Another Twist On The "Wide Range Of H335 Data For .223" Question

[otisrush]

There are a couple of recent threads on the seemingly large differences in min/max data for H335 in .223 loads. One of the conclusions I've taken from those posts is that Hornady data tends to be a bit conservative. I also think I've concluded that Hornady is the most conservative, then hodgdon.com, then Speer - in terms of ranking them most conservative (lightested loads) to most aggressive (heaviest loads).

I based a number of my .223 loads on Speer data. So, for example, I have shot a good bit (a few hundred) of 55gr FMJs over 25.2gr of H335. Given the above sources that would be not only a hot load - but I think officially "over max" in some instances. Speer, as reference, lists 26gr (I think) for max load for 55gr FMJ (their 55gr FMJ).

This load of 25.2gr is not showing any signs of high pressure or even stress whatsoever. (I'm shooting them out of an AR.) This rifle is chambered in 5.56.

Would/could a given load show signs of high pressure in a .223 chambered rifle but not a 5.56 chamber? For other reasons I've been investigating the differences between .223 and 5.56 and a longer/more gradual throat seems to be one of the characteristics of the 5.56. If true - could these same rounds that seem to be working great in my 5.56 AR not do well in a .223?

On the one hand it is disconcerting to have something over the max from one source's perspective, but well within spec from another, and yet that load appears to be doing fine.

Any insight would be greatly appreciated!

Thanks!

OR

 

[moxie]

For reloading purposes any published .223 load, regardless of the publication (Speer, Hornady, Lyman, whatever) will work safely in both .223 and 5.56 chambers.

The caveat is: Don't shoot factory 5.56 ammo or reloads loaded to published 5.56 specs out of a .223 chambered gun.

 

[243winxb]

5.56 vs 223

Don't shoot factory 5.56 ammo or reloads loaded to published 5.56 specs out of a .223 chambered gun.

Good advice. Comes from SAAMI-Nato factory ammo not for 223 chambers. http://www.saami.org/specifications_and_information/publications/download/SAAMI_ITEM_211-Unsafe_Arms_and_Ammunition_Combinations.pdf This powder company has loading data for 5.56 and 223.http://www.accuratepowder.com/ Stick with 223 Rem loading data for all, like Moxie said.

 

[Kaldor]

There are a couple of recent threads on the seemingly large differences in min/max data for H335 in .223 loads. One of the conclusions I've taken from those posts is that Hornady data tends to be a bit conservative. I also think I've concluded that Hornady is the most conservative, then hodgdon.com, then Speer - in terms of ranking them most conservative (lightested loads) to most aggressive (heaviest loads).

I based a number of my .223 loads on Speer data. So, for example, I have shot a good bit (a few hundred) of 55gr FMJs over 25.2gr of H335. Given the above sources that would be not only a hot load - but I think officially "over max" in some instances. Speer, as reference, lists 26gr (I think) for max load for 55gr FMJ (their 55gr FMJ).

This load of 25.2gr is not showing any signs of high pressure or even stress whatsoever. (I'm shooting them out of an AR.) This rifle is chambered in 5.56.

Would/could a given load show signs of high pressure in a .223 chambered rifle but not a 5.56 chamber? For other reasons I've been investigating the differences between .223 and 5.56 and a longer/more gradual throat seems to be one of the characteristics of the 5.56. If true - could these same rounds that seem to be working great in my 5.56 AR not do well in a .223?

On the one hand it is disconcerting to have something over the max from one source's perspective, but well within spec from another, and yet that load appears to be doing fine.

Any insight would be greatly appreciated!

Thanks!

OR

25.2gr of H335 with the Hornady 55gr FMJBTs is the same load I run. No pressure signs here. Not beating the rifle up. Shoots just under an inch providing Im not screwing the pooch.

If you are reloading, and your brass is sized and trimmed to .223 spec, youll have no issues running these same loads in a .223 chambered rifle, even if the brass started out as 5.56.

 

[otisrush]

Thanks for the info.

I'm not really asking about the differences between .223 and 5.56. I'm trying to figure out how a load which is apparently "way over max" from Hornady's perspective (or even Hodgdon possibly) shows NO sign of high pressure. Is it simply because those companies are more conservative than Speer and they're trying to stay out of lawsuits? That's the only explanation I can come up with if the fact I'm running them in 5.56 chamber isn't a contributing factor to something being able to be handled with no signs of high pressure.

Thanks again.

OR

 

[Rule3]

No tests agree. All done at different times, equipment, bullet, primer, methodology temp etc.

I agree the H335 is a very wide range which prompted my thread, but as most concluded the Hornady data is very conservative. I did a test of them all some time ago in a AR 15 and they all cycled the gun I have the data somewhere were I chronographed it, I posted it in a thread some time ago,
Actually I think I was shooting a Mini 14? The numbers are somewhere here on the forum,