Berger seating depth test at 100yds or 200yds?
- Thread starter ImBIllT
- Start date
I never have seen a group get any better then the second shot . Regardless how many others you shoot. Larry
I agree. I load develop with 2 shot groups at 100yrds shooting through a chrony. I'm a hunter so if i can repeat the group once or twice i call it done and move to 600 yrds and confirm again. It works for me and saves my barrels from pointless rounds being shot on loads that were not good after the second shot.
ImBIllT
Silver $$ Contributor
I have quite a few groups with 2-3 shots in a single hole with the other two causing the group to be 1-2MOA!
ImBIllT
Silver $$ Contributor
I've never had a problem where my rifle would shoot 2-3 in the same hole then open up to that size group and i knew it wasn't me pulling the shot... And i was sure my equipment was in good order.
At 100 yards I've have over 75fps of velocity spread and still put them in the same hole.
Your groups vertical or horizontal when they open up?
ImBIllT
Silver $$ Contributor
2 MOA was off. Those were 200yds groups. So I'm getting 2-3 bullets in a single hole, while shoot 3/4 to 1 1/4 MOA groups. There is a lot of 3-1-1 and 2-2-1.
Mostly vertical.
First I fire-formed 20 pcs of brass and shot about 1" groups during barrel break-in. Then, roughly following Berger's seating depth test(two three shot groups at jammed, .040" jump and .080" jump, because I only had 20 cases) with the SII 4-16 mounted, three shot groups at 100yds ranged from .536" to 1.431", but only one group went under .810". I performed a ladder test and thought I identified two nodes. NO groups were much under 1", I left the target at the range and didn't measure cause it looked like crap. I switched to a T-6, shot four five shot groups at three different seating depths, thought I found a good rough seating range, switched back to the Sightron SII and shot groups at 200 yds measuring 1.270", 2.226", and 1.657".
The four groups with the T-6 were .771"(jammed), .714"(jumping .40"), .486"(jumping .120") and at 200yds .888" or about .44 MOA(also jumping .120") . I skipped .080" because it performed so poorly with the SII when I did the three shot group seating depth tests. I figured .120" was the right seating depth.
This morning I assumed I had a good starting point on seating depth, mounted the SII again, and shot the three previously mentioned groups. 1.270"(jumping .105"), 2.226"(jumping .120") and 1.657"(jumping .135"). I would have fooled with powder charge but I'm considering a switch in brass manufacture, and figured that I could just generate some confidence in the brand new SII and see which direction to head when fine tuning seating depth.
Could I be right on a scatter node with the powder and would a scatter node cause this three in two out stuff? I did the seating depth test with what I thought was a mild load, and there are no pressure signs, but at .120" jump the base of the bullet is well below the neck and you can hear it crunching powder when you seat a bullet.
The Norma brass, of which I now have 18 pcs, was simply trimmed to length and loaded up. The 140pcs of RWS has been trimmed to length, had primer pockets uniformed, necks turned, and is waiting to be weight sorted. It has considerably less case capacity and thus I wanted some Norma brass in case I failed to achieve the desired velocity(measured by sighting in at 200, then firing groups at 100 and 500 and measuring POI). Because my hunt is looming and I wanted to get the gun shooting, I opted to simply start shooting the Norma brass and worry about the RWS brass later. The drop from 100 to 200 suggests velocity is in the desired range and the soft Norma brass is bugging me, so I'm now wanting to go ahead and use the RWS brass if I manage to get the time. Is there any chance that the brass being unsorted could be the culprit? I can't say I ever shot unsorted brass in a gun that I wanted to be accurate, but I've read of enough guys saying that they don't do it that I figured I could get away with it.
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ImBIllT
Silver $$ Contributor
Most pressingly, would you question the scope? On the average, the T-6 is beating the Sightron SII 4-16 quite handily. On the other hand, today at 200yds, two of the the three groups came close(in terms of MOA) to the two large groups fired with the T-6. But, back in the Weaver's favor, the two best groups with the Sightron were on par with the two worst groups with the Weaver, and the two best groups with the Weaver(which were both the same load, and consecutive groups, although shot on two different days) blew anything shot with the Sightron out of the water.
If this was a short action, it would be no trouble at all to flop the SII onto my F-TR gun and flop my T-36 onto the new gun, shoot both guns, and the answer would be clear quickly. Being a long action, I'll have to take both scopes out of their rings, shoot, then swap rings again when I'm done. I'd really rather not do that. My T-6's from HBR were not sitting on any guns, so that wasn't the biggest deal.
If this was a short action, it would be no trouble at all to flop the SII onto my F-TR gun and flop my T-36 onto the new gun, shoot both guns, and the answer would be clear quickly. Being a long action, I'll have to take both scopes out of their rings, shoot, then swap rings again when I'm done. I'd really rather not do that. My T-6's from HBR were not sitting on any guns, so that wasn't the biggest deal.
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Vertical that is what bullet speed does .
But my Es is under 8 . Most of my problem is from the wind and mirage .
Seldom have a vertical problem .
Many of times I have see a 2’ change in condition from sight into finish .
Gong shooting is different then paper . It can be 2 hours from sighing in till you finish shooting without any more Practice . Many of time I have seen 8 to 10 hit the first 10 shot and missing the last 5 shots .
Our last gong championship we had 14 hit out of 16 shots in the first realy . The shooter hit 2 in the final shoot off .
Larry
I hope this doesn't sound too harsh, but I think you need to take a step back and decide on what you're really trying to do. Are you trying to prove that one of your scopes is defective? Are you doing a seating test? Are you trying to decide if testing at 200 yards is better than at 100 yards? Are you testing cold bore accuracy for long range hunting? Frankly, reading this post, it seems to me you're producing confusing data while wearing out your barrel and wasting time and money.
I would suggest this. First of all, you need to get a reliable scope on your rifle and leave it on there, unless of course you're actually testing your scopes. Then you need to make reasonable testing plan. Shooting five shots and going home is NOT a productive day at the range. Make yourself some rounds for sighting/fouling/warming your barrel or buy some good factory ammo. Shoot a few of these to get your barrel warm/fouled and then move on to the actual testing.
If you have a reasonable charge weight already, then do some seating tests. I like to load 40 or 50 rounds so they're all long and set at my deepest Jam value. I take my Wilson seating die and arbor press to the range and shoot the first three, then I progressively seat a batch of three rounds shorter and shoot them based on a pre-determined plan which I have printed out to bring with me to the range. The idea is to test various jumps out to the maximum reasonable value using only three rounds per group. It is unlikely, but not impossible, that a bad three shot group will turn into a good five-shot group.
Then, I examine favorable three shot groups and seat five remaining rounds at that length and confirm the good looking group of three with an identical group of five. Depending on how much ammo remaining, I might explore 5 shot groups a bit longer and a bit shorter than whatever seating depth has revealed itself to be promising. By the time I run out of my 40 or 50 rounds, I normally have determined the best seating depth for that particular recipe and gun combination.
If you can't seat at the range, you can pre seat a batch of ammo at home and decide if you want to shoot batches of three, go home and make more ammo at the most favorable seating depth, and return to the range for confirmation. Or perhaps you want to make up a big batch of 5 shot groups at various seating depths. One requires two trips to the range and the other requires more ammo, some of which you know will be so-so or even bad.
All this is done at 100 yards very early in the morning in still air for obvious reasons. If you can truly compensate for the wind by adjusting your aim point during load work up testing, then you won't be posting on this forum because you will be too busy autographing World Champion posters with your picture on them. Testing at short range requires precision measurements so I scan my targets and use On Target software to measure the holes and accurately record data to the nearest .001".
On Target is cheap and easy to use. It outputs data that you can paste into a spread sheet for further study. Once you have digitized data it's a snap to use M.S. Excel in order to make a graph like this one.
It shows a seating test which shows that a jump of .010" is the clear winner. I plot the MOA, the ATC (the same as Mean Radius) and the Vertical Height of the five shot groups. This is dead simple if you use On Target software to measure the target. This test is further documented and detailed in my test log #632 which is a M.S. Word file with all the data I might need to duplicate this recipe. I also save the target measurements along with additional data for each group in case I want to go back and graph, for instance, the MOA vs MV or any other parameter.
Depending on my goal, this particular seating test might lead to doing some fine tuning tests of the seating depth between .005" jump and .015" jump. Or I might call .010" good and move on to fine tuning a charge weight test, a neck tension test, or a comparison test between two different kinds of primers.
The point is that you can't really decide where to go unless you first know where you are at the moment. The best path can usually be found by carefully gathering data and studying it carefully to learn what it's telling you. Then you can isolate a different parameter and test it based on your previous knowledge which should be a solid jumping off place, not for example some shaky batch of data gathered when you used a scope which you can't trust.
I would suggest this. First of all, you need to get a reliable scope on your rifle and leave it on there, unless of course you're actually testing your scopes. Then you need to make reasonable testing plan. Shooting five shots and going home is NOT a productive day at the range. Make yourself some rounds for sighting/fouling/warming your barrel or buy some good factory ammo. Shoot a few of these to get your barrel warm/fouled and then move on to the actual testing.
If you have a reasonable charge weight already, then do some seating tests. I like to load 40 or 50 rounds so they're all long and set at my deepest Jam value. I take my Wilson seating die and arbor press to the range and shoot the first three, then I progressively seat a batch of three rounds shorter and shoot them based on a pre-determined plan which I have printed out to bring with me to the range. The idea is to test various jumps out to the maximum reasonable value using only three rounds per group. It is unlikely, but not impossible, that a bad three shot group will turn into a good five-shot group.
Then, I examine favorable three shot groups and seat five remaining rounds at that length and confirm the good looking group of three with an identical group of five. Depending on how much ammo remaining, I might explore 5 shot groups a bit longer and a bit shorter than whatever seating depth has revealed itself to be promising. By the time I run out of my 40 or 50 rounds, I normally have determined the best seating depth for that particular recipe and gun combination.
If you can't seat at the range, you can pre seat a batch of ammo at home and decide if you want to shoot batches of three, go home and make more ammo at the most favorable seating depth, and return to the range for confirmation. Or perhaps you want to make up a big batch of 5 shot groups at various seating depths. One requires two trips to the range and the other requires more ammo, some of which you know will be so-so or even bad.
All this is done at 100 yards very early in the morning in still air for obvious reasons. If you can truly compensate for the wind by adjusting your aim point during load work up testing, then you won't be posting on this forum because you will be too busy autographing World Champion posters with your picture on them. Testing at short range requires precision measurements so I scan my targets and use On Target software to measure the holes and accurately record data to the nearest .001".
On Target is cheap and easy to use. It outputs data that you can paste into a spread sheet for further study. Once you have digitized data it's a snap to use M.S. Excel in order to make a graph like this one.
It shows a seating test which shows that a jump of .010" is the clear winner. I plot the MOA, the ATC (the same as Mean Radius) and the Vertical Height of the five shot groups. This is dead simple if you use On Target software to measure the target. This test is further documented and detailed in my test log #632 which is a M.S. Word file with all the data I might need to duplicate this recipe. I also save the target measurements along with additional data for each group in case I want to go back and graph, for instance, the MOA vs MV or any other parameter.
Depending on my goal, this particular seating test might lead to doing some fine tuning tests of the seating depth between .005" jump and .015" jump. Or I might call .010" good and move on to fine tuning a charge weight test, a neck tension test, or a comparison test between two different kinds of primers.
The point is that you can't really decide where to go unless you first know where you are at the moment. The best path can usually be found by carefully gathering data and studying it carefully to learn what it's telling you. Then you can isolate a different parameter and test it based on your previous knowledge which should be a solid jumping off place, not for example some shaky batch of data gathered when you used a scope which you can't trust.
ImBIllT
Silver $$ Contributor
Your first paragraph is spot on with what I have ended up doing.
The scope I'm now questioning is brand new and was the scope that I intended to hunt with. After a fair bit of shooting I wanted to rule it out, so I put on the T-6.
I didn't get the gun put together till a couple weeks ago and the hunt it's for begins Nov. 4th, so because I didn't have my large batch of brass ready, I threw together my small batch of Norma brass, which has resulted in a small number of shots per day.
Im still working on a Wilson seater. This is for a wildcat.
I can't get factory ammo. This is a wildcat.
The five shot day was because I thought I had a whole new box of coated bullets but when I opened the box they were naked. I had five coated bullets left and the condition was as good as it was going to be for a good long time. I figured that if the seating depth I liked at 100yds the day before would shoot on a cold bore at 200yds, then it was a winner. Not only did it shoot well, it was the best five shot group the gun has fired yet.
I assumed that because I just hadn't got into that seating depth range until I put on the T-6(I've never had to jump a bullet .120" to get it to shoot) that the SII was probably ok, so I put it back on. I wasn't finished prepping the brass I might be using, and wanted to confirm this scope issue quickly. I also wanted to shoot ammo for some reason other than checking the scope, and checking the scope on a different gun would involve a lot of swapping around because this is my only Remington 700 L/A that is currently shootable. So, I loaded some ammo centered on the previously successful seating depth with three shots to get back on, and three five shot groups to evaluate the scope/smaller seating depth ranges. I'd hoped to find some meaningful correlation among the three groups, or that all three groups were bad. Instead, I shot two groups that were better than than some of the previous seating depth testing, but the group that was supposed to be small for sure was one of the worst groups I've fired!
I have changed so many things that very little data is common to a particular situation. The result is that I largely have insufficient data to determine anything concrete on my own. I was hoping that someone here with tremendously more experience than I(although I'm not a complete novice) would recognize something among the weeds to point to.
I need to evaluate the scope situation now. I can pull my T-36 from my F-TR(haven't shot a match in three years) gun, and reposition the rings, and put it on the new gun. Or, I could reposition the rings and put the SII on the F-TR gun and save barrel life on the new gun, but that would involve buying a box of 190's or working a load for 155's. I decided to switch to 155's, and haven't shot the gun since, but I'm out of 190's and don't have a load for 155's.
The scope I'm now questioning is brand new and was the scope that I intended to hunt with. After a fair bit of shooting I wanted to rule it out, so I put on the T-6.
I didn't get the gun put together till a couple weeks ago and the hunt it's for begins Nov. 4th, so because I didn't have my large batch of brass ready, I threw together my small batch of Norma brass, which has resulted in a small number of shots per day.
Im still working on a Wilson seater. This is for a wildcat.
I can't get factory ammo. This is a wildcat.
The five shot day was because I thought I had a whole new box of coated bullets but when I opened the box they were naked. I had five coated bullets left and the condition was as good as it was going to be for a good long time. I figured that if the seating depth I liked at 100yds the day before would shoot on a cold bore at 200yds, then it was a winner. Not only did it shoot well, it was the best five shot group the gun has fired yet.
I assumed that because I just hadn't got into that seating depth range until I put on the T-6(I've never had to jump a bullet .120" to get it to shoot) that the SII was probably ok, so I put it back on. I wasn't finished prepping the brass I might be using, and wanted to confirm this scope issue quickly. I also wanted to shoot ammo for some reason other than checking the scope, and checking the scope on a different gun would involve a lot of swapping around because this is my only Remington 700 L/A that is currently shootable. So, I loaded some ammo centered on the previously successful seating depth with three shots to get back on, and three five shot groups to evaluate the scope/smaller seating depth ranges. I'd hoped to find some meaningful correlation among the three groups, or that all three groups were bad. Instead, I shot two groups that were better than than some of the previous seating depth testing, but the group that was supposed to be small for sure was one of the worst groups I've fired!
I have changed so many things that very little data is common to a particular situation. The result is that I largely have insufficient data to determine anything concrete on my own. I was hoping that someone here with tremendously more experience than I(although I'm not a complete novice) would recognize something among the weeds to point to.
I need to evaluate the scope situation now. I can pull my T-36 from my F-TR(haven't shot a match in three years) gun, and reposition the rings, and put it on the new gun. Or, I could reposition the rings and put the SII on the F-TR gun and save barrel life on the new gun, but that would involve buying a box of 190's or working a load for 155's. I decided to switch to 155's, and haven't shot the gun since, but I'm out of 190's and don't have a load for 155's.
I suggest that with our 200.20X Hybrid Target or any BERGER Hybrid Target bullet that you start your bullet seating depth testing at .015 OFF THE LANDS. Then work back into the cartridge case in .005 increments to find your bullet seating depth accuracy node. Any bullet seating depth testing should be done at the lowest powder charge listed for the bullet/powder/cartridge combination you are testing. If you have any questions please feel free to contact us here. Or at techsupport@bergerbullets.com
Thanks for using our bullets!
Take care,
ImBIllT
Silver $$ Contributor
Not hybrids. They are VLD's. The original question was about the best test range for testing seating depth. After a fair bit of shooting I've determined that I have some other problem that has resulted in rather murky results with regard to seating depth. I'm going to trash the brass, finish the other gun that was chambered with the same reamer and see what I can come up with during fireforming. If that gun/scope combo will shoot, then I'll look at the scope again, as well as bedding. If not, then I'll have to figure out some new dies...my dies are definitely in question.
ImBIllT
Silver $$ Contributor
I'm not sure what range is best to test seating depth at, but I did eventually arrive at a good seating depth by testing at 100yds. Changing seating depth by .040" either way causes substantially larger groups. However, .030" more jump still shoots pretty good and .030" less jump shoots like totally crap. I still question the original scope, and will verify later. I think I was fighting problems on multiple fronts. Whatever the case, after grinding a front scope base screw, switching to properly neck-turned, uniformed, and weight sorted brass, and changing scopes, I'm consistently shooting .5-.7 MOA groups from the gun. It has put up a few in the .3 range. Most of the groups were shot in a fair bit of wind with no flags and show mostly horizontal dispersion, so it's closen enough to being a .5 MOA gun to make me happy with it. I got to shoot over a chrono this morning(I still haven't ordered one as I'm trying to decide which one to get) and it showed an extreme spread of 8fps for the first four shots! The fifth was 16fps under the highest and left me with an SD of 7.28. Good enough for a hunting gun I'd say. I probably won't test the original scope till I finish my hunt. I'm not sure what fixed the problem, but something did. My worst groups now are about where my average groups were before. The best groups are about the same, but the average groups and worst groups have definitely improved. Still not the accuracy that I was hoping for, but I guess it's good enough.
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urbanrifleman
Site $$ Sponsor
But doesn't one effect all the others? It is impossible to "isolate" the effects of one parameter.
The basis for scientific testing is that all controllable parameters except the one you are testing are held constant. So yes, you can isolate the effects of one parameter. That is the reason that most people test seating depth and test loads at 100 yds. - as the wind has much less affect on the bullet at 100 yds that is one less variable. If I hold my load constant and change seating depth I can isolate the effects of seating depth. If I hold seating depth constant and change loads then I can isolate load effects. If I hold both constant and change primers I can isolate the effect of the primers. If I use the same seating depth, powder charge and primer then I can test for neck tension, or perhaps coated versus non-coated bullets.
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