Sometimes I am Amazed

[K22]

Having abandoned Sierra Bullets because of supply and availability issues, I selected the Hornady 75 Vmax as a replacement for predator hunting applications for my 243 Win's. This means I have to engage in the dreaded load development process which I hate.

A testament to how much I hate it is that a few months ago I loaded up some test loads with Varget but kept waiting for a cloudy and low wind day to test. I had several of those days over the last few months but made excuses not to test the loads. Finally, I gritted my teeth and test them on Friday.

I know this is not usual or unique but sometimes it does amaze me how a relatively small changes in powder charge can influence group size. For example:

Test 1: 36.0 g - Group 0.958
Test 2: 36.5 g - Group 0.602
Test 3: 37.0 g - Group 1.095

Just a 0.5 grain change made a significant difference. It just made me re-appreciate how essential load development can be.

PS: If some verification tests validate Test 2, I am good to go. That enough for what I need, no more load development.

 

[Doom]

Having abandoned Sierra Bullets because of supply and availability issues, I selected the Hornady 75 Vmax as a replacement for predator hunting applications for my 243 Win's. This means I have to engage in the dreaded load development process which I hate.

A testament to how much I hate it is that a few months ago I loaded up some test loads with Varget but kept waiting for a cloudy and low wind day to test. I had several of those days over the last few months but made excuses not to test the loads. Finally, I gritted my teeth and test them on Friday.

I know this is not usual or unique but sometimes it does amaze me how a relatively small changes in powder charge can influence group size. For example:

Test 1: 36.0 g - Group 0.958
Test 2: 36.5 g - Group 0.602
Test 3: 37.0 g - Group 1.095

Just a 0.5 grain change made a significant difference. It just made me re-appreciate how essential load development can be.

PS: If some verification tests validate Test 2, I am good to go. That enough for what I need, no more load development.

While you attribute all of the change in group size to the change in powder charge you are ignoring all of the other variables that effect shot dispersion. You probably try to minimize those effects they are still there and randomly effect the dispersion of every shot.

You didn't say how many shots you used or what distance your groups were. You are also basing the results on two shots. Doesn''t matter if you shot 3, 5, or a 50 shot group. It is much more informative if you were to use mean radius to determine your precision.

 

[K22]

While you attribute all of the change in group size to the change in powder charge you are ignoring all of the other variables that effect shot dispersion. You probably try to minimize those effects they are still there and randomly effect the dispersion of every shot.

You didn't say how many shots you used or what distance your groups were. You are also basing the results on two shots. Doesn''t matter if you shot 3, 5, or a 50 shot group. It is much more informative if you were to use mean radius to determine your precision.

Thanks for the advice, I think.

4 shot groups, 100 yards.

The only parameter I changed was the powder charge, so I assumed that was the cause and effect, but I am not load development expert. All I know is it shot good for me at that powder charge during the initial test.

Ran confirmation test today, 5 shot group, 100 yards, 0.540. Seems like it will work. Groups were clover leaf in configuration. All I want to do is make a shot in the vitals of a predator at 200 yards or closer. If I can place five shots centered, 1 1/2 inches high at 100 yards within a sub moa circle I think I am good to go. Right?

I was just trying to share how amazed I was that 1/2 grain powder charge made such a significant change in group size. I am now sorry I posted this. I don't want to get into a peeing contest of load development theory and measurements.

 

[JB10]

Go with the best group size and now play with seating depth

 

[Fast14riot]

An aspect that many people, who claim statistically invalid results in a test of low data points, is the experience many shooters have to determine how likely a small sample set is to turn out. Prior experience.

If I'm shooting a test ladder and get the first two shots wildly apart, I'm not likely to shoot the rest of that data point because experience has taught me that its not a fluke. But instead I look for the good group and focus there, shooting it more and may end up with 10-30 rounds of the good group without ever completely analyzing the entire data set to the same level of confidence.

In this case, OP only required ~1/2 moa precision. Simple, low data set showed where he was likely to find it. Followed up with confirmation, and now has a larger data set for that load only. Basically, you can never shoot a group smaller with more rounds. Even with MGR measurements.

Statistics are fine, but prior experience is also important.

 

[Mcrider55]

Thanks for the advice, I think.

4 shot groups, 100 yards.

The only parameter I changed was the powder charge, so I assumed that was the cause and effect, but I am not load development expert. All I know is it shot good for me at that powder charge during the initial test.

Ran confirmation test today, 5 shot group, 100 yards, 0.540. Seems like it will work. Groups were clover leaf in configuration. All I want to do is make a shot in the vitals of a predator at 200 yards or closer. If I can place five shots centered, 1 1/2 inches high at 100 yards within a sub moa circle I think I am good to go. Right?

I was just trying to share how amazed I was that 1/2 grain powder charge made such a significant change in group size. I am now sorry I posted this. I don't want to get into a peeing contest of load development theory and measurements.

It sounds like you've got a good load workup. Now it's about deady accurate shot placement. Spend your time now shooting so when that 1x trophy buck appears, you'll be confident in your shot.

 

[Straightshooter1]

Likewise, I am sometimes amazed. . . like yesterday I went to the range just to practice and play with the EC tuner and wasn't expecting good results out of my RPR 6.5 PRC with PBB barrel with over 1,900 rounds through it. And the jump was .098" (much more than I ever loaded for Berger 140 Hyb's before) though the seating depth was left where I've been getting good results with H4831SC. (more confirmation to me that distance-to-lands/jump isn't as important as seating depth):

 

[K22]

It sounds like you've got a good load workup. Now it's about deady accurate shot placement. Spend your time now shooting so when that 1x trophy buck appears, you'll be confident in your shot.

Thanks for the vote of confidence but I don't hunt deer anymore. A double hernia surgery in 2020 ended that activity for me. I have a mesh holding my guts in place and could not drag a deer out if I got one.

I use this rifle for predator hunting. It's an old Model 7 Rem. I had a 243 Win Hart barrel installed to replace the pencil thin factory barrel years ago, 10" twist. I had to switch to another bullet since I got frustrated trying to find my old standby, the Sierra 85 BTHP. In fact, I no longer shoot any Sierra bullets because of supply issues.

This 75 Vmax seems like it's going to work well in this rifle for my purposes. The best part is that there seems to be an abundant supply of these bullets. I will be moving to the cross sticks shortly to field qualify the rifle / load comb.

 

[Gary in MD]

It sounds like you are dialed in perfectly for your intended purpose. I used that bullet for several years out of a 6mm ai and it’s an excellent bullet, deadly on big ground hogs and foxes. Also shot some great groups with it in a 243 win using IMR 4350.
But what will really be amazing is if you won’t be advised that you’re using the wrong - bullets, cartridge, rifle, scope, etc…… LOL
Good shooting and good hunting,
Gary

 

[6.5 forever]

Having abandoned Sierra Bullets because of supply and availability issues, I selected the Hornady 75 Vmax as a replacement for predator hunting applications for my 243 Win's. This means I have to engage in the dreaded load development process which I hate.

A testament to how much I hate it is that a few months ago I loaded up some test loads with Varget but kept waiting for a cloudy and low wind day to test. I had several of those days over the last few months but made excuses not to test the loads. Finally, I gritted my teeth and test them on Friday.

I know this is not usual or unique but sometimes it does amaze me how a relatively small changes in powder charge can influence group size. For example:

Test 1: 36.0 g - Group 0.958
Test 2: 36.5 g - Group 0.602
Test 3: 37.0 g - Group 1.095

Just a 0.5 grain change made a significant difference. It just made me re-appreciate how essential load development can be.

PS: If some verification tests validate Test 2, I am good to go. That enough for what I need, no more load development.

Be careful. Small test samples can be unrepeatable.

 

[Doom]

Thanks for the advice, I think.

4 shot groups, 100 yards.

The only parameter I changed was the powder charge, so I assumed that was the cause and effect, but I am not load development expert. All I know is it shot good for me at that powder charge during the initial test.

Ran confirmation test today, 5 shot group, 100 yards, 0.540. Seems like it will work. Groups were clover leaf in configuration. All I want to do is make a shot in the vitals of a predator at 200 yards or closer. If I can place five shots centered, 1 1/2 inches high at 100 yards within a sub moa circle I think I am good to go. Right?

I was just trying to share how amazed I was that 1/2 grain powder charge made such a significant change in group size. I am now sorry I posted this. I don't want to get into a peeing contest of load development theory and measurements.

I wasn't trying to "get into a peeing contest" or argue as to weather or not "nodes" exist. I was trying to point out that the size of the group difference may or may not be due to charge weight entirely. "We" often see small groups and go with those charges and it works out. In fairness we don't go back and shoot the ones that were denote as bad groups. So do we really know that 0.5 gr made a 0.5 MOA difference? I don't know. Based on a Model 7 I can see a 1/2 MOA difference is plausible.

Most everyone has some method of load development and somehow we tend to end up at similar charges in many cases using totally different approaches. You had a goal and I think you found a load that will satisfy that goal. That's really what matters.

I guess I did come on a little heavy on the rmean radius comment. Sorry about that.

 

[Coyotefurharvester]

Factory hunting rifle, repeating sub moa groups you are gtg. A few single shot, cold bore shots, that stay "in group" over time(days) and you have confirmed the load/optic. I do this over the course of a month, same target and the rifle travels as I would when hunting. Because hunting is really the first shot.

 

[6MMsteve]

Shoot and have fun

 

[K22]

I wasn't trying to "get into a peeing contest" or argue as to weather or not "nodes" exist. I was trying to point out that the size of the group difference may or may not be due to charge weight entirely. "We" often see small groups and go with those charges and it works out. In fairness we don't go back and shoot the ones that were denote as bad groups. So do we really know that 0.5 gr made a 0.5 MOA difference? I don't know. Based on a Model 7 I can see a 1/2 MOA difference is plausible.

Most everyone has some method of load development and somehow we tend to end up at similar charges in many cases using totally different approaches. You had a goal and I think you found a load that will satisfy that goal. That's really what matters.

I guess I did come on a little heavy on the rmean radius comment. Sorry about that.

No problem here. I understand what you're saying and its valid. That's why I always conduct some confirmation tests before I engage in wholesale production of a load. Thus far I've conducted to confirmation tests and the load is holding true.

I was just amazed of the difference I saw in the three test loads. Perhaps my amazement was premature. Perhaps it's because I do so little load development anymore and after reloading for 50+ years I have loads I've used for years. But our "Brave New World" of supply shortage forced me to convert to another bullet thus the load development exercise.

I am guilty of trying to get off the bench as soon as I can and get back on the sticks and in the field. Thus, I am inpatient with load development. It has gotten worse as I age.

 

[Rset]

No problem here. I understand what you're saying and its valid. That's why I always conduct some confirmation tests before I engage in wholesale production of a load. Thus far I've conducted to confirmation tests and the load is holding true.

I was just amazed of the difference I saw in the three test loads. Perhaps my amazement was premature. Perhaps it's because I do so little load development anymore and after reloading for 50+ years I have loads I've used for years. But our "Brave New World" of supply shortage forced me to convert to another bullet thus the load development exercise.

I am guilty of trying to get off the bench as soon as I can and get back on the sticks and in the field. Thus, I am inpatient with load development. It has gotten worse as I age.

For your purposes, you do not need to chase bench rest loads. Go shoot, have fun, and be glad you are not at the bench.

 

[K22]

For your purposes, you do not need to chase bench rest loads. Go shoot, have fun, and be glad you are not at the bench.

Amen

 

[LHSmith]

Amen

If you look up "going down the rabbit hole" there will be a picture of a Benchrest rifle mounted on top of an elaborate front rest adorned with adjustment knobs -all sitting on a concrete bench top with a bunch of windflags downrange. Having indulged in the game for nearly 1/4 century, I can truly say I am at the point where I long for the simpler days of GH hunting with a plain old varmint rifle where I may burn up a few dozen rounds instead of several hundred per season. Competition has become "work" for me.

 

[K22]

If you look up "going down the rabbit hole" there will be a picture of a Benchrest rifle mounted on top of an elaborate front rest adorned with adjustment knobs -all sitting on a concrete bench top with a bunch of windflags downrange. Having indulged in the game for nearly 1/4 century, I can truly say I am at the point where I long for the simpler days of GH hunting with a plain old varmint rifle where I may burn up a few dozen rounds instead of several hundred per season. Competition has become "work" for me.

I reached the same point with 30 years of competitive NRA Precision Pistol. Once I reached Distinguished Expert, it was no longer fun. I tried to reach Master, but match pressure prevented me from reaching that goal. Oh, I could often shoot a Master Class score in practice but not in competition which was required to receive the official classification. An arthritic elbow ended my misery.

The reason I enjoy varmint and predator hunting is it affords me the opportunity to enjoy the beautiful country of northern Berks County and mix it up with some of my favorite people, down to earth farmers. Truth is, although the hunting is not even close to what it used to be, it is never a bad day when I am in the field. Also, trying to outsmart the critters, making shots in challenging conditions appeal to me. A short nap and a fine cigar in the field enhances the experience.

I respect benchrest shooters, their attention to detail is amazing and their ability to hit small dots is truly impressive. But I don't have demeanor for that sport that's why I never participated in it and never will. I do spend a lot of time on the range, but the vast majority of my shooting is practical off the sticks and I enjoy it even though I get a lot of weird looks.

 

[Bob3700]

The reloading for competition/ accuracy has indeed become a “Rabbit Hole“ to market expensive equipment to those OCD types that seem to gravitate to this sport.

Just go to “You Tube” and immerse yourself in the various reloading videos. The “Expert/Champion” shooter starts off annealing their brass in a $1400 ultimate machine. Then they travel across their 40x60 ft. reloading/gun room to trim their brass on a $400+ trimmer. The next step finds us sizing n expanding on a multi- thousand $ press With touch screen controls. Now the reloader uses a $700 primer seating tool with .005” accuracy Because the designer tested the unit and decreased their group size using a statistically sized sample. Powder is dispensed on a $6000 ultimate scale/ trickler. Finally, the bullet is seated on an arbor press that is instrumented to read seating pressure and that info is feed to a laptop computer. The seating pressure is graphically displayed To indicate level of consistency. I have skipped the rifle, scope, custom front rest, and e-target system used for testing. After all this, I am living in a “ Van down by the River”.

“Rabbit Hole” indeed!

 

[K22]

The reloading for competition/ accuracy has indeed become a “Rabbit Hole“ to market expensive equipment to those OCD types that seem to gravitate to this sport.

Just go to “You Tube” and immerse yourself in the various reloading videos. The “Expert/Champion” shooter starts off annealing their brass in a $1400 ultimate machine. Then they travel across their 40x60 ft. reloading/gun room to trim their brass on a $400+ trimmer. The next step finds us sizing n expanding on a multi- thousand $ press With touch screen controls. Now the reloader uses a $700 primer seating tool with .005” accuracy Because the designer tested the unit and decreased their group size using a statistically sized sample. Powder is dispensed on a $6000 ultimate scale/ trickler. Finally, the bullet is seated on an arbor press that is instrumented to read seating pressure and that info is feed to a laptop computer. The seating pressure is graphically displayed To indicate level of consistency. I have skipped the rifle, scope, custom front rest, and e-target system used for testing. After all this, I am living in a “ Van down by the River”.

“Rabbit Hole” indeed!

Oh My! This sounds like a "root canal"!