Accuracy loss after cleaning. Question?

[SuperCub]

Good afternoon folks ..... I recently cleaned my 275 Rigby using Barnes CR-10. Solvent was not allowed to sit in bore for extended period of time. 10 min tops. I use Tipton rods and a bore guide for all cleaning.

This rifle was very accurate and consistent. The load was not changed nor was the loading method. No change of scope or stock.

The following two pics are of how it used to shoot prior to cleaning. There might have been 100rds through it at this point and not cleaned by me. As you can see, it shot well. The second pic was a scope check after removing the scope and re-installing the scope (Leupold 2.5-8) in Talley QD rings. Only 2 shot groups in that one but I was confident they represent how the rifle shoots after past experience. Bottom group after scope adjustment and ready to hunt



Here is how it is shooting now after cleaning. You can see a 2nd 3 shot group under the tape.

 

[SuperCub]

Also, wind was not a factor as I shot 3 other rifles without trouble in the same sitting. Barrels in all cases were allowed to cool past three shots.

.

 

[boxhitch]

Some barrels shoot better with a bit of fouling
so from perfectly clean to a suitable condition to shoot your tried load can take a few rounds
I found this in particular with Barnes bullets, but will always hear of shooters taking fouling shots

 

[Lodi]

This sounds normal, you may need to shoot 4-6 rounds to foul the bore and "restore" accuracy. Change your cleaning routine a bit and leave some fouling, this can save on the amount of ammo needed to foul the bore.

 

[Heliian]

I'm not really seeing any difference in these pictures as one is a different target and one is zoomed, the spacing looks similar.

Excessive oil maybe? As boxhitch says, some barrels do prefer a little run through for consistency.

Wind/temp/humidity are all factors too.

This year I've been working on my clean cold shots as that is the configuration I'll be hunting with. I usually go out with a clean gun and depending on the weather will dry and re oil it even without firing a round. I also clean after my range days as it could be a month between trips with a particular rifle. I'm not a precision competitor though, maybe try that sub.

 

[Potashminer]

SuperCub - there was a thing I read about called "seasoning" a bore - it will want a bit of fouling to shoot it's best - so a freshly cleaned barrel might not shoot the same. When I was a boy, was a thing NOT to clean the rifle after sighting in to go hunting - the "knowledge" was that you wanted it in the same condition, when you got your crack at a deer, as when you last fired at a target. Of course, that ignores "heat" - most hunting shots are done with a "cold bore" - typically, you do not get warm up shots, nor do you shoot "groups" - is (usually) one "cold bore" shot - probably the biggest difference to target shooting guys - no warm up shots, no "sighters" - all the "bucks" are on that first cold barrel shot - hit or miss. So, I read, the correct "sighting in" is only the very first shot of the day - that is likely what will happen when the "chips are down" - and if you are of a statistical bent, you will repeat that first shot for four or five days, to produce a "group". What gets done for the rest of the day is the shooter's business - but that thought says nothing else is of significance for the "sighting in", except that first cold barrel shot - which, of course, is probably a bore that has been treated and stored the way that you normally would. That makes it nice if your barrel thows the cold bore shot into the "warmed up" group - but is no way that I know of to predict that, except to shoot it and find out.

 

[SuperCub]

This sounds normal, you may need to shoot 4-6 rounds to foul the bore and "restore" accuracy. Change your cleaning routine a bit and leave some fouling, this can save on the amount of ammo needed to foul the bore.

The last three shots fired in the 3rd pic were #16, 17 &18 after the bore was cleaned.

 

[SuperCub]

Other info here .....

- When I first received the rifle, it took quite a few loads before I locked onto the load in question so It may be that the rifle needs more shots to foul the bbl.

 

[Jon87]

18 rounds should be lots to foul the bore. Have a borescope?

 

[SuperCub]

No borescope here.

 

[Longstud]

The last three shots fired in the 3rd pic were #16, 17 &18 after the bore was cleaned.

I’m assuming you used wet patches of another substance to neutralize the ammonia in the CR 10! Are the cases your using the same brand and prepped the same way?

 

[hoytcanon]

Have one more coffee before hitting the range.

I don't hunt itty-bitty groups, but do want consistent hunting accuracy. I ALWAYS, shoot a couple groups before taking any rifle after big game... generally the day before or on the way to the hunt, after I am assured of an accurate set-up, I do not clean the bore until after the hunt and before storage. I have not noticed that cleaning significantly impacts accuracy "potential", certainly not after 2 or 3 shots, but I do notice POI shift with cold bore shots on target, but never enough to be significant to the outcome on game at short to medium range. If extreme distance are possible, then I tighten up my expectations and more closely control the potential accuracy inhibiting factors, at least as much as I can. I would stick with the same load and shoot a few more paced three shot groups before deciding there is an actual issue... If there is, I doubt it is attributable to the cleaning.

 

[Jon87]

I had groups open up like that on me once suddenly. It turned out to be copper. I didn't have a borescope at the time, but the patch came out with intense blue just on one spot, like a chunk of copper was stuck or something. It was very strange. After cleaning again the groups shrunk to where they were. Could try cleaning again...

 

[Hmatt]

SuperCub - there was a thing I read about called "seasoning" a bore - it will want a bit of fouling to shoot it's best - so a freshly cleaned barrel might not shoot the same. When I was a boy, was a thing NOT to clean the rifle after sighting in to go hunting - the "knowledge" was that you wanted it in the same condition, when you got your crack at a deer, as when you last fired at a target. Of course, that ignores "heat" - most hunting shots are done with a "cold bore" - typically, you do not get warm up shots, nor do you shoot "groups" - is (usually) one "cold bore" shot - probably the biggest difference to target shooting guys - no warm up shots, no "sighters" - all the "bucks" are on that first cold barrel shot - hit or miss. So, I read, the correct "sighting in" is only the very first shot of the day - that is likely what will happen when the "chips are down" - and if you are of a statistical bent, you will repeat that first shot for four or five days, to produce a "group". What gets done for the rest of the day is the shooter's business - but that thought says nothing else is of significance for the "sighting in", except that first cold barrel shot - which, of course, is probably a bore that has been treated and stored the way that you normally would. That makes it nice if your barrel thows the cold bore shot into the "warmed up" group - but is no way that I know of to predict that, except to shoot it and find out.

I season my cast iron…

 

[Potashminer]

Is true - one would normally season a porous cast iron device (fry pan or cannon barrel) with grease, lard or other carbon producing stuff so that subsequent things do not stick - about totally irrelevant to modern barrel steel in small arms, but old stories and "knowledge" dies hard.

 

[SuperCub]

I’m assuming you used wet patches of another substance to neutralize the ammonia in the CR 10! Are the cases your using the same brand and prepped the same way?

I use Windex for this. The other rifles I had with me were all cleaned on the same day, the same way. All shot very well, esp the 222 and 6CM.

All loads were exactly the same using the same materials and methods of loading. Probably all the same batch numbers as well.

 

[SuperCub]

After cleaning again the groups shrunk to where they were. Could try cleaning again...

Good idea ....... I might try a few more through it as is and if this does not work out will try what you say

 

[Jon87]

Good idea ....... I might try a few more through it as is and if this does not work out will try what you say

It could be you knocked something loose in the first cleaning maybe. It doesn't take much for things to go wonky sometimes

 

[SuperCub]

It could be you knocked something loose in the first cleaning maybe. It doesn't take much for things to go wonky sometimes

I do have an extra set of Tally rings here I could use to put another scope on it if it came to that.

 

[Longstud]

I use Windex for this. The other rifles I had with me were all cleaned on the same day, the same way. All shot very well, esp the 222 and 6CM.

All loads were exactly the same using the same materials and methods of loading. Probably all the same batch numbers as well.

Im not trying to be a know it all but windex has ammonia in it. If not neutralized it can cause rust to develop very quickly in certain barrels. A 50/50 mix of vinegar and water will neutralize the ammonia but I always use nitro solvent on a few patches and then oiled patches followed by dry patching.