A friend of mine has recently purchased a new Savage 12BVSS in .22-250. Initial accuracy was extremely good...in the neighborhood of 3/8" Yesterday he brought it to me with a dramatic decrease in accuracy. It hadn't been cleaned for about 50 rounds. I put a dozen or so bore cleaner soaked patched through it. The scope mounting was checked as well as the bedding screws. The barrel remains free floated. All seemed OK. The first group shot with it was a disappointing 1 1/2". The next two groups went 5/8 and 3/4" So, my question is: What effect does bore fouling have on accuracy? Would fouling have that dramatic of an effect?

Sometimes. Dutch.

Short answer is sometimes - YES.

I had almost the same scenario, a 22-250 and a mass produced (rough) factory barrel. Accuracy was good for 15-20 shots before it needed a scrubbing. It also would walk when warming or cooling, but that's another discussion.

Moly plating bullets solved the problem in this tube. I have gone as many as 150 shots in between cleanings although it was still shooting as well as ever at that point! I just couldn't stand it any longer and reflexively cleaned it!

In high intensity cartridges in marginal tubes, cleaning is a big factor in their performance.

Redial

I would say this is true, especially in certain calibers. My .17Remington's accuracy goes to hell in the fast lane after 10-15 shots. I have to clean the rifle then in order to retore it. With other calibers it doesn't seem to make much difference so long as I'm under 25 shots or so.
Best wishes.

Cal - Montreal

After you have made sure that all is well with the bedding and that you are sure the barrel is free of copper, then try a different bullet.

I would go with a 53 Sierra HP and see how it works or any match bullet.

Oh, one more thing, don't ever forget that something could be wrong with the scope it's self. I have seen guys put a lot of money into having their rifles rebeded only to find out that the problem was with the scope.

Some rifle's in small calibers can be very touchy, at least until the barrel is broken in and sometimes this can take as few as 50 rounds or up to 200 rounds.

I use to have a Rem 700 BDL in 22-250 that was just terrible for copper fouling in only 20 rounds. Sometimes I could spend 2 hr.'s cleaning the barrel using Sweet's, Shooters Choice and JB. But it now has a new Shilen barrel,so very little cleaning has to be done now.

Big impact! It takes 5 rounds or so to foul my barrels up enough so they shoot optimally and I can get 6 or 7 good 5 shot groups and then I have to clean. Sometimes it's as few as 2 good groups if the loads are hot or I used slower powders. I shot molys for awhile but decided I was actually spending more time cleaning that crap out of my barrels than copper fouling, even though the gun stayed accurate for a bit longer. Barnes bullets were even worse, even with their own special cleaner. Get to know your gun. -Rod-

I had a Ruger 77/22 Hornet that after 15 to 20 shots the accuracy went south fast. Cleaning restored the accuracy in it as well. It took about to two hours of aggresive cleaning to get it out. I put up with that for about 2 years and traded it. I would rebarrel that rifle with a good stainless match grade barrel, break it in properly and be done with it. And yes some barrels require a few fouling shots to settle down and shoot. Other don't.

Shoot Safe, Shoot Straight.....RiverRat

Two hours I've never spent two hours cleaning a rifle in my life. Geez.

Benchrest shooters will clean their barrels after every group - 5 shots. They will absolutely remove any trace of copper. Copper fouling has major detrimental effects on accuracy. The rougher the barrel and the higher the velocity / pressure and "softer" the jacket metal makeup the more the barrel will copper foul. These guys consistantly shoot 5 shot groups that are 0.10 to 0.15 extreme center to center spreads at 100 yards.

I wish I hadn't spent two hours either trust me. I don't mind cleaning a barrel, that is part of shooting but GEZZZZZZZ that is too much. That was the copper foulingest barrel I have ever seen. The blue would just keep coming out of the barrel. For that reason I will never own another Ruger.

Shoot Safe, Shoot Straight........RiverRat

I've had great success buying "shot out rifles"
that really just needed advanced care and cleaning. If you need to live with a rough bore alot can be done beyond breakin. Minor solutions can be had with JB or Flitz polishing. If the need for moly is required , I strip the bore and apply MS moly to prep the bore as per instructions, then shoot moly plated bullets over a moly lined bore, I have eliminated key holers and pattern shooters with this method many times.
Moly bullets alone tend to plate only short distances at a time progressively plateing over fouling as their use increases, this causes build up that compounds the original problem, if applied
correctly moly is easy to live with. Although nothing beats a good custom barrel!

The primary factor that affects the flight of a particular bullet design down a particular bore is bore friction.

It determines bore transit time, and A) the more consistent it is, and B) the more perfectly it times the bullet to emerge during the slowest portion of the muzzle swing cycle, the more coincidental the individual bullets' POI (Point Of Impact) will be.

Copper fouling essentially 'puts on the brakes', and prolongs the transit time, altering it either into, or out of, syc with the muzzle's harmonic swing.

If you're shooting short strings which don't create a lot of copper fouling, then your most natural bore state will be unfouled, cleaning will be a critical part of your accuracy, and loads should be developed and tuned to a clean bore.

If you're shooting long strings, your most natural state will be fouled, the bore will require fouling shots to achieve a steady state, and loads should be developed and tuned to utilize that state.

Greg

Gerg, I appreciate your imput here. I have read your articles over on the hide, and have learned a lot from them. I do have one question, my 300 WSM rifle I use for F class competition is nearing the end of its competitive accuracy. The throat has moved forward .018" in the last 7 relays. I am going to tear it down after the next match in October. Since this match is 60 shot for aggregate match, to try to stay in the sweet spot, I am considering loading for the first relay at the present sweet spot, .003 longer for the next 20 shot relay and .003 longer still for the final 20 shot relay. In other words try to keep up with the throat erosion that is bound to occur. According to the log book the barrel has 1479 rounds on it and for approximately the last 300 rounds it has become more critical of seating depth. Any insight from you would be appreciated.

Shoot Safe, Shoot Stright......RiverRat

Dear clerkofkirk:

I notice you say you put several patches thru the bore. A thorough cleaning means using BRUSHES. Did you BRUSH out the bore well and THEN run patches thru until they come out clean (relatively)?

I look at cleaning a barrel just like cleaning anything - you have to keep cleaning until it's clean! Patches not only help clean, they are also indicators of how clean the bore is - short of owning a bore scope. Brushes do the heavy cleaning of stubborn fouling solvents can't get to in a reasonable amount of time.

[ 09-25-2003, 20:16: Message edited by: sonofagun ]

sonofagun,

I use Sweet's and nylon brushes after using JB and/or Rem Bore Cleaner. I clean completely b4 going to the Sweet's.