[TedH]

I have a Model 70 Winchester 375 H&H that was made in 1960.  I have been tinkering around with this thing for quite a while and can't get it to shoot to like it should.  It will shoot light bullets with light powder charges pretty good, usually under 1.5 moa.  Such a load is a 250 gr. Sierra at 2500 fps.  However, when I turn up the volume groups open up to 5-6 moa.  Even most factory ammo that I have tried looks more like a shotgun with 00 buck from about 20 yards.  I am convinced that the higher the chamber pressure the worse the accuracy.  Let me tell you what I have tried already.  I have tried three different scopes, replaced the stock with a synthetic and free floated the barrel.  Two sets of mounts/rings.  Numerous combinations of bullets and powders.  Any other ideas?  I have been told that it could possibly be uneven locking lugs causing the problem but I smoked them and cycled the bolt and both lugs do seem to touch, although not across the entire face of the lugs. I am about to sentence this rifle to a life as a collector, but I have a hard time leaving a gun clean too long!

 

[alyeska338]

Ted,
As a last resort (before tagging it collector) I would send it off to someone who specializes in accurizing the Model 70's.  My guess given what you had done to it was the locking lugs, but that may not be the case.  A friend of mine had a Mauser (venezulan?) that wouldn't shoot a decent group with anything besides very weak loads and that was the culprit.  There are a lot of 'smiths out there that specializing in squaring the actions, lapping the lugs for at least 80% contact, etc...  Before giving up I would try that.

Sorry I don't have any real solutions, it is over my head.  I was hoping someone else would chime in.

Good luck.

 

[TedH]

Alyeska338,
Thanks for your response.  Do you have any recommendations for a gunsmith to check this rifle out?  I do not know of any in my area that I would trust to do that kind of work to a rifle of this value.

 

[MikeG]

You can check the lug contact pretty easily yourself, without damaging the rifle.

Get a bottle of the Reminton bore cleaner that is abrasive (mildly).  I forget exactly what the bottles are marked, but you will know what it is by the fact that there is a steel ball in the bottle, to help shake it up.

Shake it up really good and put a dab on each lug, and cycle the bolt handle up and down a couple hundred times (not kidding - it's not much of an abrasive).  The resistance provided by cocking the spring should put enough pressure on the lugs.  Might have to refresh the bore cleaner on the lugs a few times.

If you can't tell where the lugs are contacting by doing this, cold-blue the contact surfaces then try again (should only take a few strokes if you've already run through the process once).

Be sure to clean out the rifle well when you are finished.  Hoppe's #9 seems to take all the bore cleaner back out, at least it did for me.

 

[IDShooter]

TedH,
      After reading about this rifle, I think it is probably hopelessly defective and beyond repair,
and you should send it to me in order to prevent any future frustration.  <!--emo&--><img src="http://beartoothbullets.com/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=''><!--endemo-->           IDShooter

 

[TedH]

ID Shooter,
Gee,,,,,,I aint heard that before

 

[BCstocker]

TedH: Start with the basics: give the bore a thorough cleaning with a good copper solvent. Examine the muzzle with magnification- any dings in the crown? Check your screw tensions on the action- front and rear quite firmly tight, middle screw just snugged enough that you can close floorplate reliably. When checking lug contact do it with an empty fired cased (unsized) in the chamber. This will firm up the lug contact and give you a better marker imprint. If your rifle has a barrel recoil lug with screw or tension screw, experiment a bit with screw tightness. Usually less than tight works best. Check the barrel channel for evenness of bedding, like wise the action bedding. A rifle that old should have very apparent signs of where the metal is touching the wood. If it appears to rest harder in one spot (other than than the bottom of the barrel saddle at tip of forend wood) than it does the corresponding spot on the opposite side ease the high spots by scraping a bit of wood away carefully. Check to see if there are any internal wood cracks in the recoil lug support area and in the trigger mortise web. Check that action screws are not contacting the sides of the holes through the stock. See if anyone has done a glass bedding job that either needs redoing or easing in key places like under the recoil lug and around the screws. The rifle should shoot well with a bit of minor tinkering if it's typical of the model.  If you think there is too much forend tip pressure try shimming the action with a strip of business card to ease the tension and test it. If that improves the situation you can then decide whether to put in a better type of shim or to scrape down the pressure point a bit. If it still isn't shooting to your satisfaction then get a good gunsmith to check it out. Luck.