Small Rifle Primer Sizes

[Peter988]

I hand loaded the 222 for 40 years and now the 223 for the last few. I have always just asked the shop for small rifle primers. Now with the difficulty sourcing primers I find I have size 6.5, 7.5 and 4.45mm across different brands. I don’t do any range shooting - only game. The primers all go bang and the rifle shoots minute of head. So no complaints there. Just wondering what the purpose of different sizes is ?

[bladeracer]

I hand loaded the 222 for 40 years and now the 223 for the last few. I have always just asked the shop for small rifle primers. Now with the difficulty sourcing primers I find I have size 6.5, 7.5 and 4.45mm across different brands. I don’t do any range shooting - only game. The primers all go bang and the rifle shoots minute of head. So no complaints there. Just wondering what the purpose of different sizes is ?

The Remington 6-1/2 is a low-pressure primer, not for use in .223Rem, the 7-1/2 is the standard small rifle primer. Haven't come across 4.45mm, is that RWS?

[Peter988]

When you say the 6.5 is not for use in the 223. What is the likely problem ? The 4.45mm are RUAG. Looks German. They came from Cleavers a while back.

[deye243]

When you say the 6.5 is not for use in the 223. What is the likely problem ? The 4.45mm are RUAG. Looks German. They came from Cleavers a while back.

Cup thickness a good 223 load will Pierce a primer same as the cci 400 if you are using them and not piercing primers you have a very mild load , loaded properly I get another 185 feet per second out of a cci br4 primer or cci 450 than a cci400
I find the rugged 4033 same as a cci400 but they were all I could find at the time and will do in a pinch and work great in the 9mm

[Oldbloke]

4.45mm is the diameter in mm.
Just looked. Mine say 4.5 though.

IMG_20241124_163316.jpg (284.63 KiB) Viewed 1928 times

[bladeracer]

When you say the 6.5 is not for use in the 223. What is the likely problem ? The 4.45mm are RUAG. Looks German. They came from Cleavers a while back.

https://www.rebelgunworks.com.au/products/remington-small-rifle-primers-6-1-2-100pk?variant=39461574836301

Screenshot 2024-11-24 165312.jpg (28.4 KiB) Viewed 1920 times

Yes, RUAG is RWS.

[deye243]

One thing you will find with most euro primers is when you are seating them it take more effort as they are slightly bigger in diameter.

[Peter988]

One thing you will find with most euro primers is when you are seating them it take more effort as they are slightly bigger in diameter.

Yes - I loaded a couple hundred of the 4.45mm today and they were indeed tighter.

[Blr243]

I always thought if a case used small rifle primers then I could safely use any small rifle primer . Are there exceptions?

[deye243]

I always thought if a case used small rifle primers then I could safely use any small rifle primer . Are there exceptions?

Yep cci400 rem 61/2 are made for low pressure rounds like 22H and 222r and rem 71/2 and cci450 br4 are made for 223r 204Ruger and the like and I have found the raug 4033 to be low pressure as well especially in Remington and the howa rifles .

[Peter988]

Having never checked this number in the past 40-50 years I wonder how many times I might have used 6.5 in the 222.

[Peter988]

Anecdotal evidence on overseas Forums suggest people commonly use them in 223’s but keep the pressures down. Light loads.

[deye243]

Anecdotal evidence on overseas Forums suggest people commonly use them in 223’s but keep the pressures down. Light loads.

Yep and using slow burning powder like 06h helps in 223 with the soft primers I use 25.3 I think it was for about 3180 and with the other primers I get 3340 so was wrong before when I said 185fps it's 160 odd and that's with 55g speer and nos bt .

[wanneroo]

From my research, technically European and American boxer primers are interchangeable but the dimensions are a touch different. Sellier and Bellot primers are always a tight squeeze for instance and will not feed reliably in my progressive press tubes.

After that you have to figure out whether to go for regular primers or some variation of magnum. I use #41 CCI mil spec primers in my loads as these have a thicker cup to prevent against slam fires and are a magnum primer.

[Blr243]

Are the low pressure primer have warnings on the packets ?

[Blr243]

Are the low pressure primer have warnings on the packets ?

[Oldbloke]

I'm surprised too. Thought it was rifle and pistol. Had no idea there were other versions.

[Blr243]

Ob. U and me members of the no idea but still alive club

[deye243]

Are the low pressure primer have warnings on the packets ?

Nope us Shooters are supposed to be psychics .
But what from what I have seen around the forums in this country 99% of people are only loading to 222r velocities anyway so it's not much of a problem

[Blr243]

I don’t load 223 anyway but my bushmaster uses small primers. I should google the pressure s of the bushmaster vs the 223

[Blr243]

Bushmaster max pressure 38500. 223 was I think 50 or 55 thousand

[deye243]

224 is 52000 cup or 55000psi
450 bush master is 38500psi so you could use pistol primers except fed 100 that would end I tears

[Oldbloke]

Just glad I've been enlightened.

Next time i buy SR primers ill be carefully checking.

[Fester]

I have been testing lots of the different primer brands to keep my CCI stock going longer.
Some have been so tight to seat that I set up a Lee auto bench top unit to save my RCBS Universal.
Also safer if one ever goes off as the seating one is separated from the other 40 or so that could blow your fingers off.

The Ruags are working fine in .223, as were std CCI 400s.
I see no real benefit in redlining them for normal .223 use and may be less accurate.
If I did load to the point of case or primer fails, I would only only want to be shooting them at a range with glasses and help if I was unlucky enough to get my eye burned.

I have felt the gas blast burn my cheek from a 22lr Velocitor case blowing a crack.
Piercing primers could well do the same.

Those White River LR primers they were talking up were even tighter to seat, too tight for me as CCI always went in and seated with pretty ideal pressure.

Got a box of Federal in std and premium small and large that seem to go in well.
The Indian LR #34s are OK and hotter than most, I think the 6.5 CM went about 100fps faster.

[wanneroo]

Well, this thread has given me a good idea for my Youtube channel.

In 2023, I developed a good load for 9mm quickly in one project so it evolved into testing small pistol primers using that one load as a baseline and testing for how well they worked in the reloading process, such as seating and then how they performed in terms of speed and spread of velocity and then accuracy and just a general feel for how they shot. I did find there were noticeable differences in brands and performance. I plan on continuing that project as I have more brands to test this winter.

But I think I will do the same for small rifle primers. I'll develop a basic 223/5.56 load with 55g bullets and then test those primers for fit and function and we'll see what the differences are. I'll find all the different small rifle primers on the market I can get.

[Blr243]

Deye 243. Thanks for the tip Re pistol primers ok in the bushmaster. That suits me real good because I have a small amount of small rifle primers and oodles of small pistol primers

[Over The Hill]

Well, IBF, never knew this about the CCI 400. Always used these for my 223 hunting & plinking loads and BR-4 for my target loads. Never had an issue with the #400 but then I load conservatively and dont push the limits as I like to think I am extending some barrel life by not running too hot a load. Always something new to learn.

[deye243]

Well, IBF, never knew this about the CCI 400. Always used these for my 223 hunting & plinking loads and BR-4 for my target loads. Never had an issue with the #400 but then I load conservatively and dont push the limits as I like to think I am extending some barrel life by not running too hot a load. Always something new to learn.

You will still get 4000 odd rounds in a non target barrel with proper loads .

[deye243]

Deye 243. Thanks for the tip Re pistol primers ok in the bushmaster. That suits me real good because I have a small amount of small rifle primers and oodles of small pistol primers

Just depends on the brand of primer as some are very soft like fed 100 and win srp I can't even use fed 100 in my 9mm as it came I had to replace the firing pin in a new pistol and even then it was problematic cci 450 and br4 will do it no problems.

[Fester]

Well, this thread has given me a good idea for my Youtube channel.

In 2023, I developed a good load for 9mm quickly in one project so it evolved into testing small pistol primers using that one load as a baseline and testing for how well they worked in the reloading process, such as seating and then how they performed in terms of speed and spread of velocity and then accuracy and just a general feel for how they shot. I did find there were noticeable differences in brands and performance. I plan on continuing that project as I have more brands to test this winter.

But I think I will do the same for small rifle primers. I'll develop a basic 223/5.56 load with 55g bullets and then test those primers for fit and function and we'll see what the differences are. I'll find all the different small rifle primers on the market I can get.

What's your PooTube channel Wanneroo or how should I search it out?