Finding The Sweet Spot - .223Rem Loading

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Load Master

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In looking at .223Rem and Hornady 55gr FMJBT #2267 bullet, Hodgdon's website data shows Varget achieving 3,384ft/s with a charge of 27.5grs. Their "standard" load shows 3,174ft/sec with 25.5grs of Varget. I understand that the best grouping will most likely fall somewhere between these two charge levels. I also understand that most will do a ladder test to zero in on the ideal charge.

Is the "Sweet Spot" always something between the "standard/maximum" powder load, or is it a velocity driven thing for a given bullet weight and shape? In other words, if I found the sweet spot with the best grouping at a given velocity from this given gun, could I use a different powder with that same projectile to hit the same velocity and expect close to the same results?
 
This "Sweet Spot" depends on a lot of factors. These factors affect barrel harmonics which in turn affect accuracy. It is very difficult if not impossible to predict what "your" sweet spot will be with "Your" components and "Your" firearm.

The only way to know for sure is to put in some range time and see what your rifle likes.

As for your choice of bullet, the Hornady 55gr FMJ , not a good bullet as far as accuracy is concerned. This bullet although inexpensive and readily available will never be able to produce accurate loads. If you want accuray, you have to use bullets that the bench rest shooters use, all others are just throwing lead and copper down range.
 
Start at the minimum and work up towards max in .5 Gr increments. Your rifle will tell you what it likes best. Fine tuning a little after that might help. Don't expect great accuracy with a FMJ.

The FMJ bullet with the open base is a poor choice for accuracy. Almost any soft point or hollow point with a good base will shoot better. You don't necessarily need match bullets, but you do need a better bullet if you are looking for good accuracy.

Lots of people shoot the FMJ because of price, and can get accuracy suitable enough for their needs.

So I guess one question is what kind of accuracy do you need/expect?
 
What Steve4102 said covers it well. If you want to shoot a Hornady bullet any of their .223 match bullets would be a better choice, for example the 52 grain BTHP Match 2249 or an equivalent. You don't mention rifle, barrel or twist rate? My .223 Remington bolt gun is a 1:12 and will shoot bullets 55 grain and lighter. My AR rifles with a 1:7 really fare well with the heavier bullets up to around 80 grains. When you find that great load for one rifle there is a good possibility it will suck in another rifle. :( Remember, as steve402 stressed, you want quality match bullets if you expect accuracy.

<EDIT> Damn I was slow typing. Two more post in there. :) </EDIT>

Ron
 
I've found the "sweet spot" usually to be between 92% to 98% of the published data. Also I've found different manufactures bullets can make a big difference even of the same weight. Powder and even temperature can make a difference as well. It takes a lot of time to find the right combination that your rifle will like.
 
I'm dialing in a new upper right now. I'm using CE223 and 55 gr BlitzKing bullets. I started at 26.0 gr and loaded up to 27.8 gr in 0.3 grain increments. 5 shells at each charge. There is no blatant sweet spot in there, the only groups I got that were not sub-moa were because I pulled a shot. The best group was about 0.75 moa.

OTOH, I ordered a bunch of FMJ bullets for range blasters. Same loading procedures etc. I am planning on running a ladder as above, but it was windy the day I went to the range with them. I did take a dozen or so that I had loaded to 26.6 gr that showed promise from the blitzking tests and fired them. Basically 3 moa (I have not bothered to measure it yet). It was windy, so I shot a few of the blitzking loads I had also at 26.6 - roughly moa accuracy. I'm not impressed with the FMJ bullets accuracy - but they are cheap.

These were all loaded using a balance beam scale that is quite accurate and trickled to charge level. I'm confident my charges were well within +/- 0.05 gr. and perhaps better. All shots were from a front rest and a rear bag.
 
Thanks guys for the input. I seem to have once again failed at formulating my question. Let me try again.

Let me start with saying I am not looking for which bullet is best. The example given in my first post was just that, an example of how someone might go about finding the best recipe for a given bullet, powder and charge. It is also not a question about my gun. My questions is about ballistic dynamics. So, with that said:

Let's say I have the best bullet made, I have the best powder ever made, and I have the gun mounted in a gun vise keeping it from moving off of the point of aim. All test are done under identical atmospheric conditions. Let's also say I have found the best recipe for the above. Now, I change to a new, different powder. This new powder is close in burn rate to my perfect powder used above. Everything else is the same, just different powder. I go through a complete ladder test to find the recipe to match or come close to my original powder results.

Would I expect the velocity to match or come close to my first powder?
 
No. Each gun will perform best with its own best load. Each gun is different, each gun has different 'sweet spot'. Maybe possibly the sweets spots are similar and you can get lucky with two or more guns. But each gun is its own platform.
 
I've not really done more than read about it, but I think you're dealing with barrel harmonics. firing a gun is basically a transient impulse and will potentially excite any number of natural frequencies or mode shapes of the barrel. I do understand frequencies and mode shapes - I don't know how influential they are to a bullets behavior. There is a lot of discussion on Varmint Al's page about barrel tuning and harmonics.

What I get out of it is in short form is no, not necessarily. Unless the combustion process, projectile acceleration, etc. are all pretty much identical the barrel won't dynamically respond identically.

OTOH, it's hard to imagine higher mode frequencies having much displacement, so I would assume their contribution would be small to the overall situation. Whether 1st, 2nd or 3rd mode harmonics affect group size by 10% or 100% I don't know.

I picked up some nosler varmint bullets today. I was going to shoot a few using the blitzking data and see if there are any notable differences.
 
Thanks guys for the input. I seem to have once again failed at formulating my question. Let me try again.

Let me start with saying I am not looking for which bullet is best. The example given in my first post was just that, an example of how someone might go about finding the best recipe for a given bullet, powder and charge. It is also not a question about my gun. My questions is about ballistic dynamics. So, with that said:

Let's say I have the best bullet made, I have the best powder ever made, and I have the gun mounted in a gun vise keeping it from moving off of the point of aim. All test are done under identical atmospheric conditions. Let's also say I have found the best recipe for the above. Now, I change to a new, different powder. This new powder is close in burn rate to my perfect powder used above. Everything else is the same, just different powder. I go through a complete ladder test to find the recipe to match or come close to my original powder results.

Would I expect the velocity to match or come close to my first powder?

NO.

Maybe.

Prolly.

Prolly not.

Never know till ya try.
 
This new powder is close in burn rate to my perfect powder used above. Everything else is the same, just different powder. I go through a complete ladder test to find the recipe to match or come close to my original powder results.

Would I expect the velocity to match or come close to my first powder?

No, not necessarily and my thinking here is that just because two or more powders are close in their burn rate means about nothing. When the powder burns it creates a pressure curve, a sort bell curve. The concern is to measure the area under the curve. The curve has a Horizontal Axis or X axis (Time) and a vertical axis or Y axis (Pressure). The fact that two powders share similar burn rates does not mean they will yield the same pressure curve or a close area under the curve.

The velocity may or may not be close as in it's a crap shoot. I like steve4102's answer. :) Sort of absolutely, without a doubt, maybe. That would be my answer.

Ron
 
NO.

Maybe.

Prolly.

Prolly not.

Never know till ya try.
Yep.

The application does matter. I said work up in .5 Gr increments for a FMJ, and fine tuning might help. For your best bullets, best powder, etc, I would try .1 at a time. You might find a .3 Gr spread that shoots about the same, but I would want to know where that middle was. :)
 
Is the "Sweet Spot" always something between the "standard/maximum" powder load, or is it a velocity driven thing for a given bullet weight and shape?

None of the above. It is all about your gun and the inherent variables associated with it. Most notably the barrel. A specific combo of bullet, primer, COL, powder, etc may work well in your bolt action but be bad in your AR.

Varget may not even be your powder. Your model 700 may like one combination which mine abhors.

If you give specifics about your rifle, then maybe others on this forum can give you a sense of direction, but you wont know your sweet spot until you try it out for yourself.

For example I have I have a .45-70 which seems to like slower bullet speeds. When it comes to precision, it is always at or a bit lower than published charges for just about any powder combination. Just what that rifle seems to shoot best.
 
This is interesting since I'm ladder testing some loads for a
.223 single shot that I have. I'm using a 50 grain Hornady varmint bullet and R-P brass that has been sized and trimmed. All will be identical except powder which is IMR 4198 and BL-C(2).

I just ordered a chronograph so I can get velocities. This is a project for me and I'm trying to get a $200 rifle to shoot like a champ.
 
IMG_3406.jpg
69Gr-HBT (Molly Coated)- Mil-Spec cases - R15 (Exceeds Maximum Charge Weight) Primer (Winchester - Remington - Federal & CCI) 5 rounds each total twenty round group Remington 700 8in twist barrel.
 
None of the above. It is all about your gun and the inherent variables associated with it. Most notably the barrel. A specific combo of bullet, primer, COL, powder, etc may work well in your bolt action but be bad in your AR.

I will be working with a Remington 780 in 30/06 22" barrel with 1 in 10 twist. I also have an Armalite AR15 that I have a new 18" 1 in 8 twist barrel coming that I'll be playing with.

I guess what I'm trying to warp my head around, once I find that magic recipe, how can I use velocity data to save that magic point for future use. Things like primer and powder changes can affect how a round performs. I would think these changes would most certainly change velocity. My thought is if I measure that resulting velocity for that magic recipe, it might be a tool to allow me to find it again in the future. I have a good chronograph and would like to use it to document my load development. I was hoping someone with experience could elaborate on what works and what doesn't.
 
I have a notebook that I take to the range ad record everything for each load, once I have a load that I like I load some more and compare with my initial findings.
 
strolly,
The notebook works well and I too normally have one with me while testing at the range. I also log in Excel and keep details in a spreadsheet like this.

26782757205_eda111bd8f_c.jpg
 
Do you guys typically find a charge that works well for accuracy, then tweak OAL? Or tweak OAL at different charge weights? Is it possible that one charge could be inaccurate at one OAL but highly accurate at another?

I've always struggled with this dilemma. When do you stop tweaking and in what order do you tweak?

I guess when you get five shots in the same hole at 100 yards you can stop trying to improve the load...
 
weekend before last I tried the 55g VMAX with 25.3g Varget, mixed brass trimmed and seated per the Hornady manual. Fired from my son's savage model 12, 26" barrel, 1:9 twist

Clocked an average 3093fps and netted all 5 shot groups at 100 yards under 0.5 MOA with the best one below. That's the best I've ever shot anything
6F5EF2B9-93D5-4D6A-9E81-99E6E15F31D9.jpg


(Dang flyer kept me from getting them all in the same hole ;) )
 
steve4102 said: will never be able to produce accurate loads. If you want accuray, you have to use bullets that the bench rest shooters use, all others are just throwing lead and copper down range.

I have no doubt this is your experience, but it's not mine.
I have a 20" 1-in-9 that LOVES the 55gr FMJBT.

Load Master - unfortunately, your original post, while theoretically possible, in highly unlikely.
Good Luck finding that "sweet spot"

Oh & by the way - that sweet spot may change when your current powder Lot Number changes too.
Then again, it might even get better.

Oh the intricacies - LOL :D
 
Like every other experienced reloader on this Forum, I still say: "No"

to Load Master's real question. Just by keeping the same velocity
you cannot reliably get the same accuracy from gun to gun.
If you do, be happy! But if you don't, keep working.


You have asked the same question that has been asked for over 100 years.
But it isn't that easy. Unfortunately, it is often harder than it seems.
And it ALWAYS ALWAYS ALWAYS takes more time and more rounds than it seems.
 
You have asked the same question that has been asked for over 100 years.
But it isn't that easy. Unfortunately, it is often harder than it seems.
And it ALWAYS ALWAYS ALWAYS takes more time and more rounds than it seems.

Ants, I'm not looking to take shortcuts, I'm willing and able to put in the time effort to develop a process. You mention 100 year question, the tools and equipment I am using weren't available even 10 years ago. I'm a believer in mathematics and with the right inputs (variables) I'm confident the answer can come close to real world conditions. I am not discouraged and I'll continue to develop my process. Thanks for your input.
 
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