223 ackley - question

[varmintshooter]

A while back I asked about brass prep but now I am working up a load and would like to know, do I go up until I see signs of high pressure then back off or what. The velocity. I am getting almost seem to good to be true.

IMR 3031 27 gr @ 3650 with 53 vmax

IMR 8208 27.4 gr @ 3510 with 53 vmax

In your opinion is this about right? Barrel is a 24" 9 twist. So far no sign of high pressure.

[dungheap]

Generally with the .223AI, I can go to a loading manual and start at or near the top load with a given bullet. They say you gain about 10% more powder capacity with the AI, so it's "work up carefully" from that point.

For two cents' worth you didn't ask for -- try Benchmark. We got unbelievable accuracy out of 2 guns with it, the best being with Nosler 52gr Custom Competition, but it's great with lots of others, including Midsouth's 55gr Varmint Nightmare Extremes.

[Bill K]

I did about the same, start right near max for the standard 223 and work up slow and easy.. Benchmark is a good powder and also H 335, if you want to try a few others. Have fun, but play safe. Bill K

[vmthtr in Green Bay]

You load at the range? Load the same piece of brass and see how many firings before the primer pocket goes to big.

[Old Hawkeye]

That 9 twist is going to show signs of high pressures quicker than a slower twist as load charges increase, so work up VERY slowly. A 12 twist would be better suited for 53 gr bullets. 9 twist was designed for 68 gr to 75 gr bullets & the AI case could better take advantage of the heavier bullets than the standard case. Just food for thought. I've never had much luck with accuracy with lighter bullets in a 9 twist, but that was just with my particular rifles. Yours may do well. "What's about right" with regard to velocity will vary from rifle to rifle, but you are near it's maximum capabilities.

[L Cazador]

Originally Posted by varmintshooter

A while back I asked about brass prep but now I am working up a load and would like to know, do I go up until I see signs of high pressure then back off or what. The velocity. I am getting almost seem to good to be true.

IMR 3031 27 gr @ 3650 with 53 vmax

IMR 8208 27.4 gr @ 3510 with 53 vmax

In your opinion is this about right? Barrel is a 24" 9 twist. So far no sign of high pressure.

How are you measuring pressure, and what kind of chrono are you using? What is your barrel length? Your 9 twist is fine for that bullet weight, those are pretty long bullets. Any observation of pressure should be by measurement of the rim or just ahead of the rim. Expansion of more than .0008" is a sign you are close to max and will soon show as more than .001" and loose primer pockets.

[xring]

Caz , I have heard that AI Brass does not give an " Early Warning System " type response based on Case Head Expansion ..... that the Head expands all at once .....only after you have exceeded "reasonable" Pressures . Is that your experience with AI Brass ? I would be interested to know because I hope to be shooting a 223 AI this Summer .

[Bill K]

Originally Posted by xring

Caz , I have heard that AI Brass does not give an " Early Warning System " type response based on Case Head Expansion ..... that the Head expands all at once .....only after you have exceeded "reasonable" Pressures . Is that your experience with AI Brass ? I would be interested to know because I hope to be shooting a 223 AI this Summer .

I believe, if you read any good reloading book and even the fore parts to most good manuals, they all show watching and reading for pressure signs by case expansion.
Above and in the area of the cartridge base/head. And at the primer and primer pocket. This applies to any cartridge, be it a improved or standard case. usually case separation is more a issue with headspace and the brass working back and forth, than pressure, but pressure is the base cause for case's breaking down faster, than a safe load. Just follow the manuals loading charts, anneal your brass, when needed, neck size for your given rifle and keep the AOL trimmed to proper measurements and you will enjoy a safe and non-complicated time reloading and shooting your weapons. Work up a accurate load, keep your dies properly adjusted and just play sane. Bill K

[dungheap]

I agree with Bill K's comments. My shooting partner is big into measuring stuff, me not so much. I do work up slowly (often .2 increments), watch the primers like a hawk, and any sign of sticky bolt lift or difficulty in re-chambering a fired case means "back off right now."

The .223 case is tough, but that's no excuse to get careless. In the case of the .224AI, most of us are going (more or less) into uncharted territory (meaning that you just can' t open a manual and find data), so the smart thing to do is make use of what IS known , and be very careful with the unknown.

[L Cazador]

Originally Posted by Bill K

I believe, if you read any good reloading book and even the fore parts to most good manuals, they all show watching and reading for pressure signs by case expansion.
Above and in the area of the cartridge base/head. And at the primer and primer pocket. This applies to any cartridge, be it a improved or standard case. usually case separation is more a issue with headspace and the brass working back and forth, than pressure, but pressure is the base cause for case's breaking down faster, than a safe load. Just follow the manuals loading charts, anneal your brass, when needed, neck size for your given rifle and keep the AOL trimmed to proper measurements and you will enjoy a safe and non-complicated time reloading and shooting your weapons. Work up a accurate load, keep your dies properly adjusted and just play sane. Bill K

+1 on what Bill K says. One of the pressure indicators the 223 Ackley is good at hiding, is sticky bolt lift because of it's reduced bolt thrust. Measure the rim at the start of your load work and keep an eye on that number.