Copper Fouling and POI/Accuracy

[stanley52]

Ok so I am still relatively new to LRH, and obviously have much to learn. I have recently had a semi-custom rifle built, chambered in .260 with a Benchmark barrel, if it matters. I was wondering:

1) Does copper fouling change your point of impact/zero? like if there is some fouling and i use some Bore Tech CU2 and scrub it all off, is it going to change my zero?

2) Does copper fouling increase accuracy/consistency, does it hinder it, or does it help it and then eventually hurt it if there begins to be too much?

3) I know all this can vary from barrel to barrel, and i was wondering if anyone has had any experience with Benchmark's barrels (Carbon Steel Barrels)?

Thank you ahead of time for your input.

 

[justgoto]

[ame=http://youtu.be/_KRUAv3Byp4]SNIPER 101 Part 40 - Coppering and Powder Fouling - Rex Reviews - YouTube[/ame]

[ame=http://youtu.be/GcmuSXqmKjs]SNIPER 101 Part 45 - Copper Removal Issues in Long Range Precision Rifles - YouTube[/ame]

 

[Mikecr]

A change to fouling, more/less/type, affects zero(initial POI).
Copper buildup in the bore is bad for accuracy(unless your accuracy is based on it).
Oil left in a bore has to be burned out before stable fouling sets.

2 approaches to dealing with this:
Clean a bore as infrequently as possible.
Clean a bore after every use, and prefoul just before another use.

I was taught to put a gun away cleaner than it was pulled.
With this, my guns are maintained in better than brand new condition.
I hand prefoul clean dry bores before putting them away.

 

[stanley52]

Good stuff to know, but please excuse my ignorance... What is "hand pre-fouling"? After I clean my bore I always shoot 2-3 shots to carbon foul it, is this the same thing or something else?

 

[Mikecr]

I missed the context of your original question. That you intended only to go after copper while leaving carbon in the bore & would this affect zero.
This I don't know.

 

[Greyfox]

I think the copper or carbon effect on accuracy and POI is largely dependent on the barrel, load, and how you condition that barrel prior to shooting for hunting or score purposes. I try to start with a well cleaned barrel, free of copper or carbon and treated with a lubricant or barrel conditioner. This is the condition for storage. I then determine the number of shots to stabilize the POI. My accuracy standard has been established under this stable POI. Once the barrel is in this fouled condition, I check the POI under cold and warm bore conditions. I then determine how many shots I can shoot before POI changes, or accuracy degrades. This will determine when the rifle gets cleaned. When the rifle is used again I foul the barrel with number of shots required to reach my POI and accuracy standard. For hunting I am more concerned with cold bore, for competition, warm/hot bore. The perfect situation is hot or cold, no change. I have two Rem 700 5R Milpecs in 308 that condition in 4 rounds, hold POI, shoot sub .5MOA, hot or cold, and will hold this to 200 rounds. Not sure how much above 200 shots without change they will go because I stop at 200 or less and clean. I think the 5R rifling has to do with this. My two primary LRH hunting rifles, a 6.5x284 Cooper, and a 300WM Rem 700 Milspec, give same POI warm/cold but have only tested for 40 shots, which they hold accuracy and POI.