I was packing to take my Tikka 223 to the range for some CB development and I tossed a 20 pack of cheap, Russian FMJ rounds in my shooting bag to maybe do some plinking. Then I got to wondering if the copper would affect CB performance. My old reloading book, written by John Wooters says not to mix them.
I could see not shooting copper in a benchrest gun, but do you avoid mixing the two in your other rifles?
Attached Files
There always IFs.
If the toad didn't have such short legs he wouldn't bump his ass on the ground.
John
Attached Files
i am tempted to read something into that :: the first cast load through the mj fouled bore affected the average greatly .... even more interesting if the widest shots were the first, second ...
your next 20 shots were close to margin of error .. the last 10 shots might show an improvement with a little mj fouling ...
such fun !! ... reminds me of my losing poker hands ...
ken
Attached Files
joeb, 4/3/19
M10 Savage, M110 308 HV barrel,
314299, .3095, Lyman Super Moly, 15/A#9
Hornady 130 gr sp, 43/IMR4895
100 yard 5 shot group, inches, in order shot;
Clean barrel, 5 314299 sighters, 1.625, .8, 1.3, .925, .85,AVG = 1.1 then
130 Hornady, 1.6, .85, .8, 1.4, 1.825 AVG = 1.283, then
314299, 2.9, 1.8, 1.65, 1.1, 1.15, AVG = 1.72
Attached Files
lotech,
Your experience with Jbs in your 270 and 7x61 Sharpe and Hart (haven't thought of that one for awhile) hints that a little bit of copper fouling may improve JB accuracy. This matches what our CB test seem to be showing as well.
A bit of experimenting with fouling and JB would be interesting.
John
Attached Files
Cast bullet fouling shots have been mentioned here. Going back to "conventional wisdom" and its inherent flaws, and in opposition to the experience or claims of others, I've seen little need to fire more than one fouling shot in most cast bullet rifles with clean bores. Sometimes, these "clean" bores may even have a little un-removed copper jacket fouling in them.
However, with regard to fouling shots in rifles used primarily for full-velocity jacketed bullet loads, I've seen a real need for fouling shots in at least two of my rifles. A very accurate Cooper in .270 Winchester was cleaned to bare steel. It took about a dozen rounds to get this rifle shooting again. I had not only removed the copper fouling in cleaning, but had also JB'd the carbon fouling after many rounds had been fired in this rifle.
An accurate New Ultra Light Arms in 7x61 Sharpe & Hart will require about four to five rounds to get it shooting accurately after removing just the copper fouling, not carbon.
While visiting his shop thirty or more years ago, Ed Shilen remarked that there was no need to clean out all the copper in a barrel; just clean to the where accuracy isn't affected. I'm sure at the time he has speaking of jacketed bullet use only, but the advice will apply to cast bullet use as well, at least in most situations. Mr. Shilen's suggestion would require some trial and error work, but nothing difficult.
Attached Files
The question that the tests so far are obviously not answering is -- what about the JB fouling from 50 shots. What about 100, 200 shots. What about enough to affect jacket bullet accuracy? There's a lot we don't know.
Brodie is going to provide some data. Who else is curious enough to do some shooting?
John
Attached Files
Finally got to the range today (March 29)for another try at the accuracy of CB after fouling bore with JB compared to accuracy from clean bore.
Load was the same as before except for a different lot of the same 80 grain spitzer bullets.
Accuracy of four 5-shot groups of CBs starting with a clean copper free bore .84', .70" .88", 1.50" -- Average 0.98"
Accuracy of four 5-shot groups of JBs 1.66, 1.70", 3.00", 1.64" -- Average = 2.0"
Accuracy of four 5-shot groups of CBs .78", 1.24", .42", .96" -- Average = 0.85"
Accuracy of the cast bullet loads were 13% better after fouling the bore with twenty rounds of jacketed bullets.
This result is similar to the previous four similar test results all showing improved accuracy after fouling the bore with 20 jacketed bullet . Groups shrunk by between 13 and 19 percent.
This is of course the exact opposite of what we thought we knew. Every experienced CB shooter knows that jacketed bullet fouling ruins cast accuracy because that's what we have been told. But when five series of groups by three different shooters using five or six different loads all show that 20 rounds of JB fouling improves accuracy an open minded shooter should begin to question the rule that you can't mix cast and jacketed bullets.
Of course these tests so far don't cover all the possibilities. What about the fouling from 50 jacketed bullet loads, 100 loads, 200? Surely gross guilding metal fouling, the kind that we have been told degrades JB accuracy would also degrade CB accuracy. We can guess but at this point we don't know that either.
Anybody have a rifle not cleaned since the last prairie dog shoot that you have a cast bullet load for? Shoot a few groups before cleaning and a few more after cleaning and see what happens.
John
Attached Files
I have to throw in the possibility that the high pressure loads for the jacketed bullets,
may lay down ( not only?) copper , but hard smokeless powder fouling that may have
slicked up the barrels. This is particularly with the ball powders such as 748 and H 414.
>>??????
beltfed/arnie
Attached Files
INdeed, I will go with the Hoppes No.9 "Since 1909"
First of all, back in 1842 , I do not believe that people were shooting copper jacketed bullets.
Closest thing in mid 1800s was Copper cased rimfire ctges such as the 22s and the Spencer 44 rimfire.
Bullets at that time were LEAD .
Second, Google verified the 1909 date
beltfed/arnie
Attached Files
I will go with the "Since 1903" for Hoppes No 9.
Why would Jeremiah Hoppe invent it in 1842 when I don't believer people were shooting copper jacketed bullets.....
Seems to me there were ctges- rimfire that had Copper cases, but still plain lead bullets at that time.
?????
beltfed/arnie
Attached Files
Will someone delete the 2 pictures way above?
Thanks;
joe b.
Attached Files
For casual readers that have dropped on on this thread and wonder what is going on -- here is a brief summary of work up to this point.
max503 started the thread wth this question on 04 January 2019:
Attached Files
Joe,
It's a judgement call of course. My first thought was to count the first two groups before and first two after. Hard to argue that they are affected by leading because they are about average for this rifle and load.
The other approach is to throw out the whole session because the leading causes second guessing.
I think the first approach is defensible but like the second better.
John
Attached Files
John; what should I take out?
jope b.
Joe,
Thanks for your summary and plot of the data being collected on these before and after JB tests.
However, I think there is good cause to eliminate the data in the first four lines of the table - or at least most of it. After this test the bore was found to be fouled with hard to remove lead that required abrasives. I believe this caused the near doubling in group size of the 1.84 and 1.86 groups. Leading during the before groups may also have caused the 1.52 group. I discussed this in a 1-29-19 post.
Of course the summary is yours and adds to the usefulness of the test -- just my two cents worth.
John
Attached Files
Joe,
Thanks for your summary and plot of the data being collected on these before and after JB tests.
However, I think there is good cause to eliminate the data in the first four lines of the table - or at least most of it. After this test the bore was found to be fouled with hard to remove lead that required abrasives. I believe this caused the near doubling in group size of the 1.84 and 1.86 groups. Leading during the before groups may also have caused the 1.52 group. I discussed this in a 1-29-19 post.
Of course the summary is yours and adds to the usefulness of the test -- just my two cents worth.
John
Attached Files
Greetings,
My error in arithmetic, I used a different number off my working papers. (Besides, I like your numbers better) No, you did not misread; I miscalculated off wrong data.
Now, on to today's results. I shot 25 rounds cast, 12rounds jacketed, then 19 rounds cast (one case was cracked in the neck, so it went into the scrap pile while prepping cases). 5 rounds cast and 2 rounds jacketed were used to adjust scope. Load was LC82 case, Lee 170 grain GC weighed out as 170, CCI 200, 22 grains IMR 4227. Note different charge. Jacketed was 165 Speer BTSP, ADI case, CCI 200, 48 grains H414. Slightly different parameters, but if jacketed before cast improves cast groups, I think it would prove so generally across the board of variables; hence, some different round preparation. Results in inches. Groups for measurement were 5 round groups except for first group after jacketed, that was only 4 rounds. Extra rounds were shot to bring groups near bullseye but not measured. Some numbers rounded.
Results: Before Jacketed After
Group : 3.30, 2.22, 3.49, 3.72 AVE 3.18 3.79, 3.35 3.28, 3.34, 3.04, 2.68 AVE 3.05
Mean Radius: 1.28, 0.79, 1.51, 1.35 AVE 1.23 1.18, 1.19 1.28, 1.07, 1.12, 0.92 AVE 1.09
Results? After the jacketed the cast did better again. Difference in group size was 3.18-3.05=0.13. .13/3.18=.041; 4%
Difference in MR was 1.23-1.09=0.14. .14/1.23=.114; 11%
Hope I got it right this time John, otherwise I may have to stay after school and clean the blackboards.
I find it interesting looking at the group size averages the mean radius averages; looking at the targets there were a couple outliers in the groups that enlarged them, and some after groups had most rounds much closer to each other than before groups. What this seems to indicate to me is that using jacketed bullets just before cast bullets helps groups. Long term, who knows, but in the short run firing 10-15 rounds jacketed before cast would help my scoring slightly. I did not get the 14% mean radius difference, but at 11% that is still significant to me. I think my new motto should be paralysis by analysis as seen in an earlier report in the forum. I do like to work numbers in spite of my arithmetic.
John, hope your trip to the range was as good as mine, especially weather wise.
TK
Attached Files
TK,
Unless I don't understand the numbers you reported, I believe your reported percentage decreases in group size and MR are in error.
Decrease in MR = (0.95-0.77)/0.95 = 19%
Decrease in group size = (2.79 (ave. before) - 2.31 (average after))/ 2.79 = 17%.
Please let me know if I have misread something.
Note that these increases in accuracy are similar to the 14% increases in accuracy that both dbarron and I found. It is highly unusual for the results of three independent experimenters using different equipment and different loads to find such consistent results. I plan to shoot another test tomorrow that may give us at least a hint whether this is just a coincidence or something more.
This isn't an exclusive game. Are there others who would like to join in the fun. The more data, the better.
John
Attached Files
Greetings,
John, I shot 15 jacketed rounds as I was planning on shooting 15 rounds before and after. I plan on doing more shooting tomorrow if weather permits. Different loads, 22 grains IMR 4227 instead of 16, and different jacketed load (165 speer btsp over 47 grains H414 vs speer 130 grain hp over 47 grains W748. ) If things go well I will use the Chronograph too.
Looking at the above, there was about a 6.8% decrease in group size and 5.4% decrease in MR.
TK
Attached Files
wimilkman
30
Tom Acheson
22
pat i.
18
Aaron
13
BRatigan
10
MarkinEllensburg
9
Ed Harris
8
porthos
7
mashburn
6
Pigslayer
5
