What are my options???

[jjrothWA]

Have a first series Post 64 M70 in 7mmMAG, with commercial ammo I have groups that might group on a paper plate, @100 yds., even local shop couldn't get a decent group.

My reloads with Hornady 162gr, SST, are loaded to meet the lead / throat, @ 2.795, using a "Sinclair comparator [hex nut].

SAAMI chamber drawing indicates the basic dimension from bolt face to "leade / throat" is 2.725". [difference = 0.07"]

Just keep loading to the leade or look for another barrel??

My handloads show a group of 1" @ 50 yd for chronographing.

[aintright]

All your magnum cartridges are going to be barrel burners , if you don't know the rd count down the barrel , take it a good smith and get him to bore scope it before you buy a new barrel , there could be other things causing the accuracy problem .
There are some other things that could be the culprit , thouroughly clean the barrel using a one piece rod and bore guide . Contact Winchester or google action screw torque , check crown , scope base screws , rings , change scopes if you have another handy , just to see .
But if you've had it at the local shop I would assume he already checked these things . These are just the things I would look at before rebarreling .

[Johnny P]

As suggested, try cleaning the barrel first. If it is the barrel, you will need something to remove copper fouling from the barrel, and I have found either Sweet's 7.62 or J-B bore cleaning compound to work best.

[ridgerunner]

Some of the post model 70s had some issues. I had a friend who had one, that the screws that tightened the action to the stock, were too long, and bottomed out before tightening down completely. I guess it gave him fits before he found out what was going on. Hope you found out what the problem was with yours. His was also a 7mm. mag.

[joem]

Don't give up on it yet. I fooled around with a .223 for two years before I could get it to shoot less than 6" to 16" @ 100 yds. When you hit the right spot it seems like magic.

[C5M1]

Never owned a 7 mag but know a long range shooter that extended his barrel life by switching to flat base bullets. They shot good enough to win matches.



Regards, dennis

[Kurt]

What powder are you using? I have a Ruger M77 I bought new in the mid 70's. Worked up a load with H4831 that has been very accurate all these years. I have shot the Speer 175 gr. Mag Tip exclusively. H4831 has changed a couple times over the 40 years and I've reduced the charge accordingly. The 7mm likes to be pushed.

Kurt

[da gimp]

a poor crown can ruin accuracy pretty fast........... Just a question... but have you shot similar rifles with similar recoil accurately before? We have a good friend down here that was an expert with a bolt action .308, took several nice eastern Canadian moose with it, both were 1 shot kills that dropped very fast.

then a guy in their hunting party convinced him that he was woefully under gunned, so Kevin went out & bought a Rem 700 in .338 Win mag.......he never could get it to shoot & the shop he bought it from, re crowned it, pillar & glass bedded it & made sure his scope was on tight & right............

when one of our friends went shooting with him & handed him the rifle with an empty chamber when he was at the bench.......... He pulled the trigger on the empty & displayed the very worst flinch that anyone had ever seen.... & Kevin figured out why he couldn't hit with it. With good hand loads, & great coaching he has now mastered it.

None of us had thought that the .338 was a hard kicker, but to Kevin, he'd never shot anything that kicked as hard as his bolt .308Win had, he thought it was terrible. So I had to ask you, is this possible in your case too?

[Col. Colt]

The Shop I worked in had a Model 70 come in for a rebarrel - pie plate groups at 100 yards. Gunsmith started to order a barrel, but decided to clean the original .300 H&H barrel, first, "just to see". Well, it took him 3/4 of a day, but when he got done, that same barrel was shooting minute of angle! Clean and check the barrel, first. CC

[Stephan]

Yeh..clean the bore..check the crown..if no better 'credit card shim' the stock to float the barrel and see if it helps

[jjrothWA]

Tried above.
Recently made dummy cartridge by dropping Hornady 162 gr sst into chamber butt first and set a
new once-fired resizws case on it by closing the bolt.
Used a Sinclair hex nut to get the bullet diameter to case head length and compared against factory, measurement was almost .09" longer.
Worked up some load using 4064 powder for deer hunting in Michigan, using the determine length
and @ 50 yds, was getting quarter sized groups, waiting for weather to get back out a get final loads for both the downloads and MAG loads.