Reloader 17 Ladder Test .308 Berger 175gr OTM

TwoGun

TwoGun

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Minuteman
Jan 26, 2006
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Gilbert, AZ
#1
I've never done a ladder test before so I thought I'd give it a shot with Reloader 17 and Berger 175gr OTM bullets. This test was only 100yds and I decided to do it a little different than most I've seen. I didn't want to shoot at the same hole and try to interpret the data. I decided to shoot at different points and watch the bullet rise and fall over the range of powder.

The top was my first test starting with 43.7gr and finishing with 49.2gr. The wind was blowing so everything got pushed to the right. The last shot 49.2gr, I aimed at the 43.7gr point as I ran out of paper. I didn't plan shooting the 49.2gr as Alliant lists 48.7 as the max load (more or less) and I think that is correct. The loads above 48.7 do show some signs of over pressure.

Since I wanted some velocity, I decided to run a second test at 47.7gr to 49.1 grains. Since I don't know quite how to interpret this, I'm going to take a guess and say 48.6gr is probably going to be my best bet. Other interpretations would be welcome. There was little to no wind during the second run.

The scope is set dead nuts for 175gr FGMM. Assuming Federal knows what they are doing with nodes, can I assume that a different powder could have a similar node and shoot to the same point? My overall length is 2.88" (Winchester cases).

35a4ymg.jpg
 
#2
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

If you don't use the same aim point and watch the impact points rise and fall, how do you propose to evaluate your test?

The idea is to use the same point of aim and select those loads that group together as "nodes".

Yes, It's difficult at 100 yards, that's why it's recommended by many to use 200 yards as a minimum.

Just wondering.
 
#3
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

They are all the same point along a horizontal line. I took Jered Joplin's suggestion that a ladder test should be done at 100yds and thought of a way to do that and not have it look like a mess. I think it's easier to see the sine wave this way. Also, there could be an added benefit to see if the wave is throwing the bullets left and right. Although I could be wrong.

My question is what part of the wave is the most accurate. My assumption would be not the top and not the bottom.

If you look at the bottom part of the test, you'll notice that none of the shots are greater than 1/2" (lines are 1" apart) away from the point of aim. In that sense they are all accurate. Maybe 100 yards is too close.

30muavc.jpg
 
#6
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

Friend you are taking something that is designed to take all the guess work out and putting the guess work back in to the equation.

Do you have a shortage of range where you shoot? I can not see how doing a ladder test in this fashion achieves anything.

The reason we shoot long range ladders is because they work.
 
#7
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TwoGun</div><div class="ubbcode-body">
My question is what part of the wave is the most accurate. My assumption would be not the top and not the bottom.
</div></div>

I don't think there's anything inherently wrong with doing a ladder test along a horizontal line, but as others have said, 100 yds is a little short for meaningful results. As for determining where a node is, you may be headed in the wrong direction - your accuracy nodes will be where a string of adjacent loads have similar horizontal levels, which in this case might include for example the shots near the bottom of the "wave" where successive shots have the same level, around 46.5 grains.
 
#8
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jhnmdahl</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TwoGun</div><div class="ubbcode-body">
My question is what part of the wave is the most accurate. My assumption would be not the top and not the bottom.
</div></div>

I don't think there's anything inherently wrong with doing a ladder test along a horizontal line, but as others have said, 100 yds is a little short for meaningful results. As for determining where a node is, you may be headed in the wrong direction - your accuracy nodes will be where a string of adjacent loads have similar horizontal levels, which in this case might include for example the shots near the bottom of the "wave" where successive shots have the same level, around 46.5 grains. </div></div>

That's what I was thinking, too. I'm not even sure how many waves one can expect in the range I was shooting. To me, it looks like two waves with the highs somewhere after 43.7 and 47.7. I'm assuming the highest points are just before the apex as the bullets are flung upward by the moving barrel. So, I'd imagine one would want the areas slightly after the high points where the barrel is stationary and beginning it's downward motion. Not sure if the low part of the wave is optimal since it seems the stock may have more influence on the barrel in it's downward motion. It's all very interesting. I could have shot this at 500 but Jered mentioned the 100 yard distance and I thought I'd like to see how that looked. Next week I will probably shoot groups of 5 at 48.5, 48.6 and 48.7 and perhaps one at 49 or 49.1. If I don't like any of those, I'll revisit the bottom shots to try and find out what I'm looking at.

Shooting these at 500 yards at a public range is tedious. I suppose I could do the colored bullet trick to distinguish which shot was which. Have to buy me some colored pens I suppose.
 
#9
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

I would look in the 46.2-47.2 range. All of these have a similar vertical orientation. Whether you want to call it the "bottom" of the wave of what ever, they still have the most consistant vertical over a full grain of powder. That is what you are looking for, consistent location with minor powder variation. If these were my results, 46.7 is where I would look, and then start tweaking the seating depth.

You aren't looking for where the bullets where "flung", you are looking for where the muzzle is at rest when the bullets exit.

I would be curious to know what velocities you are getting out of these loads.

That's just me $0.02 and it's worth exactly what you paid for it.
 
#10
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

I appreciate the response. This week I'll be shooting these over a chronograph and I'll post the results.

Quickload predicts 2,700 with 46.7. Hmmm. Right where I probably want to be.

It says 2,800 for 48.6 and 2,850 for 49. These are for a 26" barrel.
 
#11
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

Based only on the information provided I agree with Huckleberry75. I would look at the 3 shot sequence between 46.2 and 47.2 as there is very little vertical deviation when changing the powder charge an entire grain.

If you are limited to 100 yards for the time being, go back and repeat this test loading 10 rounds in 0.10gr increments. Then look at the results to see if all ten shots impact on the same horizontal plane. If they do, I would load towards the middle of the charge weights to allow for inaccuracies in the the powder throws.

In my opinion, that should get you off to a pretty solid start, especially if you will only be shooting at shorter ranges (100-300 yards). You really can't complain about having an entire grains worth of flexibility in your loading that results in very little to no vertical deviation.
 
#12
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AMG04</div><div class="ubbcode-body">Based only on the information provided I agree with Huckleberry75. I would look at the 3 shot sequence between 46.2 and 47.2 as there is very little vertical deviation when changing the powder charge an entire grain.

If you are limited to 100 yards for the time being, go back and repeat this test loading 10 rounds in 0.10gr increments. Then look at the results to see if all ten shots impact on the same horizontal plane. If they do, I would load towards the middle of the charge weights to allow for inaccuracies in the the powder throws.

In my opinion, that should get you off to a pretty solid start, especially if you will only be shooting at shorter ranges (100-300 yards).<span style="font-weight: bold"> <span style="text-decoration: underline">You really can't complain about having an entire grains worth of flexibility in your loading that results in very little to no vertical deviation.</span> </span> </div></div>

Yep
 
#13
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

Twogun,
While this is not the way I work up loads,I think the sine wave pattern is interesting.The harmonics of a rifle barrel are complex with some element of whip producing vertical change in the point of impact,and with waves of bore expansion and contraction.I am ignoring the torsion that the bullet rotation produces.
My concept of trying to find an accurate load theoretically involves getting the bullet to exit at the pause at the top or bottom of the barrel whip-otherwise the barrel will be moving up or down thereby increasing the vertical-while at the same time getting the bullet to exit when the distal bore expansion is at a minimum so as to have the least amount of dispersion(a tighter group).
I would wonder if the lower and upper nodes might be at 44.0-44.4 and 48.2-3. Try shooting a group at those loads .If you do, post your results so I can see if my theory is crap.
 
#14
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

Yes, I'll give those a try and get some speed data as well.

I went back and re-read the second post in this forum titled "Powderin' It" which discusses the ladder method. I had missed this statement the first time I read it.
<span style="color: #990000">
ENTER THE "NODE." The node is the very top of the wave and very bottom. For ultimate accuracy, you want your bullet exiting the muzzle precisely when it has flexed all the way up, STOPPED [for a nano second] before it begins it journey flexing back down. This is why you had a decent group or two during the ladder test, despite differing powder charges.</span>

So apparently that author agreed with your theory that it's the top nodes that are the most desirable.

Looking at my test, it's my opinion there are three nodes there, two top nodes and one bottom node. I wouldn't think that if it wasn't for the second ladder at the bottom which would tend to confirm the last node of the first ladder. I do need to shoot some groups though to see if this ladder thing is worth a darn at 100 yards. I have to admit that I was a bit pleased with myself to have something that looked like a wave (to me) show up in my first test. But I tend to see things that I want to see and ignore things that don't seem correct (like the shot at 47.2). But this gun isn't a laser beam so having something look like a wave regardless of the oddball was nice.

As for finding the actual node, top-dead-center, so to speak, I'm thinking it should be the last charge before seeing a dip. The reason I think that is if the barrel has momentum it's going to be greatest midway through an oscillation. So, the midpoint should see the greatest shift from where the bullet actually left the barrel. It may be so great as to simulate a top node. After the midpoint of barrel travel, it's going to be slowing down and so the shift wouldn't be as great. And at the very top, there will be no shift. So one could imagine seeing three shots all in the same vertical but only one being the node, the last one.

In any case, it is interesting. I'll know more after I shoot some groups. But I'm not expecting too much.
 
#15
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

I agree I think it is interesting. Kind of shows what we are working with as far as barrel harmonics. I see what the OP was getting at. One thing it does not show that a conventional ladder test does, is velocity spread between loads. Because at 100 yds velocity does not change POI as much as it will at further distance. This is why you can have a load that groups well at 100 but then falls apart at distance. Some nodes will just naturally have less ES, kind of a sweet spot range of powder charge. Which is exactly why we get a group of shots with the longer distance ladder- least velocity spread between charges. Not an x-pert, JMHO. I would really be interested in know how accurate the load would end up being, if based off of these results. Especially at distance. Thanks for the post, a new perspective is always nice.
 
#16
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

another point that needs made here is that you effectively did an OCW test without the extra rounds. you have consistent hits along the bottom node centered on 46.7gr, with a very forgiving charge difference of 1 FULL grain charge weight.

I'd personally load up 5 at each weight 46.2 to 47.2 in .2gr increments, and fire round robin at six different targets comparing POI ONLY, then work on seating depth in and out by .003" increments once you find the center of the node. OR...if you are not seeing pressure yet, work on the top node at the high end...but frankly, that bottom node shows accuracy promise and the extra 150fps you get by moving up to the high end might not be worth the wear/tear/etc. just my novice $.02
 
#17
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

Thanks again for the observations. Both Huckleberry75 and AMG04 made the same assessment for the 45.7 to 46.7 range. I agree about not wanting wear and tear chasing speed I don't need. If the bottom node works fine, I'll have no problem sticking with that.
 
#18
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

Here's some groups I shot this morning. Nothing spectacular but it's a start. Velocities are listed along with extreme spread and standard deviation. The first group I shot was the 7.62x51 Federal Gold Medal Match. Only beat it with 48.5 gr. I'll definitely be exploring the other nodes.

19atmu.jpg
 
#19
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

Next set of groups. Probably take some of these loads to 400 or 500 yards and see what they look like. I shot the 45 grain load just to see velocities. Too slow.

28ivy86.jpg
 
#20
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

As noted by others, that is the strangest load testing i have seen. Not hard task but you for sure are making it one.
This is mostly how i do it
http://www.accurateshooter.com/technical-articles/long-range-load-development/

Shoot all loads into same POA, 100yds is not ideal for testing use longest range available
OCW/OBT
optimal charge weight/optimal barrel time
Dan Newberry n Chris long both have websites that explain in great detail ideology and process of load development.

I have no idea what if anything you gleamed from your "ladder test", very strange approach.

The technique in link is easy and gives results that can be easily interpreted into a go to load.
Each to their method of madness in load development.

PS
You want shock wave at chamber when bullet leaves barrel, research OBT/OCW

 
#21
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

I've learned I like 48.5 the best so far which is a tenth grain less of what I predicted from my initial test. It has a height of .225", appears to me to be a 12 o'clock node and has a standard deviation of 8.

The second group I like is 46.8 because it has a height of .317 and a standard deviation of 7.

The other candidate is 48.7 with it's SD of 5.

I think there are three variables one looks for. Shock wave at the chamber, little barrel movement as the bullet exists and low standard deviation of velocity. Whether or not those three cross each other's path with this powder, bullet and primer combination is a crap shoot. Considering the gun is a bone stock Savage 10FP off a bipod, I think I'm doing OK.

There's very little data I can find using Reloader 17 and Berger's OTM bullet (which was designed to have decent BC, transonic stability and still fit in a magazine).

This may all be a waste of time. No biggie.
 
#22
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

Shot 10 at 560 yards with 48.5gr. The top three I used Shooter's calc at 11.7 minutes or 47 clicks. The bottom 7, I dropped it 2 clicks.

The bottom 7 are 5 inches wide and 2 inches high. Not bad, it was a bit gusty.
ili0j9.jpg
 
#23
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

I can see the a method to this that could work and kind of like the idea.

I use OCW to test my loads also and its worked great. This in essence is a single shot OCW but the thing I like about it is it does show the barrel whip pattern pretty clearly.

If it we're me I would of loaded in .3gn increments to fine tune it a little more on the first outing though.

I would seriously consider looking at the 47.7 range and 48.9 as these charge's are printing consistently lower than the previous lower charge weights on both your tests.
Had you loaded in .3gn. weights I'm sure you would of seen a node around them both.

If you feel like trying a few more I would love to hear the results.

Good Luck
 
#25
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

I'll be finishing up this 1 lb can of Reloader 17 with some 48.7gr loads at 560 yards. I don't have much of the 1 lb can left. I've got a new 5lb can that I'll be working with and I'll do a new ladder (same method) with that can. Probably a good idea with the new lot.
 
#27
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

Weather's nice so was back at it. This is 5 shots at 560 yards (500 meters) with 48.7gr of Reloader 17, the Berger 175gr OTM.

For those interested, the scope was adjusted 3.1 mils at 27.66 inHG absolute pressure @ 89.4 degrees(Kestrel).

Looking forward to the new Berger reloading manual which is supposed to ship this month. Will be interesting to see their loads.


9viluc.jpg
 
#28
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

Just to throw a rench in hear. I'm learning a reloading process and not even shooting at paper??? A customer of mine at my barber shop has been in the shooting industry for many years and know all the names we read about.. He has many patents and has built a great business in the shooting industry. He know more about shooting than most of use combined. He has worked with special forces on loads and getting their guns to shoot bug holes.. His method is SUPER simple.. Pick your bullet and powder load them .3 ladder one each. Shoot over a chrono and you'll see node 100%. You can pull or push a shoot in ladder at target at any range 100- 500 what ever. But the chrono doesn't lie.. Load top end of node then do 5 shot seating depth ladder. That will give you best that bullet combo will do every time!!! I just got a 300 weatherby and did this. With in 25 shots I had fastest powder 4 tested and my node 84- 84.4 shot same velocity 3156. Went back did 5 shot groups 4 seating depths last group .422 5 shots 180 TTSX Norma MRP Norma case fed 215. I haven't done a fine tune seating death test or different primers yet?! Try it one time!!!! Tell me I'm wrong!! You'll owe me a beer,
wink.gif
 
#29
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

I use the video camera trick when I do mine I just set up a camera at the 500 yard line with my target just offset on the berm hidden in the bushes so it doesnt make a cute orange target at the 500 yard line. I then go down shoot all the shots take the target and video home and mark it that way. As was stated you really need to move this test out to a much farther range as at 100 you just cant gather enough data.
 
#32
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: slapdud</div><div class="ubbcode-body">Another cool trick is to take your phone and use a remote camera triggering app and get your shots live via laptop.</div></div>

do you have the tools to do this?
 
#33
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

A node may have little to do with velocity. Finding a node with a chronograph isn't really possible. You may be able to distinguish when a bullet is leaving the barrel when the sonic wave is at the chamber but it's impossible to tell the angular velocity of the muzzle as the bullet leaves.

48.7 grains happens to be a very consistent load in terms of velocity but I don't think it's an optimal load or a node (in my gun). As it turns out it's pushing bullets to the right, significantly. I know this because it's 9" to the right of my control load which is Federal 7.62x51 175gr FGMM. The Federal load does not vary in windage at all from zero to 500 meters. Of course, I suppose it's possible to have windage nodes as well as elevation nodes. However, I suspect elevation nodes are more common assuming barrel harmonics follow recoil direction for the most part.

As for remote viewing of targets, I can see those splatter targets just fine with a 60x spotting scope. However, the 100 yard range is still more convenient to shoot and that was my original intent to see if I could see a ladder at 100. Haven't convinced myself I've done that so far.

 
#34
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

48.5 +/- .2 loaded into prepped Lapua brass. OK that makes life simple & I will try it at 600 yds. Then I'll try my load of 2K MR. w/ same projectile. ALL at 600. Hell, I'll even shoot paper rather tahn letting you see what 600 looks like at 600 short range.

All this other data is messing with my head ... too much info after a long night of work !!!
 
#35
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

Be careful with 48.7 (unless you've already been there). That load is a bit warm in my gun.

I'm actually going back to 46.8 and look at what it does at 560. At some point I'll do a proper ladder at 560 and see what that looks like. Be some time, though. It's nice these old threads don't die.
 
#37
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: slapdud</div><div class="ubbcode-body">Yes i use the icam app </div></div>

These remote camera apps are interesting (and scary). So do you control an Ipad with an Iphone or does your range have wifi?
 
#39
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

Always forget wifi over aircard. I always forget I can hotspot my phone. Hmmm, possibilities possibilities.

Thanks for mentioning that app. Very clever.
 
#40
Re: Reloader 17 Ladder Test .308 Berger 175gr OTM

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TwoGun</div><div class="ubbcode-body">A node may have little to do with velocity. Finding a node with a chronograph isn't really possible. You may be able to distinguish when a bullet is leaving the barrel when the sonic wave is at the chamber but it's impossible to tell the angular velocity of the muzzle as the bullet leaves.

A node over a chrono is same velocity with in a small powder range!!! My rifle 84, 84.4 shot same velocity... 3156 that is a node top of wave?!? How can't one see that???



</div></div>
 
#43
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