CAST BULLET ACCURACY - AFTER THE BEGINNING
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- Last Post 10 November 2014
Appropos of nothing in particular, but having to do with bullet lubing: I'm doing a lot of chronograph work with my shooting. A whole lot. I noticed quite a few red flecks on my Skyscreens. Mystery--what was it, and where did it come from? It was to be found on all three screens. It took the entire time of my walk from the screens fifteen feet to the shooting bench to figure it out. The red flecks were, of course, the Carnauba Red of the bullet lube. There was a surprising amount of it, always in small flecks, but not nearly enough to create any kind of a continuous layer on the screens. Not even remotely close. But, I take this as an indication that there is plenty of lube present; that, plus I'm just not getting any leading. Of course, my velocities are relatively low, but even at over 1900 ft, no leading that I've been able to discover. Unfortunately, at that velocity level, little accuracy, either. Just putting this up as a matter of minor interest. Bill
In theory, there's no difference between theory and practice. In practice, there is. My fate is not entirely in Gods hands, if I have a weapon in mine.
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I kinda get it now. I am a lever nut so getting to 2 MOA is a goal with my peep sights that I doubt is even possible anymore! I have only one bolt and it is the only scoped rifle I own, CZ 527 223.
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those shooters on * accurate shooter * throw away barrels that won't shoot under 1/4 moa .. i know, i take them off their hands ..., got 6 or 28 of 'em in 224 y 243 y 7mm , oh, a lilja in 308 ; my collector barrel ( yep, I B weird ) is a 222 mag chambered by fred sinclair . i don't collect cigar boxes , tho ...
oh, the point ... those obsessive .. fanatic ... guys are trying to get from 0.234 down to 0.018 moa.
joe is about 80 per cent correct ... the sense is correct ... that the ” won't help ” ... list applies to a rifle that shoots 2.5 moa, trying to get it to 2.0 moa.
just to not let joe entirely off the hook, i think that if a rifle isn't free floated and pillar bedded you are just scaring cats away from your bird feeder and wasting powder when you shoot it.
hey, maybe i should write an article on how to pillar bed with no hassle ...
ken
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those shooters on * accurate shooter * throw away barrels that won't shoot under 1/4 moa .. i know, i take them off their hands ..., got 6 or 28 of 'em in 224 y 243 y 7mm , oh, a lilja in 308 ; my collector barrel ( yep, I B weird ) is a 222 mag chambered by fred sinclair . i don't collect cigar boxes , tho ...
oh, the point ... those obsessive .. fanatic ... guys are trying to get from 0.234 down to 0.018 moa.
joe is about 80 per cent correct ... the sense is correct ... that the ” won't help ” ... list applies to a rifle that shoots 2.5 moa, trying to get it to 2.0 moa.
just to not let joe entirely off the hook, i think that if a rifle isn't free floated and pillar bedded you are just scaring cats away from your bird feeder and wasting powder when you shoot it.
hey, maybe i should write an article on how to pillar bed with no hassle ...
ken
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I have wonder about this recommendation. Looking back over the military rifle national data there is nary a citation of 4895 in the data sheets. Loads are 2400, 4759 (RIP), 5744 and the odd 4198. I do not see the reward in pursuing this powder. And...fillers still spook me. I have a pristine 1919 5-groove that does not deserve a ringed chamber.
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As a greenhorn I'm left in a quandary. I went to the Accuracy Shooter site were many champion shooters in precision shooting hang out and they recommend many of the “do not” list as standard practice. Rifle bedding has tightened up many groups for jacketed shooters. I've had it twice improve a bolt action. Frank Marshall, in his writings, disagrees with this as well. The sample 30-06 article lists his ideas clearly.
It seems you are discounting techniques that jacketed bench rest shooters recommend. Is this because the inherent accuracy of lead makes these improvements useless or are the techniques useless in themselves?
How tuned and custom are your rifles you base this on Joe? Are we talking fully developed bench rest rifles or well maintained factory rifles?
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As a greenhorn I'm left in a quandary. I went to the Accuracy Shooter site were many champion shooters in precision shooting hang out and they recommend many of the “do not” list as standard practice. Rifle bedding has tightened up many groups for jacketed shooters. I've had it twice improve a bolt action. Frank Marshall, in his writings, disagrees with this as well. The sample 30-06 article lists his ideas clearly. It seems you are discounting techniques that jacketed bench rest shooters recommend. Is this because the inherent accuracy of lead makes these improvements useless or are the techniques useless in themselves?
How tuned and custom are your rifles you base this on Joe? Are we talking fully developed bench rest rifles or well maintained factory rifles?
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Jesse Miller's TIC TAC TOE chart method of looking at more than one variable.
7.5.2 THE TIC – TAC – TOE CHART
Jesse Miller, OD
How do you decide between 3 primers, 3 powders and 3 different charges? Yeh how do you do it? Well my approach is what I call Tic-Tac-Toe.
If you were to shoot 10 rounds each, that would be 3x3x3x10 = 270 rounds! Not impossible, but certainly time consuming.
If you shoot 5 round groups, using only 2 primers with each powder and 3 charges with each powder; mixing as follows:
Powder A Powder B Powder C
#1 Primer #1 Primer #2 Primer
Charge J Charge J Charge J
#2 Primer #1 Primer #1 Primer
Charge K Charge K Charge K
#1 Primer #2 Primer #2 Primer
Charge L Charge L Charge L
This assumes that the powders are all of about the same burning rate, that is close together on burning rate charts. Note that each component has been used 3 times, and yet we have only 9 groups, or 45 rounds. Record the group size in each space matching the load. Then by cross referencing, we can see which combos gave the better groups.
Now it is time to select the best combos. I don’t think primers will make as much difference as the powder charge, so we could have skimped on primers and shot more charge variations. Select the three best combos. Repeat the process using 10 shot groups (30 rounds), (Most statisticians will tell you that you need more than one or two groups to indicate which load is best.) Again, do the Tic-Tac-Toe chart to further refine your load choice.
It only took us 75 rounds (not 270) to get to get where you are ready to refine the powder charge with variations of 0.5 grain or even 0.1 to 0.2 grains.
Now having arrived at a reasonably accurate load, it is time to refine it with several 10 shot groups Now shoot several groups with the above minor variations. Keep records. Use group sizes as just as important as SD. The more groups you shoot, the better will be your choice of the load. At this point a Chronograph is useful in refining a load, if available. This provides information on Velocity, and ranges of Extreme Spread and Standard Deviation.
Wishing you loads of X’s.
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(groan...)another powder to try....fortunately I have that one somewhere. I may try it with dacron from my wife's stash, but I'm tres worried about fillers....
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H4895 can be reduced to 50% case volume in 30-06 and maintain good ignition but can also have ES increase as you reduce charges and increase airspace. Using a filler and reduced charges of H4895 has proven to me to reduce ES substantially in low power Loads with H4895, cast bullets and BPI Original Ballistic Filler.
I have had good results with 105% compressed loads with reduced charge plus filler.
Source: http://www.ballisticproducts.com/prodinfo.asp?number=BUFFER
Gary
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Pentz, Thanks for posting your results. Always good to see some actual data instead of just opinions. I hope more members will follow your example.
My only comment is that it is asking a lot from six groups to sort out three different primers and two lubing conditions. I hope you shoot additional groups with the same loads to see if you can replicate your results. It is easy to be led astray by small samples. I will look forward to your future results.
John
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I am posting this experiment as an example of my non-scientific approach; my degree is in Anthropology (retired) and not string theory. Breaking in my pristine 1919 5-groove Winchester barrel (found NOS) with only 400 cast rounds so far, been interested in finding another powder than 2400 and number of lube grooves that work best. Frankly, my rifle is a cheap date, refusing ANYTHING other than 2400, and I've tried most of all of them. 16.5 gr of 2400 is running between 1475 and 1510 FPS over my Chrony F4 at Clark Rifles. Only the 2-groove loads group worth a hoot at 100 yards; oh and it does not like CCI primers either. Have not gotten to 300 with this rifle...yet...:cool:.
Got a match at Canby this Saturday. This load will probably go all to heck with my luck!! The quest WILL continue.
1. 16.5 2400 311299/200gr. .310 GC WW primer/Two grooves lubed - - 1.360"
2. 16.5 2400 311299/200gr. .310 GC Rem primer/Two grooves lubed - - 1.935"
3. 16.5 2400 311299/200gr. .310 GC WW primer/one groove lubed - - 2.125"
4. 16.5 2400 311299/200gr. .310 GC Rem primer/one groove lubed - - 2.221"
5. 16.5 2400 311299/200gr. .310 GC CCI primer/one groove lubed - - 2.300"
6. 16.5 2400 311299/200gr. .310 GC CCI primer/Two grooves lubed - - 2.915"
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hOW ABOUT A SHOTGUN PATTERN. Or, maybe a swarm of mosquitos?
B.E.Brickey
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"A simple picture is worth a thousand words"
Sorry but I can't think of a picture that would be worth even a dozen words when you are reporting the average group sizes involving thirty groups. John
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"A simple picture is worth a thousand words"
Sorry but I can't think of a picture that would be worth even a dozen words when you are reporting the average group sizes involving thirty groups. John
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After poring over the results of the test mentioned above in an attempt to prove that the amount of lube on a CB can affect accuracy and get Joe to take that item off his WILL NOT list, I decided to do it all over again and see if I could replicate the results I got with the first 15 groups. Just finished it today. I now have the dope from ten five shot groups for each of 1, 2, and 3 grooves filled.
I believe the results say something not only about how much lube should be used but also something about lube purging as well as the reverse Goldilocks effect. But my conclusions are complicated and I don't think I can explain them clearly in a post. Since I think others may be interested, I will try to write it up and if I can make it make sense I will submit to Glenn for possible publication TFS.
I can say that Joe's WILL NOT list is safe for the time being -- at least from me. I hope others are energetically doing testing to prove that other items on the WILL NOT list shouldn't be there.
John
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Ken, It would be a good idea to find the average radius of dispersion in the test reported above but I will leave that for others. I could send the target to someone that could scan it and has the software to let the magical machine do the work. John
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I shot my test on amount of lube today. In the past I thought that I had noticed that reducing lube to bare minimum (only in the space ahead of the gas check) improved accuracy but only on the basis of a couple of groups sometime in the distant past. However, a lot of CB shooters seriously interested in accuracy at least think they have found the same thing. Of course, it is easy to see things that aren't really there unless a lot of groups are fired with condition one and condition two in competition.
My hypothesis was that varying the amount of lube sometimes makes a significant difference in accuracy and thus Joe should take that item off his WILL NOT list.
The only bullet I had handy with three lube grooves was the NOE 70RN that I wrote about in TFS # 231. I shot 5-5-shot groups each set with one, two, and three grooves lubed with LBT Blue. The load was arbitrary and untried involving CCI small pistol primers, 4.5 grains of 700X, bullets were of WW and unsorted, I weighed the powder until I saw 4.5 on the screen because dropped loads varied from 4.1 to 4.9 (about 18%.)
When testing for a variable change I usually alternate five shot groups to avoid changes in technique, fatigue, tired eyes or condition changes skewing the results. But because this was testing lube quantity and bore condition might be an issue I shot all the 1 grooves then the 3 grooves, etc. I fired three fouling shots with the same amount of lube before each of the three series. At least conditions didn’t change because I shot in a tunnel.
After I have shot the groups with one and two grooves filled it looked like my belief that less lube is better was being confirmed. Then I shot the set with three grooves lubed.
Results (average of each set of 5 five shot groups)
Groove ahead of gas check only filled -- 1.26 MOA
Two grooves filled ------------------------- 1.34 MOA
Three grooves filled ------------------------ 1.19 MOA
If I worked the Wilcox rank sum test right the results didn’t show a significant difference between one, two, or three grooves filled. So I will have to leave Joe’s WILL NOT list as is for now. I may shoot additional groups to see if the reverse of the Goldilocks principle applies to the amount of lube on bullets as the above results hint.
Not only did this test not help me prove Joe wrong but it also cast doubt on my belief that less lube is usually better. Additional groups with this and other bullets is called for.
Additionally, the percentage the worst of each five shot enlarged the best four shot group may have cast a bit of light on lube purging – or not. I will write a more complete report for the Fouling Shot.
John
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