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Spring Tube Receiver Indent Detail

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New2brass View Drop Down
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Dan Pinto, Photo Editor

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    Posted: Apr 09 2019 at 9:29pm

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2019-J

Spring Tube Receiver Detail


Early Winchester, early Rock-Ola, and all Quality Hardware manufactured receivers were of a two-piece design with the removable “Housing, Operating Slide Spring, Assembly.” The housing is commonly called a “Spring Tube.” The two piece receiver is commonly called a “Spring Tube Receiver”

The manufacturers that utilized the integral spring housing (one piece receiver) experienced difficulty in drilling the “deep hole” that was required to house the operating spring, with slight misalignment or flexing of the drill could result in the drill cutting through the right side or bottom of the integral spring housing on the receiver. The manufacturer’s options were to scrap the receiver or set it aside for later rework into a “spring tube” receiver by milling away the entire integral spring housing to accept a spring tube.

The one-piece receiver with integral spring housing is the most common receiver. These are commonly called Type 3 receivers. Please note that the “Type 1, 2, 3” receivers are definitions made by the club and not something the Ordnance Department used.

The Type 1 receiver is defined by having the operating slide dismounting slot, and the spring tube positioning lug. The dismounting slot allowed the rear of the operating slide to disengage from the receiver. The spring tube has a slide retaining lug which served to keep the slide engaged in the slide guideway.

 As you can see the slide stop detent has a hole that went all the way through the receiver. The rectangular hole for the operating slide dismount slot near the slide stop detent hole proved to be a weak point in the receiver and cracks could form between the two. As a result of the cracks, a change was made resulting in the Type 2 receiver.

The Type 2 receiver is defined as a spring tube receiver that eliminated the operating slide dismounting slot and the spring tube positioning lug. Due to not having the operating slide dismounting slot a front notch was added to the operating slide guideway in order to dismount the slide.

The rear notch on all receivers, if present, was only there for allowing the cutting tool access to cut the channel in the guideway needed for the operating slide. The slide cannot be disconnected from the rear notch.

Winchester Type 2 receivers in the 1120000 range changed the machining so that the slide stop detent no longer had a hole going all the way through the receiver. Quality Hardware appears to have not changed that detail.

The top 3 views of the spring tube pictured below, labeled Type 1, show the slide retaining lug that would fit through the operating slide dismounting slot in the Type 1 receiver. The bottom view shows a larger rectangular hole; this was to get a forming tool in to form the lug.

The rectangular hole to the rear of the spring tube is the positioning slot. The positioning slot on the spring tube would engage the positioning lug on the receiver to orientate the spring tube, so the slide retaining lug would be positioned appropriately.

If the spring tube were rotated, it would not seat properly, and this would cause a safety issue of the slide possibly becoming disengaged during firing. 

According to TM 9-1276 (1943), the spring tube with the lug could be used with the Type 2 receiver by turning the spring tube 45 degrees to clear the receiver. Doing so would cause the lug to dig into the stock as well as gouge the inner stock wall. The action would not fit properly in the stock. Perhaps Ordnance never actually tried this? Rock-ola remedied this by putting a cutout in stocks as pointed out in CCNL 328-2. However, the spring tube would have to be rotated 180 degrees.

The next set of spring tubes, labeled Type 1 Modified, were Type 1 spring tubes with the slide retaining lug cut or ground off. It would seem that there were ample amounts of Type 1 tubes that were modified. Why Rock-ola chose to mill a cutout in their stocks rather than simply grind off the retaining lug from their tubes remains a mystery.

The bottom spring tubes, labeled Type 2, do not have the lug nor the hole to form the lug. Why did they retain the positioning slot?

Type 2 receiver absent of the positioning lug would work with any spring tube type. But remember that if a Type 1 spring tube was used was used there would be the stock fit interference. As mentioned above, using a lug-less spring tube in a Type 1 receiver could be dangerous.

We expect that Type 2 receivers would not need the positioning lug. However, reporting by members indicates that at least some of the early Type 2 receivers retained the positioning lug. Changes to drawings probably followed, and machine operators were instructed to eliminate the indentation.


Although production of the Type 1 receiver ended in Spring 1943, and those receivers were to be declared "not acceptable during a rebuild, there was no attempt by the Ordnance Department to recall Type 1 receivers in use. Many did get rebuilt and were later purchased by collectors.

We are asking members with type 2 receivers to observe and report if the positioning lug is present. Please report the make and serial number so we can establish if this detail was across all manufacturers that made spring tube receivers. With this, we can define the serial ranges where this has occurred.

You can email the information to Datasheet@USCarbineCal30.com or post below as a follow-up.

As always we cannot do this without your help. Any submission of detail, large or small, that might not be known is always appreciated.

Dan Pinto

 

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jackp1028 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jackp1028 Quote  Post ReplyReply Direct Link To This Post Posted: Apr 13 2019 at 12:11pm
I have a third type of spring tube. It looks like a QHMC Type 2 with an extra positioning slot. The two slots are about 120 degrees apart. "Q" is stamped on the end. Has anyone seen this?






Here's a close-up.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote m1a1fan Quote  Post ReplyReply Direct Link To This Post Posted: Apr 13 2019 at 12:35pm
Dan, 

Fantastic article! Thanks.

I've read that the holes drilled into the receiver were succeptable to cracking. What's strange to me is why wasn't that noticed during testing? Perhaps it was and it took time to develop and deploy concrete solutions and the result was the transition to the spring tube receiver without holes? I know little to nothing about metallurgy, but the Operating Slide Dismount Slot looks like a crack waiting to happen.

For those lucky evnough to find and evaluate a type 1 Winch receiver, that area is a great place to start an evaluation. A loop is also a must as the cracks are sometimes very hard to see.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote New2brass Quote  Post ReplyReply Direct Link To This Post Posted: May 07 2019 at 4:06pm
Hardening of metal is an art. basically a receiver has thick areas and thinner areas. The material is heated to a critical temperature and then quenched. this modifies the molecule alignment and makes the material harder.
 
Thicker material has to be heated longer so the heat soaks in. the issue is the thinner sections will tend to boil off the carbon content, which is needed to harden.
 
After the material is hardened it is actually brittle. The material needs to be heated again to a lesser temperature to "draw" some of the hardness out.
 
I do not know if the type one receives developed stress cracks from quenching or drawing. It also may be the design which has inherent stress risers and subsequently cracks developed while the carbine was in use. Clearly early on this was discovered and they adjusted accordingly to the type 2 receiver.
 
This is one reason we do not see many type one receivers. The second issue was early on Winchester and Inland threaded the barrel threads on the receiver to different tolerances. I believe that the early Winchester receivers had issue with Inland barrels but the Winchester barrels fit the Inland receivers.
 
This would have been reason to reject receivers during rebuild or if re-barreling. At some point it I believe there was a rebuild order that said to scrap all two piece receivers as obsolete. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Jt22453 Quote  Post ReplyReply Direct Link To This Post Posted: Sep 01 2019 at 4:43am
One of my carbines only has front notch. Is that a common occurrence? All my others have both the front and rear notch.



Edited by New2brass - Sep 01 2019 at 10:31am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jackp1028 Quote  Post ReplyReply Direct Link To This Post Posted: Sep 01 2019 at 9:56am
@Jt22453, Pictures please.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote New2brass Quote  Post ReplyReply Direct Link To This Post Posted: Sep 01 2019 at 10:45am
Originally posted by New2brass New2brass wrote:

The Type 2 receiver is defined as a spring tube receiver that eliminated the operating slide dismounting slot and the spring tube positioning lug. Due to not having the operating slide dismounting slot a front notch was added to the operating slide guideway in order to dismount the slide.
The rear notch on all receivers, if present, was only there for allowing the cutting tool access to cut the channel in the guideway needed for the operating slide. The slide cannot be disconnected from the rear notch.

So yes, there were front notch only receivers. You need the front notch absent the type 1 receiver cutout to dismount the slide.

An example is that early Inland type 3 receivers only had one notch
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Jt22453 Quote  Post ReplyReply Direct Link To This Post Posted: Sep 01 2019 at 11:24am
Thanks Dan, I never really noticed it before. I wasn’t sure if it was something different or not.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote painter777 Quote  Post ReplyReply Direct Link To This Post Posted: Sep 02 2019 at 6:17pm
Not taking any Spring tubes in to account.

If Jt's Carbine is a early Inland with the one slide detach.
You can ID it as Inland because you can see the far left starting point of the channel is Rounded off....... Correct?

I've had NPM and NPM/U receivers on my mind which all had just the one slide detach slot. 
But the far left has the Squared starting point for the channel?
IIRC so were the UN-Quality's (1 Detach and Squared left end channel) ?


Pic of NPM-U

Link
https://www.milsurps.com/attachment.php?attachmentid=101508&d=1562439450

http://www.uscarbinecal30.com/forum/uploads/3657/2019JPainter.jpg


Edited by New2brass - Dec 12 2020 at 9:46pm
Living Free because of those that serve.....
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Post Options Post Options   Thanks (0) Thanks(0)   Quote New2brass Quote  Post ReplyReply Direct Link To This Post Posted: Jan 27 2020 at 9:49am
Charlie, Missed your post.
 Inland was not the only one with the round cut and one notch.

Only the front notch is a detach notch. The rear notch is for getting the cutter in the slot to cut channel.

The US&S observation is a good one and a clue. Many think they copied another receiver, but there are differances.
Both NPM/U and Un-Q from what I have observed have all the same features including the front ring comma.




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Post Options Post Options   Thanks (0) Thanks(0)   Quote Rebel92 Quote  Post ReplyReply Direct Link To This Post Posted: Oct 19 2021 at 3:36pm
on a type 2 spring tube, does it matter if the positioning slot is facing up or down if the receiver does not have the positioning lug? 
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Post Options Post Options   Thanks (2) Thanks(2)   Quote New2brass Quote  Post ReplyReply Direct Link To This Post Posted: Oct 20 2021 at 9:07am
A type 2 receiver would use a type 1 modified (tab ground off) or a type 2 spring tube.

Note how the type 2 tube retains positioning slot for the positioning lug, if present.

If your receiver does not have the positioning lug then it does not matter the orientation of the spring tube.

If your tube has the tab, then you have to rotate so it does not dig into the stock.
Rockola actually notched the stocks for the tube tab rather then grinding the tab off


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Post Options Post Options   Thanks (0) Thanks(0)   Quote carbinekid Quote  Post ReplyReply Direct Link To This Post Posted: Oct 20 2021 at 10:04am
I don’t know how I missed this info for so long… I always assumed the positioning slot in the tube was a drain hole. The more you know!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Rebel92 Quote  Post ReplyReply Direct Link To This Post Posted: Oct 20 2021 at 10:09am
My tube and receiver are smooth, no notch or retaining lug. Just making sure. Recently got a QHMC and its giving me issues, trying to make sure I leave no stone unturned. 
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