H335 for 62gr .223...?

Saluki91 · May 5, 2021

Getting ready to work up a load for my 16" 1:7 5.56 AR, and I am confused by what I'm reading.
62gr Hornady FMJ w/ cannelure
LC Brass
WIN #41
H335

My confusion comes from information overload... every source I look at shows me different load data.
Hornady .223 - 20.1gr to 22.9gr
Hornady 5.56 - 21.2gr to 25.4gr
Hodgon - 22.5 to 24.ish (no 62gr data, but they do list 60gr and 63gr)
Lyman Book - 22.5gr to 25.0gr

Variety may be the spice of life, but I don't want my loads to be spicy... I want them to be safe and accurate.

Is the 5.56 data the best place to start? Since it has the highest max load, is it also a good place to finish?

As always - Thanks!

EricBu · May 5, 2021

335 is fine for 62gr, I prefer RL15, but have loaded tons with 335. There is 3 data sets. .223, .223 Service Rifle and 5.56. If your gun is a heavy barrel match and stamped .223, you need to stick with .223 or .223 Service Rifle Data. If your barrel is 5.56 or Wylde, then you are good to go with using ANY of the above data sets. Most AR's sold today without a heavy barrel are "usually" 5.56, only you will know for sure if running mil surplus in it caused pressure signs. If you've habitually run mil ammo (IE, boxes labeled M855 5.56, or any NATO nomenclature for 5.56) and have not seen pressure signs like flat primers, or extraction problems.......you are "likely" good to go to use any of the above data sets. As always, Mr. Safety says start low and work up for your gun...don't just start with a hot load and wait to see what happens.

Saluki91 · May 5, 2021

EricBu said:
335 is fine for 62gr, I prefer RL15, but have loaded tons with 335. There is 3 data sets. .223, .223 Service Rifle and 5.56. If your gun is a heavy barrel match and stamped .223, you need to stick with .223 or .223 Service Rifle Data. If your barrel is 5.56 or Wylde, then you are good to go with using ANY of the above data sets. Most AR's sold today without a heavy barrel are "usually" 5.56, only you will know for sure if running mil surplus in it caused pressure signs. If you've habitually run mil ammo (IE, boxes labeled M855 5.56, or any NATO nomenclature for 5.56) and have not seen pressure signs like flat primers, or extraction problems.......you are "likely" good to go to use any of the above data sets. As always, Mr. Safety says start low and work up for your gun...don't just start with a hot load and wait to see what happens.

I should have noted that the rifle is 5.56. I edited to reflect that - Thanks!

Charlie98 · May 6, 2021

From another thread...

Charlie98 said:
I just did some load testing this weekend with a new AR build... 18" rifle-length barrel.

24.5grn H335 and the Hornady 62grn BTHP... 2850fps

Dale Alan · May 6, 2021

You can start with the Hornady .223 load and use the Hornady 5.56 load as your max .

lordpaxman · May 6, 2021

Saluki91 said:
My confusion comes from information overload... every source I look at shows me different load data.

This is normal. Most published reloading sources differ in the testing setup as well as the components hence come up with similar but different numbers. And guess what? You’ve got a different testing setup than theirs, most likely. You also didn’t mention COL but that’s a big factor you need to consider. If you’re concerned but this variety of data, a chrono can help evaluate how your test loads compare to the published data.
Since you wanted safe and accurate, it would not hurt to start with .223 data, perhaps a node is lower than the 5.56 starting data. You have a 5.56 platform so that should dictate your max. Good luck.

Klaatu Barada Nikto · May 6, 2021

You didn't mention if the LC brass is 5.56 or .223, it does make a difference. 5.56 brass is thicker and has less interior volume.
Also follow the 5.56 COL data, there is a difference in the distance of the leade.
The shorter leade in the .223 barrel can cause pressure spikes if you run a factory spec 5.56.
This is the primary reason why many shooters will run 223 in a 5.56 rifle but not the other way around.
Some of the competition shooters will chime in about the diminished accuracy when running 223's in a 5.56 chamber.
https://www.topbrass-inc.com/blogs/news/223-remington-vs-5-56-nato-what-s-the-difference

Spare Parts · May 6, 2021

Ditto on 16" AR 1:7. This is my go-to plinking round.

CCI400, LC brass, HDY 22760 FMJ-BT, 24.5gr H335, COL 2.250"

Yes, the data is all over the place. Hornady X doesn't have data for their 62gr bullet. I contacted Hornady Support, and they suggested using the 60gr VMAX data. We're on our own...

My field notes have a H335 ladder from 21.7 to 24.5. No pressure signs in the notes. 24.5 gave me the best group.... that particular day. I was running a GI trigger group back then.

I don't know OP's experience level, and no offense intended - be careful. Smaller increments at the top end. Check for pressure signs. What do "pressure signs" look like? See "mk262 clone" on u-toob.

Like Johnny says, "don't blow your face off."

Saluki91 · May 6, 2021

Spare Parts said:
Ditto on 16" AR 1:7. This is my go-to plinking round.

CCI400, LC brass, HDY 22760 FMJ-BT, 24.5gr H335, COL 2.250"

Yes, the data is all over the place. Hornady X doesn't have data for their 62gr bullet. I contacted Hornady Support, and they suggested using the 60gr VMAX data. We're on our own...

My field notes have a H335 ladder from 21.7 to 24.5. No pressure signs in the notes. 24.5 gave me the best group.... that particular day. I was running a GI trigger group back then.

I don't know OP's experience level, and no offense intended - be careful. Smaller increments at the top end. Check for pressure signs. What do "pressure signs" look like? See "mk262 clone" on u-toob. Like Johnny says, "don't blow your face off."

Thank you for your response, an no offense was taken! I like my eyes and ears just where they are... don’t need them relocated due to careless or sloppy loads!

BillWM · May 6, 2021

Klaatu Barada Nikto said:
You didn't mention if the LC brass is 5.56 or .223, it does make a difference. 5.56 brass is thicker and has less interior volume.
Also follow the 5.56 COL data, there is a difference in the distance of the leade.
The shorter leade in the .223 barrel can cause pressure spikes if you run a factory spec 5.56.
This is the primary reason why many shooters will run 223 in a 5.56 rifle but not the other way around.
Some of the competition shooters will chime in about the diminished accuracy when running 223's in a 5.56 chamber.
https://www.topbrass-inc.com/blogs/news/223-remington-vs-5-56-nato-what-s-the-difference

try googling .223 and 5.56mm. Claiming pressures differ and case thickness differs is not what the stats say.

"The dimensional specifications of 5.56 NATO and .223 commercial brass cases are identical. The cases tend to have similar case capacity when measured, with variations chiefly due to brand, not 5.56 vs .223 designation. The result of this is that there is no such thing as "5.56 brass" or ".223 brass", the differences in the cartridges lie in pressure ratings and in chamber leade length, not in the shape or thickness of the brass"

The difference is the chamber: "The exterior dimensions of the 5.56mm NATO and .223 Remington cartridges are identical.[13][60] While the cartridges are identical other than powder load, the chamber leade, i.e. the area where the rifling begins, is cut to a sharper angle on some .223 commercial chambers. Because of this, a cartridge loaded to generate 5.56mm pressures in a 5.56mm chamber may develop pressures that exceed SAAMI limits when fired from a short-leade .223 Remington chamber. As the chambers differ, the head space gauges used for the two chamberings differ"

Taken from here: https://en.wikipedia.org/wiki/5.56×45mm_NATO

Klaatu Barada Nikto · May 6, 2021

BillWM said:
try googling .223 and 5.56mm. Claiming pressures differ and case thickness differs is not what the stats say.

"The dimensional specifications of 5.56 NATO and .223 commercial brass cases are identical. The cases tend to have similar case capacity when measured, with variations chiefly due to brand, not 5.56 vs .223 designation. The result of this is that there is no such thing as "5.56 brass" or ".223 brass", the differences in the cartridges lie in pressure ratings and in chamber leade length, not in the shape or thickness of the brass"

The difference is the chamber: "The exterior dimensions of the 5.56mm NATO and .223 Remington cartridges are identical.[13][60] While the cartridges are identical other than powder load, the chamber leade, i.e. the area where the rifling begins, is cut to a sharper angle on some .223 commercial chambers. Because of this, a cartridge loaded to generate 5.56mm pressures in a 5.56mm chamber may develop pressures that exceed SAAMI limits when fired from a short-leade .223 Remington chamber. As the chambers differ, the head space gauges used for the two chamberings differ"

Taken from here: https://en.wikipedia.org/wiki/5.56×45mm_NATO

Could have sworn I mentioned chamber leade as a cause for variations in pressure, .062" vs .125".
The cases are not identical, the radius at the shoulder to neck varies and there is a difference in case thickness.
Again, another google search proves that there is indeed a difference in brass thickness and pressures as a result of that.
https://ultimatereloader.com/2018/08/05/223-vs-5-56-facts-and-myths/

H335 for 62gr .223...?

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