I use 2206 with 20" barrel and 69 Targex @ 3k. So if you drop 20fps per inch for your 16" you should be able to push into the early 2900's
I use 2206 with 20" barrel and 69 Targex @ 3k. So if you drop 20fps per inch for your 16" you should be able to push into the early 2900's
Out beyond ideas of wrongdoing, and right-doing, there is a field. I will meet you there.
- Rumi
I'm the same as Tahr I load 69 Targex and 2206 for just over 3k from a 20" and they shoot the same POA as the Targex 80grn which I also loaded with 2206 for just over 2800fps
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Yep went into town before and picked some up. Will hoon up a ladder this afternoon
Greetings @Nathan F,
I am getting around 2,960 fps from the 69 grain Sierra HPBT with 25 grains of AR2206H which is as compressed as I like to use. This is in a T3x with a 570mm barrel. Before discounting the Hodgdon/ ADI data there are a couple of factors that may already be raising pressure. Hodgdon data is for Winchester cases which are one of the lighter cases at around 97 grains including fired primer. I don't have a weight for the Norma cases but Sako and Lapua both weighed around 105 grains. These cases would give more pressure with the same load as the Winchester. I also don't know the construction of the Targex projectiles. If these are anything other than a cup and core type they could push up pressure as well. Published data has a bit built in for such differences but how much? Reading some of Ken Waters Pet Loads articles he found large differences in velocity an pressure in .222 cases of different manufacture and from my weighing the .223 cases are little different. I don't have much faith in primer appearance for guessing pressure and ejector marks often mean you have gone too far already, perhaps much too far. To me 2,800 fps from that short barrel seems to be what you should expect. Perhaps it is time to add a rifle for the longer stuff.
Regards Grandpamac.
Right I’ve just finished. Settled on 26.5gns of 2206H. A little over max but no pressure to speak of. I wanted more speed to at least have 800 ft/lbs of energy at 300 yds which is the self imposed limit with this rifle.
Greetings again,
That is impressive velocity, much more than I would have expected. To be on the safe side you may wish to do a little test. Take two of your cases fired with that load and load and fire them ,with the same load, two more times. If the cases will still hold a primer after that then the load should be fine. If not then a re think is needed. A friend developed a cracking good load for one of his rifles. Great velocity, wonderful accuracy and no signs of pressure. Life was good. Unfortunately none of his new cases could be reprimed due to loose pockets. Rifles have been blown up with loads that showed no signs of excess pressure, one of the reasons I tend to use velocity as an indicator of pressure.
Regards Grandpamac.
Hmmmm- just to put some more context around what @grandpamac is saying - if I run this load in GRT ,it predicts 2961 fps with my cases, which have a middle of the road 30 grains of water capacity. Pressure is indicated at 69030 psi, SAAMI max for 223 is 55,000 psi. If you get a case with a bit less capacity or a weak case someone could get hurt . . . .
I don't know if I'd place too much importance on ft/lbs; they don't seem to really correlate to meaningfully getting a bullet of suitable construction to penetrate to, and make a decent hole in, the important squidgey bits.
The rifle blowups I'm aware of have all been the result of either using the wrong powder accidentally, or an obstructed bore.
How do we really define "safe" ?
A Tikka T3 action (as here) with .223 surely must have a huge safety margin of action strength, well in excess of where the brass will fail.
The real risk here would be risking a case failure (which is hazardous in itself - especially in a T3 with the plastic bolt shroud which fragments in this event) if reloading these cases multiple times, or simply that your brass will be more or less single-use.
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