. I just wanted to confirm my thoughts.
Thanks again
boxs

[rwsmith]

Originally Posted by boxs

I've loaded a over a thousand rounds using Winchester WSP Primers in 9mm. I experimented (starting low-working up) with various loads and have some favorites. My question is- if I change nothing but primer brands do I need to start over? I have a chance to buy some CCI.
TIA
Boxs

If all else is the same, back off a few 1/10ths of a grain and work back up.

[ArchAngelCD]

Like said above, if you were at or near the max charge you should drop down and work back up but since you said you are loading mid-range loads you will be fine with the CCI primers.

I use both CCI and Winchester primers in my ammo and have never found the need for 2 separate loads for the 2 primer brands.

[Andy Griffith]

The only time you'd run into a real problem is if you change from regular to magnum or "toxic metal free" primers.
Stay away from "TMF" or "Green" primers.

Pistol primers- use what you can get...cheap, as brands don't matter too much. Just don't start with a hot load from an old (30 or more year old) manual.

Rifle primers- the same goes for them too, but there seems to be more differences, so a load might have to be re-worked up.

Just keep good notes.

[fredj338]

IF your loads are well off max, then swapping pirmer brands has never shown any pressure increases for me. If you have worked up to a max load, then backing off 5% & work it back up w/ the diff primer is prudent. At max, everything can affect pressures.

[chief38]

I usually buy one of 4 brands - Federal, Remington, CCI or Winchester Primers depending on what is available and which one is less expensive. I have never found any reason to alter the amount of powder I use and I do chronograph my loads. There are VERY SLIGHT variations but not even enough to make note of. Basically ........ a NON ISSUE.

I like the Federals because they are usually the last expensive.

I like the Remington's because they are packed in SMALL PACKAGES unlike the "shoe boxes" the Federals come in.

The CCI primers are usually the most expensive of the four.

The Winchester I usually will shy away from simply because I am pissed that they don't Nickel Plate them anymore.

They all work just fine and I have never had any major issues with any of them.

[Forrest r]

CCI primers are know to be harder than other primers. If you use them in semi-autos or revolvers with heavy springs/triggers, you'll be fine. Some older semi-auto or older/target revolvers have a hard time with consistent ignition using the cci's.

Just something to think about.

Years ago I found a smokin deal on cci sp primers, used to own 3 different semi-auto 9mm's & 1 38super. I just like the 1911 45acp better & sold the other pistols. So I ended up with 15,000+ primers left over & a bunch of target revolvers to use/shoot them in. I ended up selling them & buying federals, they go bang in everything.

[jmmitc06]

As mentioned by Rule 3, you should 'technically' re-do your load workup with the new primers but also as mentioned by the aforementioned and others, if you are not at max load it should not be concerned.

Here's a little data to guide your decision making:

As per page 57 of the 48th edition of the Lyman Reloading Manual (2002).

Primer Type Velocity FPS Pressure PSI
Rem. 9.5, 2509, 52800
Fed 210 Match, 2508, 53100
CCI 200, 2526, 54000
Win WLR, 2539, 54700
CCI 34, 2545, 55400

For 308 Winchester load (other load data not given). While not the round we are looking at here, even in a powerful cartridge such as this, primers make little change in pressure, only a difference of 2600 psi for pressure in the 52-55k range. So more than likely it will not impact your load, to be safe take it down .1 grains and check.

[arjay]

One of the last tweaks I do on a pistol or rifle load,as long as its not a max charge,is shooting for group size with different primers.Sometimes it's a big difference,sometimes not.

[DWalt]

I did some experimenting long ago regarding use of Small Rifle primers in .38 Special and .357 Magnum loads. I found no discernible difference in grouping or muzzle velocity between SR and SP primers. At least for me, using SR primers simplifies logistics, and I have used them for a long time. I've never tried them in any caliber other than .38/.357, EXCEPT for full loads in the 9X23 Winchester, where SR primers are mandatory due to the much higher chamber pressures of the 9X23. No problems there either.