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Ackley Improved Question...Experts needed...
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I posted this in the reloading forum, but I'm posting it here as well, as it may attract a little more attention from the folks I'm trying to target here. Thank you!
I have both volumes I and II of P.O. Ackley's Handbook for shooters and reloaders. When looking up the load data for .300 Improved Magnum, it says "Loading data is same as for the .300 Weatherby". Now...Here's my question...We all know that Weatherby calibers are designed around the freebore concept, to reduce pressures. Standard and Ackley Improved calibers are not. Am I going to see excessive pressures loading Weatherby loads into my Ackley cases, which will more than likely be seated .005" off the lands.
I also noticed something else that is very interesting...and I'm assuming it also has to do with the freebore concept. If you look at the load data for IMR 4831 or 4350 for a 200 or 220 grain pill, the .300 Win Mag has almost identical velocities as the .300 Weatherby...and it does it with less powder!...a couple grains less powder! I'm assuming that my advantages might be seen with higher velocities than the .300 Weatherby, while using Weatherby loads...Is this a correct assumption.?.? I verified these numbers in several different reloading manuals.
All three of these cartridges are overbore...I don't want to be using more powder to achieve the same thing I can already achieve with a standard .300 Win Mag...thus causing faster throat errosion, etc...but if I'm able to achieve better velocities b/c I've done away with the freebore concept, I can see a potential advantage to the Weatherby loads in the AI.
What are your thoughts.?.?
Do I use the Weatherby loading data as PO Ackley advises...and if so, do I have to worry about my seating depth.?.? ...or do I seat like a standard caliber and expect higher velocities???
All thoughts would be greatly appreciated![:)]
I have both volumes I and II of P.O. Ackley's Handbook for shooters and reloaders. When looking up the load data for .300 Improved Magnum, it says "Loading data is same as for the .300 Weatherby". Now...Here's my question...We all know that Weatherby calibers are designed around the freebore concept, to reduce pressures. Standard and Ackley Improved calibers are not. Am I going to see excessive pressures loading Weatherby loads into my Ackley cases, which will more than likely be seated .005" off the lands.
I also noticed something else that is very interesting...and I'm assuming it also has to do with the freebore concept. If you look at the load data for IMR 4831 or 4350 for a 200 or 220 grain pill, the .300 Win Mag has almost identical velocities as the .300 Weatherby...and it does it with less powder!...a couple grains less powder! I'm assuming that my advantages might be seen with higher velocities than the .300 Weatherby, while using Weatherby loads...Is this a correct assumption.?.? I verified these numbers in several different reloading manuals.
All three of these cartridges are overbore...I don't want to be using more powder to achieve the same thing I can already achieve with a standard .300 Win Mag...thus causing faster throat errosion, etc...but if I'm able to achieve better velocities b/c I've done away with the freebore concept, I can see a potential advantage to the Weatherby loads in the AI.
What are your thoughts.?.?
Do I use the Weatherby loading data as PO Ackley advises...and if so, do I have to worry about my seating depth.?.? ...or do I seat like a standard caliber and expect higher velocities???
All thoughts would be greatly appreciated![:)]
Comments
I posted this in the reloading forum, but I'm posting it here as well, as it may attract a little more attention from the folks I'm trying to target here. Thank you!
I have both volumes I and II of P.O. Ackley's Handbook for shooters and reloaders. When looking up the load data for .300 Improved Magnum, it says "Loading data is same as for the .300 Weatherby". Now...Here's my question...We all know that Weatherby calibers are designed around the freebore concept, to reduce pressures. Standard and Ackley Improved calibers are not. Am I going to see excessive pressures loading Weatherby loads into my Ackley cases, which will more than likely be seated .005" off the lands.
I also noticed something else that is very interesting...and I'm assuming it also has to do with the freebore concept. If you look at the load data for IMR 4831 or 4350 for a 200 or 220 grain pill, the .300 Win Mag has almost identical velocities as the .300 Weatherby...and it does it with less powder!...a couple grains less powder! I'm assuming that my advantages might be seen with higher velocities than the .300 Weatherby, while using Weatherby loads...Is this a correct assumption.?.? I verified these numbers in several different reloading manuals.
All three of these cartridges are overbore...I don't want to be using more powder to achieve the same thing I can already achieve with a standard .300 Win Mag...thus causing faster throat errosion, etc...but if I'm able to achieve better velocities b/c I've done away with the freebore concept, I can see a potential advantage to the Weatherby loads in the AI.
What are your thoughts.?.?
Do I use the Weatherby loading data as PO Ackley advises...and if so, do I have to worry about my seating depth.?.? ...or do I seat like a standard caliber and expect higher velocities???
All thoughts would be greatly appreciated![:)]
If you do not get an answer by fridayI will have my dad call you. He is really into the a.i., and I am sure he will have the answer.
Good to see you over on the "Experts" board.
Which "Improved" case are you/will you be working from? The H&H or Winchester length?
Any 300 Magnum is running on the overbore side of things, but when you are looking at performance, you can't look at overbore.
I don't believe you will run into pressure problems as long as you don't seat the bullet right on the lands, or crimp. I have a standard 300 Winchester, and run top loads in it seated 0.015 off the lands with no problem. I also have two RUMS...one is a 700 Sendero SFII, and the other is a rare Browning A-Bolt II SS. I seat the big RUM just off the lands also, and run into no problems.
That was a good observation you made also. In my Browning A-Bolt 300 Win, I regularly launch a 150 grain BT/Accubond at 3400+FPS(74 grains of IMR 4350). I run a 130 grain Barnes XLC at 3700 FPS(81 grains of WW 760). The observation should have been, that the benifit from more powder capacity is only gained in shooting heavy for caliber VLD bullets...like the Berger 210 VLD or the Nosler 200 Accubond.
If you haven't already, give Nononsense a jingle. I am sure he could write a novel for you on this subject.
Best
Step two, start with a upper end load for the parent case and work up slowly from there
Step three, using Woundabeast data in a non-freebored chamber is even dumber than trusting Parker's data.
SW (and to not burn another post)
Parkers data is from the 50's and maybe the early 60's. It was developed by the "traditional" methiod of increesing the load until you had to beat open the bolt, than back off 1gr. Aganst a real pressure gun, his loads were 5-10gr above the charges that yield SAAMI pressures. Also, the linters in a lot of the powders were changed (along with the load data) after his books were written. To paraphrase Phil Sharpe (because I don't have his book handy to quote), a contempory of Ackley's "we took a number of worked up loads that several experanced reloaders thought were safe by examination and had them tested, all were in excess of specification, some by as much as 15000 CUP"
Depends on the amount of "improvment" done, in a "not much to be gained" cartridge, than yes, the mid level is a better place to start, but in a "lot to be gained" case, starting closer to the top makes more sense. IE a 223AI vs a 30-30AI.
Try using stock weatherby data, in a weatherby chamber WITHOUT the freebore. Good way to distroy a decent rifle. In the sample MW gave, the room taken up by blowing out the caseing is his "safety factor". The same thing happens if you work up a load at "stock" OAL, and than use the same data with the bullet touching the lands. What was the old rule of thumb when working at "contact OAL", wasn't it "use the starting load for your max, and start 10% below that"?
I just happen to have a rifle chambered for the .300 a.i. (300 h&h blown out to a.i.), the increased case capacity makes up for the 'free bore' of the weatherby. I have shot factory .300 weatherby ammo to fire form cases with no problems (and they shoot quite well). I use .300 weatherby data and get slightly more fps in the a.i. case that the weatherby data states (chronographed).
This is a .300 Mag A.I. case...and with that being the case, I would imagine I shouldn't have any problems using the Weatherby data in my rifle either. Are you seating your bullets close to the lands? Thanks!
Step one, NEVER trust the data in Ackley's books. Interesting. But,I never trust the information in any one book by itself. Moreso the the velocities than the powder loads. I'm usually just finding a starting load though.
Step two, start with a upper end load for the parent case and work up slowly from there. I typically start no higher than midrange on the parent case. It doesn't hurt anything if you have a light load and decide to work up your next trip out to the range. FWIW, I'm guilty of starting at the high end of the parent case load. I ended up interpolating a powder from a similar speed/pressure powder. I ended up backing off a ways. I didn't do that again. Conversely, I've gone 4 gr. over the book load...3 yrs. before it was published.
Step three, using Woundabeast data in a non-freebored chamber is even dumber than trusting Parker's data. I agree completely. That just doesn't make any sense to say that. However, in Roy's defense, I will say he recanted his statement that you can hit an animal just about anywhere with that much velocity and kill it. That is just wrong and he eventually he had to face that. Also, I do believe he was the first one that incorporated free-bore into a standard production rifle. The velocity gained in that method is pretty incredible. It's a trick we use today to gain velocity and our very own 5.56 round is based on that premise.
ECC,
I would use the books to find a starting load and work up to the velocities you want. Once you get into the upper end start looking hard for pressure signs. If you load this round to headspace off the belt you will give yourself a bit of pressure relief. If you load this round to headspace off the shoulder (neck sizing) you wont. I prefer to headspace off the shoulder for accuracy purposes, I also think you'll get a little better case life. But, it's a little like the freebore. If you want hunting accuracy, it's better to give the relief and have that slight drop off in accuracy. Because, you will still get pretty good accuracy headspacing off the belt. You will also probably have better extraction in hot weather.
quote:Originally posted by Tailgunner1954
Step one, NEVER trust the data in Ackley's books. Interesting. But,I never trust the information in any one book by itself. Moreso the the velocities than the powder loads. I'm usually just finding a starting load though.
Step two, start with a upper end load for the parent case and work up slowly from there. I typically start no higher than midrange on the parent case. It doesn't hurt anything if you have a light load and decide to work up your next trip out to the range. FWIW, I'm guilty of starting at the high end of the parent case load. I ended up interpolating a powder from a similar speed/pressure powder. I ended up backing off a ways. I didn't do that again. Conversely, I've gone 4 gr. over the book load...3 yrs. before it was published.
Step three, using Woundabeast data in a non-freebored chamber is even dumber than trusting Parker's data. I agree completely. That just doesn't make any sense to say that. However, in Roy's defense, I will say he recanted his statement that you can hit an animal just about anywhere with that much velocity and kill it. That is just wrong and he eventually he had to face that. Also, I do believe he was the first one that incorporated free-bore into a standard production rifle. The velocity gained in that method is pretty incredible. It's a trick we use today to gain velocity and our very own 5.56 round is based on that premise.
ECC,
I would use the books to find a starting load and work up to the velocities you want. Once you get into the upper end start looking hard for pressure signs. If you load this round to headspace off the belt you will give yourself a bit of pressure relief. If you load this round to headspace off the shoulder (neck sizing) you wont. I prefer to headspace off the shoulder for accuracy purposes, I also think you'll get a little better case life. But, it's a little like the freebore. If you want hunting accuracy, it's better to give the relief and have that slight drop off in accuracy. Because, you will still get pretty good accuracy headspacing off the belt. You will also probably have better extraction in hot weather.
The starting loads for the Weatherby or the Win Mag.?.?
Edit:
Now I'm thinkin' DUhh!! That would have been so easy to say in the first place. Sorry for the long and windy, roundabout answers.