Sierra .223 Rem load data confusion

[markm87]

Aren't the case capacities different ? NATO / commercial (.223 Rem ?? )

No. There's some weird brass flavors that have thicker webs/walls. But the main stays are all really close.

 

[Doom]

I have 2000 more Hornady 55gr FMT-BT W/C (#2267) to load, with NATO cases, using H335. (I load to 90-95%) Was going to start at 22.0gr and work up, etc

The other powder I was using was AA2200, but ran out. I was using 23.3gr to 23.5gr (Commercial cases about a grain less) of AA2200, and shot fine with NATO and comm cases, ejecting around 4 o'clock.

Got it. I'm curious about the photo you posted. Is this info from remanufactured ammunition?

 

[RoDog]

Test Rounds : Commercial (5 cases) and NATO (25 cases). 22.0, 22.5, 23.0, 23.5, 24.0 (L to R)

H335 - Hornady 55gr FMJ-BT W/C #2267, Ill test next weekend, ill borrow my friends AR..... AR15 A2 , 16", 1 in 9, Carbine Gas System. Barrel Contour - Government,

 

[RoDog]

Tested OK. Look at charges on other pictures. 22.0gr - 24.0gr of H335 ( Commercial and NATO cases )
H335 - Hornady 55gr FMJ-BT W/C #2267 - AR15 - 556 NATO BARREL - Carbine Gas System. Barrel Contour - Government

 

[David Milisock]

Sierra publishes load data for .223 Rem, and separates it by bolt gun and AR-15 applications. In their .223 cartridge guide, AccurateShooter.com mentions the AR being more sensitive to pressure than a good bolt gun, and I've always assumed that to be the case.

Why would the max published bolt gun load for a given powder/bullet/primer/COL be lower (sometimes significantly so) than the same for an AR-15? This is Sierra's load data for their bullets and Hodgdon powder (I've got a bunch).

components     bolt max   AR max   diff
45gr / H322      25.3      25.7    -0.4
45gr / H335      28.3      27.7    +0.6
50gr / H322      24.9      25.2    -0.3
50gr / H335      28.0      26.4    +1.6
52gr / H322      24.3      25.2    -0.9
52gr / H335      27.6      26.7    +0.9
52gr / Varget    26.7      27.5    -0.7
55gr / H322      23.9      24.3    -0.4
55gr / H335      27.5      25.7    +1.8
55gr / Varget    26.9      27.2    -0.3
69gr / H335      25.7      23.8    +1.9
69gr / Varget    26.4      26.1    +0.3

H335 looks like what I'd expect: a reduced load compared to the bolt gun load. Varget looks backwards on the lighter bullets, and H322 looks backwards all around (except if you look at the data for the 63gr SMP with H322, where the bolt gun load is slightly higher).

I'm not particularly concerned with the actual number on the published max loads (I'll work up the load from a safe starting point), but I'm curious about this pattern. Is there something about H322 (and maybe Varget) that would generally have you running a hotter load in an AR than in a bolt gun?

If in the AR they use a 5.56 or a Wylde chamber?

 

[RoDog]

Got it. I'm curious about the photo you posted. Is this info from remanufactured ammunition?

That's my label I make with a Brother QL-800 printer

 

[Laurie]

If in the AR they use a 5.56 or a Wylde chamber?

In fact even longer-throated as it appears to be that of the Colt AR15-A2 HBar off the shelf XTC rifle that is optimised for the 80gn SMK seated out to 2.550" COAL. (Wylde sees this bullet at c. 2.440" when just off the lands and true 5.56 NATO isn't much different).

As per the norm for manuals, the bolt-gun data will use the very restrictive SAAMI 223 Rem chamber and internal barrel specs. Sadly, only Lyman touches on any of this (differences in 223 rifles' chambers) in its recent editions' handling of the cartridge.

There is some interesting material here on this issue with pressure tested results and chamber dimension specs.

https://www.luckygunner.com/labs/5-...oaded,possible pressure levels of ammunition (.

 

[David Milisock]

In fact even longer-throated as it appears to be that of the Colt AR15-A2 HBar off the shelf XTC rifle that is optimised for the 80gn SMK seated out to 2.550" COAL. (Wylde sees this bullet at c. 2.440" when just off the lands and true 5.56 NATO isn't much different).

As per the norm for manuals, the bolt-gun data will use the very restrictive SAAMI 223 Rem chamber and internal barrel specs. Sadly, only Lyman touches on any of this (differences in 223 rifles' chambers) in its recent editions' handling of the cartridge.

There is some interesting material here on this issue with pressure tested results and chamber dimension specs.

https://www.luckygunner.com/labs/5-...oaded,possible pressure levels of ammunition (.

That's good data and good reason to make sure you know what you have. I have a Howa 1500, (Weatherby Vanguard) in 223 with 1 in 12 twist and an Colt AR 15A2 Hbar in 5.56 NATO with a 1 in 7 twist. I never shoot the 5.56 in my 223, even though in theory I could shoot my 223 ammunition in my 5.56 I do not because of the fast burn rate of the powder I use and the over SAAMI specification pressure.

 

[drop_point]

To reiterate, there are .223 Rem bolt-actions and there are .223 Rem ARs. Then there are 5.56 NATO ARs. The bolt-action .223 Remington can handle more pressure, but a 5.56 NATO, even in an AR, will take more pressure than a .223 Remington.

I had some ammo I got mixed up once and shot my 5.56 V-Max load in my .223 Rem Model 700 and ruined the extractor and blew the primer.