Fitting a new bolt to a M14/M1A rifle info please

[Pop]

The bolt I got is very nicely made the specs on it are a hammer forged 8620 steel and the heat treated with a nice black finish afterwards.
What the problem seems to be not head space or any interference it seems the bolt lugs are a little to wide and won't drop down into the slots they go down maybe a little less then half way,fit compared to the Poly bolt is a lot tighter other then that,the bolt face don't come in contact with the barrel I was just wondering if it is as simple as machining the barrel side of the lugs until it drops into place then I could do a actual head space measurement. I don't see it touching any where else other the sides of the slots.
Any thought on that?

I would absolutely not machine anything off of the bolt lugs, even on the front side. Have you tried marking all the surfaces (sharpie works) and seeing where the rubbed off ink shows the bind?

 

[dimeN]

is there any irregularities/machining chatter on the receiver .. on the barrel side of the bolt lug recess ? thats what i had on my norc ... it takes very very little to crowd the lug ( fulton bolt is large )
- it would be good for you to purchase "the US .30 cal gas operated service rifle book by Jerry Kuhnhausen (it'll explain in detail how to lap a bolt ... that would be money well spent )

good luck

 

[maxinumarmor]

Haven't tried that but was my next step it would only confirm what I am already find though.

I would absolutely not machine anything off of the bolt lugs, even on the front side. Have you tried marking all the surfaces (sharpie works) and seeing where the rubbed off ink shows the bind?

 

[maxinumarmor]

I will track it down thanks.

is there any irregularities/machining chatter on the receiver .. on the barrel side of the bolt lug recess ? thats what i had on my norc ... it takes very very little to crowd the lug ( fulton bolt is large )
- it would be good for you to purchase "the US .30 cal gas operated service rifle book by Jerry Kuhnhausen (it'll explain in detail how to lap a bolt ... that would be money well spent )

good luck

 

[Pop]

Haven't tried that but was my next step it would only confirm what I am already find though.

Make sure you cover the entire front surface of the bolt lugs, if you find a rub mark on the inner portion of the front of the left bolt lug then it's definitely binding on the barrel.

 

[maxinumarmor]

I say the front side of the lugs because there is no pressure all would be applied to the back side of the lugs the only wear the front side would see is locking in and unlocking as the bolt is cycled.

I would absolutely not machine anything off of the bolt lugs, even on the front side. Have you tried marking all the surfaces (sharpie works) and seeing where the rubbed off ink shows the bind?

 

[Pop]

Given a choice between taking material off the front of the bolt lugs or the protruding rear of the barrel (I'm still convinced that's where you'll find the bind), I'd choose the barrel. That's just me though, a gunsmith would probably advise you to replace the barrel and ream the new one to fit instead.

 

[maxinumarmor]

Under stud but right now the lugs touch on both side front and back and go down into the receiver slots a little less the half way & no contact with the barrel.

Make sure you cover the entire front surface of the bolt lugs, if you find a rub mark on the inner portion of the front of the left bolt lug then it's definitely binding on the barrel.

 

[maxinumarmor]

Makes sense it would be like grinding a wrench to fit it works but you just weakened the wrench and it is more likely to break.

Given a choice between taking material off the front of the bolt lugs or the protruding rear of the barrel (I'm still convinced that's where you'll find the bind), I'd choose the barrel. That's just me though, a gunsmith would probably advise you to replace the barrel and ream the new one to fit instead.

 

[maxinumarmor]

I understand it would be like machining your forge crank journals down more then .030 you lose all your Harding surface causing accelerated wear.

From what I understand, the problem is that the bolt and receiver lugs are case hardened as required to stand up to the wear-and-tear of operations. If you remove too much metal (more than a few thousandths) you will remove the hardened metal and the be subject to extreme wear. In the case of bolt locking surfaces is that wear will open your headspace quickly, eventually to the point where the rifle is unsafe.

 

[Pop]

Exactly.

If you have a chance to get some good, clear closeup pics of the bolt in partial battery and the various wear points once it's been inked, I highly suggest posting them in the Main Battle Rifles section and M14Forum - the gurus there have the deep knowledge.

 

[maxinumarmor]

Will do. I have been over there also doing some reading looks like there are a few people going to the Fulton bolt with the same or similar issues.

Exactly.

If you have a chance to get some good, clear closeup pics of the bolt in partial battery and the various wear points once it's been inked, I highly suggest posting them in the Main Battle Rifles section and M14Forum - the gurus there have the deep knowledge.

 

[45ACPKING]

For that fulton bolt to be installed it needs to be lapped in. The procedures mates the bolt lugs and receiver lugs. This can only be done IF experienced hands can determine if the bolt is suitable.
If you do not already understand what is involved in fitting a bolt to an m14.... It's wise to send it to a reputable smith, with an actual track record for M14 work such as Casey at Tac Ord. Don't mess with it yourself.
I've had many customers in the past when I had my M14 shop open, who sent fulton bolts, LRB bolts and NOS usgi bolts that simply were to big at the lugs to safely instal without risking the case hardening.
I agree with tac teachers advice.
If yer gonna bother spending the time and money installing such a bolt, you are far better served replacing the barrel with a reamable aftermarket (krieger or non chrome lined criterion).

I'll add this , if yer wanting to gain a solid understanding of the processes involved in correctly and more importantly, safely install bolts, barrels, trigger components, ect... Hit up Brownells for a copy of : The 30 cal Service Rifle handbook, a shop manual vol I & II. Essential to have for building and performing the more advanced procedures for both the M1 Garand and M14 rifles.

 

[maxinumarmor]

On further examination yes mine is not suitable for my receiver the lugs are too big and I don't want to mess with it not a strait forward install like I was hoping I'm going to use the rifle as is, I also have my eye on a James Rivers set up as a NM just need the sites which I have also. Thanks for the very useful information saved to file.

For that fulton bolt to be installed it needs to be lapped in. The procedures mates the bolt lugs and receiver lugs. This can only be done IF experienced hands can determine if the bolt is suitable.
If you do not already understand what is involved in fitting a bolt to an m14.... It's wise to send it to a reputable smith, with an actual track record for M14 work such as Casey at Tac Ord. Don't mess with it yourself.
I've had many customers in the past when I had my M14 shop open, who sent fulton bolts, LRB bolts and NOS usgi bolts that simply were to big at the lugs to safely instal without risking the case hardening.
I agree with tac teachers advice.
If yer gonna bother spending the time and money installing such a bolt, you are far better served replacing the barrel with a reamable aftermarket (krieger or non chrome lined criterion).

I'll add this , if yer wanting to gain a solid understanding of the processes involved in correctly and more importantly, safely install bolts, barrels, trigger components, ect... Hit up Brownells for a copy of : The 30 cal Service Rifle handbook, a shop manual vol I & II. Essential to have for building and performing the more advanced procedures for both the M1 Garand and M14 rifles.

 

[maxinumarmor]

bump