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Developing a new load,how many rounds would you expect to fire? Choose a bullet; load and shoot ten rounds with ten different incremental powder charges (ladder) Try to spot sweetest spot,with highest velocity.Often not as conclusive/easy as I hope! NOW WHAT EXACTLY DO YOU DO NEXT? ps My max. oal .243 Rem. vls is 2.71 I use 2.69. Data tables/manuals all seem to test at shorter lengths . | ||
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I start with the bullet I want to use, see what powders the manuals say will push it the fastest, then do an incremental increase in charge weight to look for pressure signs. Two rounds of each charge, beginning with the starting load data, until either pressure shows or book max is reached. For a hunting rifle, the bullet will be seated for the pressure tests OFF the lands or maximum length for feed and function, whichever is shortest OAL. Any leftover rounds of charge weights that show excessive pressure get the bullets pulled. I then work with deeper seating depths in .005" (.127mm) increments and five shot groups until hopefully a sweet spot is reached. Usually it takes me about 100 rounds to feel sure of the results. But with three shot groups it can be done in about 75 rounds if there is a sweet spot. About 7500 if there isn't. ![[Smile]](images/icons/smile.gif){kind=icon} [ 08-09-2002, 13:49: Message edited by: steve y ] | |||
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I start up like Steve. Except I also make two rounds in a load that is hotter than book max. (sometimes a hotter load is more accurate) I then seat the bullet 0.10 to 0,2 mm from the lands and make seven rounds in each load (like prescribed in the Speer #13 manual) 5 different Loads in 1-2 grs. increments usually finds the sweet spot pretty quick. I have not found that changing a load by 1/2 a grain changes accuracy. Bullet alignment, concentricity does for me. (I check every load by rolling it over a black glass surface) case Prep: Pocket uniforming, flashhole ditto, flashhole deburring. Like Steve about a 100 rounds. is enough. K&B Niels | |||
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I always work up loads either at the range or in the bush. I have 2 presses mounted to a board with Redding powder measure in between. One press with seating die and the other with resizing die. The board is clamped to either the benchrest, vehichle or other bench. I normally set the sizing die so that there will be about .003" headspace when fired cases are resized. One of my objectives in doing this is to have the rifle shoot the same loads and to the same point as when new unfired brass is used. Mike | |||
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Here is a link to the Load Your Own forums, where I've posted my OCW (optimal charge weight) method of load development. I've mentioned that here as well, though I found that the whole concept seemed to part a lot of hair! It works, and it works well. You'll have to let go of some time honored misconceptions, but if you'll try it you will find (as others have) that it's a sound and reliable method of developing not just a decent load, but the best load for your rifle. In most cases, you'll expend about thirty rounds or less total. Go here: http://www.loadyourown.com/ubb/Forum11/HTML/000276.html And also check out the reloading pages at Snipershide.com where you'll find further information. Good luck, let us know how things go... Dan Newberry green 788 | ||
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quote:Excellent post steve. ![[Big Grin]](images/icons/grin.gif){kind=icon} quote:Hey trans-pond, I've probably got more reloading time at the press than Dan has time breathing. His reference to "time honored misconceptions" is a pitifully veiled slam on anyone who is willing to mention that Dan's OCW (AKA Mythical, mystical & magical Universal Charge - MUC Load concept) is full-of-beans. I do agree that there is a Best Load for each and every firearm out there. And the law of probability mandates that out of all those millions in the same caliber, there will be a few that prefer the same Load. But to think there is a MUC Load in each caliber that is the "Perfect Load" for that same caliber in ALL firearms is simply in-experience making a laughable, ignorant statement. Notice that is not a "veiled reference" to the MUC Load concept. Back before Dan was born, there were a couple of products on the market that could help him with his "parted hair" - Wildroot and Brylcream. But of course, his hair would not be "parted" if he paid homage to the the very old, experience proven, time honored, reloading methods of those who have gone before all of us. I use a few more Test Bullets than steve mentioned, but that is just me. I've no doubt it is possible to get a fine Load in as few as 75 bullets IF everything goes well. Best of luck to you in your Load Development. [ 08-09-2002, 17:40: Message edited by: Hot Core ] | |||
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Hot Core ! You foget something!!! HOW YOU DEVELOP A LOAD ![[Roll Eyes]](images/icons/rolleyes.gif){kind=icon} .Anders �sterberg | ||
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I,m likely not as scientific as most but seem to get a few decent loads over the years. I start with the bullet that will fit the application and pick as slow a burning powder as will not be compressed at max load. I then look at at least 3 data sources and start a load at 3 gr below max in a magnum and 2 gr below in a standard case. I seat to 20thou from the lands and shoot a three shot group. If it is decent I duplicate it. If not I switch bullets immediatly. I find that the bullet has 90% of the influence on accuracy. Finnaly I will chrono the load to see if it meets my expectations. I will then increse at 1 gr increments to max, then check accuracy again. On a decent rifle I can get a decent load in 30 rounds. I sometimes have to try 4-5 different bullets to find the right load but usually 2 powders will suffice. BR | |||
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quote:Hey +P, The "short version" is similar to what steve posted. Basically what you can find in any good Component Manufacturers Manual. For a slightly longer version, I've refined those methods a bit to fit my criteria of determining where the SAFE MAX Pressure is located and where the Harmonic Convergance is for the specific case/primer/bullet/powder combination in each specific firearm. For example, I start with Match Grade bullets Seated to Kiss-the-Lands and increase the Powder "IF" the Pressure Indicators allow me to do so. I do this while I watch for Harmonic Convergance(the Audette Method) as the Powder level is increased. This basically Benchmarks the firearm to let me know it's accuracy potential. Occasionally a rifle shoots the Hunting Bullet better than the Match Grade bullet. Beats me as to why this happens, but I've got one rifle right now that is this way. (If you understand Bullets, this really makes no sense at all.) I repeat this with 4-5 Powders picked just as Steve does to see if one performs better than the others in this specific firearm. Then I move on to the specific "Hunting Grade Bullet" I want to use. With a bit of luck, it will be similar in weight to the Match Grade bullet. I work the Hunting Bullets toward SAFE MAX and again watch for the Harmonic Convergance. Once I know where it is for that specific Load, I begin varying the Seating Depth to tighten the Harmonic. I usually use the Load that provides the best Harmonic Convergance found below the SAFE MAX level. If however I can SAFELY increase the Powder 2-3gr from that point, remain under the SAFE MAX and only loose 0.25" on the Harmonic, then I'll go with the higher performance Load, even with it slightly less accurate. I always use fully Prepped Cases and Match Grade Primers(when possible). I see where some folks believe Prepping Cases is a total waste of time. If they see no "benefit" from it, then I agree they should quit wasting their time. As for me, I'll continue to use fully Prepped Cases in ALL my Loads. It gives me a bit more "confidence" in the final Load which makes it worth doing for me. So, I do use a few more bullets than steve, but I enjoy getting the "Trigger Time", so I don't normally count how many I'm using to develop a specific Load. Once I get the Hunting Load I like, then I go to 1-shot groups from a cold, clean, lightly greased barrel to duplicate the condition of my rifle afield. Just did that yesterday and my "new" 308Win Hunting Load for this year made a nice 0.55" combined three 1-shot groups from the bench. Now I get serious on field position shooting. That is a bit more than trans-pond originally asked for and it dosen't answer his original question of "how many". But, I hope it answers your question and made some sense to you. Best of luck to you. [ 08-10-2002, 05:04: Message edited by: Hot Core ] | |||
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| <green 788> |
Hotcore, You mentioned: "If however I can SAFELY increase the Powder 2-3gr and only lose 0.25" on the Harmonic, then I'll go with the higher performance Load even with it slightly less accurate." I'm fairly certain that you can alter the seating depth of the bullet slightly after gaining those 2 to 3 grains, and you'll get back onto the harmonic node. Maybe you've tried this and it hasn't worked for you, but I've had good luck doing it this way. Take a look at this thread from last month. I have found, like Buzz has, that OAL tuning after optimal powder charge is determined does tighten groups. http://www.serveroptions.com/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=6;t=005191 Anyway, take care and be well, Dan [ 08-10-2002, 05:21: Message edited by: green 788 ] | ||
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quote:Hey Dan, I completely agree with you on this point. I do go back and try varying the Seating Depth and you are correct, sometimes it does allow you to improve the Final Load. Best of luck to you this Deer Season! | |||
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For decades, I've followed the above load development routine. I recently had my bad shooting (2 MOA) Win 70 in .338 Win Mag rebarreled with a premium Lothar Walther and tried the reversed process. That is, I selected powder, 2 bullets and a starting load for each. I then fired 3-shot groups with bullets seated progressively deeper. Next session saw me with the same seating depth that had given the initial best groups and I started increasing charges by .5 gn. Within 58 rounds, I had eliminated a bullet the rifle apparently didn't like (1.37 MOA)and confirmed a load that grouped 5 x 250 Sierra GK into .72 MOA  Call it luck, maybe ? One experiment doesn't make a law, I know but I'll try it again anyway with my next development. BTW, I was amazed at how the Lothar Walther bbl. reacted at once to a minute change in seating depth or a .5 gn powder. [ 08-11-2002, 12:44: Message edited by: Andr� Mertens ] | |||
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