[rbaker]

I have just started reloading in 9mm, 357 sig, and 40 is there really any difference in small pistol primers?

[kotengu]

Yes, but probably not a difference you'll notice unless you're shooting very well and competing or shooting off a rest. The main difference I look at is the "hardness" or how sensitive they are to a strike. There are also differences in how "hot" they are, but with pistol cartridges as you described that really doesn't play much.

If you were shooting a long range rifle we could have a long discussion, but for general pistol use it won't make that much difference (assuming they're the appropriate size primers for the caliber).

[rbaker]

Thank you

I don't mean to sound stupid,but what you are saying is I can substitute winchester for cci on a data sheet with no other effect than how hard they are to set off?

[P95Carry]

Just chipping in quickly ......... for general handgun useage ... a primer - is a primer - is a primer!! Magnum primers ... so called ... do in theory give a hotter flame and so...in theory .. a better powder ignition ... only really of use IMO when there is a case full of slow burning powder in hot loads.

Otherwise, yeah . it's pretty much a metal hardness factor. I used to do a lot of compo's years back ...... and backed off my revo mainsprings to smooth the action a bit.

For my reloads .... CCI primers were a disaster . very hard to get reliable strikes. OTOH ..... Federals were great ... and accepted the lighter strike just fine. Even Rem were pretty reasonable.

In long term .. it is useful IMO to stick to a brand ... just for consistency' sake ...... and for me Fed primers are my choice.

[MonkeyMan]

As long as you're loading on the low end of the scale you shouldn't have any problem swapping Winchester for CCI. One of the signs of pressure problems is the primer flattening and the harder the primer the more pressure it takes to flatten it. In most of my pistol loads I use either Winchester or CCI according to what I have on hand, but then I hardly ever venture into max load territory.

I have done a bit of chrono testing on loads where the only difference was the primer and couldn't see much of a difference. Ambient temperature and humidity seem to make more of a difference.

Of course, YMMV.

disclaimer: I am not a professional reloader nor do I play one on TV.

[Bottom Gun]

Different manufacturers' primers may affect your group size slightly. At least they do in a couple of my rifles.

FWIW, I use small rifle primers when I load pistol. They are harder than small pistol primers but no difference otherwise.
I wish I could do the same with large primers, but there is a dimensional difference.

[rbaker]

Thanks guys

I was a bit worried about that. I have another ? I was doing a 9mm load and the min over all length is 1.2 which will not go into my SW sigma mag what should I use as a powder reduction to make it smaller? 1.15 or so

[Zak Smith]

rbaker,

Another data-point on the primer question in light to moderate handguns loads: To see what the effect would be, I substituted Winchester Small Magnum Primers (WSPM) for regular Win. primers (WSP) in a 9x19mm load that is a 115gr at about 900fps (powder was VV-N320). The Magnum-primer loads were about 30fps faster than the normal loads, which was about equal to the standard deviation of the velocities.

With regard to over-all length (OAL), I don't have a reference handy right now, but I seem to remember that the maximum OAL of 9x19 is in the range of 1.165". Most of my 9mm's will run reliably with OAL less than 1.155" or so (with the right type of bullets). Any longer than that, and the ogive of the bullet would ram into the rifling, or they would not run through the magazines.

Making sure your loads are the right OAL for the recipe is important because if you shorten them, the initial ignition volume will be decreased and the pressure will increase markedly. This is dangerous. But on the other hand, if you increase the OAL, eventually your pistol or mags will jam.

For plinking/practice loads (ie, not near MAX) with round-nose bullets of 115 or 124gr, I set the nominal OAL to 1.125. For full-power loads, I use about 1.142". I have a few special loads that need to be as short as 1.090" because of the ogive of the bullet (it's "straight" longer), or for the bullet base to get enough purchase on the case-walls. My 90gr Gold Dot load is one of these.

hope this helps
Zak

PS- You mentioned reducing the powder charge as you decrease OAL. This is not the way to do it, because the effects are nonlinear. Start with a known recipe, and keep the OAL the same. Alternatively, start extremely low and work up slowly the normal way. There is no good way to measure pressure directly without special equipment.

[Quantrill]

Another factor to consider: CCI, in the past, for some reason had slivers of paper in their packaging of primers. If these became too numerous and worked their way into a progressive press, it could really screw things up. Also CCI had varying heights of anvils which in a progressive press could tilt the primers as they were fed. These 2 items always kept me from using CCI in my progressive presses. I do not know if they still have these defects and these defects would have no effect on single stage presses. Quantrill

[Zak Smith]

re: CCI primers.

I've put about 500 CCI primers through my Square-Deal B (SDB) with no problems so far. They are a buck cheaper than WSP per thousand.

-z