Leading - how many shots until it becomes aparent?

[303Guy]

How soon should I be able to detect leading in the bore?

I have fired test loads and seen no apparent leading and then gone out and fired a string of seven shots with no apparent leading. On another occasion, I have detected lead smear on the first shot. Now I am seeing none from shot to shot - only three fired! It is a new lube I am using. The velocity would be close to 1900fps, maybe a bit less, I don't know. Powder charge was from 35gr to 40gr of H4350/AR2209 behind 200 to 245gr bullets. There was flame cutting on at least two of those bullets. I ran a cotton ball wad, soaked in cutting fluid through the bore and it came out free of any lead flakes. The second, drying wad was pretty clean. Also, there was no tell tale resistance to the wad being pushed through.

[Bigjohn]

In my experience, leading can occur from one round fired or it can accumulate from a string of rounds fired.

To explain the aforementioned statement; if the conditions required, either with the cartridge or bore exisits; it only takes one round for leading to occur. For it to occur over a string of shots; the same conditions must apply for all cartridges fired.

If the barrel is not suitable for cast then you are likely to have leading result from all firings no matter what changes you make to cartridge/boolit.

I hope I have been able to put into words which you can understand what I am saying.

John.

[44man]

Leading depends on so many factors that it can't be guessed what causes it or the lack of it.
Even the alloy changes things. I get more lead---just loose strands that wipe out on the first patch---with straight WW metal. If I add antimony and tin or even go the other way by mixing a 50-50 lead, WW alloy, leading stops.
I feel the WW alloy is off and the metals do not have an affinity for each other. It might be just a lack of tin to bind them into a solid alloy and some metal is rubbing off in the bore.
This shows up fast in my BPCR. No leading with a 20 to 1 or 30 to 1 mix but a few WW boolits will lead the crap out of the rifle. Harder boolits do not lead. I shoot greatly oversize boolits too.
Then it depends on what is in your WW metal depending on where they were made.
It might take 50 pages to list reasons why or why not but the total answer will never be found, even a powder change can blow away a lot of work.
I can't tell anyone why their gun leads! :Fire:

[dwtim]

I work from the other direction: I set a goal for the minimum acceptable rounds before leading is detectable.

Handguns:

A load that produces fouling visible to the eye while at the range, and with 50 rounds or less, is a reject. My experimentation has demonstrated that if fouling doesn't accumulate by 100 rounds, it never will. That is the ideal. However, a single bullet that was seated incorrectly (and usually damaged in the process) can change this, and so can a bullet with bad fill out and a correspondingly underdeveloped base. Every once in a while, I accidentally let one through and it ruins a shooting session.


Rifles:

Due to time constraints, I unfortunately have not had the opportunity to fire more than 40 rounds out of one rifle, in one session at the range. So far I have recovered no more than a sliver and some tiny flakes of lead. I did experience lube accumulation, though, so I've determined that .313" is the best diameter for my LE rifles.

However, I'm not using your anti-Elk ballistic missiles :), so I don't how my experience translates.

[303Guy]

However, I'm not using your anti-Elk ballistic missiles :), so I don't how my experience translates.:mrgreen:
I love those missiles!

Thanks for the replies! They do help me to get a fix on things.

I was working on the principle that the load and bullet design and lube should prevent or control the leading. I did not take into account the finer details like alloys. So, a small amount of tin. Thanks.


If the barrel is not suitable for cast then you are likely to have leading result from all firings no matter what changes you make to cartridge/boolit.

Mmmmm..... Now there is a can of worms! See my new thread.
(The gun that shoots crap with cast doesn't seem to lead!? As Homer would put it - Doh!):mrgreen:

[jonk]

Depends. I've gotten awful leading in 2-3 shots. Or a few thousand with none.

But then we have to define 'leading'- most any load I shoot will leave a slightly silver/gray color in the grooves of the rifling but it wipes out with one patch if I'm doing my part. I don't consider this leading. Other loads will leave little lead shards in the bore as described above. As long as they aren't sticking to anything, I don't worry about this either; in point of fact if they just wipe out it tells me my lube is good and keeping them from plating to the bore.

Where I worry is when I get long gray streaks that are fairly thick. A quick scratch at the rifling near the muzzle with a dental pick shows how deep these can get. That's something to worry about. And to get back to the original question, if I have a problem that is causing that, usually it happens within the first 5 shots.