Author Topic: Parameters to use to find a good load.  (Read 296 times)

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Offline GrampaMike

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Parameters to use to find a good load.
« on: March 07, 2008, 02:27:03 PM »
Parameters to use to find a good load.  (rules are general unless rifle, pistol or revolver is specified by you rule)

Over the years of reading/shooting/loading about hand-loading and accuracy from the experts and the not so-experts what rules-of-thumb have you followed?  For example:

1.  Only use loads from accredited load manuals.

Following to only narrow selections from Rule 1.

2.  Keep the load density between 80% and 95%.
3.  Keep the load pressure between 75% and 87.5%.
4.  Keep the percent of powder burnt to the minimum of 95%.
5.  Keep bullet x (this number seems to vary) thousands of an inch from the lands.

I have always wondered which ones have been proved, which ones are from observation, which ones are just hoping.

What are some that you know that work?

Mike


Grampa Mike
U.S. Army Retired

"Say what you mean, mean what you say"
Father of 2 GREAT sons, and 9 grandchildren.

Offline Tom W.

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Re: Parameters to use to find a good load.
« Reply #1 on: March 07, 2008, 03:19:33 PM »
The easiest thing to say is to follow the loading manual.


 After you get that part down, you can then branch out a bit.
 A lot of what people call "unburnt" powder isn't what it seems.
 You didn't specify if you're referring to rifle, pistol, or revolver, so a general blanket will have to cover. It's best to use a powder   that will fill your case in such a manner that a double charge will overflow. Maybe a bit messy, but better than a blown firearm.
I make up a dummy cartridge  with a bullet that was previously colored with a magic marker, to see how long to seat my bullets in my rifles. It can go from ridiculously long in my NEF, to a specified  length in my re-chambered 30-06 a.i.
That works well for me, so that's o.k.

Remember, this isn't rocket science, you're just safely launching a missile. ( O.K., maybe it is...)

But the best thing for most people is to follow what's printed in the most current loading manual that you can get. The powder manufacturers have theirs, and the bullet manufacturers have theirs.
Tom
Alabama Hunter and firearms safety instructor

I really like my handguns!

Offline Catfish

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Re: Parameters to use to find a good load.
« Reply #2 on: March 08, 2008, 04:24:32 AM »
There are to many variations to follow set rules. I shoot alot of Bullseye in handguns and your case is abt. 20% full at most, very accurate. I also shoot alot of Win-296 in handguns where pressure is near max. also accurate. I have had guns that shot best with the bullets jammed into the rifling's and others that shot their best with a jump of .030 to .040. Some gun only do their best with 1 load and others seem to shoot anything well.

Offline LaOtto222

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Re: Parameters to use to find a good load.
« Reply #3 on: March 08, 2008, 05:53:17 AM »
You could write a book on this subject :o I start with data out of a load manual. I really like the Hornady and Speer manuals best, but also use Sierra, Nosler, Lyman, Hodgdon and then I have a bunch of older manuals that I refer to also. I pick out a likely load. One that includes a bullet,powder, primer and case that might work. I start with the lowest powder levels and load them up in small increasing increments. The increments are decided on by the case capacity. I load to the standard OAL recommended by the load manuals. If I find a load that looks promising while working up the load ladder. If I do not find that any thing works out, I start over with a different powder or bullet at this point. There is no use trying different bullet seating depths if you can not get it to shoot straight at standard OAL. If I find some thing that looks good - I can tweak the load a little to see if that helps. I then start working with OAL unless it is a pistol cartridge (those I leave alone for OAL). I find out how far out I can put the bullet, then determine how far out I need to step my cartridges, depending on how far I have to go. If I start getting close (less than .020") to the lands and the loads are looking good, I back off the powder charge about 5% and watch for over pressure signs. If you can not find a decent grouping with this combination, then I start over with a different bullet or powder and go through this all again. After you fine tune a load this way, you can experiment with primers. Just remember if you used a standard primer to develop the load and you go to a magnum primer, back off the loads again and work back up. I generally use Remington 7 1/2 primers for my small capacity rifle rounds to start with. Many loading manuals use this primer and for good reason, they work consistently and are relatively cheap. How far to back off depends on where you were to start with. If you are at the top of the recommended powder charge, then back off. How much depends on the powder being used and capacity. Unfortunately there no set thing to do, like always seat bullets into the lands, always use this bullet, fill the case up to 95% or more with powder. Every gun is a thing unto itself. Even two identical guns one made right after the other can like different loads. You can make generalizations, but that does not mean your gun will fit them. Like use a powder that fills the case or nearly fills the case; this is generally true, but not always. Seat your bullets into the lands; This is true of many bench rest rifles that have been HIGHLY tuned and painstakingly prepared loads but not guns in general. Out of the many varmint rifles I have, 1 shoots best into the lands. Most I have found do better in the .040" - .020" range. Go figure, but that is what makes it a challenge.
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