Advantage to rifle primers?

[crovello]

I have just begun to load 38 super. From what I have read hear and other places it seems it is nearly universal that small rifle primers are used in 38 super IPSC loads. I understand that the material a rifle primer is made of is harder or thicker than pistol primers. I would assume that this would be adventageous in high pressure loads.

My question is is there any other difference in the two primers. Does the rifle primer have a larger or hotter flash?(I do not know the correct terminoligy for this) I asked two different people working in two different gun shops and got two different answers.

I have just loaded 40 identical loads with the exception of the primers. I loaded 20 rifle and 20 pistol primers. I will chrono these rounds this weekend weather permitting.

I just wanted to know what I should expect.

Dave

[sargenv]

I believe that Rifle primers in addition to being a bit thicker and used for higher pressure loads contain a bit more priming mixture to ignite the harder to ignite slower rifle propellants. In a pistol you generally do not have a need to ignite more than about 18 grains of relatively fast burning shotshell or pistol powders. Rifle primers are depended on to ignite 15-30 grains of much slower propellant. I would say that comparably, the rifle primers should have a bit more priming mixture to ignite the slower rifle powders than the small pistol primer does. How much is up to the manufacturers to know. I do notice that small rifle primers sit higher than small pistol primers, so they do have a bit more capacity. What might flatten a small pistol primer may or may not flatten a small rifle primer. What may flatten a small rifle primer might blow out a pistol primer.

That's how I understand it.

Vince

[Guest Larry Cazes]

I believe that Rifle primers in addition to being a bit thicker and used for higher pressure loads contain a bit more priming mixture to ignite the harder to ignite slower rifle propellants.

This is NOT the case for either PMC or Winchester. when I was researching the new PMC green primers I talked to both over the phone. Customer Service at both companies told me that the only difference between rifle and pistol primers is the thickness of the cup, which makes the primer less sensitive.

[.40AET]

Search for "Small rifle primers" brought up 3 pages of discussions.

Small rifle primers have a longer flame with a greater duration of burn time. Picture a long .308 case, the flame needs to get as far into the case as possible. You will get better ignition from the SR primers and protection from the higher pressures. In your .40 test of SR vs. SP, the SR should yield a higher velocity. Not enough to be concerned about testing 20 rounds.

Larry- CCI had a little different story. They are the ones who told me about the longer flame of the rifle primers. It may only pertain to their primers. It would be nice if all of the primer companies printed some sort of data on all of their primers.

[MikeFoley]

Difference in my .40 cases is about 20 FPS higher velocity with WSR than WSP.

FYI, FWIW.

[D.Hayden]

For me WSR vs WSP... Avg was 18.8fps faster with WSR, with a better SD.. probably too small a sample to count on.

[MikeFoley]

I just did some chrono work on Feb. 15 with WSRs, and here are the results:

STI EDGE .40S&W (5 inch barrel)

ProChrono

Temperature @ 60 Fahrenheit

4.6 gr. VV N320, 180 gr. Zero JHP, WSR primers

Dillon 650 OAL 1.143 Crimp .418

test group 1-once fired Fed. nickel cases-loaded 2-3-5

Avg. 932 fps/5 shots

High 941 fps

Low 926 fps

ES 15

SD 6

test group 2-once fired Win. brass cases-loaded 2-3-5

Avg. 937 fps/5 shots

High 946 fps

Low 926 fps

ES 21

SD 8

test group 3-once fired Fed. brass cases-loaded 11-21-4

Avg. 943 fps/5 shots

High 958 fps

Low 925 fps

ES 33

SD 12

[Carlos]

Any thoughts on large Rifle primers in large pistol cases such as .45 ACP? Thanks, D.

[Guy Neill]

While small pistol and small rifle primers are the same dimensionally, that is not true of large primers. Large pistol primers are shorter than large rifle primers. If large rifle primers are used in pistol primer pockets, the primer will not seat below flush as it should. In a worst case situation this could result in slamfires, or bind cylinder rotation in revolvers.

The power of different primers is dependent on both the amount and composition of the priming compound. When I was with CCI, the small pistol and small rifle were close in power, but not the same, with the rifle being a bit more powerful. The rifle primers did (do) have thicker cups as well.

Guy

[crovello]

It seems that I am getting conflicting information here as well as at my local gun shops. Perhaps it is dependent on the primer manufacturer. I am using CCI small rifle primers and 40AET had contacted them directly. I guess I should make the effort to contact the manufacturers myself.

Thanks for the input and I will let you know what my chrono tells me.

Dave

[.40AET]

I have a similar test waiting with Winchester SR & SP primers for .40 cal. I don't know when I will have time to get the chronograph to the range, but I will post the results as soon as I have them.

[sargenv]

Personally, I'd probably not use Large rifle primers in loads for Large pistol primers unless I was really desperate. I have probably 5 or 6k of large rifle primers now that I am not going to use for a while since I just don't shoot my 308 and 30-30 all that much anymore. For me I probably have a lifetime supply. For Large rifle I have Fiocchi, Norma, Winchester, Federal, CCI BR, and Remington Magnum Large rifle primers. I don't even own a magnum rifle anymore. Maybe I can find someone locally to take them off my hands, i could probably use the cabinet space.

Vince

[Guest Larry Cazes]

For me WSR vs WSP... Avg was 18.8fps faster with WSR, with a better SD.. probably too small a sample to count on.

Thats actually a pretty small variation. I would have thought that the difference due to manufacturing variations over different lots would have been greater just by itself.

[D.Hayden]

That's what I was thinking... too small a sample size... confidence coeiffecnt is low (or something like that)

[MikeFoley]

I have tested many more of these than the above 3 groups, and always found similar results. Vikings501 also uses them in his .38supercomp and .40s&w loads with similar test results. 15-20 fps is all you gain, really.

[crovello]

I just got back from the range and I have results that may surprise you. I loaded this ammo at the same time. All new starline brass and did not make any adjustment between loads. The only difference is the primers I used.

These are light loads as I am working my way up with new powder for me.

One string of 15 rounds each

new Starline brass

Zero FMJ 125gr

vv N350 7.2gr

OAL 1.252

with Winchester small pistol primers 1157fps 144PF

with CCI small rifle primers 1293fps 161PF

Difference of 136fps and 17PF

I will be stocking up on small rifle primers. I also noticed that my standard deviation was also better with rifle primers. I only had two different loads to test this with so it may not hold true after more testing.

This seams to be one way to improve performance at no additional cost.

I worked my way up to 8.8gr of N350 to make major (168PF) and the next time I chrono I will try both primers with this load just to make sure of my data.

Just thought you might want to know

Dave

[Tree Rat]

Big disparity...I think I'd marry up brands before I drew any conclusions even though you definately got a boost, it appears, from the CCI SR Primers.

Here is what I saw with Winchester stuff.

http://www.brianenos.com/forums/index.php?...topic=15186&hl=

TR

[crovello]

Tree Rat, I was surprised by the difference. I know I used two different brands of primers and I am sure that had some effect. I already have some loads ready to chrono using all CCI primers. Some small rifle and some small pistol.

Either way you look at it, it surprised me that a primer could effect the velocity that much. I would have expected 20 to 30 fps difference at best.

Dave