Primer delema

[nodakjohns]

So as everyone knows primers are in short supply. I am in the process of assembling a 6.5 and am a reloader for the few calibers i shoot. I have never had a need for small rifle primers so never acquired any. Much to my misfortune i am now scrambling to find some. CCI 450 seem to be nonexistent. Question is has anyone tried small pistol primers in lieu of small rifle primers ? (Don't blame me for putting that thought in my old noggin! blame an ol FL rock an roller utuber lol)

[Oso Polaris]

Yes. During the last great shortage, reloaders were forced to try all kinds of different combinations of bullets, powders, and primers. I tested different brands and types of primers in a group of .223 reloads. What I found is that the small pistol primers were hotter then the magnum small rifle primers (#450 and #41) and provided an extra 25fps of velocity. In short, totally safe and you'll just need to do some testing to dial in your desired velocity/accuracy taking into account the extra velocity that the small pistol primer provides.

[Happy2Shoot]

So a primer sold for igniting 3 to 10 grains of powder at a typical max pressure of 20 to 30 kpsi is hotter than the one sold for 20 to 30 grains at 55 kpsi?

I've never done a test, so I'm just thinking out loud.

I have read email conversations with primer company reps posted on the internet stating small pistol and small rifle are the same. I also fine this hard to believe.

What about primer cup thickness and protection from slamfire?

Primers are mysterious to me. They have the least amount of numerical data published by the manufacturers. They change the compositions over the years without notifying the public. They explode!

Until I see it in writing on a manufacture web page I'll keep to standard practices.

[Happy2Shoot]

@nodakjohns

Where abouts do you live? Maybe a member lives near enough to help you out a little?

Not asking for an address of course, just an idea.

[Oso Polaris]

So a primer sold for igniting 3 to 10 grains of powder at a typical max pressure of 20 to 30 kpsi is hotter than the one sold for 20 to 30 grains at 55 kpsi?

I've never done a test, so I'm just thinking out loud.

I have read email conversations with primer company reps posted on the internet stating small pistol and small rifle are the same. I also fine this hard to believe.

What about primer cup thickness and protection from slamfire?

Primers are mysterious to me. They have the least amount of numerical data published by the manufacturers. They change the compositions over the years without notifying the public. They explode!

Until I see it in writing on a manufacture web page I'll keep to standard practices.

Yeah I get it. I was as surprised as you that the CCI small pistol primer was actually hotter. I did not do a workup on every pistol primer or rifle primer. I used what I had on hand, which was the primer of choice for both small rifle and magnum small rifle. I think you are hung up on powder volume and should think of it in terms of ignition / powder burn. Yes pistol has less case capacity, but effectively all of the powder must be burned within 4" barrel, unlike a rifle barrel of 16" - 26". With pistol the primer must effectively ignite all of the powder at once, which is different then rifle ignition of a constant burn down the entire barrel length.

I was also surprised to find that standard small rifle primers by Zap (S&B primers) were definitely hotter than major brand of magnum small rifle primers. They were second only to the CCI small pistol primer.

Another interesting point on Primers was a in-depth study/test of primers to determine the impact of primers on performance/accuracy. There were some surprising result with impact on SD/ES of loads just based on primer. As it turned out at that time Wolf primers were a better primer, based on lowest SD, then Federal Gold or CCi BR primers.

[grayfox]

I do not recommend it, don't substitute. You're asking for trouble.
Your putting together an AR style, if I read it correctly.
The pistol primer is designed for pistol pressures (~11-12ksi) yet rifles go up to 62ksi -- the grendel will be up to 52,000 psi. Also the pistol primer is shorter than rifle so sits lower, plus the cup is thinner. Blown primers/gas blowback through the primer hole, so do not recommend. 5.56 ammo goes up to 56,000 psi.

Look for other rifle primers, Wsr, cci#41, federal 205AR, even a regular federal 205M would be better than pistol ones.
Not Remmy 6 1/2, however, 7 1/2 ok. And Wolf has some SRPs.
Cci400's have been used in an AR but they also have a touch thinner cup, I can't recommend but some folks use 'em.

I guess, and this is just a guess, if you were doing a 300 BO and subsonic or something, then pistol primers might be ok... a guess.

Surely there's a reloading/shooter buddy who can sell you a few SRP's.

[grayfox]

The Web has several places where the brisance (hotness) of primers is listed, plus primer sizing specs.

They all differ somewhat, but not intended to be mysterious.

[VASCAR2]

I remember reading that CCI magnum pistol primers were the same as CCI small rifle primers. I did a search and this is what popped up.


NOTE 1: According to Speer/CCI Technical Services - Both the CCI 550 Small Pistol Magnum and CCI 400 Small Rifle primers are identical in size. Both primers use the same cup metal and share the same cup thickness. Both primers use the same primer compound formula and same amount of primer compound.Feb 21, 2013

[grayfox]

Dang. Missed that one. Now that you mention it I do recall slightly a post on that one case a ways back...

[Klem]

I guess, and this is just a guess, if you were doing a 300 BO and subsonic or something, then pistol primers might be ok... a guess.

.

Pistol primers work in subsonic Blackout however the magnum rifle 450's impart 20fps more and give slightly better results.

Here is the difference shooting 220SMK subsonic Blackout at 100yds, red dot scope, bench rested.



At 24K lbs peak pressure a subsonic Blackout is 10K lbs less than a 9mm handgun round. A small pistol primer will handle 24K lbs till the cows come home. I would consider using pistol primers in a rifle cartridge in a pinch; even if is pierces the pressure is governed by the tiny flash hole, and contained by the bolt in battery.

[tdbru]

just because the CCI 550 and CCI 400 are the same, doesn't mean that ALL small pistol and small rifle primers are the same. i would proceed with extreme caution myself. if i recall correctly pistol primers are generally made with thinner metal for the cup than rifle primers. obviously not in every instance, as stated above. if the cup is thinner and subjected to rifle chamber pressures, you run the risk of ruptured primers. this can wreck the firing pin hole and firing pin. not saying that will happen every time but the risk of it is higher. fortunately the SAAMI max chamber pressure spec for the 6.5 Grendel is not as high as, say the 5.56x45 NATO round. stay on the look out for srp of course. if i read correctly you' in the process of a build, but are not done yet. keep looking for srp while you finish the build. hopefully some show up before you're done and ready to shoot. if you're still going to use spp then see if you can find small pistol magnum primers. they may have thicker cups than the standard small pistol primer.
-tdbru

[nodakjohns]

Of course i really don't want to use my small pistol primers. But its nice to have options. I think i read about converting some type of russian brass to 6.5 grendel and then being able to use large rifle primers (which i have).

[nodakjohns]

I live in gods Gods country...Minnesota!

[Oso Polaris]

Of course i really don't want to use my small pistol primers. But its nice to have options. I think i read about converting some type of russian brass to 6.5 grendel and then being able to use large rifle primers (which i have).

If you are forced to get creative with your reloading components then be caution - only load a few rounds for preliminary testing and back off the charge by 0.5gr of powder to compensate for any extra primer velocity. As to using Russian brass you just need to check the style of primer that the brass is designed to use. Often it is Berdan style primers (2 small holes that are off center), which are not compatible with our Boxer style primers (one center hole). Most AK brass/steel cases are Berdan, and the new WOLF Steel 6.5 Grendel ammo features a Berdan primer.

Just plan ahead. There are some AK (7.62x39) brass cases that are Boxer primer, but this is few and far between.

[nodakjohns]

If you are forced to get creative with your reloading components then be caution - only load a few rounds for preliminary testing and back off the charge by 0.5gr of powder to compensate for any extra primer velocity. As to using Russian brass you just need to check the style of primer that the brass is designed to use. Often it is Berdan style primers (2 small holes that are off center), which are not compatible with our Boxer style primers (one center hole). Most AK brass/steel cases are Berdan, and the new WOLF Steel 6.5 Grendel ammo features a Berdan primer.

Just plan ahead. There are some AK (7.62x39) brass cases that are Boxer primer, but this is few and far between.

Ok thank you good advice.