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"Death From Above"
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Well with all of the recent news about SAI receiver bridges being out of wack I decided to check mine for unusuall wear.
What I discovered shocked me. I found the bolt had turnred into a mushroom on the back end from smacking into the hammer. The bridge was just fine. So as so many of us here do I sent my M21 into SAI for inspection and repair. I specifically noted that I want nothing done to the rifle before I was consulted. I got a call from a very nice woman in the repair dept the other afternoon. I was told that the wear on the bolt was "normal" and that if I would like them to, they would replace it. I dont need to tell you what I told them to do. One of my concerns was the bolts are supposed to be as hard as the receivers. I was wondering what would happen when they lapped the new bolt into the receiver. If the bolt was soft maybe the receiver was too. So I asked! What will happen when you lapp the bolt in. will the lapping go through the hardening? WIll the headspace be opened up to a dangerous point as I am shooting the rifle? WHat she said next blew my mind. "The receiver is as hard as the bolt"! I said great that justifies my concerns because obviously the bolt is soft enough to mushroom at the back end! WHat she said next knocked me off my seat. "we dont lapp our bolts into the receivers so you dont have to worry about that. I said so how do you insure good lug contact? Are the bolts and receivers made to such close tollerances like the GI ones that you dont have to lapp them in? She put me on hold for a min and when she came back she said she just spooke to the production manager and he said that after a few rounds fired the bolts seat themselves. If that were the case the bolts and receivers would be soft and the headspace would open up. I can see the parkerizing wearing off but hey???? Now I was always under the impresion that bolt lug contact was an important asppect with these rifles. My question to the forum is am I wrong??????
 

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Bolt lug contact is important in that it should be even, so that the bolt lugs and receiver lugs can all equally share the burden of pressure they are intended to support. Im probably not stating anything that you dont already know 82nd... I guess Springfield just lives in their own world. Maybe all their stuff is perfect...... GI2.....?
 

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"Death From Above"
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Discussion Starter #3
I will be putting some dykem on the lugs when I get it back. I am curious to know where I stand. I begged them to just send me the rifle back with the barrel installed short chambered and the new bolt. They wanted no part of that.
 

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Lapping at home is pretty easy. Might not end up perfect, like our top smiths do, but it can be a big improvement.

I dismantle the bolt, put some compound on the lugs when installed, use a cleaning rod to apply pressure to the bolt, and just work the bolt with a small screwdriver jammed in the extractor shaft hole.

Doesn't take long, and your dykem or a magic marker will show much better contact.

Bubba taught me this method, and You Know Bubba ...
 

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"Death From Above"
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Discussion Starter #5
I have lapped in a few bolts and using 80 grit silicone carbide grease it still takes me at least 40-60 minutes to get the 70-90% contact I want. It takes me a long time I guess. I have been using the brownells lapping tool.
 

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The even contact part of it is important because it's inseparable from good seating and pre-ignition lock-up of the bolt. Most SAI rifles seem to be passable out of the box or we'd have heard otherwise. Maybe that's what the production manager was trying to say. But it's not something to tempt fate with. You can pull your op rod back with one finger and observe how quickly even a fully lapped & seated bolt starts to lift.
 

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lapping the lugs suggestion, an opinion only...

I will be putting some dykem on the lugs when I get it back. I am curious to know where I stand. I begged them to just send me the rifle back with the barrel installed short chambered and the new bolt. They wanted no part of that.
It is acceptable to lap the lugs to 60% and the results will not be different then going farther, This also prevents going through the harden surfaces.

What you have described is an ongoing problem of quality control in the commercial market place in general. When buying a M1A it is worth the time and cost to try and locate a Springfield receiver with a serial number under 45.000. I won't go in to the details they have been discussed many times on this Forum.

Today's M1A products are being put on the market at a buyer's beware situation.. If you read the similar Posts regarding failure to please the customer you will see a large percentage of them have to do with just his type of issue. $ 5.80 an hour employee taking the complaint calls answers all your questions. Art
 

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MGySgt USMC (ret)
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I have lapped in a few bolts and using 80 grit silicone carbide grease it still takes me at least 40-60 minutes to get the 70-90% contact I want. It takes me a long time I guess. I have been using the brownells lapping tool.
40-60 minutes to do the lapping job is actually sort of fast for many bolts and receivers. I figure 1 12/ to 2 hours as the norm and one took me almost 4 hours. I clean all the lap off frequently, measure the lugs from front to rear to see how much I'm taking off and check the headspace quite a few times as I do it.
 

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MGySgt USMC (ret)
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I don't have the blueprints handy while I am typing this, but one of the two parts of the bolt and receiver is probably not as hard as the other. We have to remember the parts are only surface hardened and not hardened all the way through or they would crack as the bolt hits the rear of the receiver heel.

Mushrooming of the rear of the bolt means they have a bad bolt that was not surface hardened correctly.
 

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"we dont lapp our bolts into the receivers so you dont have to worry about that. I said so how do you insure good lug contact? Are the bolts and receivers made to such close tollerances like the GI ones that you dont have to lapp them in? She put me on hold for a min and when she came back she said she just spooke to the production manager and he said that after a few rounds fired the bolts seat themselves.
This is pretty amazing. And disturbing.

I wonder if they lapped bolts int he past and stopped as a cost saving measure? I have a Scout built in 2002 and the bolt does appear to be lapped. Not quite 60%, but there is quite a bit of wear on the lugs facing the ejection port.

This seems like pretty bacic stuff to me. Wonder if there are any other parts not properly finished with the expectation they will "wear in" to the proper specs?

What they are actually selling is an unfinished firearm. So the real cost of a SAI M1A these days is adding the cost of a full blown go over and redo by a qualified M1A armorer.

Not telling people that can lead to a lot of trouble for them. All they need is one instance of a catastrophic failure and all that money they thought they saved by not doing it right will be out the window, unless they can point to an "expert" on the M1A that swears they did it right.
 

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MGySgt USMC (ret)
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Major Jim,

To my knowledge, and I've looked at a LOT of M1A's from Devine, Texas and SAinc. rifles since 1974, the only time SAinc. ever lapped the bolt in was on their custom guns.

G.I. bolts were never lapped in, they and the receivers were manufactured to spec and they always had plenty of contact from correct machining.

P.S. We never lapped lugs on G.I. NM M14's as there was never a need to do so.
 

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"Death From Above"
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Discussion Starter #14 (Edited)
Unfortunatly my hands are tied at this point. I can only hope that the luggs have decent contact. If I lap the bolt in I will be opening up the headspace.

Yup 700 rounds It was still a virgin and here is what I got for my money

Here is a SAI bolt next to a SA USGI bolt


Gus I mentioned the fact that the GI bolts were not lapped in to the GI receivers, on the same breath I asked if there were made to as close a tolerance that they did not see the need to lap in the bolts. SHe could not answer me.
This rifle was built in the custom shop, all the super match conditioned rifles are. That is where it is being repaired.
 

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"Death From Above"
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Discussion Starter #17
Way ahead of you on that one brother, I did ask! She said no way its a liability issue. Brilliant idea though! I knew there was a reason I liked you!!LOL
 

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82nd - When you get it all back, just send the bolt and receiver to Smith and have 'em treat it. Im thinking I might tear mine apart and do it...

Yup 700 rounds It was still a virgin and here is what I got for my money
Remember that discussion many moons ago about Springfield's "prices"....?

Im just teasing. DI2 - I own Springfield's too...
 

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MGySgt USMC (ret)
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Gus I mentioned the fact that the GI bolts were not lapped in to the GI receivers, on the same breath I asked if there were made to as close a tolerance that they did not see the need to lap in the bolts. SHe could not answer me.
This rifle was built in the custom shop, all the super match conditioned rifles are. That is where it is being repaired.
That bolt was DEFINITELY not heat treated correctly and it is NOT normal wear. The bottom portion of the rear of the bolt that is mushroomed is from the hammer doing the damage on firing or even dry firing and there should not be that much damage from over tens of thousands of rounds fired.

I'm sure the Lady answering the phone could not answer you. I'm sure she didn't know about bolt lug contact.

Generally speaking from what I have seen over the years, SAinc. bolt lug to receiver lug fit is not as good as original, though most are serviceable. However, sometimes you run across one where the left bolt lug does't contact at all and yes, they should not be that way.
 
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