.223 load using 55gr FMJ + SRM Primers + Reloder 15?


April 23, 2010, 08:53 PM
I've been reloading pistol calibers for a little while now. Looking to start loading for my AR-15. For various reasons, here is all I have on hand: CCI 450 Small Rifle Magnum primers, Hornady 55gr FMJ-BT bullets, and Reloder 15 powder. No books list an actual load for these components, but I hear stuff like this can be done so long as I carefully back off the charges sufficiently and work up. How far should I back off due to the magnum primers? I don't have a chrono, so I'll have to just use my own judgement on all of it.

I hear the CCI 450's make a good AR-15 primer because of the thicker cup. I hear Reloder 15 is a solid AR-15 powder, but is better with bigger bullets and longer barrels. None of my load data books list anything close to my combination, so any information would be appreciated. I just want decent plinking loads with acceptable accuracy.

Online I read of some people loading 55gr bullets on top of 25 grains of Reloder 15 with ok results... I also read that 27-28 grains is the max load.... would 24 grains be a good start or should I back off further?

Gun is a 16" barreled M&P-15. Thanks in advance. :o

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April 23, 2010, 10:11 PM
As you have noted, Rel-15 does work much better in heavy bullet loads. Alliant lists 25gr as the max under the 62gr FMJ with CCI400 primer. A nominal 10% drop for a starting load will give you a load of 22.5gr.
I would start at 23gr of Rel-15 using 55gr FMJ and CCI450 mag primer and work up. You would possibly get better results with a slightly faster powder and the 55gr bullets.


April 23, 2010, 11:52 PM
I like 25.0gr of RE15 under a 55gr FMJ with regular primers... Not sure about the magnum primers though.

April 24, 2010, 09:34 AM
I've been using Reloder 15 for about 18 months now. I wanted to use a universal powder for 55, 69 and 80 grain bullets. I found that R15 shot notably more accurate with the 55 grainers compared to H335 but is a bit dirtier.

My final load was 26.7 grains R15 with a bulk 55 grain soft point and the Wolf qqqsr223 kvb-223m primers. I have an average velocity of 2978 over three separate tests.

Out to 300 yards the POI of this load is almost identical to a load of 24.9 grains R15 with a 69 SMK, with the same primers. My targets are IDPA zero zones, so I'm less concerned about the size of the group and more interested in the percentage of hits in that zone.

As a note, I've tested Ramshot TAC recently and I'm really happy with it. I'm getting better accuracy at a higher velocity with a cleaner burning powder that costs less, especially since R15 has gone up a lot in the past year. My tests loads are exactly the same as I listed above but with 25.7 grains of TAC. If you haven't committed to R15, definitely test TAC.

April 24, 2010, 01:36 PM
I use RL15 for 69-77gr. bullets and faster powders for 55gr. bullets. The RL15 does work nicely with 60gr. Nosler btips with 25.0 grains for me. I use CCI400 and Rem 7 1/2 primers with very good results and don't think the CCI450's would be neccessary for that powder.

Ramshot Tac and X-terminator work well with 55 grain bullets and could possibl benefit from the CCI450 primers although I have never had a problem lighting them off with the previously mentioned primers.

May 4, 2010, 02:48 PM
Thanks for the advice so far.

As for the suggestions to try other powders/primers... the whole point of this thread is that I am poor and need to work with what I have on hand. Maybe I wasn't clear enough in my original post.

I just want to make sure I'm not going to make a horrible mistake by loading 55gr FMJ-BT over ~23.0 gr of RL-15 with SRM (Magnum) Primers. I just want a safe, decent plinking load and don't have enough rifle experience to know how much the magnum primers will affect the load.

April 2, 2013, 12:48 PM
know this thread is old, but one of the few regarding rl 15. posted same response on another thread. I too have plenty of this powder laying around, was frustrated at how many people steer you away from this poweder/load especially when it's the very first powder in the Lee manual and Lee 223 die instructions.

worked up loads yesterday using LC brass at 1.75 trim length, Fed Match AR primers and 55grain FMJ pulls. started at 24 grains but didn't get any grouping until I hit 26.4 grains. It was like magic. bullets were almost touching at this point. seating depth did not seem to have much/any effect in this gun. loading at or near max OAL after measuring my leade. shooting out of 16" 5.56 chamber AR getting roughly 2750 fps at 26.4. will focus more in this range and slowly work up. showing no signs of pressure. this powder will fill the case pretty full. Using a drop tube and still at the point where shoulder meets the neck.

at the lower load volumes, this powder burns pretty dirty but will clean up as you get into the proper range and it burns more thoroughly.

July 24, 2013, 03:10 PM
Weird that this thread came up again, I was just shooting this load this past weekend.

The CCI SRM Primers + 25 gr RL-15 + 55 gr FMJ-BT load is a functioning plinking load with no signs of pressure. It's also very clean (I think the magnum primers burn up more of the powder, leaving a pretty clean gun).

Groups were nothing to write home about (fist at 50 yards) but it was a very hot day with a very hot barrel and a 4moa red-dot, so I'm sure I could have done better. Maybe I'll start off shooting paper next time I shoot this load to try to give better information.

One interesting thing that I've noticed is that people seem to have come to the conclusion that you can stuff about as much RL-15 as you want into a .223 case and not run into pressure problems.

July 25, 2013, 12:53 AM
I've used IMR 4198 , 3031 , and H335 along with SRM primers for years now, using 55 gr. Spire Points, 52 and 53 gr. BTHP's in my .223, I've never had any problems with over pressure, or any other problems. Course, I'm shooting bolt rifle.

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