.223 speed can't figure this out...

[Rsadams]

I have cronoed both Remington 55gr. And imi 55gr both fmj .223 out of my m4 both at a little over 2900 fps... Today I ran some fed. Xm193 5.56 and it of course was a little over 3000 plus fps... Speeds are not exact I can pull the crono and give the exact numbers if needed..

I am now at 24.5 gr of TAC at 2.210 coal so I can crimp the canalure using the hornady 55gr fmj... But still under factory .223 speed at around 2780 fps. I would think that since 25.6 is the max in the hornady manual for 5.56 and 23.9 for .223 I would at least be at factory .223 speed but no..


Just FYI I am using CCI s/r primers and have tried both once fired Remington and imi .223 brass TAC and hornady 55gr fmj w/c... I am not trying to load to 5.56 pressure but would like to at least get to .223 speeds. The 24.5 of TAC shot very well and maybe I just need to step it up a bit or just leave it it shot so good but I was only shooting 25 yards for a point of aim to shoot over the chronograph.... The gun is a sig m400 gassed right with sprinco white standard spring H buffer and bcm bcg..

Gun ejecting 5.56 at the 3:30 and .223 at the 4 o'clock position like it should but of course the CCI s/r primers were a little flat and some cases had slight scuffs on the heads. That doesn't worry me as you can tell the hand loads were weaker.. and imi brass is soft..and the CCI s/r primers are known to flatten easy but they were nothing I would worry about even still had fairly good round edges..

What are you guys loading TAC to get .223 speed out of your 16 inch barrel m4s?? Just wondering for reference.. I would not be scared to bump it up a bit. Likes I said the 24.5 shot well but I may be losing my shooting range at the end of the month over lease dispute , god I hope not but In which case I am screwed.. and there will be no need to reload because I will not be able to shoot anymore. So I have that amount of time to find a load so I can at least load the thousands of fmj and put them in a can and seal them up or whatever.. so times a factor... Shooting is a big part of my life like all of you and the thought of having to stop or even ending up having to go to a crap range which the only other range around here is is about to bring me to tears...

Sorry so long...
Shawn

 

[Clancy]

Try a faster powder. I love benchmark in the 223/55 gr ammo.

 

[varmintshooter]

+1 for benchmark

 

[Knotwild]

I also love Benchmark. Using the max Hodgdon recommends and I get right around 3000 fps with a 55 gr. Varmegeddon in a 16" 5.56.

 

[Rsadams]

Thanks everyone I guess I am the only one using TAC anymore...

 

[Jdne5b]

Tac is great for heavier bullets, just not the best for big speed and 55gr bullets.

 

[Zero333]

for 55 grainers it's hard to beat the accuracy of Benchmark

 

[vegas]

I've used 25gr of H335 and 55gr FMJ-BT at 2.25 to get just a hair over 3000fps out of a 16" barrel. I never had much luck with TAC from an accuracy perspective, ymmv of course. I looked back at my old data and show 25.2gr with TAC at 2.25 and the same bullet but didn't record the velocity for some weird reason.

 

[Fast14riot]

25gr of H335 under a 55gr bullet is a common recipe and generally hits right around 3k fps.

 

[JAlfred]

http://accurateshooter.net/Downloads/sierra223ar.pdf. http://accurateshooter.net/Downloads/sierra223ar.pdf

For more velocity, page 6 has data relevant to your Interest.

TAC and lightweight bullets have fallen out of favor in a lot of circles due to reports of gas port erosion with lighter bullets.

I would run a faster powder, if I felt the need for speed. The kind of casual shooting I am likely to use 55 gr FMJs for I would be satisfied with reliable function and lower velocities.

 

[snowpro440]

H-335 is the go to powder.....

 

[nmkid]

In my .20 Practical, (.223 necked down to .20) H-335 has produced groups waaaayyy beyond my expectations. Too bad I spent so much time trying other powders. I should have just tried H-335 from the get go, as advised.