Accuracy loss with/without bore cleaning

Zey

Zey

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Precision forum rather than reloading forum because I want a BR point of view.

So yesterday, I shot a bunch of test loads out to 200. The first ones were a smokin' .75 MOA. Sweet! Then my next ones opened up a bit, maybe 1.25" MOA. Then they opened up to 2.5" and so on.

One would think, ok, so going hotter with this powder/bullet/whatever combo is counter productive for accuracy. But then I start thinking, maybe this "carbon fouling" issue I keep reading about is playing a part.

I've read Mysticplayer's article about LR load tuning and he doesn't mention barrel cleaning during the tuning process. I didn't use his "Audette Ladder test" as my rifle isn't bedded and I'm missing many of the recommendations to eliminate error.

It's a factory rifle..... Hm...Hmmm. Thinking. Or maybe I need to be doing this more so with a match barrel...
 
I just read an artical about cleaning. The artical was about how accuracy was found to be as good with 100-500 shots without cleaning. This was a 308win that the artical was about.The writer found the only loss of accuracy was a few shots after cleaning and after 500 or so. The message the writer gave was he found the gun to be as accurate with well over 150 shots. In your case is your barrel fully free floating while your shooting, is your barrel heating up and not having a chance to cool. I'm sure there guys here who could tell you alot when it comes to long range shooting. I can say I still clean my guns more often then not and I have found a couple of my rifles take a shot or two before they seem to shoot dead on. I have found my smaller 22LR rifles to be effected more from a cleaning. I had a 22LR out today and I found it took nearly 15-20 shots before it started shooting as expected. I do run and oil soaked patch threw my barrels a couple times after using solvent.
 
You did not mention the caliber or make/model of rifle.

First, if your rifle is not bedded and the if the barrel is not free floating, then shooting (heat) can cause things to happen.

I break in my new barrels. After that, I do not clean until accuracy degrades or I cannot stand the waiting - whichever occurs first. In 308 I might clean 2 or three times per season of about 700 rounds. Stainless match barrels just don't foul very much.

Fouling is not likley the cause of the group opening up. More likley it is the barrel warming up.

If a barrel has been well stress-relieved and is free floating, heat won't make much difference. But on a dead-calm day (or shooting centre fire indoors) barrel heat can distort the sight picture.
 
Yep. That sounds about right. It's a Rem 700 tactical in .223. Stupid Hogue stock touches the barrel around the bipod. I knew it....

The barrel does get pretty toasty. Looks like I gotta shovel the $750 on that medalist stock .
 
No need to buy a stock, just get a piece of bar stock bigger than your barrel, wrap sandpaper on the bar stock and sand away the parts that are touching.

Test for free floating by using a $5 (or any denomination) bill. If it slides under the barrel from front of stock to the recoil lug you are good to go.
 
CyaN1de said:
No need to buy a stock, just get a piece of bar stock bigger than your barrel, wrap sandpaper on the bar stock and sand away the parts that are touching.

Test for free floating by using a $5 (or any denomination) bill. If it slides under the barrel from front of stock to the recoil lug you are good to go.
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CyaN1de on the same topic how many shot's you throw down range before swabing the barrel?
 
In my sako manual for my stainless synthetic rifle it says a barrel can start to corrode after 24 hours if you do not clean it.
 
logan1080 said:
In my sako manual for my stainless synthetic rifle it says a barrel can start to corrode after 24 hours if you do not clean it.
Click to expand...

There is some truth to this: I recall reading how the powder deposits in a barrel can soak up humidity leading to corrosion, so keep your cleans clean.

Point is though, corrosion aside, not that much effect on accuracy. I've noticed the same thing: roughly 500rds before I start seeing a difference.
 
Over the years I think I've generally overcleaned by doing a really thorough scrub after every use. The result was that sometimes it took as much as 6 or 8 shots for the barrel to settle down and shoot well. On the other hand, I'm also concerned about leaving powder residue in the barrel. So what I do now just run one wet patch (Hoppes) thru the barrel, followed by a dry one. This seems to get out most of the visible powder residue out and the rifle seems to shoot well again after one or two foulers.
 
I just run a boresnake through barrel dry once then a few times with a little bore cleaner solvent on it. Do this after every use or every 20 shots if at the range. Seems to keep barrel clean.
 
Zey, I make the barrel gap wide enough so firm pressure squeezing the barrel to the stock and it will not touch. Bipod rifles can take quite a bounce when fired. A bigger gap may not be the most appealing but small groups usually make that go away.

Definitely barrel heat will play a role in group expansion. Factory barrels are not stressed relieved and will likely warp as it heats up.

Simple test (after opening up the forend AND bedding the action) - shoot two groups from a cold barrel. This establishes a baseline.

Now keep shooting until the groups open up. Keep track of how many rds you fire and how hot the barrel gets.

Let the rifle cool back to ambient and see if groups now look like the first two.

Jerry

PS as to cleaning, let the barrel tell you. I had one that would grenade bullet if not cleaned after rds 17. I had one rifle that wouldn't shoot until at least 10rds were fired - horridly copper fouled but was one of the best cold bore rifles I have ever owned. I cleaned my Shilen 223 after 150rds as I was feeling really guilty - no change in accuracy. Will likely not clean it until the fall.
 
I don't actually mind the gap that much. Like you say, the tight group makes it all good.

Key thing I need to move up the list are either a new stock or some mods to this one, and to bed this thing. Thankfully I'm pretty experienced with fiberglass and epoxy owning a 1972 yacht, lol. I'll easily be able to do that job.
 
mysticplayer said:
PS as to cleaning, let the barrel tell you. I had one that would grenade bullet if not cleaned after rds 17. I had one rifle that wouldn't shoot until at least 10rds were fired - horridly copper fouled but was one of the best cold bore rifles I have ever owned. I cleaned my Shilen 223 after 150rds as I was feeling really guilty - no change in accuracy. Will likely not clean it until the fall.
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Thanx mysticplayer I thought that I was :onCrack: because my grouping's were getting better the less I cleaned it.
 
If you don't clean after every single round, yer #### will fall off! :eek:

NAH ! I'm just joking ! :D

Seriously now, it's all mentioned by the experts above! I went a few hundred rounds or maybe halfway through the season before I cleaned my sniper rigs. I did not even bring cleaning rods to the Nationals! I might have cleaned them AFTER the NSCC matches when I got home, but I realized that the barrels grouped well dirty. :)

Discover what works for your rifle and your ammo combination! It's all part of the learning curve!

Cheers,
Barney
 
If you have a socket set, find a long one about the same diameter as your barrel in the area that needs opening, and use that and some coarse sandpaper to open it up. If it is wood, re-seal the channel with oil finish, varnish or something. I open it up enough that a piece of ammo box cardboard will pass under the barrel. Paper is not eneough clearance.
 
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Ganderite said:
If you have a socket set, find a long one about the same diameter as your barrel in the ara that needs opening, and use that and some coarse sandpaper to open it up. If it is wood, re-seal the channel with oil finish, varnish or something. I open it up enough that a piece of ammo box cardboard will pass under the barrel. Paper is not eneough clearance.
Click to expand...

I like to use a strip of 1" emery cloth run under the barrel and worked in a "shoe shine" motion. It gives a perfectly even gap from end to end, and is hell for fast.
 
Zey said:
Precision forum rather than reloading forum because I want a BR point of view.

So yesterday, I shot a bunch of test loads out to 200. The first ones were a smokin' .75 MOA. Sweet! Then my next ones opened up a bit, maybe 1.25" MOA. Then they opened up to 2.5" and so on.

One would think, ok, so going hotter with this powder/bullet/whatever combo is counter productive for accuracy. But then I start thinking, maybe this "carbon fouling" issue I keep reading about is playing a part.

I've read Mysticplayer's article about LR load tuning and he doesn't mention barrel cleaning during the tuning process. I didn't use his "Audette Ladder test" as my rifle isn't bedded and I'm missing many of the recommendations to eliminate error.

It's a factory rifle..... Hm...Hmmm. Thinking. Or maybe I need to be doing this more so with a match barrel...
Click to expand...

Also what you didn't mention is that you changed powder charge's with each group??? That will for sure have an effect on groups openning up more so then barrel temps.
 
Richard, Marc and I all shot the BC Provincials with 6BR's, and hosed more than 250 rounds down range and never cleaned the whole time. The three of us were in the top three.

Factory barrels are different. They often REQUIRE a good layer of copper in them to work more consistently, as the bores in them can be pretty crude.

I can expect that the odd flyer will start to appear after about 400 rounds, so I clean before then in a 6BR. I use Varget, which is a clean powder.

In my 6XC and 6.5-284 I clean after every trip to the range. The Norma cartridge is known for throat fouling affecting accuracy, and the XC has a non-lapped RKS barrel and it just gets grubby and copper fouls badly.

My factory 204's just never get cleaned. I shoot the $hit out of their 1000 round life on gophers and then sell the action. I did clean one once, and the spooge that came out resembled ball point pen ink. Even so, it still groups .5-.75 inch! at 1ooM
 
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