500 yard ammo testing

Ganderite

Ganderite

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F Class loads cannot be developed at 100 yards. Neither can target rifle loads. I prefer to do the initial testing at 500 or 600 yards and then test the “winners” at 1000. A lot of wheels seem to fall off between 900 and 1000 yards.

A railgun sits on a concrete table and returns to battery for each shot. 10 shots can be fired in 30 seconds, to reduce wind effects.

Back in the day when we were making commercial target ammo for DCRA type target rifle shooting, I gave our ammo to a member of GunNutz to test for me. He had a rail gun he could shoot at 525 yards. This took all the shooter skill out of the test and gave me more meaningful data from one day to the next.

About 10 years ago he tested some of my 308 handloads for me.

Winchester brass Federal 210M primers
Vht N140 155 Sierra Palma bullet

Velocity would have been around 2950 fps.

His barrel would have had an Obermyer chamber and was either a Krieger or Obermyer barrel. This group measures 1.8" high. Production ammo using similar components, made on a Dillon 650 would group at or just under 3".


RAILGUN308AT525.jpg
 
Jim, you may be offended/surprised to note that I routinely F-Class load develop at 100 yards. (ok...121 yards) If a load does not group at 100, it sure as heck doesn't group at 1000.

The issue is to find a relaible trend. If you ladder test and fine a trend that culminates in a tight group, it isn't a fluke. It will worlk well at longer range
 
Op. I usually completely have ur back and have argued the same point all day. But it's true. 100y is fine.

I will not say 100% effective, longer range tuning is good to do but... It does work
 
I can't understand, but if you ar eload developing at 500y , there is a chance that you may not even make it on paper.

OR is this a load that had already been put on paper at shorter distances. I have had POI changes 2" or 3" with just 100ft/sec difference in velocity @ 100y

I will alays start my tests at 100y.
 
I have had too many promising loads (at 100 yards) turn out to be dogs at the distances I shoot at.

If you are saying you start at 100 to find a good laod, then test at longer distances, that will work.

What I meant was, and I am sure you will all agree, just because a load groups well at 100 it does not mean it will work well at 300 to 900. And, for 1000, the only way to know if it will work at 1000 is to try it at 1000. Actually, with the new higfher BC bullets, it may be that 1000 is less of a challenge, and the problem may only be for 1200 yard ammo.

As for getting on paper, that is not an issue. We all know our sight settings for each distance and that will get us within a foot of center. For the rail gun, all that happpens is that 3 shots are fired to warm/foul the barrel and the target wear center (about 18" square) is placed over the 3 holes. This way the group does not wander off the paper tken home for examination.
 
For interest, here are some rails guns at Rosebud. As far as I know we are the only club in Canada running the Unlimited class of short range BR where you can use the rails in competition. The rail guns take the physical element of aiming the rifle away, and you are left with a straight wind reading contest. Much harder than it sounds. Matches can be 5 or 10 shot groups at 100 and 200 yds. Winning aggregates are around .2" - .25" moa.

IMG_5725.jpg



IMG_5720.jpg



IMG_5726.jpg
 
Wow, look at how thick that barrel is on the last picture. That is one beautiful piece of kit - I even love the machine-marks.

Lots of good info and thoughts on this thread.
 
An opportune exit time will often give tight hundred yard groups with a crap load, but timing barrel whip won't keep a crap load together farther out. At some distance, consistent ammo is going to trump how the barrel wiggled.

What you often see with a shooter with his first chronograph "discovering" that some of his loads had wild extreme spreads but shot well at 100. At this point he will usually write an article proclaiming that 100 fps velocity spreads don't make much difference, instead of concludeing that 100 yards doesn't mean much.
 
Ganderite, I am with you on testing further out. Found way too much stuff happens at 200yds and beyond. I now start at 200yds. confirm at 300m. For me, this minimizes the affect of wind.

I love that group you show. Except for 2 shots, that group has ZERO vertical. Now that would be the rig to test if bullet tip deformaties affect trajectory.

Nice toy.

Jerry
 
rpollock said:
For interest, here are some rails guns at Rosebud. As far as I know we are the only club in Canada running the Unlimited class of short range BR where you can use the rails in competition. The rail guns take the physical element of aiming the rifle away, and you are left with a straight wind reading contest. Much harder than it sounds. Matches can be 5 or 10 shot groups at 100 and 200 yds. Winning aggregates are around .2" - .25" moa.

IMG_5725.jpg



IMG_5720.jpg



IMG_5726.jpg
Click to expand...

Great pics. Just love these things. How heavy?

Is there a crane or hoist we don't see? :)

For those wondering what the fuss is about a winning 1/4 min group, remember that is EVERY SINGLE shot fired over the course of a match (25rds?) on any given Sunday no matter what mother nature is doing.

Under ideal conditions, you shoot 1 hole - that is some serious tech.

Someday....

Jerry
 
There is no weight restriction in the unlimited class. If you can get it on the bench you can shoot it. Typical rail gun would be 50 lbs. There are few rules in unlimited, however you cannot have the rifle fixed to the bench, and you must feed single shot, no magazines or semi autos. The upper half (with the barreled action) slides on rails over the lower half (which has the adjustments for aiming the rig). Upon firing the recoil slides the top half back and you manually return it to the forward position for the next shot.

An aggregate or agg, is the average of 5-10 shot groups or 5-5 shot groups depending on the event. You do this at 100 yards then at 200 yards. For example if someone says a .25" agg, this is either 25 or 50 shots.

One other thing, rails are normally shot heads up, ie looking at the field of flags, instead of through the scope. The scope may provide information about mirage or where the last shot landed, but it is not used for aiming except during the initial setup on the bench.

Here is another rail, less the barreled action.

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IMG_7044.jpg


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Here is a rail with an action block instead of a barrel block. Rather unusual, even for the unlimited world.


DSC01005.jpg
 
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Although a bit off topic, I am very surprised that the block for the barrel only make contact at 3 points. I would have expected the hole in the block to be round. I can't tell if there is a lug to keep the barreled action from rotating.

Well, for shooters that don't use their scope much, that blue one looks to be graced with a boosted MARCH.

I think he is trying to look THROUGH the target :)

I am afraid to ask how much?

Jerry
 
Those are beautiful rigs. I have a very crude one, in comparison.

In one picture you can see the steel spikes in the feet. The rig is tapped with a hammer, to set the gun in the concrete bench.

yes, some very interesting testing can be done. Deformed tips vs deformed bases. Weighed cases vs extreme spread weight cases. Thrown vs weighed charges. Prepped primer pockets vs not, etc.

I have done it all. And some guy who once shot his Remchester off a sandbag will dispute my findings.

BTW. At 100 yards the test results show almost nothing. At 500 they can be seen. At 900 they are more clear, but air currents can do too many things for routine testing.
 
Ganderite said:
Those are beautiful rigs. I have a very crude one, in comparison.

In one picture you can see the steel spikes in the feet. The rig is tapped with a hammer, to set the gun in the concrete bench.

yes, some very interesting testing can be done. Deformed tips vs deformed bases. Weighed cases vs extreme spread weight cases. Thrown vs weighed charges. Prepped primer pockets vs not, etc.

I have done it all. And some guy who once shot his Remchester off a sandbag will dispute my findings.

BTW. At 100 yards the test results show almost nothing. At 500 they can be seen. At 900 they are more clear, but air currents can do too many things for routine testing.
Click to expand...

So what are some of your findings for these variables? I would be interested in hearing if you actually found a point of diminishing returns or not. Don't get me wrong, I like making my own ammo to the best of my ability, but if something doesn't actually make a difference, well, you know...Especially the weighed cases vs. ES cases, as I'm sure you know, there seem to be many opinions on this topic.
 
It all helps. It is a question, as you suggest, of diminshing returns.

I was testing for target rifle applicaitons. Iron sights shot off the elbows. Beyond a certain point the "improvements" get lost in the noise.

A rail gun will show you what works, or what is better. A pressure gun tells you what is consistent and what is not. Inconsistancies show up at long range. They have to. But only shooting at long range will tell you how much it opens the group.

In a primer pocket test, I found that deburring the inside of the flash hole (noted needed in lapua and Norma brass - but I used Winchester or Hornady) made a noticable improvement in ES and SD. Uniforming the flash pocket made no difference whatsoever.

Weighing cases made a noticable improvement.

Tighter necks worked better than less neck tension.

Neck turning for an ordinary rifle made no difference at all, or, made the resylts worse.

The ammo tested in that group in the picture was weighed cases with deburred flash holes on the inside. The cases were full-lenght sized and the the necks were neck sized with the de-capping pin/button removed, to make for maximum neck tension. The powder charges were weighed. Primer was a Federal match.

Not a very fancy handload, but the results are plenty good enough to shoot at a 2" bull. If I miss, it is my fault, not the ammo.

The single biggest improvement in SD and group size came from adding the extra neck tension. It makes for better ignition and pressure curves.

An easy experiment for every handloader to try.

It is important to have a "standard" load to shoot alongside the "improvement" load. Only one variable can be tested at a time.

It takes several 10 shot strings to reach a conclusion that has some statistical validity. Remember, flyers can go into the group, disguising what happened.
 
Did you ever compare case weight to volume?

I found that cases could be all over the map weight wise but as long as the volume and annealing/alloy were the same, it shot well.

Recent testing of my FTR 223 had one of the smallest groups shot at 200yds with brass that had some of the widest weight spreads BUT the volumes were DEAD ON.

But I see where a rig like this will really separate the what if's to must do's.

And I am glad you are the type of shooter that understands how to run an experiment to give reliable data.

Any clue why there were two vertical flyers? I would love to know how important tip shape it to vertical dispersion. I have my opinions but no hard data to back it up.

I am very interested in your higher neck tension theory. I too run slightly higher neck tension BUT not high enough to cause bullet seating problems. I think you can size the neck too much and get real wonky runout in the bullet.

Might have to build one of these to separate fact and myth....someday...

Jerry
 
Interesting, I always thought tight necks may aid in SD or ES numbers but never had the means of getting good data, so I stayed with the "less neck tension=best" crowd. May have to experiment a little this spring...

I have also read, just the other day actually, that leaving the top off of your can of powder will help the gases in the powder equalize or something? Apparently they had tested the difference in group size between a freshly opened can and one that was left to sit with the lid off for a week or so, and the results favored the opened can. Just wondering if you have ever come across anything like this as well?
 
Mystic Precision said:
Although a bit off topic, I am very surprised that the block for the barrel only make contact at 3 points. I would have expected the hole in the block to be round. I can't tell if there is a lug to keep the barreled action from rotating.

Well, for shooters that don't use their scope much, that blue one looks to be graced with a boosted MARCH.

I think he is trying to look THROUGH the target :)

I am afraid to ask how much?

Jerry
Click to expand...

Some use a round barrel block. Some use a V block. Preference and theories abound.

There is tremendous clamping force on the barrel. They are cylinder in shape shooting mild cartridges. No need for lugs. You wont find them on BR rifles at all.

Lots of guys build rails themselves. If you have to buy one, that black one above will run $3000 from Jay Young. I think that is pretty good actually considering all the machining.
 
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