H335 powder for 223/556 only getting 2850 FPS

H20FOWL

New member
I am working a load up for my 556/223 with the Hornady 55 Gr FMJ SP with the 335 powered. I was using the hornady load data book and it seemed to run slow. I used the Hogdon load data from there site and it was 25.2 Gr (Max)of the powder. I loaded 10 at this with no pressure signs but only averaging 2850 FPS. Hogdon stated it was around 3250. I want it around 3100 FPS. I am using the RSBS Small base die set for AR. Has anyone else had issues with getting the H335 powder to 3100 FPS. I am shooting a 16" Daniel Defense Barrel LWT. I also have so AR Comp powder i want to try anyone had any luck with that powder. Thanks
 
That is a little slow for a 16" barrel. In my 20" barrel I get around 3162 fps with Hornady 55 FMJ's at 25.3 grains of H335 using RP brass and RP 7 1/2 primers. I'd guess your 16" barrel at a velocity around 2950 fps but different guns, different cases, different primers , seating overall length, temperature, and other factors can cause differences. Chronographs not reading exact speeds and how far the screens are placed from the muzzle can makes some difference. Lot's of shooters load 25 grains of H335 in various cases. I'd be satisfied with that velocity if I was getting good accuracy in your 16" barrel.
 
Their velocity is based on a 24" barrel; you have 16". That alone accounts for 200 fps easily. If your bore is on the tight side, that accounts for the rest. Let alone that the gas system of your gun takes more out of the equation or a half dozen other variables can skew the results.
 
your can work up higher than you are, you stated no signs of pressure, keep going until you start to see some.

hodgdon max is 25 .3, but only at 49ksi. your safe up to 55kpsi and even higher with a 5.56. just keep working up until you see signs of over-pressure, then back off.

I am curious to why you feel you need to get to that magic velocity though? hunting reasons? the only time I feel the need to work over max published loads is when shooting highpower(600 yard), but I don't think that's your goal since pushing a 55gr bullet...

hodgdon shows 25.3 pushing 3200fps out of 24" barrel. I have a tough time getting my loads anywhere near published velocities out of my 16" barrel, so I rarely care about velocities unless using a specific bullet that needs a certain velocity out to a certain yardage that I want it to be effective, like monolithic. over-max loads are almost never the most accurate load for 300 yards and under.
 
Malaysian surplus 55 gr ammo chronographs at 3300 fps from short barrel ARs.

I have not pulled a bullet on one, but I would bet dollars to donuts they are using H335 or something very close.

CAUTION: The following post includes loading data beyond or not covered by currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.

attachment.php


Left to right 223 55 gr H335 in my Ruger #1
1) unfired, extractor groove .329"
2) 28 gr, extractor groove .329", 11% overload 69 kpsi [Quickload]
3) 29 gr, extractor groove .329", 15% overload 80kpsi
4) 30 gr, extractor groove .3295", 19% overload 92kpsi
5) 31 gr, extractor groove .3320", 23% overload 106kpsi

Notice how the threshold of long brass life is between 29 gr and 30 gr?
 
skizzums said:
your can work up higher than you are, you stated no signs of pressure, keep going until you start to see some.

hodgdon max is 25 .3, but only at 49ksi. your safe up to 55kpsi and even higher with a 5.56. just keep working up until you see signs of over-pressure, then back off.

Not exactly, in fact not at all.

Hodgdon data is listed at 49,300 CUP not PSI.

There is a difference and these two (CUP and PSI) should never be interchanged.
 
thanks for the help my gun cycles good and the grouping is good i just wanted to match the FPS as the duty round i carry. Just wanted to match the same FPS for practice. Going to work some loads up for the AR comp powder and see how it works
 
From 2015? Missed that detail. My bad.

Today I ran 4 loads of 10 each, 55gr SGK, H335 and cci 450 SRM primers.
Last loading , 24.5 gr ran 2950-2985 with no pressure signs.
But I'm gonna back up to 24.9 and call it good. But I'm going to test that load with cci SR primers also just for comparison..
 
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