#1A vs. #1S ?

[Alan in GA]

Is the barrel contour the difference?

 

[357Maximum]

Contour and sometimes length. Some 1S are 26" in length . The 1S in 4570 and 475lb I have are 22".

357

 

[El Numero Uno]

Not JUST the contour; A's have 22" light weight barrels. The 1S has been 26" medium weight from the beginning, except for the 45/70(22"). And EXCEPT that in recent years several other chamberings have been made in the 22" barrel. And now this year, we have a 30/06 No.1S with a 24" barrel.
I did not want to confuse this any farther by bringing up the AB's and AH's. And then there is the 1S-C; a 45/70 with a 26" C weight barrel(the same contour as the 375H&H).
Guess sometimes simple questions do not have simple answers when it comes to Rugers! :)

 

[ThomTender]

Is the RSI an entirely different contour or just a 1B shortened. Considering making my own from a caliber of my choice. That's if Ruger will sell me an RSI forearm. What do you think ThomTender

 

[gewehrfreund]

The RSI has the "A" weight barrel, just 2" shorter.
I doubt very much that Ruger will sell you an RSI fore-end, or any wood, even if they had it, which they don't seem to stockpile anymore.
Your best bet is going to be an aftermarket stock supplier, or a want ad on the internet gun forums.

 

[Alan in GA]

My 'just acquired' #1S 475 Linebaugh has a 22" barrel with a good bit larger OD at the muzzle than my 250 Savage #1A, understandably!

 

[RJ556]

gewehrfreund, are you sure the #1 RSI has an "A" weight barrel, just shorter? My KM77 RSI at the muzzle measures approximately .510" (18" barrel, I believe). My K1A at the muzzle measures approximately .565", (22" barrel). If the #1 RSI had a "A weight" barrel, Ruger could chamber their RSI's in calibers up to 35 Whelen as the did in some 1A's. Just say'n. RJ

 

[gewehrfreund]

Well, they have chambered it in 338 Federal, and I can't imagine Ruger producing a separate weight barrel just for the RSI

 

[021]

Well, they have chambered it in 338 Federal, and I can't imagine Ruger producing a separate weight barrel just for the RSI

I also thought it was a smaller diameter, and seems like this was discussed somewhere that it couldn't be made in anything bigger than .30 caliber. But, I'm wrong a lot. :)

 

[RJ556]

Well, it's easy enough to find out the answer to this one. If someone will please put a caliper on the muzzle of their No.1 RSI and report the measurement. I know there isn't hardly anything protruding from the sight base to measure but you can also measure just in back of the front sight base and we can compare that measurement to that of a 1A, just in back of the front sight base. My money says, the No.1 RSI barrel contour is not the same as the 1A, but smaller. RJ

 

[gewehrfreund]

Keep your money in your pocket.
If I can remember and no one beats me to it, I'll measure them both at 20" when I get home today. I'm hoping Lee or someone else who actually knows will chime in and verify that there was a small run 338 Federal in the RSI; that would pretty much end the smaller profile discussion. . . . . .maybe.

Also, I've seen more than one of the CHP 357 Magnum rifles rechambered to 358 Win., 35 Rem. and even 350 Rem Mag. Not to say this was advisable, but presumably some professional type did the rechambering and wasn't overly concerned.

 

[RJ556]

gewehrfreund, If you have both, measuring them will tell us for sure. I don't know why Ruger would use a different profile for M77 RSI's and No.1 RSI's. The front sight base is a different part number for the 1A and the 1RSI and it is not because of the muzzle cap screw because the muzzle cap screw does not even touch the front sight base. RJ

 

[El Numero Uno]

Not aware of any 338 Federals in the RSI; they were all AB to my knowledge. The 303 British got made in the RSI in very small numbers; like about ~20,
Understand now that 6 308 RSI's were made this Spring; that is the number I heard.
In the discussion of barrel contours, I think the M77 Ultralights have a contour thinner than the A weight No.1's.

 

[gewehrfreund]

I was thinking there were some RSIs in 338 Federal, but maybe I was confusing it with the AB. At any rate, the AB and A barrels are definitely the same profile.

I did measure my only RSI and two of my As, and at the 20" mark, they all measure right around .580"
Case closed?

 

[ThomTender]

I just measured my RSI in 7 MM at the very end of the barrel. Its .680. Then I measured my 22/250 B and it measured at the 20"mark .690. That's pretty close. Now to think about what caliber I might want and then have someone measure the barrel at the 20" mark. Who knows what kind of an RSI you might be able to come up with. Thomtender

 

[RJ556]

gewehrfreund, If this is the case, then you are correct. I re-measured my KM77RSI and it definitely measures .515" at the muzzle of it's 18.5" barrel. The front sight base is also much smaller than the FSB on my K1A. So it is evident that Ruger uses a smaller barrel profile on their M77 RSI's than on their No.1 RSI's. Tom, I am assuming you were measuring the outside diameter of the front sight base on your RSI for that .690" measurement. That is about what I get when measuring the diameter of the FSB on my K1A. So, being this is the case, I see no reason why Ruger does not chamber their No.1 RSI's to calibers up to .35 As we all know, they did 35 Whelen in the K1A. RJ

 

[gewehrfreund]

Well, why Ruger made/makes the decisions they do is something that we will probably never know, and I suppose it adds to the allure of collecting and using their products.