Primer vs. FPS?

[saibot]

Experts-

I'm in a middle of a run of 9mm (MG 124HP, 4.1 Solo1000) and have been using Winchester small pistol primers and getting very consistent cartridges (little over 126 PF out of my M&P FS9). I didn't realize that I'm low on my Winchester primers and will be switching to my stash of CCI primers. How will, if at all, this affect my FPS? Have any of you noticed a measurable change between the two? I know I should chrono them to verify but I just don't have time (...and I'm lazy) to measure them. Since I'm on the hairy edge of acceptable PF I'd hate to drop below with the new rounds.

Many thanks!

Edited November 22, 2010 by saibot

[LexTalionis]

126PF is pretty crazy. A 1% variation in chrono readings will put you at sub-minor. I've used both Winchester and CCI, but I load to 130PF just to be safe, so I've never chono'd the differences.

[saibot]

Ya I realize it's darn low but there is something about that exact load that is super consistent. Like an OCW load. Any more/less and the ES/SD is substantially higher.

[G-ManBart]

Ya I realize it's darn low but there is something about that exact load that is super consistent. Like an OCW load. Any more/less and the ES/SD is substantially higher.

I do a lot of chrono testing to know that doesn't mean much (if anything), and it's also pretty well established that low ES and SD numbers don't have a direct correlation to accuracy. So the whole "I want the really consistent ES and SD numbers" sort of thing, is for no good reason....shorter version, it's a waste of time.

To put the PF in perspective, if you go sub-Minor, you're shooting for fun, not score, and it's literally as if you weren't at the match. Most people would be pretty pissed if that happened, after spending a bunch of money on a big match. So what will you likely do? You'll crank up the charge, for just that match, and then the gun is going to feel weird, seem to be really snappy, harder to control, and your performance will suck. That's reality...people do this all the time, and it's really silly. Find a load that will shoot 2-3" groups (or better) at 25yds and makes 135PF+, then load buckets of them, never have to worry or make changes if you're going to travel to a match, and spend time worrying about things that actually might help your performance.

To answer your original question, go chrono two or three strings of 20rds of your load with the Win primers, and do the same with the CCI primers (I like to alternate between brands when doing that sort of test), and you'll have a good idea of the difference between the two. Yeah, I know you're thinking "chrono 120rds?"...yes, and that's on the small side. I've seen the statistics run and 30rd strings are a more accurate representation (well, if you do a couple of them), but 20rd strings (several of them) works pretty well. R,

[Powder Finger]

Ya I realize it's darn low but there is something about that exact load that is super consistent. Like an OCW load. Any more/less and the ES/SD is substantially higher.

I do a lot of chrono testing to know that doesn't mean much (if anything), and it's also pretty well established that low ES and SD numbers don't have a direct correlation to accuracy. So the whole "I want the really consistent ES and SD numbers" sort of thing, is for no good reason....shorter version, it's a waste of time.

To put the PF in perspective, if you go sub-Minor, you're shooting for fun, not score, and it's literally as if you weren't at the match. Most people would be pretty pissed if that happened, after spending a bunch of money on a big match. So what will you likely do? You'll crank up the charge, for just that match, and then the gun is going to feel weird, seem to be really snappy, harder to control, and your performance will suck. That's reality...people do this all the time, and it's really silly. Find a load that will shoot 2-3" groups (or better) at 25yds and makes 135PF+, then load buckets of them, never have to worry or make changes if you're going to travel to a match, and spend time worrying about things that actually might help your performance.

To answer your original question, go chrono two or three strings of 20rds of your load with the Win primers, and do the same with the CCI primers (I like to alternate between brands when doing that sort of test), and you'll have a good idea of the difference between the two. Yeah, I know you're thinking "chrono 120rds?"...yes, and that's on the small side. I've seen the statistics run and 30rd strings are a more accurate representation (well, if you do a couple of them), but 20rd strings (several of them) works pretty well. R,

Finally it's in print, I used to shoot 182 PF 38,9X23, or what ever the case of the week was all the time practice, local, state, area CHMP,

Nats. everything.

[Kyle O]

126 PF! Man, you gotta give yourself some cushion! Tweak that load up a little bit (if your playing games). If your busting bottles by the creek, then go ahead.

But, you'll be kicking yourself in the arse, if you fail at the chrono at a match.

Once, I used to push it close, then one day at the chrono, my first 2 shots were below pf! That last shot put the average over the floor (I was shooting Major), but not before the sick feeling set in.

First thing I did was turn that adjustment bolt up on my press when I got home.

[GForceLizard]

Ya I realize it's darn low but there is something about that exact load that is super consistent. Like an OCW load. Any more/less and the ES/SD is substantially higher.

If that's the case then changing the primer is totally going to screw up your load.

[MarkCO]

Since no-one has bothered to answer your question...

WSP gave me about 30 fps more velocity than CCI in my 9mm minor load:

147 MG over WSF with WSP at a PF of 132.

147 MG over WSF with CCI at a PF of 128.

[saibot]

Since no-one has bothered to answer your question...

WSP gave me about 30 fps more velocity than CCI in my 9mm minor load:

147 MG over WSF with WSP at a PF of 132.

147 MG over WSF with CCI at a PF of 128.

Thanks for the info!

This is just what I was looking for.

[G-ManBart]

Since no-one has bothered to answer your question...

WSP gave me about 30 fps more velocity than CCI in my 9mm minor load:

147 MG over WSF with WSP at a PF of 132.

147 MG over WSF with CCI at a PF of 128.

Thanks for the info!

This is just what I was looking for.

The reason nobody else gave you that info is, that unless you're using his exact load, and his exact gun, your results are going to be different. R,

[Flexmoney]

Experts-

... I didn't realize that I'm low on my Winchester primers and will be switching to my stash of CCI primers. How will, if at all, this affect my FPS?

It will still be too low.

(MarkCo...how is that for directly answering the question? LOL)

[G-ManBart]

Since no-one has bothered to answer your question...

WSP gave me about 30 fps more velocity than CCI in my 9mm minor load:

147 MG over WSF with WSP at a PF of 132.

147 MG over WSF with CCI at a PF of 128.

Actually, the question was answered....go chrono because any other answer is a guess.

You saw the above change with your load, in your gun (were they compared on the same day, back to back, with a significant number of rounds fired?), which is interesting, but that doesn't mean he'll see the same change with his load in his gun...especially since it's a different powder, different bullet, etc.

Most loads have at least half of your 30fps difference just in SD alone, so was the 30fps really all primer? It would take a lot of testing to sort out just those two, much less differences in powder, bullet, gun, etc.

Just to be clear, I'm really not trying to be picky with your response it's helpful, but needs to be put in context....there are very few absolutes in reloading, and while you saw it, that may be an anomoly. R,

Edited November 23, 2010 by G-ManBart

[MarkCO]

It will still be too low.

(MarkCo...how is that for directly answering the question? LOL)

Perfect!

[Flexmoney]

Thanks for the data points.

I used to see a variation of (IIRC) 30fps between Federal Small Pistol and Federal Small Pistol Magnum. Same load, same gun.

As Bart says...the only real way to know (given the variables) is to chrono the load in the gun.

Yet another reason to load to 135+ power factor.

[Bob DuBois]

I like Solo 1000 but this stuff is very heat sensitive. Soon as the Temps get back in the 80's your not going to come close to making PF. This is a powder that you don't run on the minor floor or it's going to bite you.

It slows down big time if it's warm.

[G-ManBart]

I like Solo 1000 but this stuff is very heat sensitive. Soon as the Temps get back in the 80's your not going to come close to making PF. This is a powder that you don't run on the minor floor or it's going to bite you.

It slows down big time if it's warm.

Good point. I have a Solo 1K load with MG 147gr CMJs at 1.125" and 3.85gr (average of 10) and it went 133PF at 18*F, and 129PF at 35*F. I'd probably have to bump it over 4.0 for warmer weather. It also seems to vary a bit from lot to lot...one more thing to mess with. Still, it's a nice, soft shooting powder. R,

[Jan R.]

I have used both interchangeably, but in 38SC major loads with similar results. You'll really need to chrono as was mentioned to be sure.

Jan