New M305s binding operating rod and misaglined rod guide and piston - Help?

Odd Shot said:
DarceMegacre, can you post pics of the gas cylinder from the muzzle end which shows the splines?
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The more I look at it, the more i'm tempted to say that the spines on the gas cylinder may be out of place.
Keep in mind, nothing lines up really perfectly on these rifles (cheap communist shop class construction).

The barrel still looks slightly under-indexed. Would be interesting to see what it would look like properly indexed and maybe with a different gas cylinder.

Have you tried removing the flash hider and the gas cylinder yet?
 
Odd Shot said:
Have you tried removing the flash hider and the gas cylinder yet?
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Nope I haven't touched the flash hider yet, mostly because it was so easy to sight in I'd rather just leave it in place but if I'm having consistency issues after the oprod guide is mounted securely I will replace the gas cylinder.

I have a feeling when I remove the gas cylinder it will clearly show that the lands inside the mounts were machined crooked. Wouldn't be noticeable on an over indexed barrel but I'd prefer the gas port and front sight to be properly aligned and I can replace the gas cylinder later and probably replace everything forward of the front barrel band while I'm at it.

Still confused about what I'm supposed to do about the castellated nut though. Can that get cranked off with a good set of vice grips if I don't mind burring the finish as I will just be replacing it?
 
you need castle nut pliers. $15 at Brownell's

I found it impossible to remove it without the speciality pliers
 
I can send you my pos that I replaced, just pay for shipping and ship it back when your done.

Grab a pair of vice grips and a grinder to make a castle nut tool.

Don't forget about the set screw.

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From what I can tell it looks like there are two "halos" on the underside of the flash hider near at the rear of the bayonet lug. So I'm guessing it was welded on. I will probably put a few hundred rounds through and then see what the fit looks like then and maybe make some more adjustments.

I have a feeling I will be pretty darn consistent where I'm at with the rifle now, considering what my groups looked like with the Norc ammo and a binding oprod (horizontal was bad but lateral was under 3 MOA).

I'll be back with a range report later in the week! Thanks for all the help guys!
 
yomomma said:
I can send you my pos that I replaced, just pay for shipping and ship it back when your done.

Grab a pair of vice grips and a grinder to make a castle nut tool.

Don't forget about the set screw.

DSCN4504.jpg
Click to expand...
I made mine out of a little 4" long vise grips like these, heat the castle nut up with a torch to the point where it's not so hot you can't grab it and then undo the nut. I put mine back on with a light coating of nickle anti seize on the threads.
 
DarceMegarce said:
From what I can tell it looks like there are two "halos" on the underside of the flash hider near at the rear of the bayonet lug. So I'm guessing it was welded on. I will probably put a few hundred rounds through and then see what the fit looks like then and maybe make some more adjustments.

I have a feeling I will be pretty darn consistent where I'm at with the rifle now, considering what my groups looked like with the Norc ammo and a binding oprod (horizontal was bad but lateral was under 3 MOA).

I'll be back with a range report later in the week! Thanks for all the help guys!
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I think Barney (Tacticalteacher) is going to have a STROKE if you don't let him play with this rifle. From what I have read and heard from others he is our go to person in these parts. He also has some of the tools you need for sale including the castle nut pliers.

Rodney
 
Well an update:

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Looks like the pin channel in the barrel boss was drilled/milled off centre in order for the oprod guide to be in line with the gas cylinder rather than the receiver and barrel. That's my guess anyway, not sure exactly how they put it together.

Anyway the barrel boss is dimpled and feels pretty tight now and I filed away some material in the pin channel so I can fit it correctly. So I will probably see how that works and then go to the red loctite if the oprod guide is still being pushed off centre. I hope I don't need the loctite!
 
Not for nothin, but being brand new, why not just return it as defective? Why go through all this if its a warranty issue? Did you get it from a retailer? If yes, I'd return it if it were my money....
 
Well the crooked gas cylinder will have to be replaced I guess, no matter what I do it keeps pushing my oprod guide off centre, causing the jamming to return. So for now I will just turn off the gas system to prevent further hassle and we'll see how well she groups operating the action manually.

I guess I will have to post a WTB ad in the parts section for a Norc gas system....
 
I still don't understand how an out of index gas cylinder would force the op rod guide out of index as well on firing
 
DarceMegarce said:
Okay thanks!

Deciding now if I want to go with a new M1A gas system from Brownells or find a Norc cylinder somewhere. Already have some offers from EE so I should be able to figure it out!
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Just to clarify, if getting a non-Norco gas cylinder you obviously also need to get the matching non-Norc piston, gas plug, and spindle.

Call Springfield Armory directly. They may sell you these parts directly. But it may be better to go with USGI spec parts.

The M1A by Springfield may not be exactly to USGI spec
 
Well I took it out today with 20 rounds to sight it in with the gas turned off and it does cycle very well manually and shoots well too. It got pretty cold and was getting to be low light by the time I was sighted in but my final 3 shot group at 50 meters was about .8 inches and I'm sure I can tighten that up a bit with some practice with the aperature sight. Also this was with the steel cased Norc FMJ.

I have a lead from another member in Ontario who can help me out with a used Norc gas cylinder so hopefully I can try that out soon and maybe wind up with a really fantastic shooter to scope for the spring!

Also, I don't mind the manual action with the gas turned off at all! I may continue to shoot that way when doing groups in the future.

Another interesting thing I found out is that the windage screw on the rear sight can be loosened and tightened with the rim of a .308/7.62 case.
 
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