Shooting Cast after Jacketed Bullets

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Last Post 28 July 2019

CBA President

John Alexander posted this 07 April 2019

First I have to apologize to any and all members who were following the thread of a similar name about the effect on cast bullet accuracy of jacketed bullet fouling. I accidently deleted it and as far as I can determine that is irreversible.

I was responding to Joe's request to delete his previous posts of his tables and graphs since all but the one he posted today were incomplete. i deleted the immediate past graph successfully. When the screen came back it was on joe's graph that he started the thread with and when I deleted this first post it took the whole thread.

All that I can do is apologize and ask Joe to repost his most recent table and graph. I will repost the data I posted yesterday because some may not have seen it yet. I hope others who posted recent comments will also repost.

John

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CBA President

John Alexander posted this 28 July 2019

Just before going to a CB match yesterday I bore scoped my rifle and could see slivers of what looked like lead in the corners of the grooves. Further cleaning didn't seem to remove it. Based on the research above that, at least for me has discredited the old saw about JB fouling ruining CB accuracy, I quickly loaded up a few full charge JB loads to take with me to clean out the lead.

The first thing I did on the first target was blast those JB loads into the backstop and then started the match shooting without cleaning. I don't know if it removed the lead or not. But I have pretty good evidence that the JB fouling didn't hurt the CB accuracy. I fired one of the best scores ever, for me, in the match.

At this very moment some old CB shooter somewhere is telling a younger one that JB fouling ruins CB accuracy.

John

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John Alexander posted this 31 May 2019

One of the advantages of shooting cast bullets is that the lower pressures cause less gas erosion and so barrels last longer. Only a few argue with that. However, I don't think we know how much longer or even how to define it so a fixed number is justified. Interesting topic but probably should have it's own thread.

John

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shastaboat posted this 31 May 2019

I have no idea. I think I'll be dead before that. I use a lot of 2400 for bottle neck cases. I'm sure I have 5000+ rounds through my Browning A-Bolt Medallion .223/5.56 and that is after at least 2500 jacketed rounds before I went to cast.

Because I said so!

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John Alexander posted this 29 May 2019

Sounds like you must have some high mileage on some of your rifles. How many CB loads does it take to wear out a throat?

John

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shastaboat posted this 29 May 2019

John,

I do not compete but would agree that cleaning between shots may be the ultimate procedure but obviously for my needs it just wouldn't work. I've been known to shoot as many as 500 rounds a day at these squirrels but generally around 300 rounds per day. I have cleaned after 100 rounds generally and then it is a trip back to the Toy Hauler for a lunch and beer break and cleaning break. The cleaning break is much easier if I fire a couple of jacketed rounds first. I figure 50% hits on squirrels out to 200 yards so the math is a bunch of squirrels to feed the crows, buzzards, hawks and an concessional eagle. Even the coyotes might get fed.

Because I said so!

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John Alexander posted this 29 May 2019

Shastaboat,

I and others have observed some of the same things you mention. It is quite common for some CBA competitors to bore clean after every target card to maintain best accuracy.

On the other hand I, and others, sometimes find loads that produce a stable bore condition that never (as in whole match or even whole season) needs cleaning and maintains top accuracy. I consider this the holy grail but can't always achieve it.

What is new to me in your post is the possibility that the hard powder fouling can be removed by firing full charge JB loads. if this is as effective as a quick bore cleaning (solvent - brush - dry patch) it might be the best procedure for match shooting and could even be done in the middle of a target card by a couple of quick shots JB into the backstop if wayward shots indicate fouling. Of course the JBs and CBs would have to make clearly different holes in paper or others might object to shooting JBs during a CB match.

John

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shastaboat posted this 29 May 2019

I'm not into the scientific testing and mathematical posting of results as some of you. I do know that when I'm out shooting Nevada Pot Gut Ground Squirrels (1/2 the size of a Prairie Dog) (Belding Ground Squirrel) out to over 200 yards with cast .223/5.56 that as powder fouling increases up to 100 rounds fired and accuracy decreases that if I fire 2-3 JB full power loads that accuracy increases until it degrades again with powder fouling.

Maybe it is the powder fouling that needs to be worried about. Actual bore cleaning doesn't show any JB fouling and blue/green patches but the removal of the powder fouling with even Hoppes #9 sure allows a dry patch to run smoother through the bore. And after powder fouling is removed accuracy certainly returns.

Because I said so!

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John Alexander posted this 25 May 2019

Test #11

The leftovers of another batch of gas checked bullets that were a bit too small to shoot well tempted me to run another test of before and after groups. I have a hangup about throwing bullets with three cent gas checks back in the pot. So i often find an excuse to add a three cent primer and a few more cents worth of power and shoot them. A good example of the lure of the sunk cost fallacy even on folks who know about it.

Procedure was the same as my earlier tests with the 223 Tikka. Conditions were a bit extreme a with nice sunny 65 F day but with a mostly 12 o'clock wind gusting to maybe 30 mph busy blowing off targets, caps, and anything loose of low density off the benches.

Before CB groups: 1.04, 1,44, and 96 moa -- Average = 1.15 moa

Jacketed bullet groups: 1.14, 1.24, 1.28, and 1.08 moa -- Average = 1.18 moa.

After CB groups: .74, 1.84, and 1.02 moa -- Average = 1.20 moa.

This test showed a 4% increase in group size in the cast bullet groups fired after the jacketed bullets instead of a small decrease like the heavy majority of the other ten tests so far.

Side note -- The jacketed bullets were bulk Remington 55 grain pointed soft points seated as far out as possible. The cannelure was about .2" beyond the case mouth. This was still 0.112" short of touching the lands due to the "freebore" caused by 11,500 rounds fired. Since these still grouped near 1 moa it shows how tolerant a JB can be to seating depth.

John

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John Alexander posted this 19 April 2019

There is an interesting set of remarks about jacketed bullet fouling and accuracy over in the

Does The Amount Of Time In Between Firing And Cleaning Effect The Effort Required To Remove Lead?

What we need to extend our experiments is a prairie dog shooter who also shoots casts in the same rifles. Mashburn seems to know about serious JB fouling.

John

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John Alexander posted this 14 April 2019

I think Joe's remarks about what we know so far are about right.

I also think that it is pretty obvious that the dire warnings that a bit of JB fouling (up to at least 20 shots) degrades CB accuracy would be pretty hard to support in spite of the fact that we have been hearing them as absolute truth for at least 70 years.

John

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joeb33050 posted this 14 April 2019

Is it possible to get enough jacketed bullet fouling in a barrel to degrade cast bullet accuracy?

We don't know.

Will shooting cast bullets in a jacketed bullet fouled barrel remove that fouling?

Maybe-Probably

Will a slightly-moderately jacketed-bullet-fouled barrel degrade cast bullet accuracy?

Probably not, at cast bullet accuracy averages around 1 moa.

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joeb33050 posted this 14 April 2019

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RicinYakima posted this 13 April 2019

I am finding this very interesting. My memory of firing old military rifles with 50 years of fouling was that they shoot cast better after cleaning. BUT I never tested this hypnosis. Just cleaned down to bare metal with reverse electrolysis and then began shooting cast. Keep up the good work!

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John Alexander posted this 13 April 2019

TESt #10

Yesterday, 4-12-19 I fired another test of CB accuracy after fouling with JB loads. It has been questioned if the CB fouling before the string of JBs might have prevented normal JB fouling because of the lube deposited in the bore preventing adhesion of the copper in the first eight tests. Joe’s test #9 investigated this possibility. I followed Joe’s lead in shooting test #10 by firing the jacketed bullets starting with a clean dry bore to see if JB fouling deposited on clean steel had an effect on CB accuracy. My test #10 follows.

Clean bore with Hoppe’s # 9 followed by the copper remover Sweets 7.62 until no trace of fouling can be detected.

4 5-shot groups with Sierra 69 gr MK and 18 grains of Reloader 7 - .98, 1.06, .82, .90 moa – Average = .94 moa.

One fouling shot.

4 5-shot groups with same CB load as before -.72, 1.14, .96, 1.24 moa. Average=1.03 moa

Clean bore with Sweets, 30 minute soak.

One fouling shot

4 5-shot groups with same CB load - .40, 1.34, .98, 1.68 moa. Average = 1.10 moa.

Summary

This test #10 again failed to show that JB fouling degraded CB accuracy.

John

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John Alexander posted this 11 April 2019

I missed what Joe was doing with his last test (#9)

This time the JB to lay down fouling was done on a clean bore where it may adhere better instead of a CB fouled bore which might avoid copper fouling by providing a dirty surface.

Because his average accuracy was worse than his previous "before" CB groups it may be telling us something.

I will try a similar test in a few days to see if I get similar results.

John

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CBA President

John Alexander posted this 10 April 2019

Ken,

I sometimes during the CBA nationals we will drive the 40 miles or so to the Sierra and buy a few pounds of factory seconds. The bad news is that there isn't a major discount. The good news is that they seem to almost always minor bleminish and seem to shoot as well as the ones in boxes. Nosler is 15 miles down the road and the seconds are discounted even less but shoot fine. I think the cheapest jacketed bullets are probably the bulk FMJ sold to the folks that like ARs, AKs and such.

I agree, heavier JB fouling is what we should test next. Brodie is going to do a bit of that with his "new" Mauser.

John

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Ken Campbell Iowa posted this 10 April 2019

... joeb: ...

well, there goes my little billfold card that states 3 absolute rules for cast bullet success. it was getting a little tear-stained anyway ...

**************

i wonder if sierra/hornady would have a bucket of reject bullets cheap so we could get a barrel real copper fouled .

if shooting cast removes copper fouling, is it the lead or is it the gunpowder ?? ... or the graphite on the powder ??

thanks for your test . ken

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joeb33050 posted this 10 April 2019

Shot Tuesday

6 PM Tue., 2 patches with odorless paint thinner, 3rd patch clean, nylon brush with #9, 2nd patch clean, overnight,

6 AM Wed.,-bore wet with #9, dry patch had some black stuff, another #9 wet patch and wait.

10 AM Wed.,black stuff on patch, another #9 wet patch, wait

2 PM Wed., black stuff on patch, another #9 wet patch, wait,

6 PM Wed., black stuff on patch, another #9 wet patch, wait,

4 AM Thu., a little black stuff on patch, another #9 wet patch, wait,

11 AM Thu., no black stuff on patch. The black stuff is probably Moly, from the cast bullets.

NO blue/green, no copper.

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Larry Gibson posted this 09 April 2019

joe

Interesting tests and I applaud you for posting.

Mike Venturino had an article published in Handloader magazine several years back where in he stated accuracy with his cast bullets (mostly in milsurp rifles) was just as good after shooting jacketed. On the other forum I concurred with him as that was my was also my experience. He responded to a couple posts about his article and received such a raft of criticism from self styled experts (my simple post was ignored......for once) that I don't believe he has posted there on that forum since.......

It's enlightening to see actual test results.

LMG

Concealment is not cover.........

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