Small pistol primers in 223 loads?

[Eurodriver]

I have a few thousand small pistol primers CCI500. I have CCI450s as well but try to save those for my precision 6GT loads. I never load 9mm pistol - only 45 so I decided to use a bunch.

I loaded up the following 5.56 load and tested:

Berrys 55gr .224 FMJ
26.0 gr XTerminator
LC Brass
CCI450 & CCI500
COAL 2.24”

Rifle used was a Colt 6920

No pressure signs. No appreciable difference with velocity, SDs, or accuracy. No slam fires.

I even loaded randomly and couldn’t tell any difference when shooting.

For me I’m going to keep doing it. But I’d love to know what the differences are in primers between SRP SPP and SRPM or if I’m missing something about why I shouldn’t do this.

[gaijin]

I’ve used SRP in 9mm and .38 Super for years, but never tried SPP in rifle cartridges.

The “accepted wisdom”, or story line was, the SPP Cup was thinner and you’d be in danger of a slam fire in a semi auto rifle using them. If I’m not mistaken the CCI 41 primers were made for that purpose or reason.
Your experience doesn’t support that, but perhaps you’ve been lucky to date.

I know from experience the SRPM have failed to ignite on occasion in striker guns, or 1911/2011 that were lightly sprung.

I’d be interested in hearing more on this too.

[sinister]

Small Pistol Magnum and Small Rifle 400s have the same dimensions and fit the same pockets. They both use the thinner primer cups (compared to 450s and military 34s).

You'll do OK until you don't -- then expect gas fissures between the primer cup and pocket, and bolt face etching.

Small Rifle 400s are meant for low-pressure rifle cartridges (think .30 M1 Carbine).

CUP THICKNESS

Different primers have different cup thicknesses. You can see the importance of cup thickness when primers are considered for semiautomatic rifles that have free-floating firing pins.

Handgun primers have thinner cups than rifle primers, making them easier to ignite with the typically weaker firing pin fall of handguns. Small Pistol primer cups are .017' thick, while Large Pistol primer cups are .020' thick. This is the reason using handgun primers in .22 Hornet rifle loads sometimes results in pierced primers in some guns.

Obviously their substitution in the high pressure .223 Remington would not be a good idea.

Even the same type of primers from different manufacturers can have different cup thickness. Federal primers tend to have thinner cups than Winchester, Remington and CCI primers. On occasion this can be handy.

Some revolver trigger and action lightening jobs may result in a lighter hammer fall that results in not all the primers going off. A switch to Federal pistol primers can make the load 100% again.

The same thing can happen in cold weather with some “modern” bolt actions with light, fast firing pins. These are supposed to whack primers with the same approximate energy as an old-fashioned 98 Mauser strike, but under some adverse conditions they can occasionally use a little help. Federal primers can provide that help.

With Remington small rifle primers, the 6 ½ primer has a thin cup and is not recommended for higher pressure rounds like the common .223 Remington. It was intended for the .22 Hornet. When Remington introduced their .17 Remington round in 1971 they found that the 6 ½ primer was not suitable to the high-pressure .17. The 7 ½ BR primer was developed for this reason.

According to Remington, the 7 ½ has a 25% greater cup thickness and they state on their web site: 'In rifle cartridges, the 6-1/2 small rifle primer should not be used in the 17 Remington, 222 Remington or the 223 Remington. The 7-1/2 BR is the proper small rifle primer for these rounds.'

CCI/Speer Technical Services says: 'The CCI 400 primer does have a thinner cup bottom than CCI 450, #41 or BR4 primers... [with] the CCI #41 primer... there is more 'distance' between the tip of the anvil and the bottom of the cup.' so that is their AR15 recommendation, although it seems like there are no complaints with using the BR4 and 450 primers by AR15 shooters and reloaders, in general.

The #41 just gives you a little more safety margin for free-floating firing pins and would be the best choice for commercial reloaders who have no control over the rifles their .223 ammo is used in.

Another factor which determines the strength of a primer cup is the work-hardened state of the brass used to make the primer cup. They are made with cartridge brass (70% copper, 30% zinc), which can vary from 46,000 psi, soft, to 76,000 psi tensile strength when fully hardened.

Manufacturers specify to their brass suppliers the hardness of brass desired. It is possible that a primer manufacturer could choose a harder brass in order to keep material thickness down and reduce costs. Winchester WSR primers are somewhat thin, yet seem to be resistant to slam-fires and this is likely due to this hardness factor.

Large rifle primers all appear to have the same cup thickness of .027', no matter what the type.
This also affects pressure tolerance. Cases that utilize small rifle primers and operate at moderate pressures(40,000 psi) should use CCI 400, Federal 200, Rem 6 1/2, or Win WSR. Such cases include 22 CCM, 22 Hornet and the 218 Bee. These primers can also used in handguns such as the 9mm., 357, etc. Other cases that use the small rifle primer can use the above primers only if moderate loads are used. Keep to the lower end of reloading recommendations.

Cases that utilize Small Rifle primers and operate at higher pressures (55,000 psi) should use CCI 450, CCI BR4, Fed 205 and Rem 7 1/2 etc.

MATCH or BENCH REST PRIMERS

The difference between match primers and standard primers is the degree of testing and quality control used in their making.

Hornady reports that in their research that match-grade primers performed very, very consistently from load to load as measured in their pressure tests.

CCI states that Benchrest cups and anvils are selected for exceptional uniformity. During the assembly operation, the operator who meters the primer mix into the cups (or 'charger') is chosen from the most experienced workers with an outstanding record of consistency. The BR line runs at a little slower pace to provide time for extra inspection.

[Eurodriver]

Thanks Sinister. Now that you mention it, I have heard of bolt face etching before. Considering I'm loading hot 5.56 pressure rounds with CCI500 primers for no other sake than experimentation, I should probably just keep using the CCI450s I have for the sake of the Colt's bolt.

The below was interesting, however:

"This also affects pressure tolerance. Cases that utilize small rifle primers and operate at moderate pressures(40,000 psi) should use CCI 400, Federal 200, Rem 6 1/2, or Win WSR. Such cases include 22 CCM, 22 Hornet and the 218 Bee. These primers can also used in handguns such as the 9mm., 357, etc. "

So while CCI400s are in the same category as CCI500s when it comes to the 5.56, they both can be used with no issues in 9mm. That is good to know because I have some CCI400s as well

[sinister]

Rock on.

Bad bolt face etching:

[DG23]

So while CCI400s are in the same category as CCI500s when it comes to the 5.56,

Not according to Speer.

[markm]

I've ruined some firing pins with import pistol primers in .223 loads. We tried some of those Croatian whatever primers (Unis Ginex?) that are out there right now in .223 years back to see if they were good like Wolf primers. They pierced fairly easily.

I didn't ruin a bolt because I was watching for it and could see the black carbon in the primer strike area of the spent casings.

[Eurodriver]

Not according to Speer.

Speer uses CCI400s?

[DG23]

Speer uses CCI400s?

Going to apologize now for the long ass post...



Ever looked in a Speer manual?



CCI (Cascade Cartridges, Inc., or CCI.) was founded by Dick Speer (brother of Vernon Speer, who founded Speer Bullets) and Arvid Nelson in the early 1950s.



With respect to .223 or 5.56 ammo they can call for 400's, 450's or 41's in those manuals depending on the particular book and loadings.

You will not find any published data from Speer or CCI where they call for CCI 500 pistol primers in .223 or 5.56 loadings. (mark gave good, experienced advice above as always)


400's in pistol ammo? Not a problem if your pistol will reliably light them off (and all but the lightest of hammer springs usually will). I no longer buy small pistol primers for this very reason...

I experimented one time with the Speer plastic training rounds (no powder - primer powered only), CCI 400 primed 9mm cases and one of my Beretta 92F's to see just how low I could go on the hammer spring before they would not light off properly. (Cheap / low noise, indoor plinking fun with a real Beretta pistol (no airsoft crap)

A standard 92F hammer spring is rated at 20lbs. A 'D' spring is rated at 16. I had zero issues with the 400's at 12 and there is no way I would ever need or want to run a hammer that light in normal 92...

These things are freakin cool.



At indoor plinking ranges (20 to 25 feet) out of your own REAL pistol the POI on paper is surprising close to what you would see (close to what I usually expect anyway) with real ammo. Makes a nice pretty little hole where you actually aim at with your exact trigger and sights (not some airsoft copy gun shit) with very little report. Unless you are shooting at bricks the plastic bullets pretty much last forever. A thick scrap of carpet hanging behind the target is the best way I have found yet to catch them just past the paper without ricochet worries or bullet / wall damage.

Different primers are going to have different brisance and even if you can't 'see' it or notice it in one place (amount of sparks coming out of the end of the barrel) you will be able to see it elsewhere. A CCI 500 SPP will make a consistent defect on the back of that carpet scrap where that plastic bullet hit at. Those woven fibers are going to move some while soaking up that energy and it will be fairly consistent in appearance from spot to spot on the back of that bullet backstop. Some deformation yes but definitely not severe. One can safely conclude just from looking that the backstop will last for a long time using those primers to power those projectiles.

You start using CCI 550 SPM's and you are going to notice bigger dents. Switch to CCI 400 SR or CCI 450 SRM and you will really start to notice the difference in damage to your backstop. You won't want to shoot at the same spot repeatedly with confidence any longer using the magnum primers and will either add another layer of carpet to your backstop or start moving the POI around on the one to spread out the damage.