EWMN said

Zebulon said
The K series Weaver scopes all had one inch tubes. The J series were smaller. They were all built in America with steel tubes but were not sealed and filled with inert gas, which made them liable to fogging in some weather conditions. 
The K4 was by far the most popular. 
What many younger folk don't realize is the impact of the Weaver post-WWII K series on the centerfire rifle market. Before Bill Weaver,  a 4X hunting scope was as costly as many popular big game rifles. When the K4 became available, there was a consequent push for scope friendly rifles. Winchester was slow to recognize this and lost market share to Marlin because the 336 came drilled and tapped for a top mount. The Savage 99 had a similar advantage as did the 740 and 760 Remington rifles. 
In 1966, my first deer rifle was a Remington 600 carbine in 6mm Remington caliber. It cost me $99 USD. McBride's mounted a new K-4 in Weaver rings and bases and bore-sighted the rifle, all for $40. Check the 1966 price of a Leupold & Stevens, Redfield, or Bausch & Lomb four power scopes, and a set of Buehler-style rings and bases. The K-4  was a watershed product. 
The K-6 was just as nice and was the most middle distance varmint scope you could buy for the money. Nothing else was even close. 
  

Thank you sir for sharing knowledge. It got me wondering about when I first started deer hunting. My pal-pal, dad and uncle Wiford all were using Remington 742s that they purchased in the mid to late 60s. Pretty sure they all had Weavers and im guessing k-4s. My dad has pal-pals rifle I'll get a good look at it next time I'm over there. But im more interested in looking at his beautiful browning 243 purchased new in 1964 /65. Its mounted w/ a 3x9 Redfield mounted at time of rifle purchase. I believe that ol' 243 has a sako action.
  

My fir deer rifle was a Marlin 336 purchased  new in i believe 1979, I was 8. I got a Winchester model 70 ranger in 30-06. Still have both.

Zebulon said
The K series Weaver scopes all had one inch tubes. The J series were smaller. They were all built in America with steel tubes but were not sealed and filled with inert gas, which made them liable to fogging in some weather conditions. 
The K4 was by far the most popular. 
What many younger folk don't realize is the impact of the Weaver post-WWII K series on the centerfire rifle market. Before Bill Weaver,  a 4X hunting scope was as costly as many popular big game rifles. When the K4 became available, there was a consequent push for scope friendly rifles. Winchester was slow to recognize this and lost market share to Marlin because the 336 came drilled and tapped for a top mount. The Savage 99 had a similar advantage as did the 740 and 760 Remington rifles. 
In 1966, my first deer rifle was a Remington 600 carbine in 6mm Remington caliber. It cost me $99 USD. McBride's mounted a new K-4 in Weaver rings and bases and bore-sighted the rifle, all for $40. Check the 1966 price of a Leupold & Stevens, Redfield, or Bausch & Lomb four power scopes, and a set of Buehler-style rings and bases. The K-4  was a watershed product. 
The K-6 was just as nice and was the most middle distance varmint scope you could buy for the money. Nothing else was even close. 
  

Thank you sir for sharing knowledge. It got me wondering about when I first started deer hunting. My pal-pal, dad and uncle Wiford all were using Remington 742s that they purchased in the mid to late 60s. Pretty sure they all had Weavers and im guessing k-4s. My dad has pal-pals rifle I'll get a good look at it next time I'm over there. But im more interested in looking at his beautiful browning 243 purchased new in 1964 /65. Its mounted w/ a 3x9 Redfield mounted at time of rifle purchase. I believe that ol' 243 has a sako action.

Zebulon said
At a guess,  Bert's K6 is a series D scope and so marked. I remember looking through a new K6 at McBrides and thinking maybe I should get it. There was a price bump from the K4 and the abandoned farm property I was allowed to hunt on could be still-hunted, so I opted for the K4. 
Of course, I could have just pulled the scope off while ground stalking. The Weaver mount system was quite good about returning to zero. I didn't know that at the time. 
  

It is actually a "60-B" (when Weaver first began manufacturing the anti-fogging nitrogen filled scopes).  It has very clear optics, and iit is perfectly suited to both the 22 WMR and 22 Hornets that I like so much.

The 60-B was first offered in 1960 and was replaced by the 60-C in 1965.  Because my Model 61 is a 1960 production riffle, I specifically chose the K6 60-B as the scope to put on it.

Bert

Of course, I could have just pulled the scope off while ground stalking. The Weaver mount system was quite good about returning to zero. I didn't know that at the time. 

EWMN said

Bert H. said
This is the Weaver K6 that I installed on my 1960 production Model 61 22 WMR rifle.
 
Bert
  

Thats a awesome k-6. Is that a 1 in. Or 3/4 ?. 
  

1"

The K4 was by far the most popular. 

What many younger folk don't realize is the impact of the Weaver post-WWII K series on the centerfire rifle market. Before Bill Weaver,  a 4X hunting scope was as costly as many popular big game rifles. When the K4 became available, there was a consequent push for scope friendly rifles. Winchester was slow to recognize this and lost market share to Marlin because the 336 came drilled and tapped for a top mount. The Savage 99 had a similar advantage as did the 740 and 760 Remington rifles. 

In 1966, my first deer rifle was a Remington 600 carbine in 6mm Remington caliber. It cost me $99 USD. McBride's mounted a new K-4 in Weaver rings and bases and bore-sighted the rifle, all for $40. Check the 1966 price of a Leupold & Stevens, Redfield, or Bausch & Lomb four power scopes, and a set of Buehler-style rings and bases. The K-4  was a watershed product. 

The K-6 was just as nice and was the most middle distance varmint scope you could buy for the money. Nothing else was even close. 

Bert H. said
This is the Weaver K6 that I installed on my 1960 production Model 61 22 WMR rifle.

 
Bert
  

Thats a awesome k-6. Is that a 1 in. Or 3/4 ?. 

Ben said

Bert H. said
This is the Weaver K6 that I installed on my 1960 production Model 61 22 WMR rifle.
 
Bert
  

Now if Bert could just figure out how to sight it in!  (you left yourself WIDE open on that one! 🙂 )  btw... did you make you're batch of "Champipple" yet? 
  

It is sighted in... but I am still scrubbing all of the crud out of the bore that you left in it.

No I did not make a batch of Champipple... instead, I bought a 6-pack of Oly beer.  I had to arm wrestle the crackers & Cheese Whiz out of my wife's clutches.

Bert H. said
This is the Weaver K6 that I installed on my 1960 production Model 61 22 WMR rifle.

 
Bert
  

Now if Bert could just figure out how to sight it in!  (you left yourself WIDE open on that one! 🙂 )  btw... did you make you're batch of "Champipple" yet? 

Bert