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View Full Version : Should I"over index" My Barrel?


Prince Humperdink
11-30-2011, 07:18 PM
What would You do(besides the right thing and buy new barrel)?I could tighten up the barrel and hope for a bit more headspace,(I could mount the sight on the side and be"Gansta").As long as it tilt tested ok and doesn't rub I could have accuracy enough for Deer hunting,or just keep sizing to fit that chamber?I want to be able to use factory ammo at some point,and I will get a new barrel someday,but funds won't permit anytime soon.I need to be as cheap and bubba as possible,but don't want a total POS.
Ryan
canes7
11-30-2011, 07:28 PM
No. What is the history of this barrel?
Prince Humperdink
11-30-2011, 07:36 PM
No. What is the history of this barrel?

It was from a private sale,it was a an SAI takeoff that had a TE of almost one,but we'll say one.It indexed all the way by hand,so in My excitement I went ahead and peened the shoulder so it would crush and index correctly.Checked HS with a Forster Field gage and it swallowed it(I think I had to add 4 pieces of scotch tape to stop it from closing).I'm not going to send it back as I already"modified" it,and I was making "custom"rounds from once fired brass,and sized so it closed on stripped bolt,but not with a slab of tape on the back of the cartridge.Fired 80 rnds and checked,only a couple needed any trimming,but I don't want to be doing that.

I was sure that a barrel this"new" would headspace,but I suspect that someone got too aggressive with a reamer and that is why it was pulled.
Ryan
LEAD POISON
11-30-2011, 09:24 PM
Can't you just bore the chamber out and put in an insert????
canes7
11-30-2011, 11:06 PM
That's one of the big problems with M1A's and especially SAI parts... they do require custom fitting. I've read a couple horror stories from some of the big name M1/M1A builders about that and have experienced it once myself. M1A's are not like the USGI Garands we are so familiar with. SAI's tolerances are not what USGI stuff was and they get away with it because they have a shit ton of receivers and a shit ton of barrels to match up to them.
timshufflin
11-30-2011, 11:07 PM
I would not over index it because I don't even think that will help. Stand down, relax, get you a new barrel. What's the word on the streets regarding m14 bolts? Are any longer than others?
Prince Humperdink
11-30-2011, 11:25 PM
I would not over index it because I don't even think that will help. Stand down, relax, get you a new barrel. What's the word on the streets regarding m14 bolts? Are any longer than others?
I was wondering about the bolt length as well,maybe like a -65 series equivalent of M14 bolts.
timshufflin
11-30-2011, 11:32 PM
Prince, the thing is though that you used 4 pieces of tape to pass just field! What is that, like .008 or so? That's a ton to make up bro.
Prince Humperdink
11-30-2011, 11:36 PM
Prince, the thing is though that you used 4 pieces of tape to pass just field! What is that, like .008 or so? That's a ton to make up bro.

I know,I'm just grasping for a Rainbow...I didn't need anymore bad news,and when that bolt fell down,so did my heart :(
LEAD POISON
12-01-2011, 12:01 AM
OKAY Call SAI talk to one of there service guys.There really good.
They may have a remedy.It's worth a try.
Prince Humperdink
12-01-2011, 12:33 AM
Prince, the thing is though that you used 4 pieces of tape to pass just field! What is that, like .008 or so? That's a ton to make up bro.

it was actually 3 pieces,but still too much.
Punch The Clown
12-01-2011, 07:17 AM
Scotch Tape and Masking Tape are 2 different animals. NATO and SAAMI differ by 8 thou on the 308/762. I was reading a very damn informative thread regarding this right here on BT yesterday. Some reals pearls to be found in that thread.
timshufflin
12-01-2011, 09:25 AM
What kind of bolt is this and is this barrel chrome lined. I thought I better get to the basics as I never asked. Stu nails it, what gauge you using , NATO or .308? You said scotch tape, that's probably only .001 or less thick as compared to masking tape. Heck, this thing may headspace.
Prince Humperdink
12-01-2011, 12:56 PM
What kind of bolt is this and is this barrel chrome lined. I thought I better get to the basics as I never asked. Stu nails it, what gauge you using , NATO or .308? You said scotch tape, that's probably only .001 or less thick as compared to masking tape. Heck, this thing may headspace.

The bolt is a new SAI,barrel is pulled SAI,not chrome lined. Gage is Forster .308 Field(1.638),tape is 3M Scotch tape(not masking tape).
jjones
12-07-2011, 01:00 PM
What happened, did you get it to headspace?
Prince Humperdink
12-07-2011, 05:52 PM
What happened, did you get it to headspace?

I tightened it up just a tad more.It still closes on a Forster Field,but now only 2 pieces of clear tape.All of the ammo I have loaded was handfitted to the chamber using stripped bolt.I set My dies to a loaded round closing w/stripped bolt,but not closing w/2 pieces of Scotch tape.After firing and reloading I am finding that MOST need no trim at all after sizing,and if it does trim it is very minimal,and accuracy has been good.I read that 7.62 Nato was acceptable to a length of 1.645 and I believe I should be right there w.a 1.638 gage and 2 pieces of tape(that stuff is THIN).I think using 7.62 brass and ammo would be within safe limits.
Ryan