Headspace question, need help!!!

[Hecklerusp45]

I have a friend that has a M1917 that he has owned for many years and never fired. He recently decided that he may want to fire it, so he purchased the "go" and "no go" headspace gauges. He removed the extractor from the bolt (he was told this was the correct procedure) and found that the bold would close just fine on the "go" gauge. He then tried the "no go" gauge and found that the bolt would also close on the "no go". So, how big a problem is this? Is the rifle safe to shoot? If not, how do ya fix it?

[George in NH]

Sir,
As a matter of course, the striker assembly should also be removed from the bolt before using the gauges. I cannot relate why but in observing qualified personnel checking headspace on arms they would always detail strip any bolt they were checking. If you can obtain a copy of "Hatcher's Notebook" you will find detailed directions for checking headspace. Also, the chamber must be as clean as possible for an accurate reading. It may be that this rifle really does not headspace and the barrel must be replaced. Or you can obtain a "field" gauge and check the chamber again. If the bolt does not close on the "field" gauge you can safely fire the rifle. Having written that, I would offer that any rifle that closes on the "field" gauge would probably have high throat erosion and muzzle wear readings and should soon be replaced. HTH George in NH

[Col. Colt]

The M1917 Enfield action has VERY strong "camming action", serval times greater than a M1903 Springfield. In checking headspace, you should use almost no force and a stripped bolt body or your results will be invalid, and you may damage the headspace gauge and/or rifle. If you apply any force at all, the Enfield will cam the bolt closed, even if the headspace is (or was) fine! So a valid test requires a stripped bolt and a light touch. CC

[Dan Shapiro]

Don't forget that the M1917 cams like a Brit rifle NOT like a US rifle.

[Hecklerusp45]

Thanks for all of the help. I will pass this info on to the owner of the rifle in question.

[4F4Nam]

Personally, I would shoot the bitch and look at the brass for problems.

Ed

[chuckindenver]

ok,,,to check headsace on a 1917.
remove the cocking assembly.
install gage. felt resistance on the gage is a pass, even if it closes.. i wouldnt have wasted money on a go, no go, and feild reject are whats important on a used rifle.
if it fails no go, try field reject..if it fails...then try new bolt assembly.

[us019255]

I learned how to use gauges (in general, not just chamber) from my Grandfather when I was about 4. He was a German toolmaker. When I became an adult, I was amazed to find that many people thought you should have to use force on a gauge, or a micrometer. The whole trick is, as has been stated, to clean things and use a very gentle touch.

[dave]

Many 1917's have loose but not dangerous headspace. Chambers may be a touch too long which is not dangerous but hard on brass (for reloading). If space between bolt face and barrel face is exccesive you could have head separation, which is bad!

[fguffey]

“Many 1917's have loose but not dangerous headspace. Chambers may be a touch too long which is not dangerous but hard on brass (for reloading). If space between bolt face and barrel face is excessive you could have head separation, which is bad!”
Excessive space between the bolt face and face of the barrel is equal to unsupported case head or excessive case head protrusion, “which is bad”? Bad? More like catastrophic, the face of the M1917 barrel has a cone, the P14 barrel face is flat. The case head protrudes .090 thousandths from the bottom of the extractor to the head of the case, the 98 Mauser type protrudes .110 thousandths. I have 12 M1917 bolts, no matter what bolt I use the effect on head space when changing bolts is .001 thousandths.

I have 30+ 1903A3 type bolts, I do not have a 1903 bolt that will change head space .001 thousandths.

Again, I have an Eddystone with 0.16 thousandths head space, as in the chamber is .016 thousandths longer than the case, or the chamber is field reject length + .002 thousandths, I form cases for my ‘generous’ chamber from 280 Remington cases, the shoulder on the 280 is .051 thousandths ahead of the 30/06 shoulder, when forming 280 cases to 30/06 cases for my m 1919 I adjust the die off the shell holder .014 thousands, the first time I fire my formed cases O have .002 thousandths head space or put it another way my cases are .002 thousandths shorter from the head of the case to its shoulder than the chamber when measured from the bolt face to the shoulder of the chamber.

Then there is the receiver design, under most conditions firing a minimum length 30/06 case in a long chember will have 000 effect on the case if the shooter knows what they are doing.

And M1917s with long chamber is said to be tracked to an arsenal in UTAH, it is believed a smith tested all M1917s with a field reject gage, and, in doing so, he stretched the receivers.

F. Guffey

[IditarodJoe]

Or you can obtain a "field" gauge and check the chamber again. If the bolt does not close on the "field" gauge you can safely fire the rifle.
George is correct. GO and NOGO gauges are only appropriate for use when installing a new barrel. For checking headspace on an existing rifle, the only gauge you should be using is a FIELD gauge. If the stipped bolt doesn't close completely on a field gauge with very light finger pressure, then the headspace is acceptable. HTH

[fguffey]

“how do ya fix it?”

The ‘ya’ meaning ‘me’?


“Again, I have an Eddystone with .016 thousandths head space, as in the chamber is .016 thousandths longer than the case, or the chamber is field reject length + .002 thousandths, I form cases for my ‘generous’ chamber from 280 Remington cases, the shoulder on the 280 is .051 thousandths ahead of the 30/06 shoulder, when forming 280 cases to 30/06 cases for my M1917 I adjust the die off the shell holder .014 thousandths, the first time I fire my formed cases I have .002 thousandths head space or put it another way my cases are .002 thousandths shorter from the head of the case to its shoulder than the chamber when measured from the bolt face to the shoulder of the chamber”

I fixed the problem with longer cases from the head of the case to its shoulder, my chamber is not adjustable, my press and dies have threads, I could mindlessly adjust the die down to the shell holder plus an additional 1/4 to 1/2 turn but that would result in a case that is sized to minimum length or in reloading terms would best be described as full length sized.

The instructions you have received, if followed, will result in you/him purchasing another gage, the field reject gage, and that would make three gages, the go, no and beyond gage, again I said I formed cases from 280 Remington cases, I said I formed 280 Remington case to 30/06 cases that were field reject gage length meaning instead of the case body/shoulder juncture being 1.948” from the head of the case the formed- case case body/shoulder juncture is 1.962” from the head of the case.

I do not know who Joe is, I hope I have the luxury if disagreeing with him, I believe it is bad advise to instruct a shooter to chamber a round knowing the chamber is longer by .005 thousands than a go-gage length chamber, remember the ‘minimum length case/full length size case’ is .005 thousandths shorter than a go-gage length chamber, the no go-gage length is ..009 thousandths longer then a minimum length case and .004 thousandths longer than a go-gage. And the field reject gage is .014 thousandths longer than a minimum length/full length sized case.



F. Guffey

[jaie5070]

For what it's worth. A stupid thing I did ONCE was to fire sveral rounds in rapid succession. The three rounds were on a stripper clip and loaded just fine. When I looked down at the ejected third round, It had no case neck. Non of the three did. I had just fired three rounds of 7.65 argentine in my 1917. I was rattled for the rest of the days shooting. The rifle is fine and did not exhibit any abnormalities when firing the 7.65.
john

[fguffey]

“It had no case neck”

Your 7.65 BM/Argentine case necks became part of the shoulder, the Argentine case length is 2.110, the 30/06 case length is 2.948, meaning when the case formed to the chamber the case length would have shortened when the shoulder was erased and formed .102 thousandths in front of the argentine shoulder, what all this means is your cases did not loose their necks, the necks of your fired cases became part of the shoulder and part of your shoulders became part of the case body.

Same thing happens when 308 W ammo is fired in a 30/06 chamber with one exception, the 308 W head spaces on the case body/shoulder juncture because of the diameter of the 308 W is larger in diameter by .011 (+/-) thousandths than the chamber body at the point of contact.

Then there is the difference in diameter of the 308 bullet and the 7.65 BM bullet, again, there are +/- numbers, the 7.65 bullet could be .311, the up side? The pressure would have been reduced when the case formed to the chamber, pressure would have increased when the 7.65 bullet hit the forcing cone.

Back to the part where one set of rules are applied to head space, case head separation and catastrophic failure, Hatcher moved the shoulder forward .080 thousands knowing a case would not stretch that far without failure, he ejected 30/06 Hatcher modified +.080 thousands wildcats. (.080 thousandths added to the length between the case head and case body/shoulder juncture) A couple of smiths built 5 magnificent 7mm wildcats using the same 03 type receivers Hatcher used, they had 5 case failures out of the first 10 cases fired when forming. Not appreciated, I claimed I could have fixed the problem had I met them at the range, anyhow, they changed their methods and techniques when fire forming cases for all designs of receivers.

F. Guffey

[chuckindenver]

again...checking headspace on a 1917 or P14..is felt resistance of the tool..17,s cock on close and have a lot of camming pressure, so much that they can wear the locking lug weighs out, i have seen a few 17,s with this issue, and have posted pictures on how to tell.
you can see this when the barrel is removed, and only at this time.
look in the face of the receiver, and you will see were the locking lugs of the bolt have been wearing on the face of the weighs, if you can feel a step with a screwdriver or finger nail...its toast.. you might be able to fix it temporary, but it will wear again, sooner or later you will have a case head failure.
1917,s are 3.5% nickle steel and only surface hardened, they are strong but very soft as compared to other bolt action rifles.
every 17 that iv worked on that was said to have failed a no go..passed when i checked it..
do a test fire with a factory round...{not GI ball} Remington, Winchester or Federal factory 30-06..and look close at the fired case. chances are its fine,
Go is to check a new short chambered barrel, and usually finished till it closes on a Go..No Go is used as the rifle has been shot, to check normal wear, Field Reject is just that if it fails that tool., then its time to look to see why..
checking the headspace on a cock on open rifle isnt the same as cock on close.

[fguffey]

The length of the chamber from the bolt face to the shoulder/datum of the chamber determines the length of the chamber. In the perfect world the chamber length for the 30/06 chamber is equal to the length of the go-gage no matter what brand or manufacturer of the rifle. In the perfect world a minimum length/full length size case is .005 thousandths shorter when measured from the head of the case to its shoulder than a go=-gage length chamber, meaning there are not two different head space gages used for the Springfield and a different gage used for the Enfield M1917.

The Enfield, be it an Eddystone, Remington or Winchester, is unique in my opinion, I check head space for the Enfield with a field gage when checking for go-gage, no go-gage or field reject length chambers, and I can use a 280 Remington new, unfired, factory loaded round, checking head space does not lock me up.

Cock on close and the wedge, I have read that on other forms, something like cut and paste, and to me it makes no sense, in my opinion it is about bad habits, cock on close is not about sizing the case when closing the bolt, back to the difference on length between the chamber and case, there is .005 thousandths difference, meaning there is no reason for the rear of the bolt lugs to contact the receiver unless the shooter is lazy and allows the lugs to cam over to cock the firing pin assemble, that in my opinion is a bad habit.

Then there is the clearance at the bolt root, shove the bolt forward to close/cock then rotate the bolt down while closing, so the question, when does the trigger contact the cocking piece?

Again, I have an Eddystone with .016 thousandths head space, or put another way the length of the chamber in one of my Eddystones is .016 thousands longer than a go-gage length chamber, or put another way the chamber in one of my Eddystones is .002 thousands longer than a field reject gage. I form 280 Remington cases for this one chamber, when fired, the Remington formed cases increase in length .002 thousandths from the head of the case to the shoulder of the case, I am a fan of cutting down on all that case travel. An Eddystone with a long chamber is not rare or unique.

Again, A smith in Utah was accused or it is said he was responsible for the long chambers, seems it is believed he used a field reject gage to check M1917s for chamber length, then there is the tapered/wedged lugs thing that cause his accusers to believe he did not know what he was doing, again, I check the length of the chamber if the M1917 with a field reject gage in thousandths, that beats go-gage length, no go-gage length or field reject gage length, I choose 14 choices over 3 any day, for me? All of my dies when installed in the press are adjustable in thousandths, I am the fan of transfers, standards and verifying.

F. Guffey