CCI #41 primers are almost impossible to fully seat

[nitesite]

The only rifle round I load which uses small rifle primers is for a Bushmaster AR-15. So, in order to best protect me from slam-fires, I bought a few thousand CCI #41s sometime in 2006.

These things have been a freekin pain-in-the-butt to fully seat. Been trying for over a year now to figure out why. I know that #41s incorporate a harder primer cup than any other primer, and that the anvil design requires a deeper strike to touch them off. Sounded like a good idea when I bought them.

I personally shot another bunch of factory-new LC XM-193 cartridges, and after tumbling & sizing/de-priming I removed the crimps and cleaned the primer pockets. So tonight, I once again sat down to seat some of these #41 primers in some of my once-fired LC brass. I quit at forty.

These #41 Bastidges simply won't crush flat enough to leave the primer below flush with the case head, unless I really crank down on them several times and turn them between tries. I'm using a Lyman T-Mag press which is basically a single stage, so I have the mechanical advantage of a compound lever with more power than a hand primer could ever give me.

I used my digital micrometer to compare several brands of primers I have on hand for width as well as the height of the cup (not including the anvil).

All of them (CCI 400, CCI 450, Rem 6½) were .1745" dia and .1135" high, which is exactly the same as these durn CCI#41s. Using the same batch of brass, the only primer I have trouble with during seating is the #41. All the other SR primers smush into the pocket just fine with minimal effort.

It appears to me that the hard primer cup of a #41 requires a tremendous amount of force to seat below the the case head. The cup just doesn't want to flatten below flush and set the correct gap for the anvil.

Damn, this is frustrating after loading and shooting thousands and thousands of .223 rounds using other primers with 100% success. I'm about to quit trying to use up these #41s.

They might make a fun display when I'm burning trash.

 

[counterclockwise]

Same experience here. I use the RCBS turret press primer installer, which works on the ram down stroke (Handle up). This is after I use the RCBS primer pocket swager tool on the press to remove the military primer crimp. I too, wrestle, turn, re-strike, etc. to try to get the obligatory .001 to .003 inch below the rim face on my LC XM193 cases, once fired. Some CC41 primer faces wind up so flat that they look like an over-pressure clue. I was advised to get a tool that actually end mills a few thousandths off the pocket bottom after decapping. This would be an "off-press" casing prep. exercise. It is the "Perfect Primer Pocket Uniformer" or something close.

 

[mc223]

You might want to recheck your decrimping operation to be sure you are not pushing a burr inside the pocket. I have loaded thousands of peices of LC brass with the CCI #41 without a hitch.
On a secondary note, the reason I use the #41 is they perform better with some of the powders I use. Unless you have actually experienced a slam fire with your rifle, The use of the #41 may not be needed. Rem 7-1/2 and fed 205 have worked well for me. I did have a short issue with WSRs piercing. I Quit using them.

 

[Doug b]

Nitesite, load your rifle via the magazine and not by hand and hitting the bolt release is your best protection from a slamfire.The inertia spent stripping and chambering a round from the mag. SHOULD prevent a slamfire and you're free to use whatever primer works best.

 

[FieroCDSP]

I suspect the CCI primer cups might be too deep. I've run into this every now and then with pistol brass and regular CCI primers. My solution was to get an adjustable primer pocket uniformer. With it set at the proper depth, many of those pockets had material removed from them (winchester seem to be my biggest foe) then the primers seated just fine. It's time consuming, though.

 

[rg1]

The only solution is a primer pocket uniformer. It'll cut all the pocket bottoms square and flat and to the same depth. A couple turns by hand and it'll cut the radius at the bottom of the pocket just enough to gain the extra few thousandths that you need to seat consistently below flush without having to crush or flatten the primer. The EJS Possum Hollow primer pocket uniformer tool isn't too expensive and works nicely. It's also nice for cleaning primer residue from fired cases.

 

[Slamfire]

I personally shot another bunch of factory-new LC XM-193 cartridges, and after tumbling & sizing/de-priming I removed the crimps and cleaned the primer pockets. So tonight, I once again sat down to seat some of these #41 primers in some of my once-fired LC brass.

I have seated thousands of #41's in Federal, W/W, LC (old stuff), strange range pickups, etc. I remove the crimp with a Dillion pocket swager, and somethings I cut the pockets to depth. Not really had much of a problem.

I wonder about your brass. Lake City is a GOCO operation, and the contractors are just cranking the brass out as fast as they can. It is not like the military is into reloading. If the stuff goes bang, and the military buys it, thats what they want. And that is also all the scandal avoiding Military managers are interested in doing too. Getting ammo out the door and leaving the troubles for the next guy. I have no doubt that the Lake City contractor is free to vary primers, pocket depths, pocket diameters, as long as they keep that production going.

 

[bobaloo]

Just another vote for a primer pocket uniformer. I've got one that fits in my cordless drill. When I'm loading .223 it sits on my left leg. I grab a piece of brass and hit the primer pocket with the tool for a couple of seconds, then into the press. Leaves the bottom of the pocket clean and smooth and makes sure the edges are smooth. Just finished 5K of .223 and only had a couple of rounds that gave me trouble.

 

[mokin]

This is very interesting. I bought 1000 CCI#41s a couple of years ago to reload 7.62X39mm brass for an SKS. I figured the hard primers would be a good countermeasure to the reputation SKSs have for slamfires. I developed a great round (reliabel and accurate) just in time for that brass to become extinct leaving me with quite a few of these primers. While developing a round for an M-1 Carbine I found that it wouldn't reliably fire the rounds loaded with #41 primers-all other primers worked fine. At the time I figured the rifle just wasn't hitting the primer hard enough to detonate it. I didn't think it could be a seating issue. I'll see if I can check the depth....

 

[Don't Tread On Me]

Yes, get the EJS tool. It chucks up into a drill (if the drill has a large chuck) and you can quickly uniform the pockets. The extra added bonus is you no longer need to clean the pockets anymore as this cutting tool does that while it is shaving out excess brass.

I had a really hard time seating CCI BR's in twice fired brass. CCI 41's which were used after the 1st firing were tight, the BR's were almost impossible to seat after the 2nd firing. A couple of spins of the EJS tool cuts the pocket square and to the proper depth. Primers seat with total ease like they are suppose to.

Priming on a press should be a breeze. Remember, whether they seat going up with the handle or down, there's a lot of leverage and it shouldn't take much effort. It should almost feel like it is sliding in. Hand priming is different. If you are really cranking on the handle on your press to seat primers - that is WAY too much force.

It isn't the primers. It is the unfortunate realization that you have to do an extra step in the brass prep of .223 to keep reloading cases. It stinks, but there's no way around it. This process can be done on the cheap or on the fast and easy. How fast and easy all depends on how much you want to spend. Cheap is slow, expensive is usually faster. You have to weigh the costs against your time and patience.

EJS is nice because it's cheap ($20) and it is reasonably fast. A rare occurrence in the reloading world. But no matter what, it's another step - which slows the total reloading process down, adds time and effort.

 

[FieroCDSP]

On the bright side, once you uniform a pocket, you'll never have to do it again.