I have a Win M70 Lightweight Carbine in .243(stamped on the barrel as such). I bought this for my first ex-wife in the 80's and once I got it set up it was a real tack driver with 100 grain bullets and 41 grains of IMR-4350, COL was set using a factory Winchester power point loaded round. The rifle has performed well for years and is now one of my sons rifles but a couple years ago the accuracy started "falling off" a bit. I wasn't concerned until I noticed it has gotten real bad. I have had 3 different scopes on it so I know its not the scope or bases, I've tried working up new loads for it and tried varying the seating depth, new brass, different bullets. I worked on the bedding. I've "really" cleaned it more times than I can count and also let it get dirty again to see if that makes a difference.
Years ago the load I mentioned above shot 3 shot groups in 3/4" or under and 5 shots was about the same. Now I'm getting 4" groups, I will shoot 2 shots that look promising then a couple fliers then another back on the starting group. Yesterday I shot two 5 shot groups as described then shot a 2.5" group with Barnes 85 grain Triple shocks and 43 grains of IMR-4350 seated .020" off the lands. This was my best group in a long time with this rifle but still un-acceptable.
I have doctored (tuned) a lot of rifles with excellent success but this one is getting me down, I'm about to have it re-barreled but wonder if I'm missing something first?
I looked at the crown and it appears fine but I may have it checked out before I spring for a re-barrel.
What do you all think?

Cleaning is one thing. Copper removal is another. Try some Sweets or Patch Out that will attack copper fouling. Most 243s should provide good hunting level accuracy for 2500 rounds unless it was loaded really hot. If throat errosion is the issue you might try seating bullets out a little further.

I am having the same problem with a brand new Rem 700 in .243 that I bought this summer.

I have put a second scope on it, checked the bedding, and shot different powders and bullets ranging in weight from 80grs to 105grs and always the same result: 3 to 4 inch groups.

Factory will do nothing about it. I am going to try recrowning and if that does not work I plan to rebarrel it.

Big disappointment as I bought it to replace a post 64 Win mod 70 of the same caliber that had a shot out throat. It is the least accurate Rem 700 I have ever encountered.

Barstooler

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Originally posted by Barstooler:
I am having the same problem with a brand new Rem 700 in .243 that I bought this summer.

I have put a second scope on it, checked the bedding, and shot different powders and bullets ranging in weight from 80grs to 105grs and always the same result: 3 to 4 inch groups.

Factory will do nothing about it. I am going to try recrowning and if that does not work I plan to rebarrel it.

Big disappointment as I bought it to replace a post 64 Win mod 70 of the same caliber that had a shot out throat. It is the least accurate Rem 700 I have ever encountered.

Barstooler

Get some Cerrosafe & make a chamber cast incuding @ least 2" of the throat. Check to see if the chamber is off center.

I had a M700 Mountain Rifle DBM in 280 that shot as you describe. After making a chamber casting it was found that the chamber was .004" off center.

I contacted Remington & they said, "that should not affect accuracy"! WTF! If you call 3" groups @ 100 yds accurate, I guess it doesn't.

I traded the rifle for a M700 CDL in 280. That one shoots just fine.

For the OP, get some "Wipe Out". Best damned cooper remover there is. After you remove all the copper, expect to fire 8-10 rounds for the bore to start to hit the sweet spot again. My guns shoot a little erratic right after cleaning down to the bare bore, but after a few rounds, the hit their original POA.

Thanks guys for the help and suggestions. I've tried a copper remover on it as well as a good standard cleaning many times with no improvements. The real mystery to me is how the accuracy used to be there and now its gone.

glass bedding time

Snellstrom,

Well the way I see it, it's down to one of two possibilities.

Either your ex-wife put a curse on the rifle when she left, or you've got copper in the barrel.

For the first one, you need a witch doctor and a dead chicken.

For the second one, you need one of those new foaming bore cleaners. I've used the foaming cleaners to pull every bit of copper out of a bore, and makes it like a virgin bore. You may likely have to break in the barrel again before accuracy will come back.

I've pulled a bunch of copper out of buddies rifles that were "clean". Just because the patch comes out without any blue or green on it, doesn't mean it's clean.

After the foam treatment and re-breaking in the barrel, see if the accuracy is back. If not, then I would have it bore scoped at a smith's to see the actual bore surfaces.

I very much doubt you've shot it enough to wear the throat out. Most hunting rifles won't see that many rounds in a lifetime.

I have the same problem with a 243, I figured it was time for a new barrell.

is there anything particular about the groups' opening up? do they spread all over or in any particuar direction? th e reason i ask is because i have a good shooting, originally not bedded mauser in 7x57 that started throwing fliers left and right. i found that over the years the back screw compressed the wood enough to allow the magazine and reciever come in contact. when that happens left and right fliers are the norm, so i bedded it with a pillar at the rear screw and it was back to normal.
i don't think .243's are normally hot enough to erode throats for many many shots. it sounds allot like a bedding/mechanical type problem.

Bedding issue, fouled bore, or bad crown is my guess. A trip to the gunsmith for a look with a bore scope will eliminate or confirm the last two.

I'm gonna guess either copper fouling or bedding. And I'm leaning toward bedding more than copper fouling. Although a through cleaning can't hurt. I mean down to the metal. And a re-set of your COL. Plus, some rifles just do not like certain bullets. Does it do poorly with all bullets?
IMO, if the rifle was just dirty, the groups would be large but kinda concentric. Like it was shooting but bigger. Since the shots are kinda bouncing around, I'm leaning toward bedding. The rifle is old enough that some stock compression has taken place and the action is moving.
I'm sure there's been some throat erosion but if it's a hunting rifle, I doubt that it's enough to really matter unless the rifle has been fired like an automatic repeatedly.

Seems to me the only reasonable solution I've heard so far was the witch doctor/chicken method. Glass bedding? Now that sounds like voodoo to me.

I would clean the barrel with J&B Bore Paste.

Wrap a patch around a used brush, coat it with J&B and give your barrel ten strokes...

Push a couple of wet patches through the barrel... And repeat with the J%B at least five times...

Then shoot your most accurate load again....

If your barrel is still not shooting good it might be time to get a new one...

Snell-Buddy.....sad to hear about the .243 Win. Carbine.

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Seems to me the only reasonable solution I've heard so far was the witch doctor/chicken method.

And a whole cushion full of needles, too.....

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I would clean the barrel with J&B Bore Paste.

My sentiments exactly; a coupla good applications of Forrester's Foamy Stuff followed by JB Bore Cleaner. If the barrel isn't squeeky clean after that then you got a problem I don't know how to deal with.

quote:

Barnes 85 grain Triple shocks and 43 grains of IMR-4350 seated .020" off the lands.

Try 'em short - the Barnse's we've worked with in .243 Win., 7mm Rem. Mag., 300 Win. Mag. & 300 Wea. Mag didn't like being out there close to the lands; actually in every case we got the best results with them crimped with a Lee FCD in the foremost groove. The finished rounds appeared very short but they ended up shooting excellently.

quote:

I found that over the years the back screw compressed the wood enough to allow the magazine and reciever come in contact.

Had a similar issue this summer with a Buddies Heavy Barreled .22 Hornet. From an absolute Tack-Driver to +2.5" groups (with Flyers). We took the scope off, lapped the rings, re-mounted it, scrubbed, scratched our heads and got out the Doll, a Dead Chicken & the needles - to no avail. Then during one of our rituals we noticed that the bolt handle had started making contact with the wood at the base of the handle (just a small indentation) in the bolt handle notch. About ten minutes later after a coupla swipes with a file, some rolled up medium & fine grit sandpaper, a drop or two of oil and we were back on track again.

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I will shoot 2 shots that look promising then a couple fliers then another back on the starting group.

Two groups normally depicts instability in the optical system (you've already checked this) or bedding.

I would venture similar with your issue; most likely a bedding issue. Action screws, barrel channel, bolt notch, safety, trigger housing; probably an easy fix that's gone astray over the years, don't imagine the barrel & throat are toast. I'd sit down with the rifle and go over it with a fine-toothed comb before deciding to replace any major components parts. After all a new custom barrel or re-chambering certainly holds the promise of small groups; but not if it's installed on an unstable platform.

I've got a Rem 243 like that also....

funny, but I found working with mine is that it doesn't group worth a darn, with ANY bullets at regular velocities you'd shoot a 243 at...

however, if I redline the velocity ( over book maxes) or download it to 2400 fps or lower...then it turns into a tack driver...

my conclusion on this, is that the throat was cut with a pretty dull reamer, or was one of the last barrels cut before they 'reset' the equipment back to a starting point...

make sure that the receiver screws are not too loose or too tight. A 243 will erode the throat pretty quickly, especially if used for any high rate shooting. Cleaning without a bore guide can also cause premature throat erosion.
The first thing I would do is try different tension on the receiver screws, then i would take a close look at the crown of the muzzle. If you have the tools to measure cartridge overall length, that will give you some indication of the condition of the throat.
If none of the suggestions you have received so far have made a difference, your best bet would be to take it to a gunsmith & see what they think.

Have you thought to have it rebarreled to a 7-08 or even a .260? That would probably clear up your problems and give you a vastly superior cartridge.

Vastly superior? Maybe if the 7mm-08 or .260 had a fast twist and the .243 didn't. If they both have fast twists, 115 DTACS at 3k fps vs a 142 Matchking at 2750 fps, vs a 168 Berger at 2750 fps I think you'll see they're VERY close.

Stillbeeman
The rifle is my sons and he already has a .284 Win which does everything a 7-08 does and more and he has a 6.5x55 Swede which covers the .260.
If we re-barreled it it would be a .243 again or a 22/250 but most likely a .243 still because it is legal for game animals in Colorado and can still shoot 55-60 grain bullets for prairie dogs and coyotes.
Thanks to everyone for the helpful suggestions I am busy for the next few weeks with Deer and Elk seasons but after that I'll be playin' with it again.

I was thinking the same thing as airgun 1 -- I suspect a bad crown. This is something that can gradually grow worse over time as you have stated has happened.

quote:

I am busy for the next few weeks with Deer and Elk seasons

Quick-Power,

That's something Good to be "Busy" with....

Waidmannsheil!

Hey Gerry I like the "Quick-Power" play on words with my last name!
However I am told my ancestors are from Finland, I'd be curious to know what my last name means in Fin.
As for the .243 I am going to have the crown looked at and get my "smith's" opinion on it and the barrel.I'll then proceed with his findings, thanks all for the suggestions many of which I already have tried or looked at.

Hmmm. Eastern plains of Colorado. Has it been used to shoot prairie dogs. The bbl. could be shot out if it has. Often overlooked is the possibility of a scope or mounts problem. I once traded a rifle off, only to find out later that I had not one, but two bad scopes. You could also try seating your bullets out a little farther to compensate for throat wear, but you've probably already done that. Also the crown could be worn from cleaning. Most rifles need to be re-crowned before their bbls. are shot out.

I went back and re-read your posts and see that you have tried everything except re-crowning or re-barreling. Good luck.

quote:

Hey Gerry I like the "Quick-Power" play on words with my last name!

Good on Ya!

Go Elk & Deer Hunting.....the .243 Win. will still be there in the Spring.

My buddy & I trotted off to a US Military Training Area the other for a couple of days; he got a Spike Red Deer Stag & I got real lucky and walloped 4 Hinds.

Right now Hunting's #1 priority - got no time for rifle projects at the moment; got a couple but they're all the way in the back of Gun Safe collecting dust.

Finish, Whew! Now there's a weird language (I guess not if your a Finn); supposed to have some common roots with Hungarian. Both languages are apparently difficult to master.

Just curious if you have chronographed any of your loads. My original .243, a Model 70 Westerner, was my first and only centerfire rifle for a number of years. I shot it a lot. Eventually, the accuracy started to really suffer. That was when I discovered that the handloads that used to group an inch or so at 100 yards were now grouping 3 to 4 inches were also chronographing around 2500 fps instead of the 2950+ they had before. Barrel was shot out. Sold the action to my buddy who used it for his custom .22-250 AI. Don't be surprised if the barrel is shot out. After all, if it is over 20 years old and has been used on prairie dogs, it would not surprise me.

How much have you shot it? Just a thought. There was a very good aritcle in either Precision Shooting or Varmint Hunter last year about Throat and Barrel erosion. The author took about 15 of his rifles and measured throat erosion over 2 or 3 years. Every time he would shoot he would measure the throat. He came to the conclusion that of his standard calibers .243 Win and 25-06 Rem were far and above the worst throat eaters. Don't quote me but I believe he had .001 throat erosion after 25-30 some shots on average w/ I'm sure was some form of varmint type load. I wish I still had the article but I don't. By the way I am not a .204 fan but he had over 100 shots to .001 of erosion. Good luck as I had a .243 I almost left in the trash at the range a few times also LOL. So I am figuring bedding, copper or barrel has gave up the ghost as 2ndtimer said.

I have a 25-06 that shoots very well. After a while, the groups will start growing. It's letting me know that it needs a thorough cleaning. After a cleaning session, it groups like it should.

Of all the rifles I've owned over the past 50 years that had accuracy problems were from bedding problems.
Have a good gunsmith bed it properly and you will most likely have a rifle that shoots well.

Back in the mid 90's when I was target shooting a lot my local gun dealer showed me a customer's Winchester Mod 70 30-06 that wasn't shooting worth a damn. He gave it to me with a box of cartridges off the shelf and asked me to shoot it and let him know if it was the gun or the shooter. I shot a 5 round pattern of about 4 inches or so and concluded it was in fact the gun. But something was just not right with the action. It seemed to be binding a bit. So I took the barreled action out of the stock and it worked fine. Then I saw some lines on part of the bolt, I forget which part. The lines lined up with one of the action screws. I filed the screw down a mm or 2 and put it back together and brought it back to the range. Less than 1" group at 100yds. Don't know if Winchester put the gun together that way or if the customer overtightened the action screw and compressed the wood, or what, but it shot like a dream with factory ammo after that screw was shortened.

Barnes says to jump the bullet 50 thou. If the gun shot before it will shoot again.

Well I had already checked the throat and seating depth and nothing was outrageous there the barrel appears to be in great shape and today I had Kevin Weaver of Weaver Rifles look at the crown for me. Crown checks out so I'm headed towards bedding the rifle.
Thanks for all the suggestions and help!
Most of the suggestions I was aware of or had tried but I love these discussions of internet troubleshooting a rifle, helps keep me on my toes and sometimes you all come up with something I haven't thought of.
I will post results after I bed it but it will be awhile because I have a project or two ahead of it.
Thanks again

Have the barrel bore-scoped. Pay particular attention to the 3"-4" inches just in front of the chamber.

With a rifle which could be almost 30 years old, stock warping is not uncommon. Any pressure points along the barrel channel will play the devil with accuracy. I'd bed it.

But first, check the stock/action screws. The middle should only be snug. The front and rear, a bit more.

2 fixes I kinow of .. Cut 1/2" off the muzzle and re crown . Put it in a synthetic or laminated stock .. Bed it ...

This sounds like my rifle. I used to shoot 100 grain spitzers out of my Savage 110c. It would shoot around 1". One summer, I loaded ~50 60 gr hollow points. After that, I can't get the 100 grain balls to shoot under 4". I am able to get 90 grain ballistic tips to shoot but I hate the way these performed on deer.

Any ideas? I've tried cleaning as well.