Reloading 223/5.56 with H335

[wild_weasel]

Over the Holidays I have indulged myself developing new loads for my 9mm's and 5.56's. Most of my reloading to date for the 223/5.56 has been with CFE223 and WW748, so I picked up a pound of H335 to try. My Hornady manual recommends a maximum charge of 23.0gr of H335 with their 55gr FMJ-BTs, while the Hodgdon 2013 load guide list 25.3gr of H335 as the maximum load with 55gr bullets. I’m starting with Hornady’s recommended load of 23gr but plan on working up to a charge of 25gr which should duplicate the Eagle (Federal) AE223 factory load. As it turns out my RCBS Little Dandy powder measure throws 23gr of H335 with rotor # 23, 24gr of H335 with rotor # 24, and 25gr of H335 with rotor #25, but rotor #26 throws 26.5gr of H335 which is higher than any published data I have on hand.

I'd really like to see the major bullet and powder manufacturers publish data for 16" barrels with 5.56x45 chambers loaded to mil spec pressure. For the time being .223 Rem 14" pistol data is more reprasentative of performance that can be expected out of 16" barrel as opposed to the current 24" and 26" barrels currently published.

[stphnman20]

It depends what you want out of it. For me, I use 25gr of H335 for regular pinking ammo.

[Divernhunter]

The only way you will know what your firearm does with a load is to have a chrono and test them.

[Nathan Krynn]

****I AM NOT RECOMMENDING ANY LOADS OVER STATED BOOK LIMITS, ALL WAYS WORK UP YOUR LOADS****

The original M193 load was 28gr of WC844 (h335) getting 3250fps +- 40fps out of a 20" 1/12 barrel. (this is the info I have from that time)

H335 has changed since the late 60's and 70's and 28gr is not needed to get those velocities anymore but it still over any SAMMI book limit I have ever seen.

Hornady has lawyered up over the year regarding powder charges I think.

I still use H335 for my 5.56 loads (yes I meant 5.56) but I do not give them to others or recommend my powder throw to anyone as it is over SAMMI .223 specs and any book max loads. However I get very consistent loads out of it and never have had an over pressure problem.

I use #41's and LC brass too.

[bigedp51]

Your Hornady load data is for a bolt action rifle with a short SAAMI throat and a 1 in 12 twist. AR15 5.56 load data will be for a longer throat which reduces pressure and a different twist rate.

If you do a google search you will find that with mixed brass and 55gr FMJ bullets 25 grains of H335 is the most widely used load for blasting/practice 5.56 ammo. This keeps the chamber pressure well below max and is easy on the rifle and brass.

I also load all my 55gr ammo with 25 grains of H335, remember .223 brass is not made as strong in the base area as Lake City 5.56 brass and 25 grains of H335 will not overstress .223 brass in larger military chambers.





Remember unless the load data specifies it is for the AR15 5.56 your looking at short throated SAAMI loading data for the .223.

I have a factory Savage .223 with a 1 in 9 twist and it has a longer throat than my two AR15 rifles do. If you look at the factory bolt action web pages for the .223 you will see different twist rates and many .223 rifles have longer throat lengths.



Below are the pressure variations when firing .223/5.56 ammunition in the different throat lengths.



Also remember the .223 and 5.56 are both loaded to the same exact pressures, BUT are fired in rifles with different throat lengths. The SAAMI interchangeability warning for the .223/5.56 did not come out until 1979 when the military came out with the M855 cartridge and lengthened the M16 rifles throat length.

The pressures listed below are the exact same chamber pressures but are measured three different ways.

52,000 cup (SAAMI copper crusher method)
55,000 psi (SAAMI transducer method)
62,000 psi (European and NATO transducer method measured at case mouth)

Below is the milspec pressure requirement for commercial contract M193 5.56 ammunition, please note that 52,000 cup is the same as 55,000 psi using the transducer method.

MIL-C-9963F
15 October 1976
SUPERSEDING
MIL-C-9963E
12 May 1970

MILITARY SPECIFICATION
CARTRIDGE, 5.56MM, BALL, M193

3.7 Chamber pressure.

3.7.1 Measurement by copper-crush cylinder52,000 pounds per square inch (PSI). The average chamber pressure plus three standard deviations of chamber pressure shall not exceed 58,000 PSI.

3.7.2 Measurement by piezoelectric transducer55,000 PSI. The average chamber pressure plus three standard
deviations of chamber pressure shall not exceed 61,000 PSI.

[CK_32]

It depends what you want out of it. For me, I use 25gr of H335 for regular pinking ammo.

Ditto^

I load 24.5 to give to take for high or a low throw.

[rsrocket1]

I found 25.0g H335 to be the most accurate out of my 20" AR. I simply duplicated the speeds of the most accurate commercial loads I've used and it turned out to work best with 25.0g and gives me 3000 fps.
Here are the results from a few years back:


Sorting by headstamp did make a difference, but for most of my plinking, I just use any case I find. The group will open up some, but it's still good enough to have fun with.

[bsumoba]

This is what I got with H335. It is the top section. I used 55gr Blitzking and a M&P15 Sport No pressure signs at 25gr and will probably stick with that as I got well under sub-MOA from my initial testing.

Just as a FYI, the bottom targets are 55gr FMJ and Benchmark

[ke6igz]

I use 25 gn of H335 behind a 55 gn bullet. I get 1 MOA accuracy out of my 20" barrel AR15.

[bigedp51]

The charts below are from Quickload using the 55 grain Hornady FMJ-BT and 25 grains of H335. The pressure differences you see are from internal case capacity variables using the same powder charge. The higher pressure is the default Quickload internal capacity of 28.8 and the lower pressure is from Lake City brass with a internal capacity of 30.4.

Below, 52,000 psi at 2950 fps, 28.8 case capacity



Below, 48,000 psi, 2700 fps, case capacity



The point being "ANY" type or manufacture of .223/5.56 case will be well below maximum pressure and very safe to shoot when using mixed brass.

[BajaJames83]

I'm actually loading some .223 right now 55gr bullet over 24gr of H335 I used to load with the WC844 but that has since dried up.

[damndave]

I use 25gr H335 over the 55gr Hornady FMJ-BT with pretty decent accuracy out of my 16" scoped AR. This load shoots 1moa in a R700 and 1-2moa in the AR.

Not bad for a progressive press loaded round.

[edfardos]

23.5 gives 2600fps. Accurate in my ar15 with 1\8 twist. Never tried to push it harder.

[DazedandConfuzed]

Mine likes 24 grs. H335 behind Hornady 55gr FMJBT.

[wild_weasel]

Here are the results of my last trip to Field Time. Over the holidays I had plenty of time to experiment with H335 and standard Tula small rifle primers in my 223/5.56 reloads.

Beginning with H335 I started at 23gr and worked up to 25gr with Hornady 55gr FMJ-BT, Winchester standard small rifle primer, and NATO brass; all loads using 23, 24, and 25gr were 100% reliable in my rifle. What I did notice was that H335 has significant muzzle flash compared to W748 or CFE223 that I normally use.

Next I wanted to see what Tula small rifle primers were capable of. I substituted them for the CCI#41 or Winchester small rifle primers I normally use with 55gr FMJ bullets and W748 powder and as you can see got good results; they were 100% reliable and no hang fires. Using my Lee Auto Prime I made sure to firmly seat the primer anvils to the bottom of the primer pocket and had no issues in the 200 rounds I tested.

Both targets are 25 shot aggregates fired at 25 yards using an AimPoint PRO optic.

55gr FMJ-BT 25.0gr H335 WSR



55gr Midway Blemished FMJ-BT 26.0gr WW748 TULA 223 SRP (non magnum)