Load Testing

[dannyjbiggs]

Not a bench-rester, but use the same or better gear that is also F-Class legal. I load test from a concrete bench, under cover, not on the ground; because I'd rather "short range test" sittin' than layin'. Layin' can come later. Don't use wind flags in testing at 200 yards, don't even want to test short range in the wind.

I watch the weather report for what I consider "perfect days", i.e., full cloud cover to light drizzle rain. Otherwise, very early morning or late evening...those times when target mirage and wind are absent and the rifle scope is perfectly clear at max power.

After breaking a barrel in (over a chronograph, everything is over a chronograph), at whatever initial load I've used on past barrels; I mull over my last 5-shot break-in group performance and decide on a series of loads .02 grain apart under/above that charge with a spread which will surely take me into pressure. I go home and mull this resulting data over, and select a particular group/charge to adjust the barrel tuner on. I pick my "perfect day" for the tuner test, shooting a series of 3-shot groups spaced at 2 increments apart on the tuner using a common aim point and clicking windage for linear group spacing...allowing ALL to stream over the chronograph...pick my 2 most promising and consecutive group(s) and go to 5-shot groups as needed. Mostly a single 5-shot group set between those two groups is enough. A 10-shot group can confirm it. Normally, I have the barrel tested and tuned at 75 - 80 rounds. Then, I'm ready for the prone 1,000 yard test.

See...no differently than most of you do! :-\

Dan

 

[johara1]

I don't see one the most important equipment in load testing mentioned . Wind flags……. without them testing is worthless, siting at a bench or the ground doesn't matter but no flags ……. no answers…….. you can not see a 1mph. change at 1000, at full value that is a big deal, with flags . Now what do you see without them?……… jim

I understand the value of reading the wind and I have some experience with small bore prone shooting. My approach to load development has been to minimize the effect of the wind on the data by only testing on favorable days. This does not eliminate the effect of wind on group size completely but it does keep it to a manageable level Fortunately I am now retired and live close enough to a good range where I can pick favorable days for testing. But you have me thinking that I probably should add some wind flags to the process, I may learn something with that. I understand mirage, is that good enough for load testing at 100 yards.

Do you know how much a 10 mph full value wind will move your bullet ? What is a favorable day?What do you see the mirage with? If your using your scope to see it, it's too late because it focused on the target ……….. you need wind flags for development…………. jim

 

[wapiti25]

Be aware that the clamp screws on Caldwell are very lose/sloppy. I have two. They work for hunting guns not a 6 PPC bench grade gun. Should be OK for your XTC gun, the price is reasonable. My Caldwell's are the Bench rest type

 

[memilanuk]

I've done my initial short-range load development (screening, really) both ways - from prone and from the bench. Generally speaking, for me, the results from the bench have been more repeatable. Tuning at 300 and beyond is done prone or from the bench, depending primarily on the layout of the range I'm at. One range, you can't hardly see the 300yd targets from prone, and if you can, they are at an uncomfortable and non-standard angle. On the other... the 100/200yd berms block much of the 300yd line from prone, but 500/600 there aren't really any good benches to be had. So I use what is available.

 

[chkunz]

Not a bench-rester, but use the same or better gear that is also F-Class legal. I load test from a concrete bench, under cover, not on the ground; because I'd rather "short range test" sittin' than layin'. Layin' can come later. Don't use wind flags in testing at 200 yards, don't even want to test short range in the wind.

I watch the weather report for what I consider "perfect days", i.e., full cloud cover to light drizzle rain. Otherwise, very early morning or late evening...those times when target mirage and wind are absent and the rifle scope is perfectly clear at max power.

After breaking a barrel in (over a chronograph, everything is over a chronograph), at whatever initial load I've used on past barrels; I mull over my last 5-shot break-in group performance and decide on a series of loads .02 grain apart under/above that charge with a spread which will surely take me into pressure. I go home and mull this resulting data over, and select a particular group/charge to adjust the barrel tuner on. I pick my "perfect day" for the tuner test, shooting a series of 3-shot groups spaced at 2 increments apart on the tuner using a common aim point and clicking windage for linear group spacing...allowing ALL to stream over the chronograph...pick my 2 most promising and consecutive group(s) and go to 5-shot groups as needed. Mostly a single 5-shot group set between those two groups is enough. A 10-shot group can confirm it. Normally, I have the barrel tested and tuned at 75 - 80 rounds. Then, I'm ready for the prone 1,000 yard test.

See...no differently than most of you do! :-\

Dan

Thanks for your very detailed and informative response. I am sure this will also be of value to others. I am also interested in what front rest and rear bag equipment you use and also any bench technique that you think is important. It may be that there is little difference in equipment and technique between load testing from the bench and bench rest competition but that is only speculation on my part after reading some of the replies. Thanks again.

 

[chkunz]

I don't see one the most important equipment in load testing mentioned . Wind flags……. without them testing is worthless, siting at a bench or the ground doesn't matter but no flags ……. no answers…….. you can not see a 1mph. change at 1000, at full value that is a big deal, with flags . Now what do you see without them?……… jim

I understand the value of reading the wind and I have some experience with small bore prone shooting. My approach to load development has been to minimize the effect of the wind on the data by only testing on favorable days. This does not eliminate the effect of wind on group size completely but it does keep it to a manageable level Fortunately I am now retired and live close enough to a good range where I can pick favorable days for testing. But you have me thinking that I probably should add some wind flags to the process, I may learn something with that. I understand mirage, is that good enough for load testing at 100 yards.

Do you know how much a 10 mph full value wind will move your bullet ? What is a favorable day?What do you see the mirage with? If your using your scope to see it, it's too late because it focused on the target ……….. you need wind flags for development…………. jim

Thanks for the reply. Yes I know about how much a 10 mph full value wind will move the bullet but it is moot since I do not load test in those conditions. Although I know how to read the mirage and where to focus the scope to read it, again I do not test in conditions that require that concern. I am fortunate to be retired and have access to a good range and can do my load testing in favorable conditions. I would define a favorable day as one in which the wind is mild enough so that I can smell my own farts. Do you have any recommendations on bench rest equipment and bench technique? Thanks again for your reply.

 

[chkunz]

I do all initial load development at 100 yds, prone, with the exact same setup (bipod, rear bag, etc.) that I use in competition. It works very well for me. If you're not capable of consistently shooting under half a minute with a good load while shooting prone, this may not be the best method. Afterward, I use the same computer-based methods advocated by Mozella for target/load evaluation. As far as wind goes...well, I'm fortunate enough to have convenient access to a 100 yd indoor range. Wind isn't much of a consideration . Once I have selected what I think will be the "final" load parameters, I then do further testing/validation at 300/600 yd. At that point wind does become a big consideration here in SD, so I try to do that very early in the AM as soon as the range opens when wind conditions are usually pretty calm.

All good information, thanks. It sounds like you shoot F Class and that gives you an advantage with the load testing equipment and technique. I will be shooting from the bench and will need to select equipment and technique suitable for that. Thanks again.

 

[chkunz]

I've done my initial short-range load development (screening, really) both ways - from prone and from the bench. Generally speaking, for me, the results from the bench have been more repeatable. Tuning at 300 and beyond is done prone or from the bench, depending primarily on the layout of the range I'm at. One range, you can't hardly see the 300yd targets from prone, and if you can, they are at an uncomfortable and non-standard angle. On the other... the 100/200yd berms block much of the 300yd line from prone, but 500/600 there aren't really any good benches to be had. So I use what is available.

Thanks, any information on equipment and bench technique you would like to share?

 

[memilanuk]

Thanks, any information on equipment and bench technique you would like to share?

Nah...

On a more serious note... while I have shot a couple legitimate Benchrest matches (NBRSA VFS with a .30 BR) and done reasonably well, my 'equipment and bench technique' are, from what I gather, not entirely standard... so I'll forego discussing them in any detail and skip the part where various people tell me I'm all wrong.

In general, though, I think investing in a few wind flags (even just streamers) down range, and/or some sort of mirage board (you can make one yourself with some paint and tape and a piece of 1/4" plywood) will help a lot in terms of 'seeing' all the weird little eddies and such that can go on even @ 100-200 yds on supposedly calm days. Even if you do nothing more than wait for the condition to look the same as the previous shots, it's probably going to help reduce that variable (disturbance) in your testing somewhat. And yes, it can move your shot up and down - spend some time trying to shoot Xs on a score BR target and you'll see what I mean.

 

[noload]

To the equiment concern, Lesser expensive rests and bags will work, if you know how to modify them so they work well...Thats the cheap $150 rests. I don't know how deep your pockets are, but there are way better choices with equip thats already useable the way it is. Those rests start at ~$700. Eyeball some of the pictures online of guys shooting bench rest and F class, and you will see what you need. If it looks expensive thats what you're looking for. Technique can come latter.

 

[chkunz]

To the equiment concern, Lesser expensive rests and bags will work, if you know how to modify them so they work well...Thats the cheap $150 rests. I don't know how deep your pockets are, but there are way better choices with equip thats already useable the way it is. Those rests start at ~$700. Eyeball some of the pictures online of guys shooting bench rest and F class, and you will see what you need. If it looks expensive thats what you're looking for. Technique can come latter.

That is usually the way it goes, so the saying "buy one, cry once". The replies so far have not got into the specifics on equipment as I had expected but it looks like the F Class folks use the same equipment on the bench that they use in competition and that makes since. It is also sounds like the expensive bench rest equipment works as you would expect but there does not seem to be much between that and sand bags. Thanks for your reply.

 

[SHootSTraight22]

To the equiment concern, Lesser expensive rests and bags will work, if you know how to modify them so they work well...Thats the cheap $150 rests. I don't know how deep your pockets are, but there are way better choices with equip thats already useable the way it is. Those rests start at ~$700. Eyeball some of the pictures online of guys shooting bench rest and F class, and you will see what you need. If it looks expensive thats what you're looking for. Technique can come latter.

That is usually the way it goes, so the saying "buy one, cry once". The replies so far have not got into the specifics on equipment as I had expected but it looks like the F Class folks use the same equipment on the bench that they use in competition and that makes since. It is also sounds like the expensive bench rest equipment works as you would expect but there does not seem to be much between that and sand bags. Thanks for your reply.

That's what everyone's been telling you is to do load workup just as you would be shooting a match.. In my case I shoot from the ground on a bipod at best.. If your just looking for certain brands of equipment to buy then possible reword your question in a new thread, I'm sure some guys have recommendations...

 

[dannyjbiggs]

Thanks for your very detailed and informative response. I am sure this will also be of value to others. I am also interested in what front rest and rear bag equipment you use and also any bench technique that you think is important. It may be that there is little difference in equipment and technique between load testing from the bench and bench rest competition but that is only speculation on my part after reading some of the replies. Thanks again.

I use a Neo-SEB front rest and a SEB rear bag, each bearing modifications that I've made.

Dan

 

[chkunz]

Thanks to all who replied, it is all very helpful. Here is what I think I have learned. Except for Danny Biggs I did not get as much specific feed back on equipment and technique as I expected. Thanks Danny for all the detail, it is helpful. The F Class folks appear to already have what they need and a lot of the technique from shooting matches translates to load development at the bench. Also, F Class folks have the opportunity to do some load development at the same time they are shooting in competition if they choose to add that to what they are already doing. For us conventional prone (sling) shooters we can look at what the F Class folks and the bench rest folks are using as our guide to buy appropriated equipment and the good stuff is not cheep. For the front rests SEB and Farley appear top of the line but Sinclair has some good looking equipment and basically have three levels; competition, varmint and light weight. Even the light weight is probably better than sand bags. One significant choice is what to do about windage adjustment and no one commented on that. Caldwell makes less expensive equipment and it may be a good choice for an occasional load test but I did not get a lot of comments on Caldwell. The choice of front and rear bags is intimidating and will definitely take a lot of consideration. Also it looks like the bags do not come prefilled so that is something else to learn. Thanks again for all of your replies.

 

[barefooter56]

Trex,
Little tip on the Caldwell rests. If you get the one that has the 3/4 inch diameter post. You can upgrade to a SINCLAIR top, post and handwheel if you wish. The AP or ALL-PURPOSE top is the one to get for factory rifles. It can hold stocks from 1 1/2 inch to 3 inches wide.

 

[Mozella]

Do you know how much a 10 mph full value wind will move your bullet ? ........ snip……….. you need wind flags for development…………. jim

Yeah, I know exactly how much a 10 mph full value wind will move my bullets. I also know exactly how much a 7.6mph 30% value wind will move my bullet. The problem is, as experienced veterans know and new competitors quickly find out, is recognizing how much wind you actually have and from what direction(s) it's blowing. Once you figure that out to a high degree of precision, it's easy to win all the F-class matches you want because you'll be the only one able to do it. I'm not ashamed to admit that I can't read the wind perfectly. I also know that wind flags are not much more than a hint. What I do know is that any of the tiny variables I'm trying to sort out when searching for a good load are WAY smaller than the variables associated with even light winds. That's why testing in windy conditions is pretty much a waste of time.

Homing in on a recipe which you hope will improve your precision from .4MOA to .3MOA is not an easy thing to do if your data is flooded with statistical noise because of wind. Even light winds are a relatively large factor when it comes to changing the point of impact and mistaking a 6mph wind for a 4 mph wind will cause an error which makes it really tricky when you're trying to pick the fly shit out of the pepper such as doing primer testing or evaluating the difference between a .005" jump and a .002" jump.

Superb equipment and superb loads are not nearly as important as wind analysis, at least in typical F-class matches and it only takes one event to learn this unfortunate fact.

However, a precise load is always a good thing and finding it is well worth your time. But doing so is best done under optimum conditions. For me that means shooting like a bench rest shooter from a solid concrete bench using a heavy rest (even though I use a bipod for F/TR matches) and testing only under zero wind or near zero wind conditions. If there is enough wind to "read", that means there is too much wind for accurate testing, at least as far as I'm concerned. In other words, searching for the best combination of bullet, powder, charge weight, seating depth, primer type, and so-on and so-forth is plenty complicated without the added mystery of wind thrown into the equation.

In my opinion, adding the problems associated with shooting prone or at long ranges doesn't make any sense if you're searching for a good load. After you find a reliable and precise recipe, then is the time to hone your prone shooting skills, bipod technique, wind-reading ability, and all the other factors associated with doing well in a match.

 

[savagedasher]

Being retired and many of good friends is how I get to test. Good friends is how I test. Two have over 30 national records between them shooting black powder.
One is one of the best rim fire shooter and has nation records. The friend that brings all together. Has shot Skeet, Trap. Pistol Center fire bench rest. His ranch is where the testing Happens. He has 100 and 200 yard range . His reloading room is second to none. Gun smith lives a mile away. I don't think their is a rest or a toy ever made for shooting that we haven't tested. Two years another friend and the gun smith and I have ben testing along with all the others the RAS tuners along with all other friends. My self I like reloading. I have friends that are some of the best at shooting. When I change something and they all test it I know if it is working..
Here is a few things that I know works.
Case prep annealing And internal volume works
. Bags Rest and hardness and position works
Tuning the barrel to a load works.
Wind and mirage is friend of some and not others.
The best advice I can give Have good friends and share the information. Larry

 

[CharlieNC]

Good advice Larry!!

 

['Freak]

Sinclair’s Lightweight base, top, and a rear bag makes for a handy height adjustable lightweight shooting rest setup that beats heck out of two sand filled bags, one or both of often enuf placed on a wobbly stack of wooden spacer blocks. The LW rest does fine unless a rifle wants to be pushed against the forend stop, for which the LW base is too light. I bought my LW rest base with an AP Windage Top during a period when a Sinclair heavy iron base couldn’t be had, and I’m glad I had to wait.

For another $100 over the LW, their Gen. II Heavy Varmint ductile cast iron base has a larger footprint and utilizes the same 1”-14 tpi post and larger handwheel w/thrust bearing as their Competition rest, up from the courser pitch and skinnier ¾”-10 tpi post of old, still used on the LW. The Gen. II HV rest base also got the Competition’s ½”-20 tpi rest legs, so will use the same Speed Screw, up from the 3/8”-16 tpi legs of the old base, and still on the LW. Speed Screws are available with either the ½”-20 tpi or the 3/8”-16 tpi threads. Any of the Sinclair tops can be used on either size post.