Gunsmithing The subject of headspace?

[Phil McGrath]

I've made the decision too get into more of the precision game, and being a service rifle guy (M1/M14/M1a guy) that runs irons, this is a big leap into bolt gun territory for me. Like everyone I have a budget and with that said this project wouldn't be possible without some wheeling and dealing along the way. As a starter for motavation I was gifted a very low round count (under 200rds) 40x tube and if I read the barrel date correctly EQ, it was made Oct 2019? The original owner's reasoning for rebarreling was he wanted a longer tube, different contour, differnt chamber and ROT not because the factory tube sour.

So here is the question, I was wondering is Remington's H/S all over the place, up and down or is it reasonable too assume they at a minimum try too target the lower end of the H/S range on there target rifles even though the barrel is marked 7.62 Nato?

 

[Threadcutter308]

I've made the decision too get into more of the precision game, and being a service rifle guy (M1/M14/M1a guy) that runs irons, this is a big leap into bolt gun territory for me. Like everyone I have a budget and with that said this project wouldn't be possible without some wheeling and dealing along the way. As a starter for motavation I was gifted a very low round count (under 200rds) 40x tube and if I read the barrel date correctly EQ, it was made Oct 2019? The original owner's reasoning for rebarreling was he wanted a longer tube, different contour, differnt chamber and ROT not because the factory tube sour.

So here is the question, I was wondering is Remington's H/S all over the place, up and down or is it reasonable too assume they at a minimum try too target the lower end of the H/S range on there target rifles even though the barrel is marked 7.62 Nato?

My suggestion is that you assume the headspace is off, purchase both a "Go" and a "No Go" gauge from Dave Manson and simply check it yourself. I would be willing to bet that the headspace is off and is in need of a 'Smith's attention.

 

[Phil McGrath]

My suggestion is that you assume the headspace is off, purchase both a "Go" and a "No Go" gauge from Dave Manson and simply check it yourself. I would be willing to bet that the headspace is off and is in need of a 'Smith's attention.

Yes, checking that goes without question I have access too reamers and gauges. More too the point, does Remington strive for the tight end of H/S on there target type rifles? I can work with the H/S being on the tight end but being too long is a waist of my time..... It would be a shame too give up on the barrel before its really had its day in the sun.

 

[Howland]

If it were my barrel, I wouldn't be satisfied just knowing that it falls somewhere between SAAMI minimum and maximum. That's a 0.010" spread. There is no substitute for knowing exactly what the headspace is for your chamber.

I've used the Hornady comparator with acceptable results but you have to add the difference of the case head to shoulder at the datum point of your modified case and that of a fully expanded case from your chamber.

 

[Ledzep]

You can massage a lot of headspace problems away in a M700 with the recoil lug thickness. Especially if you have access to a surface grinder.

 

[Phil McGrath]

If it were my barrel, I wouldn't be satisfied just knowing that it falls somewhere between SAAMI minimum and maximum. That's a 0.010" spread. There is no substitute for knowing exactly what the headspace is for your chamber.

I guess I'm not being very clear...... Gauges, reamers, tools, finding out the chambers H/S is not the issue. Generally speaking, does Remington on avg. chamber there rifles using minimum spec H/S or do they strive for somewhere in the middle of the H/S range?

IF Remington uses a min spec H/S chamber I have a good chance of being able too recycle this barrel buy making the chamber longer a few thou if need be, I do not want too set the chamber back. However if Remington is known for using on avg. middle of the road or long generous H/S figures I may not have enough material to work with after truing the bolt and receiver.

 

[smoothy8500]

I guess I'm not being very clear...... I may not have enough material to work with after truing the bolt and receiver.

Funny how we'll use surplus barrels and bolts as long as they fit on an M14 and stay under the Field Reject gage, but come here and everyone can't wait to unscrew and throw away the factory Remington barrel. Not too many people reuse a factory barrel so it may be a while till that knowledgable person answers.

 

[Phil McGrath]

Funny how we'll use surplus barrels and bolts as long as they fit on an M14 and stay under the Field Reject gage, but come here and everyone can't wait to unscrew and throw away the factory Remington barrel. Not too many people reuse a factory barrel so it may be a while till that knowledgable person answers.

That's ok, I found out what I needed too know with the help of Ledzep's suggestion. See you next door.

 

[SB545]

I guess I'm not being very clear...... Gauges, reamers, tools, finding out the chambers H/S is not the issue. Generally speaking, does Remington on avg. chamber there rifles using minimum spec H/S or do they strive for somewhere in the middle of the H/S range?

i don't know the answer to your question but my initial response is that they strive for increased head space in your wallet. they sell guns and don't spend much on quality control. if they have current standards i'd guess they are pretty loose when compared to other manufacturers.

 

[LRI]

Yes, checking that goes without question I have access too reamers and gauges. More too the point, does Remington strive for the tight end of H/S on there target type rifles? I can work with the H/S being on the tight end but being too long is a waist of my time..... It would be a shame too give up on the barrel before its really had its day in the sun.

Unless the gun comes from the Remington Custom Shop, HS will be somewhere between "GO" and "NO GO". It's a pass/fail exercise. The volume of product circulating through that company's main production doesn't allocate for someone plugging a set of gauges in .001" increments.

"Good accuracy" does not instantly mean HS is GO+.0000000000000000001" either. More than one rifle has parted the oceans and delivered sterling accuracy after going in and loosening it up a bit. X2 if it's a pinch neck type fire form cartridge.

 

[Dobbs02si]

I have only tried it once, but I swapped out a sporter 7rm for a sendero. With a depth mic from GO hs to shoulder, they were within half a thou. Probably luck, but they were close.

The second half of the question-Both barrels required a +.006 shell hold to bump the shoulder on fired brass to not rely on the belt for HS. Use that information as you will given it was only 2 samples.