Do primers affect velocity?

[Baynewrady]

Noticed people will typically include the primers they use in their load data. Do different make of primers have an impact on FPS? Like if I have a recipe that uses Federals, would I potentially have a different load/PF if I switched to Ginex? 

[Joe4d]

maybe... a different amount of spark will change the effective burn rate,  For instance..Its quite common for magnum primers to give a bump in velocity..  I just chrono'd some 38 shorts and Federal small pistol magnums gave me about 15 fps more velocity than same load loaded at same time with winchester small pistol. Have no idea where Ginex fall on the spectrum. Now loading federal small pistol ( not magnum) and winchester small pistol, probably not much difference.

[StefVanHauwe]

I've been told by a competitive shooter, who already reloads his own ammo for almost 3 decades, that a different primer rarely significantly increases the PF, but in some rare instances it can increase, but no more than max. 0.5-1.5 PF. Myself, I've reloaded 9 mm major ammo over the past 4 years with CCI, Federal, Magtech, Fiocci and Winchester SPP, but I have not noticed any PF changes using otherwise same reloading components and COAL's and testing with a Labradar to measure the PF.

[Joe4d]

yeh its not much,,, quick math I went from 125 pf with fed small pistol magnum, to 123 pf with winchester. so not rounded 1.7 pf difference. If I was shooting USPSA I would be fubared, but I wouldnt load that close if I was. Icore is 120 pf so goal was 125 and some change. I will just shoot the federals at matches.
If you are loading to shoot I wouldnt worry about primer change... If you are headed to a major I would chrono the exact components, and try to get close to same weather.

[Jim Watson]

Little if any.  Velocity ranges overlapped with six out of seven primers I tried with my 9mm load of HP38.  Strangely, Remington Small Pistol gave slightly higher velocity than the rest, including even magnum and small rifle primers.  

[HesedTech]

On 8/16/2023 at 11:02 PM, Baynewrady said:

Do different make of primers have an impact on FPS? Like if I have a recipe that uses Federals, would I potentially have a different load/PF if I switched to Ginex? 

Lot's of good answers here and if you go to YouTube there are videos testing the differences, especially between Magnum and standard primers. The main differences I have found are the hardness of the cups and the depth or height of the primers. Fed, & CCI about the same size, Ginex, Muron, and ZRS are all smaller in depth/height. 

 

They all go bang and the hardest cups are magnum and Muron.

 

If a small change in velocity will put you under PF then load them hotter. 

[Maximis228]

Short answer... No

 

Long answer... I mean... technically yes, but not really.

 

This is from loading well over 300K 9 major over the last decade. YMMV.

[motosapiens]

short answer is probably not, but you should double-check. I found with clays powder in 45 that I got a significant difference (as much as 50fps) between federal, cci, cci magnum and winchester magnum primers. 

 

with 40 and 9mm i have never noticed enough of a difference to worry about. I'll be testing 38sc next month because i have several different brands of primers and I don't want my wife to surprised by chrono at a big match.

[Sniperboy]

Once upon a time the answer was "no".  Mainly because people were comparing domestic regular primers (Federal, Winchester, CCI) to their magnum counterparts.  In this instance its not much - if anything magnum primers give insignificant increase. 

 

With the influx of foreign primers, the answer may change.

 

My local friends and I have recently found that Fiocchi primers may actually REDUCE the velocity.

Tell you what, typically people are scared of increases in velocity, sudden loss of velocity sucks more.

We all ofcourse had pet loads that we liked, we only changed the primer.

 

(All of us used to use Fed or Winchester)

Person #1 used Vectan loads with Fiocchi primers.  Suddenly had 1 out of 20 jams due to light loads.  Chrono shows a wide fluctuation in velocity.  Then it jammed while chrono, there was a massive dip in velocity.

 

Person #2 used titegroup with Fiocchi.  Some variation in velocity.  No jams.

 

I used titegroup with Fiocchi.  No variation.  No jams.

 

I used N320 with Fiocchi for the first time.  Could not get past 5 shots before a jam or stovepipe.  It was a fun weekend pulling 200 rounds to salvage components.

Here's the data, do with it as you wish.

[Farmer]

To me it seems to affect the larger cases more than smaller ones, ie 45 Colt VS 9mm and definitely makes a difference, at least what I’ve found in large rifle. 

[4n2t0]

On 8/24/2023 at 7:40 PM, Sniperboy said:

Once upon a time the answer was "no".  Mainly because people were comparing domestic regular primers (Federal, Winchester, CCI) to their magnum counterparts.  In this instance its not much - if anything magnum primers give insignificant increase. 

 

With the influx of foreign primers, the answer may change.

 

My local friends and I have recently found that Fiocchi primers may actually REDUCE the velocity.

Tell you what, typically people are scared of increases in velocity, sudden loss of velocity sucks more.

We all ofcourse had pet loads that we liked, we only changed the primer.

 

(All of us used to use Fed or Winchester)

Person #1 used Vectan loads with Fiocchi primers.  Suddenly had 1 out of 20 jams due to light loads.  Chrono shows a wide fluctuation in velocity.  Then it jammed while chrono, there was a massive dip in velocity.

 

Person #2 used titegroup with Fiocchi.  Some variation in velocity.  No jams.

 

I used titegroup with Fiocchi.  No variation.  No jams.

 

I used N320 with Fiocchi for the first time.  Could not get past 5 shots before a jam or stovepipe.  It was a fun weekend pulling 200 rounds to salvage components.

Here's the data, do with it as you wish.

 

You probably had a bad batch of primers or something else went wrong. Primers, foreign or domestic, simply don't move the needle all that much with pistol loads. Now, I guess if you were loading to barely allow the slide to return and the primer dropped it slightly further than maybe??? but that doesn't sound likely. I've loaded Fiocchi primers, with various powder, for years and have never experienced anything like you mentioned. In fact, I've never had a primer, of any make, be the reason a load went from good to jam but that's just my personal experience with all the primers I've loaded (all domestic brands and Fiocchi, S&B, Ginex, and Wolf/Tula for foreign)

Edited August 26, 2023 by 4n2t0

[Sniperboy]

It could be a bad batch of primers.  These were sub minor loads : ) you are correct the primers dropped it enough to cause problems and actually make me take notice, just that as drastic as I expected.

Edited August 27, 2023 by Sniperboy

[DougCarden]

You will see from 16-30 fps more going from a pistol primer to a magnum pistol primer, depending on the manufacturer.  Match primers are weighed and are more consistent for lower standard deviation.  This also depends on what powder you are using and your reloading technique.  I have some friends that load precision pistol ammo with new brass and they have low SD using match primers.  

If you are close to power factor and then change your primer you might be disappointed when you chrono.  

[DeepFried]

On 8/24/2023 at 7:40 PM, Sniperboy said:

My local friends and I have recently found that Fiocchi primers may actually REDUCE the velocity.

this seems to align with what I just found out as well. Got a fair amount of them so will chrono again after a while and see if different box is any different velocity. 

[jpm2953]

I have seen remington 1 1/2's bump up velocity over 20fps over the years with 9mm minor loads. Multiple different batches. 

 

 

Also, depends on the powder too. When loading 357 mag, when using 2400, I get higher more consistent velocities using standard SPP rather than with magnum SPP