CCI #41 military primers & .223/5.56 loads

[AKBear]

I am trying to figure out where I should start out when reloading with the following components for my Colt AR rifle with a 1:7 twist 16" barrel: 77 grain Nosler Custom Competition bullets, Lake City brass and CCI #41 military small rifle primers. I am interested in RL15 and/or Varget powder but I am still open to input on that as I haven't purchased powder yet because I am stumped with a primer compatibility issue.

My concern is according to CCI on their primer information web page it says to "use the same data as CCI magnum primers" when using these #41 primers. Thus, I guess they are magnum strength but now I can't seem to find any powder manufactures that suggest using the magnums.

Does anyone have any experience with these #41's or could some please point me in the right direction??? I have tried to "search" with no luck.

I kinda wish I went with Rem 7 1/2's which would have made things easier! The #41's were made for military type semi-auto rifles and help prevent slam-fires.
http://www.cci-ammunition.com/products/ ... aspx?id=30

 

[normo]

I have not seen magnum primer loading info for the .223 loads, but I have not looked really either.

It would make sense that CCI is saying to treat them as a magnum since the main difference between .223 and 5.56 ammo is opperating pressure, the military load is designed to run in select-fire and full auto guns needing a higher gas pressure for optimum gun performance/reliability

If you can locate specific load data for the 5.56mm you might be better off with a starting point for load developement.

I like CCI primers for my M1 Garand, they have a typically harder cup and it can help prevent "slam fires" with the floating firing pins.

Let us know what you find out, I know several guys shooting Practicle Rifle and will see if they use CCI #41 Military primers as well.

 

[colt45]

I am also trying to come up with a load for my ar.

bullet; 55grn FMJ
brass; lake city 0 & 08 head stamps
powder; BL-C2 & varget
primers; CCI #41 and CCI small rifle

Here are the things I have learned so far:

lets start with the primer, because the AR has a floating firing pin, it is possible to get a slam fire. This has been the bulk of my testing so far. when using th SR I had rounds that had slight dimpiling on the primer this went away with the #41. If this had been an older AR with more wear, I beleve that it would have slam fired or crushed the priming compound enough to make it not fire

powder; I started at the lowest and I am working up using data from the Speer #13 manual, (note on this, speer list loads using magnum primers and IMI military brass) Varget is a little finiky to get in the case. I am getting decent velocities and groups with both. I am still working on these loads

bullet; 55grn Speer FMJ One thing I have learned, almost the hard way, you need to put a very firm crimp on these or any bullet for that matter to prevent bullet set back in the AR. I roll crimp into the cannelure

I tested all of his in a Smith & Wesson MP15. When I was testing primers I would fire one and extract the live round and inspect

hope this helps. testing on hold due to hunting season

 

[Antelope_Sniper]

As you said, the M41 is a hot primer, so it will be a better fit will ball powders. The military uses a ball powder very close to H335 or BLC (2) in the standard military ball rounds.
Overall CCI primers are the hardest of the commercial primers. I've loaded CCI 200, br-4, and 400's in my Bushmaster with no problems. I would suggest the 200, and br-4 with the stick powders, m41 and 400's with the ball powder.

 

[Harpersend]

In reading you post, i remembered reading about small rifle magnum primers for the 223 somewhere. It took me a while to locate the data. It is my Lyman 47th Reloading handbook circa 1992.

They don't have the Nosler 77 grain CC bullet listed.

Here is some sample data for a 55 grain "Jacketed Spitzer" from the lyman manual with the magnum primers - test gun was AR15 16" tube
H-335 23.0 grains - 26.5 grains Velocity 2617 fps - 2967 fps
BL-C(2) 23.0 grains - 26.5 grains Velocity 2525 fps - 2949 fps
748 26.4 grains - 30.0 grains Velocity 2894 fps - 3281 fps

Compared to Lee second edition 55 grain "Jacketed Bullet" with standard primers - test tube was not listed
H-335 23.0 grains - 25.3 grains Velocity 2940 fps - 3203 fps
BL-C(2) 25.5 grains - 27.5 grains Velocity 3099 fps - 3313 fps
748 26.2 grains - 26.2 grains Velocity 3170 fps - 3170 fps

The data from both of the books some what overlap. You may try the powder manufacturer for some load data with the magnum or #41 primers.

 

[AKBear]

Thanks for your inputs - very suprised by the few responses I got on this subject however.

While doing some heavy duty searching I came across the link below (another forum) and it's just what I needed! Another reloader was using the exact components I was needing to know about, mainly Nosler 77 grain projectiles and CCI #41 primers. After reviewing the information, I now feel comfortable with using the Nosler #6 data on the 5.56x45mm and starting at the bottom of the scale with the CCI #41's. Generally, it appears to raise loads around 50 FPS over standard primers. I'll keep a close eye out for any possible pressure issues.

I think I am going to start out with Win 748 with RL-15 or H335 on deck.

http://www.calguns.net/calgunforum/show ... hp?t=54716