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Old September 14, 2018, 07:33 PM   #1
jmstr
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Remington 1903 Headspace adjustment/bolt fit

Hi,

My Question: Is Headspace ALWAYS set with changing the barrel/chamber? Or, is there anything that can be safely done to the bolt to add about .002 of headspace to a rifle?

Situation:

I have a Remington-made 1903 from May of 1942 [NOT a 1903A3].

The bolt [call it A] has a good fit. It doesn't close on No-Go gauge,
closes well on Go Gauge.
No need for Field gauge.


Long story short, I also have another bolt that I was testing to see if it fit [call it B].

It has more resistance than optimal with 'go' gauge,
and NoGo won't close more than half-way.



My 'smith said that to make [bolt B] fit, the barrel would have to have the chamber reamed about .002-003.

Yet, if I did that, then Bolt A would be over the NoGo size, and nearing/passing the Field Gauge safety specs.

This leads me to the original question above.

I was thinking [always dangerous]...

Is it possible to remove about .001-.002 from the back side of the bolt locking lugs, so that it sits that much toward the rear, and allows that increase in headspace?

or, is this a huge no-no.

Any help is appreciated. I would love to have another Remington marked bolt that fits as a backup.

thank you
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Old September 14, 2018, 10:21 PM   #2
tangolima
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First need to define "close" and "not close". "Close" means bolt handle all the way down without feeling any resistance; "not close" otherwise. In other words, no need to try really hard. You may want to check again. Perhaps you have different results.

Having said that, there is no reason to use 2 bolts. Good to have a spare of course. Keep using the loose one till... you lose it or whatever. Then start using the other one. You may need to wait so long that you forget where you put the other one.

When the time comes, it would be a good idea to take the rifle and new bolt to a smith. Ideally the lock lugs should bear on the recesses 100%, or at least 75%. The smith may need to fit the new bolt to the gun if not.

Anyway I do think it is the worst reason to lengthen a gun's chamber.

-TL

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Old September 15, 2018, 08:02 AM   #3
HiBC
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I would not deepen the chamber.

Yes,it can be tuned at the bolt.

You first must establish your replacement bolt has good bearing at the locking lugs.A high spot can confuse your .002. Pulling back of your bolt handle is an offset load that can give false results.One way to apply an axial load might be via a cleaning rod carefully inserted via the muzzle,then stand the whole thing up,cleaning rod handle on the floor.Partiallt rotate the bolt,not clear to unlock.
Then pull the bolt and read the marker.

You will have good bearing,or a high spot.I would not recommend lapping.

The bolt can be laid in a ground vee block.A new,flat stone or diamond file can be laid flat and square on the end of the vee block. Thats just one way,but the bolt lug must be dressed flat and square.You can use a Harig Head and a surface grinder if one is handy.

Once you have dressed the lug for bearing,re-measure your headspace.

I've dressed a number of bolt faces to freshen them up. I set them up in a Bridgeport with a Vee block.Lugs aligned to Y-axis. Center over the bolt (indicator) zero dials

I use a smal lCriterion boring head and a short,stiff carbide boring bar as an adjustable fly cutter.

I set it to the bolt counterbore,about .475 +,by eyeballing it to the bolt.Tighten the boring bar lock screw.Re-chech diameter setting.A .001 or .002 or .003 diameter undersize is no big deal,but you don't want the cutter whacking on the sides of the bolt counterbore. Alternatively,use gage pins to establish what your counterbore dia is.Then measure your regrind 1/2 inch endmills to find one maybe .475 or whatever you need.

Then I set Z zero by just shaving some marker ink off the bolt face.

From off the bolt in theXaxis,I dial down my cut,Z axis,and feed x axis back to the zero I set over bolt center. So I fed a diameter-set fly cutter from the botton of the bolt face,the magazine side,up to the center.

The bolt face is fly-cut clean.

You can tune the bolt that way.Or someone good with a Bridgeport can

Last edited by HiBC; September 15, 2018 at 08:12 AM.
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Old September 15, 2018, 11:30 AM   #4
F. Guffey
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I have 35 Springfield bolts that are considered 'replacement' bolts for the 03, 03A3. I have checked the effect each one would have on the length of the chamber; not one of the bolts will change the length of the chamber .001".

Again, a resource shooter, reloader, builder of politically correct military (period correct) weapons like the 03, 03A3 and all variations; he built a 1911 Rock Island 03. After building the rifle he ask for help with the head space (length of the chamber from the datum/shoulder to the bolt face) on one of the 03 forums, and as always it got ugly.

I did not get involved I did visit his shop because he had a mill for sale. After loading the mill he asked me what I knew about head space, he had 20 30/06 head space gages that went back 'almost' to the beginning. He did not like the ideal the bolt closed on the go-gage and did not close on the no go-gage.

I offered to modify one of his head space gage to a go-to-infinity gage, he did not like that ideal because the gage would no longer be period correct. That left other options; I explained to him he was looking for clearance, I explained to him his clearance was between .000" and .005". I explained to him I do not use gages on the 03 type rifle. The 03 is one of the few rifles that have a design to prevent the bolt from moving back and nothing to prevent it from moving forward. I explained to him I use the ammo I am going to fire in the rifle to determine the length of the chamber and clearance. I selected a feeler gage from one of his tool boxes, he handed me the box of Remington 30/06 ammo he was going to use for testing the rifle.

I tested all 20 cartridges for clearance, the length of his chamber was .0025" shorter than a go-gage and .0025" and .0025" longer than a minimum length/full length sized case. All of that information from measuring the gap between the rear of the third lug and in front of the rear receiver ring.

He had no fewer than 100 bolt for the 03/03A3 etc. I offered to check the effect each bolt had on the length of the chamber and then I assured him he did not have a bolt that would change the length of the chamber more than .001". Then there was the problem with finding an 03 bolt with a straight handle, I have one and he had none.

I offered to help him off set the length of his chamber with the length of the case from the shoulder to the case head, instead he contacted his resource people. He started looking for a bucket of bolts, I could not convince him it was possible to measure a bolt for its effect on the length of the chamber.

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Old September 15, 2018, 11:42 AM   #5
F. Guffey
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Quote:
The bolt [call it A] has a good fit. It doesn't close on No-Go gauge,
closes well on Go Gauge.
No need for Field gauge.
If I had the luxury of disagreeing I would disagree.

F. Guffey
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Old September 15, 2018, 12:02 PM   #6
T. O'Heir
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"...Is Headspace ALWAYS set with changing the barrel/chamber?..." Yes. However, it's a fitting thing.
The bolt should close completely on a Go. Not close completely on the No-Go. The only time you use the Field is if the bolt closes completely on the No-Go.
"...the effect each one would have on the length..." No bolt has any effect on any chamber. The headspace is either good or it isn't. Since you have 35 Springfield bolts you have the same luxury the weapons techs had. You can try 'em until you find one that works.
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Old September 15, 2018, 12:44 PM   #7
F. Guffey
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Quote:
Since you have 35 Springfield bolts you have the same luxury the weapons techs had. You can try 'em until you find one that works.
That would depend on the tech's ability and the understanding necessary to make corrections. There were tools that were not available or the techs knew nothing about them. I have taken tools to gun shows to sell; problem, I could not find anyone that knew how the tools were used and or knew the tools existed.

Quote:
You can try 'em until you find one that works.
Again, I checked the effect the bolt would have on the length of the chamber from the shoulder of the chamber to the bolt face, None of the bolts will change the length of the chamber .001".

The builder would have been happy with a bolt that would shorten the length of the chamber .002". In my opinion he should have done the math before he screwed everything together.

making the chamber longer is one thing, shortening the chamber left him with starting over or finding a bolt that would shorten the chamber. I asked him about 'the fix', he said one of his resource people sent him 5 straight handle bolts.

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Old September 15, 2018, 04:05 PM   #8
HiBC
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A bunch of noise that provides no useful information.
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Old September 16, 2018, 08:19 AM   #9
F. Guffey
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Quote:
A bunch of noise that provides no useful information.
The 'be sures': "Be sure you check head space after changing the bolt". When changing the bolt 'be sure' to order a bucket of bolts 'just in case' there is too much head space or not enough.

I have complete bolts that came two to the box, I have never been able to see the logic for packing two identical bolts in one box. The bolts are Brown & Sharp.

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Old September 16, 2018, 09:25 AM   #10
4V50 Gary
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I'd face the bolt instead of reaming the chamber. Remember you have a good fit with the original bolt and barrel. You don't want to mess with that. It's the spare bolt you want to adjust and if you face the bolt face on a lathe, you're setting it back and creating distance for the go gauge to close.
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Old September 16, 2018, 09:44 AM   #11
F. Guffey
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Quote:
I'd face the bolt instead of reaming the chamber. Remember you have a good fit with the original bolt and barrel. You don't want to mess with that. It's the spare bolt you want to adjust and if you face the bolt face on a lathe, you're setting it back and creating distance for the go gauge to close.
Quote:
Remember you have a good fit with the original bolt and barrel.
I would apply the leaver policy; I would leaver the way I founder. The builder of the Rock Island rifle has no fewer than 100 Springfield bolt. I have no fewer than 35, between us we do not have a bolt that would increase/decrease the length of the chamber form the shoulder of the chamber to the bolt face .002". And we do not want to forget he required a period correct bolt for 1911 meaning the bolt had to have a straight handle.

When it comes to case travel when fired I am the fan of offsetting the length of the chamber with the length of the case from the shoulder/datum to the case head. Again, when it comes to determining clearance there is no rifle that is easier and or faster than the 03.

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Old September 16, 2018, 09:52 AM   #12
HiBC
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Exactly,Gary.

There are a number of machining methods to accomplish the facing,whether off the bolt face or the locking lugs.

I described using a mill.

The reasons I did not immediately choose a lathe,1)The bolt handle gets in the way of chucking.OK,you can use a steady rest.Or,something like a Gre-Tan bolt truing fixture,if you have one.

I'm not sure whether you meant facing the bolt face or the rear of the lugs.
A challenge to facing the lugs is pretty hard steel and an interrupted cut.Likely in a light lathe with less than ideal chucking.
You may have a good way to do that.I'd have to think about it.


I'd more likely face the rear of the lugs using a Harig spin jig and surface grinder,because I have those. Most folks don't

And 2) I can see it(using a latheon the bolt face) on a push feed bolt,a simple counterbore with 360 degrees of steel rim around the counterbore.
But with a CRF,there is the portion cut out flush with the bolt face down to the magazine.

As I do have access to a mill,I prefer the mill to a file.

But no matter,by one method or another,we agree,do not alter the original chamber or bolt. Face the replacement bolt.

Last edited by HiBC; September 16, 2018 at 10:08 AM.
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Old September 16, 2018, 01:43 PM   #13
F. Guffey
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Quote:
I would apply the leaver policy; I would leaver the way I founder.
Between the two of us we have 130 + 03 bolts the most rare bolt is the bolt for short chambers. Once there were 3 of us, the third one died a few months ago. When it came to bolts he wanted for nothing and he did not have an 03 bolt that would reduce the length of the chamber .002",

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Old September 16, 2018, 03:24 PM   #14
HiBC
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Maybe bolt # 2 is a 1903A4 scope bolt.
Maybe bending down the bolt upset some steel at the root of the bolt handle.
Maybe that is bearing on the backside of the rear receiver ring.

That is why I said it first must be established that the #2 bolt locking lugs are bearing nicely.

The 1796 bolts you have are irrelevant.They don't help the OP.And he wants to use the bolt he has.

And the OP is not looking for a bolt to "shorten"the chamber. His bolt won't quite close on the "GO" gauge.

I'll agree with the "Leaver"policy,on the original bolt,chamber,and receiver.

That leaves fitting the #2 bolt.

Or playing silly work around ammo games as in for the (very) often mentioned 1917 with .016 headspace.

That rifle is not the center of the universe rifle that all reloading practices should be modeled after.

Its either an out of spec relic or an example of sloppy,lazy "Bubba hack" gun butchery.
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Old September 16, 2018, 04:00 PM   #15
4V50 Gary
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Opps HiBC, I was thinking of that jig that we used at school, the La Bounty jig to face the bolt face, not the lugs:


I kick myself in the arse for not making a copy while I'm there. I should go back and reverse engineer it. It's easy enough to make a on a lathe and mill.

BTW, I had to do the backside of the lugs on a Rem 700 for our blueprinting class.
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Old September 16, 2018, 05:46 PM   #16
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Yes,I think Gre-Tan and maybe PTG make a similar tool.

And for a Remington, Its the efficient choice. Thing is,we are talking a CRF 1903 and you cant get the whole bolt face with a simple lathe cut.

Those are minor details on how a guy gets it done.First comes understanding what to do.
You obviously understand.
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Old September 16, 2018, 08:03 PM   #17
F. Guffey
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Quote:
Or playing silly work around ammo games as in for the (very) often mentioned 1917 with .016 headspace.
.016" clearance, I understand you have made a common mistake but to get the length of the chamber from the datum to the bolt face (head space) the .016" must mist be added. I understand this stuff is complicated for some. When the .016" is added to the length of the chamber the chamber is .002" longer than a field reject length gage. For those that need a little help with the math the chamber is .011 longer than a go gage length chamber and .016" longer than a minimum length/full length sized case.

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Old September 16, 2018, 08:12 PM   #18
F. Guffey
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Quote:
Its either an out of spec relic or an example of sloppy,lazy "Bubba hack" gun butchery.
The rifle is none of the above, again I found 3 of them in one month. I made gages for a 30/06 chamber for a collector, shooter, reloader in Bradford, Pa. I explained to him I stamped the gages to match a set I have. All he had to do was start chambering gages until the bolt would not close. All I needed was the number on the last gage that did allow the bolt to close.

This rifle went through an arsenal and came out with all of the stamps.

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Old September 16, 2018, 08:25 PM   #19
F. Guffey
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Quote:
That rifle is not the center of the universe rifle that all reloading practices should be modeled after.
I have said there has to be something reloaders do not understand about the events/step sequence that starts when the trigger is pulled.

Reloaders believe they can bump the shoulder back, I find it impossible to bump the shoulder back with a die that has case body support and the case body includes the shoulder of the case and case body and neck if the die is not a bushing die. If it is possible to bump the shoulder back with a die that has case body support it seems someone would explain how they can bump the shoulder back. When I move the shoulder back with a die that does not have case body support when I move the shoulder of a case back without case body support the case bulges at the case body/shoulder juncture and if I continue moving the shoulder back the case develops bellows and takes on the appearance of an accordion.

And then there are things that happen when the shoulder is move forward. I think moving the shoulder forward is a bad habit. The shoulder I start with is not the same shoulder I finish with.

The rifle with the .016" clearance is the perfect example to use when understanding what happens to the case when fired in a a control feed rifle.

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