Published data and powder fit.

baltz526 · Sep 16, 2015

I saw a 300 win mag load for Hodgdon Retumbo with the 200gr Partition. the starting load was 79 with the max at 84gr. So I got out a Winchester test case I have cut a relief in neck for oal bullet tests Filled it up to base of shoulder, set the Partition. Kept reducing powder charge until I could seat a bullet at 3.340" with firm pressure. Then weighed the powder to find max powder capacity or 100% capacity with the 200gr Partition in a standard length Ruger 77. Powder weight was 72.5gr I had to dig the powder out of case to give you an idea how much pressure I was using on bullet. I can see no way a 300 win mag case will fit 80gr of powder with a standard oal, But the data was set for Winchester cases and 3.340oal and the 200 gr Partition with Retumbo.

MAinAR · Sep 16, 2015

Yep, interested in these answers as well. Way too much "predicted" info from the loading manuals these days. I load rounds every day that either QL or powder maker say is "compressed" but still have space left, in exactly prescribed loads. Market has caused tolerances to be all over the place.. QL ba rate on some of these new "green" powders is not even close. Just using what the makers publish it seems.

DrMike · Sep 16, 2015

The companies that provide loading manuals are very careful to provide solid pressure-tested data. They have too much at stake to risk an error due to what is published. The published loads published by powder and bullet providers are not predictions--they are based on hard data. Generally, those testing are using equipment that meets SAAMI standards. However, chamber dimensions can vary, often significantly. This variation introduces "wiggle" room. Also, pressure is dependent upon burn rate, which is in turn dependent upon a variety of factors such as temperature and/or bullet weight.

MAinAR · Sep 16, 2015

I agree with pressure data, what I see as being "off" across the board is case fill %. I see loads that are marked as compressed * but still have shake space, and loads that should be 97% or so and crunch them to seat bullet at published OAL length. I just live by my chrono now and load to published speeds with exact components. OP was asking about "powder fit". Just trying to understand too.

DrMike · Sep 16, 2015

Got ya! Note the difference in case capacity due to wall thickness, however. This is the reason that options are provided in QL for several brass for the 300 Win Mag. Unfortunately, it would be impractical to provide every case for every cartridge. This is the reason your measurements are so critical to precision in the projections. Taking data projected without precise input is producing generalities. Generalities can be useful, but they will always fall short of exact predictions.

MAinAR · Sep 17, 2015

Hadn't really thought about brass differences having that much effect, I understand, just hadn't thought about it.

bigedp51 · Sep 17, 2015

All reloading data in nothing more than "ball park" figures, this is because no two firearms are the same and the components used in reloading vary. If you look in the Lyman manual you will see pressure figures taken with a universal receiver and pressure test barrel. This means the chamber and bore are at "minimum" SAAMI dimensions and would generate the highest pressures.

Case capacity can vary greatly between brands of cases and this can be adjusted in Quickload. You also need a chronograph to get accurate readings from Quickload and you adjust the burn rate in Quickload until the velocities match. And even then the output of Quickload is still ball park figures.

Below are two Quickload charts, in both charts the bullet and powder charge are the same. The only difference is the case capacity in grains of H2O, the top case is a Lake City case with 30.6 grains of H2O capacity and the bottom case has 28.0 grains of case capacity. The difference between these two cases caused a 6,000 psi difference in chamber pressure.

Bottom line, if you want to get more powder in your cases use a drop tube. If that doesn't work then switch powders or change the brand of cases.

And again, all load data is ball park and why they tell you to start at the suggested start load and work up.

DrMike · Sep 17, 2015

The hand loader is still responsible to monitor his loads, noting when signs of pressure become excessive. God post, Big Ed, with excellent graphics.

baltz526 · Sep 17, 2015

I double checked the Hodgdon Data for retumbo and edited my original post. Starting load is 79gr max 84gr with the 200gr Partition at 3.340" Winchester brass. There is No Way the starting load will fit. I'm beginning to think it must be a misprint. 68gr starting load 74gr Max. Which would fit with some powder crushing. Data was printed off Hodgdon site 8/25/13

bigedp51 · Sep 17, 2015

DrMike":1mkb4ap3 said:
The hand loader is still responsible to monitor his loads, noting when signs of pressure become excessive. God post, Big Ed, with excellent graphics.

Speaking of excellent graphics I think we should have held out for 54-40 or fight with the British. That way when Alaskan cruise ships dock in Vancouver we wouldn't need our passports. (bazinga)

For you Americans who don't get it DrMike lives in British Columbia Canada.

DrMike · Sep 17, 2015

Touché. Just remember, Washington and Oregon would be Canadian if an arrogant Brit had not disgusted at fishing for salmon sans fly or at hunting deer with dogs. There were some weaknesses in administration in those days. Consequently, appreciate the GIF of the president of Possum Lodge. :mrgreen:

bigedp51 · Sep 17, 2015

baltz526":2g8l0spk said:
I double checked the Hodgdon Data for retumbo and edited my original post. Starting load is 79gr max 84gr with the 200gr Partition at 3.340" Winchester brass. There is No Way the starting load will fit. I'm beginning to think it must be a misprint. 68gr starting load 74gr Max. Which would fit with some powder crushing. Data was printed off Hodgdon site 8/25/13

Key words, drop tube.

Advanced Reloading: Controlling Cartridge Powder Column Height
http://bulletin.accurateshooter.com/201 ... mn-height/

bigedp51 · Sep 17, 2015

DrMike":2dfac7vs said:
Touché. Just remember, Washington and Oregon would be Canadian if an arrogant Brit had not disgusted at fishing for salmon sans fly or at hunting deer with dogs. There were some weaknesses in administration in those days. Consequently, appreciate the GIF of the president of Possum Lodge. :mrgreen:

I'm glad you know I was pulling your leg, I collected the British Enfield rifles and enjoyed talking to my English speaking cousins. Our family ancestors were divided and half moved to Canada and our side of the clan moved south to stay warm. :wink:

DrMike · Sep 17, 2015

I am quite familiar with the history of the northwest. The great pig war is still one of the most fascinating stories to be ignored in modern history studies. Neither nation really had the stomach to fight a war over a pig. You know that San Juan Island really belongs to Canada, don't you? :lol: Canucks are just too gracious to make a fuss about the theft.

baltz526 · Sep 17, 2015

Here is the Data pulled off Hodgdon just now. 200gr Partition

Hodgdon Retumbo .308" 3.340" 79.0 2,798 45,700 CUP 84.0C 2,962 52,300 CUP

baltz526 · Sep 17, 2015

A Drop tube is not going to get 79gr in a 300 win mag case, let alone 84gr. Off to SPS to pick up 200 180gr PP partitions

bigedp51 · Sep 17, 2015

DrMike

I'm not worried about San Juan Island, my last name is Horton and my Canadian cousin Tim Horton restaurant locations are pictured below. I'm worried my Canadian cousin Tim is sneaking up on Washington DC again trying to surround it and burn it it to the ground "AGAIN".

And all this because Mel Gibson only took 2 hours and 45 minutes to defeat General Cornwallis and win our Independence from King George and England.

So I only have one thing to say to my cousin Tim from Canada.

Just kidding Canada, but we Americans do make the best beer in North America. :wink:

P.S. baltz526 and back on topic, I never have a problem getting my beer to fit in the proper size glass or mug. :grin:

DrMike · Sep 17, 2015

bigedp51":1f2wlfb0 said:
I'm worried my Canadian cousin Tim is sneaking up on Washington DC again trying to surround it and burn it it to the ground "AGAIN".

Sneaky rascal, ain't he?

baltz526 · Sep 17, 2015

With the 180gr PP Partition I can fit a maximum of 81gr of Retumbo. The trend is, 84gr will fit with a 165gr flat base. On Paper Hodgdon data for the 200gr Partition looks interesting.

hubcap · Sep 18, 2015

baltz526":2uuv51xd said:
I saw a 300 win mag load for Hodgdon Retumbo with the 200gr Partition. the starting load was 79 with the max at 84gr. So I got out a Winchester test case I have cut a relief in neck for oal bullet tests Filled it up to base of shoulder, set the Partition. Kept reducing powder charge until I could seat a bullet at 3.340" with firm pressure. Then weighed the powder to find max powder capacity or 100% capacity with the 200gr Partition in a standard length Ruger 77. Powder weight was 72.5gr I had to dig the powder out of case to give you an idea how much pressure I was using on bullet. I can see no way a 300 win mag case will fit 80gr of powder with a standard oal, But the data was set for Winchester cases and 3.340oal and the 200 gr Partition with Retumbo.

Be honest with ya, I don,t believe the hodgdon data. At 3.340 the 200 PT would be seated .365 below the bottom of the neck. Where did hodgdon put the powder? I do not load any bullet down to 3.340 in my rem 700 top loader. My 200 PT.s are at 3.560 with about .015 jump. I,m still seated .135 below the neck bottom. I guess if you have a removable box mag. then 3.340 OAL must be used. But not retumbo. Maybe IMR4831 or something faster burning then retumbo.