Load Development questions

[squeekieslayer]

After researching all the different ways to work up a good long range load I had a plan set out in my head... then I read this page and it was basically a good summary of what i had gleaned from research and was essentially what i was planning to do.

what do you guys think? http://wildernessmeans.com/articles/hand-loading/hand-loading-for-long-range/powder

I figured after the second ladder I would use the next round with 5 bullets each to also Chrono for an ES to compare ES, Velocity and groups within my "sweet spot." Then work with the jump.... And then possibly another powder trial slightly above and below what i find in the first few rounds rounds.

Anything you guys would add? Anything you would skip? Change? Modify? Different idea all together? haha

Also, I know he advocates a .010 jam to start, then work away later.... But with this being a hunting rifle, would it be a bad idea to "jam" that much?

For what it's worth, it will be a Browning A-Bolt, 7mm rem mag, stock 26'' 1:9.5 twist barrel, McMillan stock, new trigger springs, and a modified magazine that will easily allow me to cycle bullets seated way longer than I would need to "jam" the bullets into the rifling. I have Berger 168 VLD bullets, Retumbo powder, and Winchester Mag Primers... and since these are all I have, they are going to have to be "standard" for now. I would love to play with half a dozen powders and primers... but you know how it is trying to track that stuff down.

thanks

Joe

 

[wapitibob]

Smartest thing I ever did was shoot a ladder at 400 yards. I started with book max and loaded there and down in .3 gr increments for 10 rounds then loaded up another batch and shot a 2 shot ladder going up in charge weight then back down. I'm .015 off the lands.

 

[squeekieslayer]

Thanks Bob, originally I was going to just concentrate on ES per the Gunwerks web page, but with further reading it seems that leaves out a LOT of variables. The other method I see has a good following is Dan Newberry's OCW test. To me it seems like it may be a good way to fine tune a load after doing 2 ladders to really narrow down a node.

Joe

 

[gelton]

I ran across Newberrys OCW test from someone that posted it here on Rokslide not too long ago and I am looking forward to trying it soon. If it were me, I would do his test first to find optimal charge weight and then a ladder test to find optimal COAL. According to Newberry (of course) this is the best way to do it.

 

[aron]

I don't have any interest in jamming bullets on a hunting rifle. Hear stories of guys trying to remove the unfired round and the case is extracted from the chamber leaving the bullet still jammed in the barrel

 

[squeekieslayer]

I may do that, I have gone back and forth about that. My hang up is that when i see the examples (even the ones he posted,) I have a hard time figuring out why he picks the groups he does as the ones that are best.

Another thing, I am not sure I understand how a ladder test would tell you anything if all you were doing was changing the COAL. I know that you will get slightly less velocity the more you jump, but I read that the COAL was more or less independent of powder charge. So my feeling is that you are not really looking for a "node" but rather what jump tightens the group the most while varying the jump. The ladder test finds the node where your charge is most resistant to variation in case size, powder, temp etc.

I.E. Use ladder or OCW to find the best, most consistent powder charge... then use group size to determine best jump at a given jump size.


Maybe I am wrong though, this is my first time around

Joe

 

[squeekieslayer]

I don't have any interest in jamming bullets on a hunting rifle. Hear stories of guys trying to remove the unfired round and the case is extracted from the chamber leaving the bullet still jammed in the barrel

That is what i figured. I assume that once i had my powder charge I would try to find the best grouping jump OFF off the lands afterward. Again, this is assuming that the accuracy gained/lost by jumping the bullet is INDEPENDENT of powder charge. In the article is just says that starting jammed is a good consistent place to start and it is the safest because then for any given load, you do not run the risk of causing too much pressure. Essentially, all you can do is move away from the lands, thus lowering pressure, therefor you do not run the risk of having what you think is the max charge blow up on you because you just went from a .010 jump to a .010 jam.

Joe

 

[KMD]

That is my understanding also, Joe.

Test LR loads with a jammed bullet to determine pressure threshold and get a feel for accuracy potential.
Once pressure is found and powder charge 'node' is established by analyzing vertical dispersion at distance, then one can move on to messing with seating depth. Incrementally backing off seating depth in .005 or .010" steps will test if/how bullet jump affects accuracy, and you have that baseline data of a jammed bullet to compare it against. And moving in that direction, away from a 'jammed' situation, will result in a lower pressure round. IE, toward the direction of safety. Makes good sense to me.

Not advocating using 'jammed' rounds for actual hunting, the potential problems have been stated. But 'jammed' rounds are a useful tool for establishing a baseline to compare your subsequent loads to, during the developmental process of load testing.

 

[Sam Millard]

I will offer my opinion based on a lot of personal experience loading for long range hunting rifles. First of all, never start or end your load development with the bullet anywhere near touching the lands, which is to say closer than .010". It makes no difference if you test max pressure at -.010" or +.010", nor will backing out of the lands always lower pressure. Pulling an unfired case full of H1000 out of the chamber while the bullet stays in the lands is not cool If the bullet won't shoot well at least .010" off the lands, try a different one. I've personally never seen any bullet from Sierra, Hornady, Nosler, Berger, etc. NOT shoot well that far or further off the lands.

My personal load development for my rifles and some friends' rifles has always gone like this...load 3 batches of 3 rounds with the bullet and powder of choice. Load said bullet .010" off the lands. Start the powder charge 1.0 grain below "published"max (book max, max loads averaged from info on the internet, friends, etc.)and work up to max in .5 grain increments. If pressure doesn't show at max, load one 3 shot batch at a time, .5 higher, until pressure shows on one or more cases. Step back .5-1.0 grain for the max load in that rifle. These are all shot at 100 yards with a chronograph. If the velocity is too low, the 3 shots don't hold 1/2" groups, or the ES is much higher than low teens, I scrap the load and start over. If the load looks good, I load and shoot 3-4 more 3 shot groups to verify the load. The reasoning for this is if a load won't shoot well at 100 yards, why bother shooting it at distance? 1 1/2 MOA groups at 100 yards will not tighten to 1/2 MOA groups at 1000...

Once I find a load that meets the above criteria, I load 20 or so rounds. Depending on my schedule, I might immediately take the rifle out as far as I plan on shooting it. If not, I'll do a cold bore accuracy/velocity test. Fire 1 shot and retrieve the target. The next day, week, whatever, fire a second shot on the same target, then repeat for the 3rd shot. If the accuracy and velocity hold for this, it's definitely ready for the long shots! 100% of my load development is done in prone with a bipod/rear bag.

I don't have a problem with ladder tests or OCW tests, but I think they can add variables to a process that already has enough of them. I think most folks start their powder way too light, too. High velocity, high BC, and low ES are the name of the game in long range hunting. Don't waste time and hard to find components working around the lower edge! There is so much information out there these days, on forums like this for example, that it just doesn't make sense to start low with a charge in a rifle you plan to shoot high! There are bullet/powder combos that are popular for a reason and shoot very well in lots of rifles. Try to stick with or close to them.

Probably the most important thing you can do for yourself, regardless of how you proceed, is keep detailed notes on every step taken. Include lot numbers, neck tensions, shoulder bump, case measurements, etc. Note the atmospherics when the shots are taken and whether or not you were on your game that day. Basically build yourself a data base on your rifle and load to reference later. It would be a shame to come up with a hard earned load, just to find out you can't duplicate it 6 months from now!

 

[Broz]

nor will backing out of the lands always lower pressure. !

This should be noted. I see it over and over on the net and I am here to agree with Sam, from first hand experience, pulling a bullet away from the lands and further into the case taking up case volume can and will increase pressure in some instances. I too sart them away from the lands and work from there. I take large steps (.030") in seating depth to get an idea of what the combo likes then fine tune with smaller steps.

Also one needs to determine what a person calls "Jammed" I see many hunting rounds for long range seated touching, as well as .005" into the lands, result in good accuracy. I have never had an issue extracting a loaded round .005" into the lands . But it is very important to use good measuring equipment and know exactly where touching and .005" into the lands are. That said most of my long range and ELR rigs are loaded between .015" and .060" off the lands. Just a matter of finding what your combo likes.

Jeff

 

[KMD]

Absolutely, if you seat a bullet too far into the case, that bullet will infringe on useable case capacity enough to become a factor with pressure spiking. Continually seating deeper into a case the point where pressure will begin to spike, as you are now exploding the same amount of powder in a smaller volume of area. That will indeed drive pressure UP.

However, with a properly throated rifle, this is a complete non-issue. Reason being, there isn't any need to seat a bullet deeper, just for the heck of it. And wasting that precious case capacity on bullet mass, over powder storage, makes no sense at all. With a rifle throated to run a particular bullet, deep seating bullets to the point where pressure becomes a factor simply does not factor into the equation. And if a rifle won't shoot a particular bullet within .020" of the lands, there is something that needs addressed. IE, different bullet, different reamer specs, etc...

Should add, as I feel its pertinent to the discussion:
I have my rifles throated appropriately, to where I can stay well within .030" off the lands and still cycle & feed rounds, throughout the life of the barrel. IMHO, if you have to jump a bullet much beyond that from the beginning, the throat is already too long. Unfortunatley, that phenomenon has to be dealt with, when loading for factory rifles with 'lawyer proof' sized, max. SAAMI chambers. But, that's the beauty of custom rifles...you can have your chamber spec'ed the way you want, and don't have to mess around and toy with jumping bullets umpteen thousandths off the lands to find happiness, or reliable feeding.

I can see how 'cutting to the chase' and starting @ .010" off the lands makes sense, and I do that sometimes myself. With a well built rifle, sound loading technique and good bullets, there is likely happiness to be found quite easily. Absolutely nothing wrong with that approach. But, that is not to deny the potential merits of starting 'jammed'.

Again, to be perfectly clear.
With the same powder charge, going from a 'jammed' bullet, to one seated .010" off the lands, the latter will have a lower pressure. And seating deeper beyond that will continue to decrease pressure, to the point where the infringment upon powder capacity over-rides the 'pressure relief valve' effect of a jumped bullet. Which, again, will not be a factor if your rifle was chambered in accordance with your chosen projectile...

Arguing semantics now. Use whatever works for you. Just making it apparent that there's no right or wrong answers when it comes to personal preference...its just what you prefer.

Good luck, be safe & good shooting!

 

[gelton]

Once again great info from Sam and Jeff. No doubt that seating a bullet further from the lands will increase pressure as long as it wasn't jammed to begin with (which causes pressure to rise). Funny thing is that I have been running a variant of what Sam says for a long time just that my new discovery of the OCW test got me a little intrigued to try it.

 

[Broz]

Berger may just know something about this. Here is a recommended method to get the best accuracy from your rifle with a VLD. Note seating depths can vary quite a bit and they suggest you cover a wide array of tests. I have used this methods and found it to work well. Thus the reason I start with .030" steps. Again most of my rifles are seated under .060" from the lands, but as indicated in this article from Berger I have seen rifles shoot very well at .1" plus off the lands too.

http://www.bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/

EDIT to Add: It has been my experience that the pressure rise often encountered while seating the projectile deeper in the case can occur quickly in some cases. This is more prevalent among true long range specific rifles where long high BC bullets are used. This includes custom designed reamers where we only intend to have the bearing surface of the bullet in the neck and only the boat tail into the powder column of the case. I have mostly seen this in cases where a high percentage of the case is filled with powder. For example a 300 win with a tactical match reamer and a longer throat, while using a 215 or 230 Berger. In this scenario where a powder like H-1000, Retumbo or other slower burn rate offerings are used, the available free space in the case is very limited. So at times even a relatively small move of the bullet to a deeper case depth will raise pressure. Also if brass of lower case volume like RWS or Bertram is used it aggravates this issue. This has also been seen in our 7mm-300 win builds with 180 gr plus bullets. I do believe the reason that some shooters may not have experience with this is it is a more specific problem to true long range specific rifles or where someone is trying to load for a short mag box with long bullets. In true long range rifles bullets are often longer and calibers often larger. Thus a bullet move of even only .020" or so will displace more free air space in the case than that of the same .020" of the smaller caliber bullets. I also feel this effect could be often overlooked by hand a loader that have less experience reading pressure signs or do not have access to strain gauges.

Jeff

 

[squeekieslayer]

Berger may just know something about this. Here is a recommended method to get the best accuracy from your rifle with a VLD. Note seating depths can vary quite a bit and they suggest you cover a wide array of tests. I have used this methods and found it to work well. Thus the reason I start with .030" steps. Again most of my rifles are seated under .060" from the lands, but as indicated in this article from Berger I have seen rifles shoot very well at .1" plus off the lands too.

http://www.bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/

That is the article I have printed out and planned to use once I had determined the powder load I was going with. It just seems there are a lot of ways to decide that powder level. The ladder just seemed like a way to avoid having to shoot a ton of bullets.

I would love to hear any other options or methods you guys find effective.

Thanks Sam for your input... I like your idea because I think I like shooting "groups" better... even if it is just because its more fun than shooting at one spot to make a ladder.

Joe

 

[squeekieslayer]

Sam, your method looks great... I am only concerned about 1 thing, I ony have one type of powder. I am on the wait list for a couple others. I know that one wants to shoot the max load and have that be the most stable and accurate load, but I am afraid that if I don't look at loads different than max I may miss the sweet spot for the only powder I have access too right now.

that said, I am a total rookie to load development, and it may be that most loads are most effective near their max anyway... like a bow cranked to its max poundage is more efficient.

Joe

 

[Sam Millard]

Sam, your method looks great... I am only concerned about 1 thing, I ony have one type of powder. I am on the wait list for a couple others. I know that one wants to shoot the max load and have that be the most stable and accurate load, but I am afraid that if I don't look at loads different than max I may miss the sweet spot for the only powder I have access too right now.

that said, I am a total rookie to load development, and it may be that most loads are most effective near their max anyway... like a bow cranked to its max poundage is more efficient.

Joe

I completely understand your dilemma. Having said that, certain combos work very well for a vast majority of people. If I were you, working with a powder that's not in the "mainstream" for your application, I would still do it the same way. If you are using a powder that may be temp sensitive, be sure to test that before shooting it at one extreme or the other. I will admit that using Hodgdon Extreme powders is almost cheating in that category!

If I were to do the ladder test, I would do it round robin and do it 2 or 3 times anyway. In the end, it would be like shooting groups I usually need 100 rounds with good data before I relax and just start shooting. I realize that most folks probably won't shoot that many rounds in a whole season, but serious long range shooting demands it.

Whatever you do, don't lose sight of why you're doing it. Sometimes it makes sense to just go out and shoot at distance rather than tweak that load down another .1 or .2. My rifles are constantly reminding me that they shoot better than I can!

 

[squeekieslayer]

Thanks again Sam, I do find that most of the research I see with retumbo and VLD 168's in a 7mm RM ends up being around 71 grains. Maybe I can skip to doing what you described to just find the group around max with the least ES and good groups.

Essentially, Turn the ladder test into a shorter ladder test toward max end of the load and do it 3-4 times rather than just one. That way I could look for the "node" that they all talk about on LRH, but still get an idea on groups... not to mention more samples at each load to get a better idea about ES and grouping.

Joe

 

[KMD]

If anyone has Quickload program, it is noteworthy to indicate that QL recommends ADDING 7200psi to initial start pressure for bullets engaging the lands. IE, a 'jammed' bullet has to pay a pressure penalty, that a jumped bullet is not subject to. That is precisely the reason why going from a 'jammed' condition to a 'jumped' condition will show a resultant decrease pressure, and smaller initial pressure spike.

Not arguing opinion here, this is scientific fact. If someone has pressure data that proves QL incorrect, I would welcome the opportunity to reference that information.

As far as seating a bullet deep enough to build up past that ~7200psi start pressure penalty, I crunched some #s on a few cases in QL, and found that I needed to seat upwards of .250" DEEPER to increase case pressure up that high, again! Just illustrating how far some cases will allow deep seating before building the same pressure that a 'jammed' bullet does from the outset.
This situation is exactly why I find it advantageous to determine pressure threshould with a 'jammed' bullet condition. This is the same logic laid out in the OP's link, based on measured data.
Mapping out pressure signs with a 'jammed' bullet allows the relaoder a pressure safety margin, by default, when seating back off the lands to a workable distance.

Again, I would welcome the opportunity to reference information that contradicts this scientific data. And I'm sure the huge ballistic brains @NECO would like to know that their Quickload program is fatally flawed in design.

I would encourage anyone with QL program to mess around with the seating depth of their load, to see how far you need to seat a bullet to net a ~7000psi increase in overall case pressure. Most assuredly, it will be ALOT deeper than you'd every want to 'jump' a bullet from.

Most importantly....be careful working up loads for ANY rifle!!! That is why I'm trying to cast a different colored light here, to encourage thought and discretion about this topic!

Watch for the the telltale signs of pressure! Heavy bolt lift, falttening/cratering of primers, levelling out of velocity gains with increased powder charge, case web expansion, etc. A safe working load in one rifle might very well be a dangerous one in another. I use other's load data as a reference only, and let my rifle tell me when/where to find happiness...

Good luck & good shooting

 

[brushape]

great thread

 

[Retterath]

Ladder test is the only way I load test. Easy and saves a guy time and money. It has worked great for me