Model 70 problems anyone?

[glane5910]

I've had two Win 70's now that had to be shimmed under the rear base to sight in at just 100 yds. I had a Featherweight that needed 0.041" to hit at 100 yds and be optically centered. I just tried a Model 70 Classic in 375 H&H on Sunday that was a little over 2 foot low at 100 yds with a new Leupold VX-3/Leupold bases and rings. Any one else have similar problems?

 

[DrMike]

I've never encountered that problem. Two feet low is pretty severe. It almost sounds as if the front mount was switched to the rear. Don't ask how I know such a thing can happen.

 

[glane5910]

On the 375 Classic, they can't be switched, different hole patterns. The Featherweight pushfeed have different radiuses from front to rear so aside from the obvious height differences, the mounts would have lots of gap if switched.. I tried two different sets of Warne mounts on the Featherweight with the same results. It was really bad, I was topped out on adjustment with a Burris Fullfield 2, 4.5-14 and still was hitting 3 ft low. I shimmed that one before I turned a new barrel to get it optically centered. Only thing I can think of is possibly the bbl getting threaded slightly off the center of its bore?

 

[pre6422hornet]

Only problem I have is not owning enough of them :grin:

Seriously I am a model 70 junkie and fanatic. I have never had one that needed shimmed, and I have owned all variations (pre war, pre 64, classic, FN...) except a pushfeed.

Could there be a burr or imperfection in the rings causing this? Did you lap them to take that out of the equation?

Just my 2cents.

 

[glane5910]

Thanks for the thoughts...3 different sets of bases(2 Warne, 1 Leupold), 3 different sets of hand lapped rings(1 Warne and 2 Leupold), 2 different rifles. I'm starting to narrow down the problem to Winchester of old possibly being not too consistant in giving Base/Ring makers correct specs. On the 375 H&H, There are possibly 3 different receiver dimensions. I found there is a Pre-64 Express and a Post-64 express in the H&H calibers. Now this rifle is post 64 but its a Classic Model 70 which has a slightly different receiver than the Pre-64. The Classic 70 also has different hole spacing for the bottom metal than the Pre-64. The other rifle was a Featherweight for which I'm not finding bases for a FW, only a "standard" Model 70 both pre and post. I talked this over with a Gunsmithing instructor and he concurred he's had problems in the past getting bases to be correct heights on Md 70's. In my cases, I'm going to just take the required height off the bottoms of the front bases on the mill using a small fly cutter.

 

[Oldtrader3]

I have also had the same issues with mounting scope bases on Mauser actions I have not done a dimensional study on forged actions after polishing and processing but suspect that both the action and the mount thickness are out of specification occasionally. My Mark X action needs a 0.010 shim stack under the rear mount in order to set it up and zero the rifle properly.

Once set up, It has never given me any issues.

 

[Bruce Mc]

My Model 70 is a New Haven Classic. With regular Leupold one or two piece bases and low rings I use up almost all of the elevation to get a zero at 300 yds. I only have 6 minutes of + elevation left on my VX II 3x-9x. I need to get one of the long range bases if I want to be able to dial up a spot on for 600 yds.

 

[RiverRider]

I had one of the push-feed Model 70s that required a shim under the rear base. That was about 20 years ago...I think I made the shim out of a beer can. Why not? I had plenty of them around in those days!

The Model 70s I have owned since then gave me no such problem. They have all been the newer "Classic" action.

Shimming works, but I hate to do it out of concern for ring alignment. When a desirable (to me) base can't be had to compensate for whatever the problem might be, I'll go with Burris Signature rings. They can be had to fit Weaver-style mounts or you can get the Double Dovetail type---both winners in my book, and the offset inserts can go a pretty long way toward correcting alignment problems.

 

[Oldtrader3]

Warnes or Beuhlers have not given me these isseus BTW. Plus there ae several lengths (heights avilable for both). You just have to know what they are.

 

[glane5910]

The rings aren't the problem.

 

[Oldtrader3]

The rings aren't the problem.

I was talking about base thickness dimensions. Both makers and Model 70's have some variation in base height and have several base (especially 2-piece) for the various Mauser and 70 actions. This may be an easy fix. The issue is finding somebody like me who has several of each, is nearby and is willing to help you.

Somebody here must have a mill (Bridgeport or similar #2) available for access and use as well. Even a hobby mill would probably work, if you are careful. I have even done this with a file. Bases are often pretty soft sintered or hot rolled and will cut pretty easily.

 

[glane5910]

Thx...Most of the base/ring makers use to have serial number for Win 70 bases. I'm not really seeing much of that at all anymore. That's one of the problems. You just can't look at base charts anymore and get a pick of heights(unless you have a link to share). I'm just going to use a small fly cutter and take off the amount required from the front base on a mill.
Again, thanks for your input.

 

[glane5910]

Just to give all a heads up. I found the problem with this 375H&H Classic Model 70(and it wasn't the rifle). I was about to pull the bases off and mill some material off the bottom of the front base. It dawned on me to check one more thing before cutting metal. Mind you, this was a new out of a sealed box Leupold VX-3. I ASSUMED it was optically centered out of the box. I was wrong. I was roughly 60, 1/4" clicks from the bottom end away from optical center. haven't shot it yet but I'm guessing I won't blow up the bottom of another target stand..

 

[Oldtrader3]

Sounds like a gremlin at the store had some fun before you bought the scope. This illustrates a good point though, that of taking to time to center scopes before mounting. Always a good idea. Glad that you figured it out.

 

[glane5910]

Thanks, yes it does pay to check, no doubt.... This scope came straight from Leupold to me!!

 

[SJB358]

Glad you got it fixed.. Sometimes it is the easiest things that humble us the most..

 

[glane5910]

Glad you got it fixed.. Sometimes it is the easiest things that humble us the most..

Isn't that the truth! I felt kinda dumb there for a bit. I wrongly assumed that any scope coming out from Leupold would be optically centered. Certainly a useful learning experience. I'm just glad I didn't go and take 20 thou off that front base..