Working up a load

V

VBRshaffer

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I was in a debate with my father on the most efficient way to work up loads. He believes that working the powder first then bullet seat depth is the most efficient and I believe starting with the most accurate load tested doing the bullet seat first then working on the powder charge second is the most efficient way to work up a load. I was just woundering What some of your opinions were on this subject and why you feel that it is proper way to work up loads? Also when would a good time to test primers?

On another note how do you test primers other than shooting groups. I assume that if you crono your loads that the one with the least veriant in speed would be your best load then tune the bullet seat for group?
 
I have been told on this forum before to seat the bullet hard into the lands, then work on powder charge until groups are looking pretty close. Then back the bullet out of the lands in .005 intervals until I see the where it is shooting the best and fine tune. This way you only have one way to go with the bullet. It was sound advise because it works pretty well.
 
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VBRshaffer said:
I was in a debate with my father on the most efficient way to work up loads. He believes that working the powder first then bullet seat depth is the most efficient and I believe starting with the most accurate load tested doing the bullet seat first then working on the powder charge second is the most efficient way to work up a load. I was just wondering What some of your opinions were on this subject and why you feel that it is proper way to work up loads? Also when would a good time to test primers?

On another note how do you test primers other than shooting groups. I assume that if you chrono your loads that the one with the least variant in speed would be your best load then tune the bullet seat for group?
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I'm with your Dad. Powder [actually, powder, brass, primer, bullet, barrel combination] first, then fine tune with seating depth and neck tension using a full length die with bushings.

There have been many articles written on primer testing which included the author's results. Try this as an initial source: http://riflemansjournal.blogspot.com/p/articles-index.html and then go here: http://www.jamescalhoon.com/primers_and_pressure.php and then continue your research.

There is nothing magical about a chronograph and you certainly don't tune with one. Once you've got bullets going through the same hole with your tuned load method, then if you want to know what the velocity is for historical purposes, chronograph it. :)
 
Changing two variables at the same time is usually ill advised. What I usually do is rely on experience as to where a particular type of bullet has shot the best before, to select a test seating depth for evaluating powder charge, but before I do that, I do a pressure test, one shot per charge, with the bullet almost as far into the rifling as it can be, without being pushed back as the bolt is closed (using the neck tension that I will use for my actual loads). I back it out about .003 from this point to make sure that I do not pull a bullet if I have to unload the rifle. Once I know what my charge weight limit is, at the seating depth that will produce the highest pressure for a given charge, I look at the target that I shot the test on (carefully, over flags) to see if there are any indications of a promising charge weight, based on clusters of shots. I start my next stage of investigation at the middle weight of the best looking cluster, and if I have some experience with a bullet, or bullets of similar design, change to a seating depth that has worked the best, to continue my refinement of powder charge, using two shot groups, until I see something worthy of more shots per group. With good conditions, if I have shot two shots well, as quickly as possible, and the flags held as I did, and the grouping looks bad, a third shot is not going to make it look better. I also keep in mind the probable interval between accuracy nodes as far as powder charge is concerned. For instance, I have been told, that for a typical 6PPC that nodes are about 1.2 grains apart, and my experience has confirmed this. So if I see paper between the bullet holes in a two shot test group, I may assume that I am somewhere in the middle of two nodes, and instead of fiddling around with smaller moves, consider how close I am to my max charge, and make a .6 gr. move up or down, and try another two shots. If they cut each other, but there is more vertical than I like, I will make smaller adjustments from there, and if I get no vertical difference in a group with more shots, but get a wider group than I think that I should have gotten, given the wind, I may adjust to put a touch of vertical in, to reduce the wind sensitivity. I got this from a lot better shooters than I am.

One more suggestion about shooting groups. Don't even look for a shot until you have the rifle reloaded and are in the process of aiming it. You can loose a condition (the wind may shift) if you study your shots as you take them. Those bullet holes are no going anywhere. Get your rifle ready for the next shot, and if the flags are holding, take it.
 
Thank you

I wanted to thank you for the quick respones to my questions. i will be working on load this weekend comming i will let you know how it goes thanks again
 
if this is for your long range rifle...short range results do not ensure long range results...

you need to test at something other than short range....if you base your final load on short range results you may not be happy in the end.


mike in co
 
Boyd Allen said:
that for a typical 6PPC that nodes are about 1.2 grains apart, and my experience has confirmed this. So if I see paper between the bullet holes in a two shot test group, I may assume that I am somewhere in the middle of two nodes, and instead of fiddling around with smaller moves, consider how close I am to my max charge, and make a .6 gr. move up or down, and try another two shots.
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That's good advise. I waste a lot of time, bullets, and powder, making moves so small that it doesn't make a difference, but I never really stopped and thought about changing it.
 
If you can find a seating depth that shoots a mild, medium, and hot load close to the same point of impact; that is the correct seating depth. The method to find that depth varies with different shooters. Jack Neary starts at full jam and shoots three different groups with the 3 powder charges mentioned above. Next come .002 or .003" off jam and repeat. Then .002 more and shoot. Repeat until the bullet is "jumping" at least .005". When looking at all of these groups, it will be evident which seating depth will give the most flexibility with various powder charges. Tony Boyer uses a different starting point for seating. He starts with "just barely touching the lands and tests by moving into the lands by the increments listed above. If nothing seems to work he will try coming out of the lands, but he told me that he does not like to "jump" bullets. This seems like a lot of shooting to determine seating depth, but it works for the top shooters. Also, by watching the flags and shooting with no more than 2 hours of change, one can find the load that works best in the wind. Good shooting....James

PS- I left out the hard part, i.e. don't "hold" for the minor changes to keep a good group. Shoot with the same hold for all shots while watching the wind flags. With this one can see which load provides more forgiveness in changes in the wind. Keep records. If you happen to have a "table manners" mistake such as jerking the trigger.....make a note of it and don't try to compensate with a different point of aim.
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James when you say two hours, are you referring to testing a load with the wind coming from 7 o'clock to say 9 o'clock but no wider range of wind angle within a group?
 
Listen to the MAN!

James, That is as fine a description as I have heard how to work up a load. You swamp slithers from the bayou obviously do other things then wrasslin gators and tearing the heads off of crawfish. Thanks! Tim
 
Good job James. This sport never ceases to fascinate me. I can usually find the right load or close to it. The problem I have is keeping the load worked up all weekend long. There is a gauntlet of demons lurking around at a bench rest match that will make you question whether you might have chosen the wrong sport. The next Topic of discussion should be....."How to deal with the BR Demons"



Glenn
 
I can't take credit for this method. I am just restating what I heard from Tony Boyer, Jack Neary, Joe Krupa, and other HOF shooters. They have proven this method on the various ranges throughout the US. Good shooting....James
 
Due Credit

James....as you know, "Hear say" is admissible on this forum. Very few HOF shooters post their secrets on this Forum. A lot of the stuff you read on this site is posted by people who don't shoot Benchrest. I suggest that It pays to listen to an actual Benchrest shooter as opposed to somebody who may not have understood what they heard. There is an old saying that goes like this.

"You can't teach a person how to hit,if you never played Baseball"

Thanks for posting.



Glenn
 
Mike, I have found that a load that shoots well at 100/200 yards consistently will shoot well at any distance for which the bullet is designed. Also, a load that won't shoot well at short range WILL NOT shoot well at 600 or 1000 yards On Sat., March 16th, I will shoot in our first 600 yard match of the year. I will shoot 105 gr. Hybrids pushed by 32.5 grains of Varget in my Dasher. I have not fired one of these at 600 yards as of today. I will not fire any at 600 until Sat. morning before the match. I am not worried about their accuracy because they shoot well at 100 yards. Good shooting....James
 
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james the great

Thanks James for reposting all the info you have gathered over your yrs of shooting. I am going to use this process for working my loads up from now on. You have saved me alot time and money and i thank you.
As for what shoots good at 100 /200 will not always shoot good at 1000 I have seen this in person with fellow shooter with way more experience than me. he made one raged hole at 300 yds and was over 11'' group at 1000. to say the least he was frustrated over this because in theory that group should have held 5 to 6 inches at 1000.
 
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