Loading Data; Starting Loads?

[antelopedundee]

How close to the lands are you when this happens to you?

That's not always a bad thing since when fireforming cases like 6.5-06 Improved from 6.5-06 you want stiff loads with the bullet slightly jammed into the rifling. When the firing pin hits you don't want the case to move.

 

[std7mag]

True, but with the bullet in the lands your going to spike your pressures. Butter to do so with a mid to lower charge, of the powder you intend to shoot.

 

[Brian in Montana]

The very first load I loaded for 7-08 was one of the most accurate. It was using the very lowest charge - Varget and 140grn Accubonds, but it was pretty slow. If memory serves right about 2500 fps. I had decided that for a hunting load in that rifle I wanted at least 2700 fps. I kept going up and eventually found a node about 2730fps. I have a lot of notes on everything I did with that test batch and keep thinking of going back to that very first one again just to play with it a little. It was kind of a surprise.

 

[belly-deep]

How close to the lands are you when this happens to you?

I think 0.025” but I’d have to go back and look at my notes. That’s usually where I start my hunting loads.

The thing is, book data is worked up with a certain lot of powder. You’re using a different lot. Some powders have quite a bit of lot-to-lot variation. Others have less, but they still have some.

Compound with the fact that you may be using different brass or a different primer and things get further from the book.

Maybe your gun’s chamber is cut on the edge of SAAMI spec, etc. Maybe your neck thickness is too much.

I usually load 2 each at the first couple charges and then 3 each at the next charges until I hit book max, watching the chrono all the way up. So maybe I “waste” 7 rounds per load work up, although I start with a clean barrel so the first 2 would be fowling shots anyway.

I’ve never had a case stuck in a gun, and I’ve never had a blown primer that way.

 

[belly-deep]

True, but with the bullet in the lands your going to spike your pressures. Butter to do so with a mid to lower charge, of the powder you intend to shoot.

Nosler says a starting load of a fast burning powder (relative to the chambering) and jam the bullet into the lands a bit.

I just plowed through 100 rounds of 280 AI like that, and it came out good.

 

[N2TRKYS]

I think 0.025” but I’d have to go back and look at my notes.

That's what I figured.

 

[belly-deep]

That's what I figured.

I don’t think it makes much difference to seat shorter so long as you’re not touching the rifling at any point.

I loaded up 3 different OALs as a test this summer. Velocity equals pressure, and they all shot an average velocity of about the same speed in my tests.

 

[N2TRKYS]

I don’t think it makes much difference to seat shorter so long as you’re not touching the rifling at any point.

I loaded up 3 different OALs as a test this summer. Velocity equals pressure, and they all shot an average velocity of about the same speed in my tests.

Lol. Ok

 

[Deleted member 28227]

I’d say about 50% of the time starting loads group well.

They are never “the load of choice” though, because they are usually 200 FPS or so below what the cartridge can deliver.

and then there is loading a .264mag where the published max load is 200-400 FPS below what the cartridge can safely deliver... luckily I had two very experienced guys helping me figure out loads because the data on that one is a dumpster fire... I think my current load is 5 grains over max or something crazy.

 

[belly-deep]

Lol. Ok

Seating deeper reduces case capacity, which increases pressure. I’m sure it’s not a 1:1 ratio, but I don’t think it’s the same as jamming a bullet into the lands.

How many rifles have you loaded for?

 

[cahunter805]

Seating deeper reduces case capacity, which increases pressure. I’m sure it’s not a 1:1 ratio, but I don’t think it’s the same as jamming a bullet into the lands.

That's not exactly the case. There have been many tests that show as you seat deeper away from the lands pressure actually decreases for a while and then begins to increase again. Obviously this isn't exact for every powder and rifle combination. The test I saw was a 30-06.
Also that's why many people start load work up on the lands. You will find your rifles max pressure and then changes in seating depth will be less pressure.

 

[Bigjay73]

Seating deeper reduces case capacity, which increases pressure. I’m sure it’s not a 1:1 ratio, but I don’t think it’s the same as jamming a bullet into the lands.

That's not exactly the case. There have been many tests that show as you seat deeper away from the lands pressure actually decreases for a while and then begins to increase again. Obviously this isn't exact for every powder and rifle combination. The test I saw was a 30-06.
Also that's why many people start load work up on the lands. You will find your rifles max pressure and then changes in seating depth will be less pressure.

If it's an already compressed load, you'll see a pressure rise pretty quickly

 

[N2TRKYS]

Seating deeper reduces case capacity, which increases pressure. I’m sure it’s not a 1:1 ratio, but I don’t think it’s the same as jamming a bullet into the lands.

How many rifles have you loaded for?

That hasn’t been the case for me. I guess that’s why you don’t see it recommended to start at the lowest seating depth and work to the lands.

 

[cahunter805]

If it's an already compressed load, you'll see a pressure rise pretty quickly

Just because a load is compressed doesn't mean it will be max pressure. Certainly depends on the powder of choice and also the cartridge your loading. Ever loaded retumbo in a 243win. That's compressed almost at minimum charges. Also I've seen compressed loads with velocity significantly slower than an uncompressed load. It's all about the powder choice and billet weight.

 

[belly-deep]

That hasn’t been the case for me. I guess that’s why you don’t see it recommended to start at the lowest seating depth and work to the lands.

I never recommended that. But you suggested that I had starting loads above max pressure because I was seating them 0.025” off, which is pretty common practice in the reloading world and not something that will cause such spikes.

 

[Don Fischer]

I don't do any match shooting so the best possible velocity doesn't do it for me, adequate does. Now I need to define adequate, that would be right at 1" or better at 100 yds. I have found it easy to got there with all ny rifles except my 30-06 which made it to just over an inch and I called it good, shoot, it's my elk rifle! Ya simply don't need a 1" load to hit a target the size of an elk at reasonable range! Every other rifle I have, six more CF's go well under an inch and I do load as hot as I can and still hit 1". Generally requires some bedding work. My 6.5x55 is a Mod 70 feather weight and goes an inch with fairly hot load, my back up elk rifle! The only thing done to it was adjust the trigger from 5# down to 3#! Mossberg Patriot in 243. Not a thing done to it and it keeps 70 SMK's right around 1/2" with fairly hot loads. I would not say they couldn't be made to shoot better by lowering the loads but why? I hunt, I don't match shoot!

Keep in mind, a rifle likes what it likes!

 

[claybreaker]

"Starting Loads" are called starting loads for a reason... IMHO.

 

[Don Fischer]

I might add one more thing. If you always load to the direction's your manual give you, you will never have a problem with unsafe loads. Just works out that way. Tested and approved by lawyer's!

 

[grandejuan]

I might add one more thing. If you always load to the direction's your manual give you, you will never have a problem with unsafe loads. Just works out that way. Tested and approved by lawyer's!

Another thing to remember, those "so called" max loads" most likely will chronograph pretty slow. You will probably see some significant increases in bullet drop, if you shot groups at 200 or more yards. Bring slower also means less energy carried by the bullet that may or may not matter to your game. FWIW. GJ

 

[Bigjay73]

I might add one more thing. If you always load to the direction's your manual give you, you will never have a problem with unsafe loads. Just works out that way. Tested, watered down, and approved by lawyer's!

Fixed it for you haha. Not that that's a terrible thing