Broken Scope or Dirty Barrel

[PHOENIX PHIL]

Well there's no definitive conclusions yet. I think I can safely eliminate barrel, action screw and stock issues. After a firing 5 or 6 AB loads to get the scope more/less zero'd and put some fouling in the barrel and letting the barrel cool, I shot a 3 shot group of AB's that mimicked what I had before, just under 1".

Shot some my 200gr North Forks loaded in various weights of IMR 7828. The pic is of the 75.5grain load, the best group I got, I'd say pretty nice.

Just before I shot that group I put an AB load down the barrel and just after I did the same. Again right where I expected them to be. At that point I'd say I had in the neighborhood of 20-25 shots. This tends to make me think that the barrel being dirty was not the issue. At that point however, I ran out of time as the range was closing. So I did not have the opportunity to put the other scope back on. Things are pointing towards the scope, but can't say for sure until I put it back on.

 

[PHOENIX PHIL]

Well it wasn't the scope

Got to the range today hoping to first settle on the best load for the 200 grain North Forks. I worked up some loads at +/-0.1 and +/- 0.2 grains from the 75.5 grain load that you see the results for in my prevous post. Results were a bit disappointing. The 75.6 grain load shot a touch over an inch. The 75.5gr load, 4 shots for this one, had 3 very close, but one flyer. The other loads had a similar pattern, two quite close and a 3rd flyer. That's the first issue.



Second issue was to determine if that other scope had gone bad. I had bought a cheap box of factory ammo when I got the rifle for bore sighting purposes. So I shot 3 of those before swapping back to the previous scope. Noted the group and swapped scopes. I the shot 3 more of these factory loads and had virtually the same size group, somewhere around 1.75 inches, not great but that was far better than the last shot fired with this scope on.

I then shot two 3 shot groupings of the Accubond load that was giving 0.75" groups. Both groups were in the 1.5" range, again much better than the last time this scope was on, but not near as good as it had been.

Mucho confused as to what to do next.....:wacko:

 

[sestoppelman]

I assume you have had the crown checked. How many rounds thru the barrel? I still think your groups look like hot barrel touching something, like barrel channel or the action is shifting around in the stock. Sometimes the action screws are a little long and wont fully pull the action down tight to the stock. Does it have the pressure bed spot up front? It may be time to take it to a good smith. If scope and mounts are good and all traces of copper are gone, its got to be something like the above.

 

[PHOENIX PHIL]

I assume you have had the crown checked. How many rounds thru the barrel? I still think your groups look like hot barrel touching something, like barrel channel or the action is shifting around in the stock. Sometimes the action screws are a little long and wont fully pull the action down tight to the stock. Does it have the pressure bed spot up front? It may be time to take it to a good smith. If scope and mounts are good and all traces of copper are gone, its got to be something like the above.

Other than a visual of the crown which showed nothing abnormal, nothing else.

Agree with you due to the flyers that something seems to occasionally shift.

I don't know about the pressure bed spot up front that you asked about.

I didn't bring the gun home today, instead left it with the smith at the range. His specialty overall is accuracy. He was a top sniper in the military and knows his stuff. If the screws are the issue, hopefully he'll see that. He's going to be taking the gun apart to inspect the bedding. It was supposed to come from the factory bedded, we'll see.

It was a bit warmer today than it has been and that may partially explain the groups opening, but I don't know about the flyers.

 

[sestoppelman]

Well let us know what the smith says, we can all learn something from this go-round you have had.

 

[BARTFRNCS]

Just for easy crown inspection stick a qtip in the barrel end and see if anything gets caught on the edge.

 

[Norwegianwoods]

It sounds like you have a stress point somewhere showing when the barrel starts to get hot.
Either it is the barrel itself or there is something affecting the barrel and action when the barrel gets warmer.

What I would do to check out this, is to shoot 1 shot, wait a few mins before the next shot and so on. Making a 10 shot group. Then each shot will be from a cold barrel.
If you get a good group then, you clearly have a stress issue that comes when the barrel gets hot.
If you still get flyers and you are 100% sure it was not you, then it becomes much more difficult to find out. But the first thing I would try then, is a recrowning.

 

[35bore]

It sounds like you have a stress point somewhere showing when the barrel starts to get hot.
Either it is the barrel itself or there is something affecting the barrel and action when the barrel gets warmer.

What I would do to check out this, is to shoot 1 shot, wait a few mins before the next shot and so on. Making a 10 shot group. Then each shot will be from a cold barrel.
If you get a good group then, you clearly have a stress issue that comes when the barrel gets hot.
If you still get flyers and you are 100% sure it was not you, then it becomes much more difficult to find out. But the first thing I would try then, is a recrowning.

Very good point Norwegian, I just read this and it reminded me of a Weatherby Lazermark I had some time back, same issue, I got the rifle for a song is the only reason I bought it, then made money off of the sale. It had the same issue and my gunsmith told me that sometimes fit is too tight on the rifles, (floated, but that little bit of heat makes the metal expand ever so slightly) creating a point of contact that was not the before. Try opening that barrel channel up, worked on my savage model 99.

 

[PHOENIX PHIL]

It sounds like you have a stress point somewhere showing when the barrel starts to get hot.
Either it is the barrel itself or there is something affecting the barrel and action when the barrel gets warmer.

What I would do to check out this, is to shoot 1 shot, wait a few mins before the next shot and so on. Making a 10 shot group. Then each shot will be from a cold barrel.
If you get a good group then, you clearly have a stress issue that comes when the barrel gets hot.
If you still get flyers and you are 100% sure it was not you, then it becomes much more difficult to find out. But the first thing I would try then, is a recrowning.

Very good point Norwegian, I just read this and it reminded me of a Weatherby Lazermark I had some time back, same issue, I got the rifle for a song is the only reason I bought it, then made money off of the sale. It had the same issue and my gunsmith told me that sometimes fit is too tight on the rifles, (floated, but that little bit of heat makes the metal expand ever so slightly) creating a point of contact that was not the before. Try opening that barrel channel up, worked on my savage model 99.

Thanks for those thoughts, I decided to follow up on them. I loaded up 10 of the Accubond loads and went to the range and picked up the rifle from my gunsmith who hadn't started work on it yet.

I fired 5 rounds waiting anywhere from 6-10 minutes between shots. The longer waits were due to the regular cease fire intervals to check targets. Well sure enough the groups came back.

After the 5th shot, I fired the next 5 starting immediately. By the 10th shot the barrel was plenty warm and the group was opening up considerably. Returned the rifle to the gunsmith and he repeated information that I've heard elsewhere which is that the factory bedding job leaves a lot to be desired. So he's going to re-bed the barrel, check that there's plenty of clearance on the float and also lighten the trigger which is just a bit heavy from the factory.

It'll be a few weeks before I get the rifle back but confident we've got it figured out now. Thanks again for the input!

 

[BRICKBURN]

Just for easy crown inspection stick a qtip in the barrel end and see if anything gets caught on the edge.

Good idea.

 

[BRICKBURN]

......
It'll be a few weeks before I get the rifle back but confident we've got it figured out now. Thanks again for the input!

Show me those new targets when you get it back. Then I will believe you have it fixed.

 

[BARTFRNCS]

Just a sugestion only change one thing at a time that way its easy to isolate the problem.

 

[PHOENIX PHIL]

Just a sugestion only change one thing at a time that way its easy to isolate the problem.

Indeed it is, but I'd never have thought that the cleaning issue that this started with was part of the problem. Secondly, the range is 25 miles one way and with being a dad of two young boys time to shoot is limited.

 

[BARTFRNCS]

25 miles man you got to find a closer place to shoot!

 

[PHOENIX PHIL]

25 miles man you got to find a closer place to shoot!

There's a wide open space about 200 yards from the house but the residents who call the reservation home frown on this sort of thing in a very big way!

 

[BARTFRNCS]

Im SPOILED I only have to drive a mile and a half to my 330 metre range open all day every day no cease fires no range oficers privet property. Needless to say my shooting skills are finly tuned. How Did I get this great Deal I Built the land owner a Custom rem 700 300 Win Mag That drivves tacks he shoots about a box a year. I Shoot aboot 50 rounds a a week mostly 375H&H and 300wm. I build alot of custom guns mostly on the rem 700 platfom.

 

[Norwegianwoods]

Thanks for those thoughts, I decided to follow up on them. I loaded up 10 of the Accubond loads and went to the range and picked up the rifle from my gunsmith who hadn't started work on it yet.

I fired 5 rounds waiting anywhere from 6-10 minutes between shots. The longer waits were due to the regular cease fire intervals to check targets. Well sure enough the groups came back.

After the 5th shot, I fired the next 5 starting immediately. By the 10th shot the barrel was plenty warm and the group was opening up considerably. Returned the rifle to the gunsmith and he repeated information that I've heard elsewhere which is that the factory bedding job leaves a lot to be desired. So he's going to re-bed the barrel, check that there's plenty of clearance on the float and also lighten the trigger which is just a bit heavy from the factory.

It'll be a few weeks before I get the rifle back but confident we've got it figured out now. Thanks again for the input!

Good to see that you are a lot closer to fix the problem now
Hopefully your gunsmith will get it sorted very quickly for you.

 

[PHOENIX PHIL]

Show me those new targets when you get it back. Then I will believe you have it fixed.

Finally got my rifle back after having it re-bedded, re-crowning and lightening up the trigger just a bit. The bad news is that my 200gr North Fork load is not shooting as well as it was. But the flyers seem to be gone. The spread between the bullets was fairly consistent and gave about a 1.5" group. A little more work on that load and hopefully it will come back to me.

When I was loading up for this trip, the 180gr TSX's and TTSX's begged me to give them a chance in this rifle. The IMR 7828SSC was already in the hopper so why not. Barnes lists max load at 74gr and I decided to start out here. Normally I wouldn't do that, but I've shot up to 76gr in the 200gr North Forks. Below is the pic of the TTSX group. The TSX group shot just bit less accurately at a little over an inch spread.

 

[BARTFRNCS]

Alot of animals have fallen to 2MOA guns! All bedding does is improve consistancy. You will have to start all over again in load development. or get a premium barrel.

 

[sestoppelman]

Alot of animals have fallen to 2MOA guns! All bedding does is improve consistancy. You will have to start all over again in load development. or get a premium barrel.

I agree about the bedding however I dont completely agree that you will have to start all over again in load development. If the barrel is the same, the same loads that shot well before should shoot as well or better now that its bedded at least that has been my experience having bedded quite a number of bolt guns and M1's, M1A's and so on.

I can say that because the sun is almost over the yardarm and I am having a brewski!:beer: