extra wide rib receivers

[RCS]

Anymore extra wide rib receivers surface this year ? most appear to be in the 37K to 43K serial number range with REP heat lots.

Most of them that have surfaced show the seventh round correction, but there are few originals around

Photos show standard low guide rib and extra wide guide rib

[Jersey Devil]

The only ones I've ever seen have been photos of yours!

I sure would like to find myself one of these!!

[RCS]

There are about a dozen known to collectors all are revision 1 receivers

The extra narrow rib appears on some revision 2 receivers up into the 60K serial range

[m14brian]

Man, that's rare!
m14brian

[Jersey Devil]

Robert,
Why were some receivers machined with the extra-wide (or extra-narrow) ribs?
It sure would be neat to find either that's been unmodified.
Thanks!
--Brian

[RCS]

the extra wide rib is only found on revision 1 receivers

the extra narrow rib is found on revision 2 receivers:

sn 48045 rev 2 C1IC sq bolt recess extra narrow rib and sn 48135 rev 2 sq bolt recess extra narrow rb

extra narrow rib still appears occasionally up into the 62K serial number range (I had 61981 years ago with the extra narrow rib)

Revision 2 serial numbers start at around 42442 with a -2 hand added to drawing number

revision 1 serial numbers that are very high are 49928, 49797, 49155

[Jersey Devil]

Great information, as always, Robert. Thank you for sharing it with us!

[Larry G.]

Thanks for the added information Robert. A couple of years ago you commented on a picture I emailed to you of sn 56145 rev 2 C1IC with a round bolt recess and the narrow rib.I now see where mine fits in the development.Every little bit of knowledge helps the majority of the novice collectors..

[Moorem1s]

I have 48042. It's my field grade gas trap build- that shoots like a service grade. I'll post pics as soon as I can figure it out.

[Jersey Devil]

I have 48042. It's my field grade gas trap build- that shoots like a service grade. I'll post pics as soon as I can figure it out.

That would be great, Scott. Thanks.
Also, if you email them to me I can post them for you here with your permission.
Thanks again!

[Jersey Devil]

Any thoughts on this receiver:

http://www.gunbroker.com/item/600950218

[RCS]

I have seen a double date stamped S-A 7-40 before from a friend in Calif, also saw the drawing number and heat lot code too. That's not much of a date, maybe information on the drawing number and heat lot code will be provided at some point ?

[Bubba1]

Barrel is very suspect. Markings and fonts are incorrect. Seller has been known to be honest and sell good stuff. He may not know.

Receiver has the extra small rib.

[RCS]

Was there any information on the drawing number and heat lot ? I did receive some photos of a fake S-A 12-40 not long ago, there could be more of them.

I have some information on receivers with S-A 7-40 barrels that are not direct conversions, they are all in the early 50K range with one in the 57K range. Of
course it dose not mean anything and only a guide

[Kscheel]

I've got 41218 and it is a narrow rib, -1 heat lot.

[Moorem1s]

40023 on a current gunbroker auction is wide rib. It has the 7th round fix. REP 7 heat lot.

http://www.gunbroker.com/item/711512...odal-view-item

[Jersey Devil]

I really need to find a bare, unmodified, wide-rib receiver........ugh.....someday!!