magnum primers with AR loads ?

[rebs]

When you guys load for your AR do you use magnum primers ? I have read on a different forum that H335 powder works better with a magnum primer, is this true ?
I have worked up to 25.0 of H335, a 55 gr bullet and std primer, would there be any benefit going to a magnum primer with this load ? The reason I ask is that I picked a 1000 CCI srmp's at a local gun show for 35.00

 

[HitFactor]

I have seen reloading data for max. load .223 rem that uses the magnum primer with 55 grain bullets. Per Hodgdon website the 25.0 gr puts you over max load so there may be a benefit, but Hodgdon doesn't suggest anything other than SR primers.

Loaddata.com has several records for hot .223 using the SRM primers, here is one of them.

55 Speer TNT HP, FMJ BT, Spitz SP or SP/cann Hodgdon H-335 26.0 3092
Remarks: max charge; primer: CCI 450 Magnum

Your groups should be the answer.

I have always thought that the difference between a SR and a SRM primer was the heat and the difference between a SP and a SR was the thickness of the cup.

I have never tried to produce really small groups in .223, but that may change in the near future with an new JP Enterprises rifle on the way.

 

[KUSA]

Magnum primers in an AR are ideal.

 

[damoncali]

CCI 41's are magnum primers. nothing wrong with magnumns in an AR, just work up a load and know that they're different.

 

[kala_azar]

I've only used Wolf/Tula SRMs for AR loads.

 

[goose_boy]

I use CCI 450s in my AR, partly because I read they are beneficial with ball powders and partly due to the thicker primer cup. Do I really need the thicker cup, probably not but they work just fine either way. I've had some pretty good loads, best was w748 and 53 vmax, a good one with 8208xbr and 55 vmax, rifle didn't like 8208xbr and 69 smk, got some 65 SGKs and TAC ready to try. The magnum CCI primers seem to do fine with all the powders and charges I've tried, though I may consider trying some BR primers out of curiosity.

 

[BCP]

You don't need a mag primer but it won't hurt anything either. I get higher velocity spreads with magnum primers in 223 than regular but they still shoot MOA and go bang every time.

 

[BobinNC]

I also use CCI450 primers in an AR15. No problems noted in accuracy after switching from FED 205M's. But I do use a bit of H335 for bullets under 70 grains.

 

[rebs]

if you are loading 223 for an AR with a 5.56 chamber then the rifle should stand up to hotter 223 loads right ? I mean a 5.56 chamber is rated for higher pressure than the 223 chamber, right ?

 

[mtrmn]

Rebs, once you find your accuracy load you can just about bet it will be within .223 specs, not 5.56 pressures. You are correct that a 5.56 chambered weapon will handle the higher pressures, but I've never gotten more than mediocre accuracy with loads that hot. And a slow hit is better than a screaming hot miss every time in my book. And chasing super velocity is inviting disaster-if it were possible to get super high velocities with safe pressures and good accuracy then everybody would be doing it. Just my opinion

 

[Rprecision]

I know it can be done, probably back of 10% and work up.

I have never tried it becuse I dont want to be stuck buying mag primers for a load I work up. If its a mag caliber then thats what I use.

If you have load data the supports the use of a mag primer, and there are loads that do this, then give it a wirl.

 

[TimK]

I switched from CCI SRPs to Tula SRM in my precision load. Velocity went up 40 fps, accuracy is still superb. In fact, I shot the best group of my life with this new load just last week.

 

[bigedp51]

Ball powders are double base powders and have more deterrent coatings on them to lower peak flame temperature and control the burn rate. The military uses magnum type primers because they use ball powders that are harder to ignite and especially at below freezing temperatures. If ball powders and magnum primers are good enough for Uncle Sam they are good enough for you as well.

Example page 202 of the Speer number 14 manual on the .223 has an asterisk * by H335 ball powder and at the bottom of the page it states the following:

*Magnum primer used with this powder

Now look at the links below and the photos of the Remington primers igniting, Germán A. Salazar at these links calls them "mini flame throwers". Remington ran Lake City Army Ammunition Plant from 1941 till 2001 and used Remington primers to light off Winchester ball powders loaded in military ammunition. Look at the photo of the Remington 7 1/2 primer, you could light the rocket boosters for the Space Shuttles rockets with these primers and they are not called magnum primers. Now guess what primer I use in my AR15 rifles to light off H335 ball powder.

Primers - Small Rifle Primer Study
A Match Primer Study in the 6BR Cartridge
By Germán A. Salazar

The Rifleman's Journal: Primers - Small Rifle Primer Study

Primers - Large Rifle Primer Study
A Match Primer Study in the 30-06 Cartridge
By Germán A. Salazar

http://riflemansjournal.blogspot.com/2009/06/primers-large-rifle-primer-study.html

 

[mtrmn]

The CCI 41 and 34 "military" primers are magnum primers according to CCI's website. They are designed to use in AR's. I use them exclusively in all my 223 and 308 loads, regardless of gun type. All my loads were backed off a bit and worked back up when I went to the magnum primers. No problems whatsoever. Before I started using the military primers, I loaded multiple thousands of 223 rounds with standard CCI 400 primers with zero problems. The standard advice applies, when you go with magnum primers back off your load and work back up watching for pressure signs.

 

[leadbullet]

Makes no diff

 

[rebs]

I am not into super hot loads or the fastest velocity, I just happened to get a good deal on 1000 cci srm primers and have read about them working well with H335 powder. I wanted to know if you guys use them and what effect they had on your loads.

 

[goose_boy]

I have read several times that CCI 41s and CCI 450s are the same thing, just marketed differently. Both are small rifle mag primers, have same prime formula, and have the same cup thickness. FYI