over max loads in 223
- Thread starter cjmac
- Start date
bigedp51
It depends on your rifle, my Savage .223 with a 1 in 9 twist has a longer throat than either of my AR15 rifles have so it can be loaded much higher than any manual with the shorter throat.
HOLLIGER ON .223/5.56 CHAMBERS
http://www.radomski.us/njhp/cart_tech.htm
My chamber is big enough to the fit the .223 cartridge plus two Savage company lawyers and stay below the rated pressure of 55,000 psi. ;D
Just remember both the .223 and 5.56 are rated at the same max pressure of 52,000 cup or 55,000 psi and the 62,000 psi NATO European figure is measured at the case mouth. Meaning the throat length is the only difference.
As you can see below from the link I posted above the Savage and Wylde throats are longer than the AR15.
Bottom line, work up your load and watch for signs of pressure, your throat diameter and length will govern max pressure.
HOLLIGER ON .223/5.56 CHAMBERS
http://www.radomski.us/njhp/cart_tech.htm
My chamber is big enough to the fit the .223 cartridge plus two Savage company lawyers and stay below the rated pressure of 55,000 psi. ;D
Just remember both the .223 and 5.56 are rated at the same max pressure of 52,000 cup or 55,000 psi and the 62,000 psi NATO European figure is measured at the case mouth. Meaning the throat length is the only difference.
As you can see below from the link I posted above the Savage and Wylde throats are longer than the AR15.
Bottom line, work up your load and watch for signs of pressure, your throat diameter and length will govern max pressure.
Pressure signs in 223
As said, chambers make all the difference. SAAMI is 55,000 PSI. 5.56 X 45MM NATO
CIP COMMERCIAL AND NATO/MIL SPECIFICATION (62,350 PSI). http://www.accuratepowder.com/wp-content/uploads/2010/09/WP_LoadSpec_1-23-14.pdf Be safe, follow SAAMI. Dont go over maximum.
CIP COMMERCIAL AND NATO/MIL SPECIFICATION (62,350 PSI). http://www.accuratepowder.com/wp-content/uploads/2010/09/WP_LoadSpec_1-23-14.pdf Be safe, follow SAAMI. Dont go over maximum.
Just the kind of info i was looking for. Only thing i dont like about the powder ,it doesn't fill the case at all. My goto load for 60 grain hp is varget . For 52 grain smk is benchmark or Norma 200. I have been thinking of trying ramshot TAC for 52smk or 50 grain nosler ballistic tip for a varmint load . Anyone tried it ?
A lot of guys run ramshot tac till the powder shortage came along. You may have a tough time finding it at all.
cjmac said:
Only YOUR rifle can answer that question. If your chamber is close to SAAMI max along with freebore/throat length on the long side, you may not see any pressure signs at all, even with a full case. Then again, if the tolerances are all on the minimum side you may encounter pressure before you reach published max load.
Again, you have to learn to read what your rifle tells you on this while working up loads.
cjmac said:
What's difficult is that a Manufacturer will publish a "Min-Max" with their data but people have to realize that it was obtained with a test barrel/receiver under conditions that existed at their test site.
Those of us out here that are looking for the "optimum" performance are in the same boat as "hot-rodders". The car manufacturer published specs for tuning their engines for use in a "family car". When drag racing, etc, all that really means nothing. You just have to adjust, adjust, adjust, until performance is where you want it, or at least all the performance that is possible from the setup.
If one really wants to push the envelope and be as safe as possible, buy a Pressure Trace from RSI. Then you'll see some real pressure readings rather than just trying to interpret "signs".
bigedp51
cjmac
What brand/type rifle do you have.
From what I have seen the .223 short throated rifles have a 1 in 14 or 1 in 12 twist, and the longer throated rifles have a 1 in 9 twist.
The one thing to remember is when the .223 and 5.56 are shot from their designed chamber they stay at their max rated pressure of 55,000 psi. Also remember that 52,000 cup, 55,000 psi and the European NATO standard 62,000 psi are the exact same pressure measured three different ways.
Look at the chart below and the green bars, the longer throated AR15 chamber reduced the chamber approximately 6,000 psi shooting factory .223 ammunition. And the Savage .223 I have has a longer throat than my two AR15 do and my AR15 loads show less pressure signs when fired from my .223. Meaning your throat makes all the difference in your chamber pressure, so look at the load data in the manuals and you will see that the .223 loading data is for short throated rifles with the 1 in 14 or 1 in 12 twist.
5.56 vs .223 – What You Know May Be Wrong
http://www.luckygunner.com/labs/5-56-vs-223/
What brand/type rifle do you have.
From what I have seen the .223 short throated rifles have a 1 in 14 or 1 in 12 twist, and the longer throated rifles have a 1 in 9 twist.
The one thing to remember is when the .223 and 5.56 are shot from their designed chamber they stay at their max rated pressure of 55,000 psi. Also remember that 52,000 cup, 55,000 psi and the European NATO standard 62,000 psi are the exact same pressure measured three different ways.
Look at the chart below and the green bars, the longer throated AR15 chamber reduced the chamber approximately 6,000 psi shooting factory .223 ammunition. And the Savage .223 I have has a longer throat than my two AR15 do and my AR15 loads show less pressure signs when fired from my .223. Meaning your throat makes all the difference in your chamber pressure, so look at the load data in the manuals and you will see that the .223 loading data is for short throated rifles with the 1 in 14 or 1 in 12 twist.
5.56 vs .223 – What You Know May Be Wrong
http://www.luckygunner.com/labs/5-56-vs-223/
bigedp51
cjmac said:
cjmac
Depending on the 700 model it will have a 1 in 12 or 1 in 9 twist, so if you look at the Remington webpage you will find out the twist rate and have a good idea of your throat length.
8208 XBR is a tricky powder. It was pointed out here a year or so back (and I experienced it myself) that it will turn on you quick.
We were humming along fine with a hot load to send 77 gr SMKs at near Mk262 velocities. Had zero pressure signs, and then BAM!... had a batch that was blowing primers a like a 5% rate or so.
I'd though I had brain farted and loaded it a full grain over, but pulled some down and they checked out.
The point is that you can go hot.. and over published max, but be careful because you can be near the red line and not have any indication. Also... why not shoot 77s out of that bolt gun? That's what we run out of our 1/9 20" rem 700 and they work really well.
We were humming along fine with a hot load to send 77 gr SMKs at near Mk262 velocities. Had zero pressure signs, and then BAM!... had a batch that was blowing primers a like a 5% rate or so.
I'd though I had brain farted and loaded it a full grain over, but pulled some down and they checked out.
The point is that you can go hot.. and over published max, but be careful because you can be near the red line and not have any indication. Also... why not shoot 77s out of that bolt gun? That's what we run out of our 1/9 20" rem 700 and they work really well.
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