How important is one kernel of powder?

[BoydAllen]

Also, not sure if this was said above, some barrels are at a length where they would shoot a given load faster, if they were actually cut a bit shorter. That could be thought of as a fairly dead zone where friction and decreasing pressure are close to parity in negating V gain. For those barrel/load combinations, a small increase in powder may actually net zero or a less than expected additional velocity gain, like the extra length is doing.

You have actual shooting proven data on this? IMO all of this unproven imagining just serves to confuse the less experienced among us, which is why I always tell people to not rely on the internet for things that you can test for yourself, and when you do, believe your targets. Those of us who do our own testing know the exact value of conjecture, which is as a starting point for actual testing. If that is not the intent, then the whole exercise descends into the realm of pure BS.

 

[wildcatter]

If your worrying about one kernel difference in your loads, I'd say your probably overlooking much more important variables, and definitely worrying about something you'll never be able to measure!

Id suggest when you can load all your ammo to within one kernel, it's time to spend more time on things that will make a noticable difference.

 

[davidjoe]

You have actual shooting proven data on this? IMO all of this unproven imagining just serves to confuse the less experienced among us, which is why I always tell people to not rely on the internet for things that you can test for yourself, and when you do, believe your targets. Those of us who do our own testing know the exact value of conjecture, which is as a starting point for actual testing. If that is not the intent, then the whole exercise descends into the realm of pure BS.

Boyd, I believe from other posts before this, that you don’t know how much I actually shoot, and believe that I simply theorize. I’ll give you three examples. First, .22’s. It’s indisputable that long 22 rifle barrels exceed velocity gains. Second, barrel cutdown tests.

Third, my own F-Class barrels and guns. I did not start F-Class shooting by considering, and then copying the current proven recipe, and massaging a single bullet up and down a .3 grain spread to get 40 firings from a single bin of one brass lot, in hopes of maximizing the points tallied for time and dollars spent over the next decade. Why deliberately meander? Because I’m an enthusiastic tinkerer and like to learn. I have skipped almost no caliber from .223 to .338.

There is no one else that has shot Fclass 7’s with 36 inch finished barrels. I know this because both suppliers that eventually said ok have told me only I have ordered them that long. I believe they are correct there because they resisted accepting my orders, because a straight 1.25” taper most guys shoot, but I don’t, is weight limit heavy there, and because it would be both flexy and hard on standard tenons, which 11 (identical) of my larger Fclass actions don’t use.

That’s the threshold. I have found a 36 inch 7 to shoot certain loads slightly slower than other, shorter lengths. Am I making this up - that I might have 6 rifles simultaneously barreled with different length barrels to assure reliable results, that can chamber rounds from the same several boxes, at the range on the same day, no.

 

[BoydAllen]

Boyd, I believe from other posts before this, that you don’t know how much I actually shoot, and believe that I simply theorize. I’ll give you three examples. First, .22’s. It’s indisputable that long 22 rifle barrels exceed velocity gains. Second, barrel cutdown tests.

Third, my own F-Class barrels and guns. I did not start F-Class shooting by considering, and then copying the current proven recipe, and massaging a single bullet up and down a .3 grain spread to get 40 firings from a single bin of one brass lot, in hopes of maximizing the points tallied for time and dollars spent over the next decade. Why deliberately meander? Because I’m an enthusiastic tinkerer and like to learn. I have skipped almost no caliber from .223 to .338.

There is no one else that has shot Fclass 7’s with 36 inch finished barrels. I know this because both suppliers that eventually said ok have told me only I have ordered them that long. I believe they are correct there because they resisted accepting my orders, because a straight 1.25” taper most guys shoot, but I don’t, is weight limit heavy there, and because it would be both flexy and hard on standard tenons, which 11 (identical) of my larger Fclass actions don’t use.

That’s the threshold. I have found a 36 inch 7 to shoot certain loads slightly slower than other, shorter lengths. Am I making this up - that I might have 6 rifles simultaneously barreled with different length barrels to assure reliable results, that can chamber rounds from the same several boxes, at the range on the same day, no.

Excellent. You have given your actual experience. I will say that in my experience that maximizing velocity is not the be all end all for most competition shooting that I know of. If you shot several five shot groups with flags and under favorable conditions, how did your 36" barrels group and what caliber were they chambered for? On the .22s that information has been out there for quite a while, but I tend to keep RF discussions in a separate category, since there are quite a few significant differences. Getting back to the real long heavy barrels, I am pretty sure in the long range benchrest game, barrel blocks have solved a lot of those problems, although I should probably note that the whole concept has probably become a bit dated since the current 600 yard HG record was shot with a 26" barrel.

 

[Alex Wheeler]

I have measured action flex in some of the more extreme cases and compared it to the more normal 28"HV type setup. With a BR type action I think it was never a real issue. Its an interesting discussion though.

 

[Fuj]

About that one kernel ?? I don't worry about it but, if your
scale has a 1/100 resolution, and your trickling IMR-4166,
them kernels will get your attention.

 

[Shooter13]

Ok, if you think 1 kernel makes a difference think about this. In any 100 pack of primers there is an average of roughly 4 kernals of powder differece in weight, usually attributed to the compound amount. So the primers are making a bigger difference than the 1 kernel by far. So maybe you better check out your primers and not worry about 1 piece of powder. How to I know......I have weighed over 5000 primers the last 2 years.

Okay, not being a wise guy, if you are weighing primers then are you ass u me ing that the anvil and the cup are ALL identical? Let me know your thoughts please.

 

[davidjoe]

Excellent. You have given your actual experience. I will say that in my experience that maximizing velocity is not the be all end all for most competition shooting that I know of. If you shot several five shot groups with flags and under favorable conditions, how did your 36" barrels group and what caliber were they chambered for? On the .22s that information has been out there for quite a while, but I tend to keep RF discussions in a separate category, since there are quite a few significant differences. Getting back to the real long heavy barrels, I am pretty sure in the long range benchrest game, barrel blocks have solved a lot of those problems, although I should probably note that the whole concept has probably become a bit dated since the current 600 yard HG record was shot with a 26" barrel.

Sorry this diverged off topic. About half end up as .284’s and half as Saums. I normally order 8 blanks at a time that taper to an inch from a 1.45” x -3-4” breech, but the length has varied 5 inches or so over the years, and the twists vary from 8 to 9, with most being 8.5.

The 36’s are assured of real set back potential, but there are some uncertainties as well. The first uncertainty is whether all bullets can survive them. (They cannot under some conditions, in Saums, but all can in .284’s). The second was whether they would shoot faster or not, and some loads are actually slightly slower, while others still see a gain, in a saum. In a .284, they all still see a gain, regardless of powder or bullet that I’ve tried. The longer .284 powder column I believe slows and lowers, the peak of powder combustion.

The third was improved accuracy if velocity rose, and I’ll say no, not yet that I see. This isn’t fully confirmed but so far scores are not higher with them. I didn’t know if I’d see more copper fouling at the front, and there is. As with a fast .22 centerfire those jackets get hot at the end of the barrel.

Gun handling in the bags is nice though, with such a long barrel and weight, up there. The extreme length seems to slow down or better absorb all the felt firing disturbances.

They weigh more than half of the 10kg limit at that length, but because of their taper, most of that weight is close to the action, not to the muzzle. With heavy barrels on a rest, I do prefer to find the area of stock that sits on the front bag, then utilize a small amount of compressible material between the stock and barrel that absorbs resonance and puts a modest upward lift on the barrel, such that viewed from the side, the barrel would press down on a soft shim, which would press on the stock where the stock sits on the rest.

 

[Fuj]

Okay, not being a wise guy, if you are weighing primers then are you ass u me ing that the anvil and the cup are ALL identical? Let me know your thoughts please.

Looking at it from a tool makers point of view, the same lot run
will be very close. As for Jeff sorting of primers ?? I hav'nt got
that anal yet, but I will say, I shoot with Jeff and the boys. Jeff is
normally in the top 2% I will also agree with him that a primer
will have way more influence then a kernel of powder......So do
we worry about the single kernel after the primer sort ??

 

[Alex Wheeler]

One other aspect is that there really is not a middle option here. You have your chargemaster type scales which seem to run +/- .2gn. Then you jump up to the scales that measure accurately to one kernel like the fx 120i. There isnt anything in between that I know of. A thrower, with a good technique is pretty good but only with certain powders.

 

[R.Morehouse]

I would think that if your accurate charge window is plus or minus one piece of powder you may have to revisit your load development..... I throw then trickle up on an FX 120 and I am sure I am more anal than I have to be. Wish I could fine-tune that wind reading thing as easily and accurately and I can play with the powder charge.....

Regards
Rick

 

[RegionRat]

One other aspect is that there really is not a middle option here. You have your chargemaster type scales which seem to run +/- .2gn. Then you jump up to the scales that measure accurately to one kernel like the fx 120i. There isnt anything in between that I know of. A thrower, with a good technique is pretty good but only with certain powders.

I would think that if your accurate charge window is plus or minus one piece of powder you may have to revisit your load development.....

These two comments point to the reality of the matter. All just my own opinion....

There was no choice for an easy turnkey automatic system beyond the Prometheus until the AutoTrickler/AutoThrow FX120i was introduced.

The alternatives to get below the ChargeMaster were to close a loop on a balance using something like the Dandy vibration trickler using a tuned balance beam with transducers, or to close loop on an electronic scale. Folks have been hand trickling for decades and still can if they choose. That is just reality without even getting into the effects of a kernel.

The other reality, is that it isn't very difficult to show the improvement over a ChargeMaster in terms of the powder weight ES from a sampling, or to show it on the target at distance. The AT/AT FX120i is at least a factor of three more accurate and still faster than the CM even when you accept the occasional overthrow on the FX120i. Unless you are very disciplined and protect yourself from over/under throws and electronic drift, the CM is not a +/-0.1 grain machine. It can easily exceed an ES of 0.3 grains in a batch session.

In reality you are comparing a range of powder throws something like 0.07 grains, to 0.3 grains, not a single kernel.

Many shooters know how to tune for a forgiving node. Some of them are willing to run to their margins with a CM and shoot their game. Others choose not to surrender the safety margin or spare themselves the fatigue it takes to focus on the trickle doing large batches.

So, at the end of the day, it is more about keeping your tune safety margin than it is about a single kernel.

Like Alex says, the reality is the AT/AT FX120i is the only easy alternative to keeping tune margin but certainly not the only one. Once you step away from the tedious methods or the CM, for the same trouble you are at the plus minus kernel level if you guard for over throws.

So, like BHO said once about healthcare.... "If you like your charge method, you can keep your charge method.... YMMV

 

[dcali]

Okay, not being a wise guy, if you are weighing primers then are you ass u me ing that the anvil and the cup are ALL identical? Let me know your thoughts please.

I can't remember where I saw it, but someone somewhere (maybe even here) went and measured the weights of primers before and after firing. The conclusion was that the metal (cup and andvil) were so consistent that the variation in primer weight could be attributed solely to the priming compound.

 

[RegionRat]

I can't remember where I saw it, but someone somewhere (maybe even here) went and measured the weights of primers before and after firing. The conclusion was that the metal (cup and andvil) were so consistent that the variation in primer weight could be attributed solely to the priming compound.

https://forum.accurateshooter.com/attachments/primer-test_weight-sorting-srp-6ppc_1-pdf.1070719/

I think you mean Clay's post.

 

[Ga. Dawg]

The anal side of my OCD says 1 kernel is everything.

^^^That says it all!

Mike

 

[JohnKielly]

Surely it's not worth 116 posts to date.

 

[Daddymac]

Surely it's not worth 116 posts to date.

How about one more?

I always call it splitting hairs when I hear these mostly theoretical arguments about things that usually only really matter in your head, and yes, I suffer from some of these things in my head too, but from now on I'm going to call it cutting kernels.

 

[urbanrifleman]

If your node relies on one kernel, it is not a node. Most of my nodes are .5 grains wide for single digit spreads.

 

[Link]

Is this something like mental masturbation, and hoping for a happy ending? ;}

 

[Alex Wheeler]

Here's a 1,000 yard "ladder" ran round Robin over around a 30 second time frame for all shots. I guess the answer could vary, depending on where you are within the tune. This is a 6 bra with h4895, so each increment is about 6 kernels.

Tom

View attachment 1280478

Look at that target. That barrel broke an agg record, so it's a good barrel. How big is the node? Distances matter here so keep that in mind.