Need help with some M14 information gathering

[DaveInFloweryBranchGA]

Howdy all,

If you've got an M14 of any sort with USGI sights, I'm needing a measurement taken. On the windage knob, there's four nubs or engagement surfaces that slide against the receiver and lock into the slots on the receiver.

I have a theory they are slightly longer than the same part on an M1 Garand, but am looking for confirmation and I don't have a USGI M14 windage knob to measure.

So, if you have a USGI M14 windage knob, would you measure the length of those four nubs/engagement surfaces for me?

Thank you,

[country gent]

Ill have to look in the parts cabnient and see if I have a spare or 2 here to measure, I really dont want to take one of the NMs on the rifles apart. I believe they were the same between the garand and M14 the diffrence was between NM and battle sights. If memory serves me here the battle sight was 32 threads per inch giving 1 min of angle windage. The rack and pinon were set up also for 1 minute of angle clicks on the Battle sight. The National match sight was 64 threads per inch giving 1/2 minute of angle windage. The rack and pinion were the same at 1 minute clicks, but the hoods apeture was offset giving 1/2 minute with rottation ( reason for the notch in it is to show +/-). Springfield armory and some others made a windage nob that was set up for detente balls giving 8 clicks per revolution with the standard threads for 1/2 minute clicks. There were spacers also made that did the same. I am guessing that they are equal lengths between bosses and grooves as there would be an issue other wise with fit of the bosses in the slots otherwise.

[DaveInFloweryBranchGA]

Ill have to look in the parts cabnient and see if I have a spare or 2 here to measure, I really dont want to take one of the NMs on the rifles apart. Please don't take the NM ones apart, as I'm needing information on the standard windage knob and those can be persnickety to get back together if they have the ball/spring arrangement.

I believe they were the same between the garand and M14 the difference was between NM and battle sights. [COLOR="#FF0000"]I thought so too, but I'm seeing some slop on an M14 I just put some M1 sights on. The new sights are NOS USGI surplus and are new. Near as I can tell, the slop is caused by the length of the nubs/engagement surfaces. Not sure what those are called, but they fit in the slots that form an "X" on the right sight of the receiver and function as a locking detente for the knob./COLOR]

If memory serves me here the battle sight was 32 threads per inch giving 1 min of angle windage. The rack and pinon were set up also for 1 minute of angle clicks on the Battle sight. The National match sight was 64 threads per inch giving 1/2 minute of angle windage. The rack and pinion were the same at 1 minute clicks, but the hoods apeture was offset giving 1/2 minute with rottation ( reason for the notch in it is to show +/-). Springfield armory and some others made a windage nob that was set up for detente balls giving 8 clicks per revolution with the standard threads for 1/2 minute clicks. There were spacers also made that did the same. IN this case I'm only looking at standard windage knobs, so the National Match sight knobs are not in the equation, though if memory serves, the knobs/bearing surfaces are the same on the USGI NM sights and the stock sights.

I am guessing that they are equal lengths between bosses and grooves as there would be an issue other wise with fit of the bosses in the slots otherwise. That's what I've always heard and read too, but that's not what I'm seeing on this rifle and it may be just like cracks on Eddystone M1917 receivers. No real problems, just internet rumours except for the receivers cracked by technicians not putting the wrench on the receiver correctly.

Thank you for checking in any case. If I can get that measurement, I can resolve this pretty quickly I'm thinking.

[country gent]

It could be tolerences also. but any real difrences would keep them from setting in and "clicking" each minute change. Some of the newer sights with sqyare cornwers could be a pain to get to snap over the step untill they were broken in. I have the true NM sights with 64 tpis and 3 clicks. But getting that fine thread started correctly is a pain also. I never cared for the detente ball spring conversion but it did work okay. WHat issues are you having and with what rifle Garand or M1A M14?

[DaveInFloweryBranchGA]

Not having an issue persay, just trying to confirm something I found or eliminate it as a red herring. I'm more trying to get an idea of what the manufacturing tolerances are. I've got a new knob that is working in a new receiver, but there's some slop. The nub locks into the slots in the "X," but is a good bit narrower than the slot. Lacking the government specifications, I'm looking to gather enough information to confirm tolerance stacking or problem with machining.

In order to prevent bias, I'm trying to leave out the manufacturer's of the parts in question.

[DaveInFloweryBranchGA]

Turns out a BM 59 windage knob has wider bosses and tightened up the slop in the windage knob movement to a much better "feeling" hysteresis. The windage knob now feels pretty much like my 1950's built M1 windage knob hysteresis. So good to go.

[Mk42gunner]

Dave,

Sorry I didn't see this earlier, I thin k I have a couple of NOS M-14 rear sight pinions and windage knobs in my spare parts stash. If you still need measurements, let me know and I will look for them.

As far as I know, the only difference between standard M-1 and M-14 rear sights is supposed to be the elevation pinion. The M-1 being marked in yards, and the M-14 marked in meters. In theory the later M-1 and all M-14 windage knobs should be the same.

Robert

[Scharfschuetze]

+1 on the meters v. yards.

I also think that there were some differences in MOA come ups on the range settings due to differences in the Ought-Six v. the 7.62 NATO. I no longer have access to an M14 so I can't confirm that.

[Larry Gibson]

Scharfschuetzer and Mk42gunner are correct. The M1's elevation knob is marked in yards and the M14s is in meters. A lot of M1As have M1 elevation knobs marked in yards on them and they actually are more close regulated with M80 ball with 147 gr FMJs to actual ranges than is the M1 with M2 ball. Reason is M2 ball is/was "substandard" issue ammunition. The M1s sights marked in yards are regulate to M1 '06 ammunition with the 174 gr FMJBT at 2640 fps. M2 ball was supposed to be 2700 fps and then upped to 2800 fps right before WWII. However the actual velocity of M2 ammunition was lowered to 2550 at the request of National Guard Bureau in '39 - '41 so the fired bullets would stay inside the safety fans of most ranges in use back then. Thus most all training , zeroing and "qualification was done with the substandard issue M2. Thus the M2 ammunition became the "standard" and WWII and the Korean War were fought, and won, with "substandard" issue M2 ball. That's also the reason most snipers preferred the 165 gr AP ammunition because it was still loaded to the 2640 fps standard and was more accurate, especially at longer range.

While the "clicks" on both the M1 and M14 elevation knobs are the same the correction the M1 knob range markings go to 1200 yards while the M14s go to 1100 meters; basically the same range.

Larry Gibson

[DaveInFloweryBranchGA]

Guys,

I hate to do this to you, but I already knew all that stuff about the markings, etc. Was looking for a knob with larger than normal bosses for a specific situation and found it. Problem solved, no further information needed, but thanks all for posting.