P14 head space

[mauserdad]

Thanks Gents. I should have separated into two postings the heads pace issue and the locking lug length issue. The head space issue I feel is OK. The head space issue is good using my coin field gauge. I also used the coloring of the backside of the lug. Operating stripped bolt handle about 20 times I have good wear marks on back side of both lugs. Now the locking lug issue. I have been told that the * marked bolts should have a left locking lug length of .0725. I measure my Eddystone's * at .0618. The locking lug length is what I am confused on. See above postings with pictures Thanks

[oldfoneguy]

Looking from the rear forward, its the right bolt lug that was lengthened. There should be a corresponding relief cut in the right side of the barrel face.

[mauserdad]

????? Looking from the rear forward the right bolt is much shorter????

[fjruple]

I believe everyone is trying to put in words which lug we are talking about? The right lug is the one with the ejector cut through the middle. The right lug was iincreased to made the MKI* or MKII. This is not to say that there were variations in the P14 bolt production, yes there was. There is also a lot of details in the P14 Production that we do not know. Each manufacturer did there own thing. Additionally it's quite possible the MKI* bolt was modified to fit a MKI rifle after the rifle left British service.

[Potashminer]

An issue to be considered is that unlike almost all other bolt actions, the P14 and the M1917 have inclined bolt lugs - after the initial forward motion as those lugs engage the receiver recesses, the bolt continues to move forward until the bolt handle hits its stop. Therefore, "headspace" can only be measured when the bolt handle if fully closed, unlike mausers or springfield. This was the subject of a letter written by Remington in response to various complaints that their Model 30's (made from left over M1917 receivers) were not correctly "headspaced". Forward motion can only be stopped by the bolt face coming up against a cartridge, or the extractor coming up against the rear of the barrel - nothing about the lug recesses to prevent forward movement, away from the receiver lug "seats".

[Bruce_in_Oz]

It can get quite ugly with the P-14.



A LOT of them are classic "mix-masters", having been shunted off to various "interesting, foreign parts", surplussed, randomly reassembled by "less than knowledgeable" folk and further tinkered with by Bubba. It is over seventy years since most, if not all, have been anywhere near a REAL ordnance workshop.

I've seen evil things done by individuals making a 1* bolt "fit" a standard body and barrel.

Because of the initial chaos and lack of standardization that occurred in early production, there are annoying lapses in "interchangeability". The design hacks involved in taking a mechanism initially intended for a long, fat, rimless cartridge and making it work with a shorter, thinner RIMMED round in a ludicrously short time inevitably led to "issues".

The "lockup" of the P-14 (and M-17) is HELICAL, just like a Lee Enfield. Thus, it is possible to generate a huge amount of forward leverage whilst forcing the bolt closed. The left lug "extension " should NEVER contact the rear face of the barrel tenon. Thus, the ONLY gauges worth a damn are proper, HARDENED STEEL ones. The bolt will either GO or NOT go as appropriate. WARNING! If in doubt, find a P-14-savvy gunsmith; good luck!

In an ideal world, "headspace gauging" is done with the bolt body ONLY, all the other bits removed. All you want to feel is the interaction between the barrel / chamber, bolt and receiver / body. The pressure of ONE finger on the bolt handle is all that is required. Any serious force applied during gauging is up there in "Bubbadom", with using Vernier calipers to remove staples.

[22SqnRAE]

[QUOTE=Bruce_in_Oz;458057.... is up there in "Bubbadom", with using Vernier calipers to remove staples.[/QUOTE]

I'm voting this the best comment I've seen his year! Brilliant!

[Peter Laidler]

The matter of M'17 headspace took on an even stranger aspect in the UK a couple of years ago. My friend had a new hard to find, US barrel fitted to his .300" M-17 and had to have it proofed as a result. Took it to proof house and it failed on CHS, even though it passed on his standard gauges (which I forget the spec now) but standard US spec rifle gauges. So, ever helpful, I had a set of workshop US and UK military M-17 gauges recalibrated in the calibration bay which came back with a certificate of accuracy and calibration. Once again, the rifle gauged up perfectly on the newly calibrated and certified go-no go gauges. I suggested that he submit it again - another fee don't forget - together with the US/MoD gauges, calibration certificate, cert of accuracy of the gauging test equipment. And guess what........

Yep, got it in one. Failed again! No explanation, no nothing, not so much as a bye your leave. No appeal, zilch, bugger all. Old barrel put back on rifle and rifle sold for deactivation. Seemingly the European CIP gauging standards are different to the US manufacturers and UK Military users spec. No wonder people question their antics...... Anyone else come across this strange situation

[Bruce_in_Oz]

What's the bet the "qualified personnel" at the proof house did NOT do the "strip bolt / one finger pressure" thing, but inserted "a" gauge and used more than the pressure of one finger before giving two fingers to the owner.

What the heck? They are "experts" and you would probably lose your house in legal fees if you took them to court; funny how these things work.

And who calibrates and certifies THEIR gauges, AND techniques? How regularly?

Back in the Eighties, a local dealer imported a small number of ex-East German Mosin Nagant sniper rigs. These were in "very-fine" condition when consigned; the local dealer had actually gone to the warehoudse and selected them from a larger batch. However, on arrival in Oz, they had to be subjected to a "safety test" by a certain government agency before being forwarded.

When they arrived for final unpacking, they were rusty and the bores hideous.

"Someone" had decided to "test-fire" all of them and then let them sit somewhere humid for several weeks. From "near mint" to "relic" in one easy step. NO recourse possible.

Same sort of people who "inspected" a very fine specimen of an 18th Century, British Naval flintlock pistol and fractured the cock. The fresh scratches on the frizzen were a bit of a giveaway. Dropping it, cocked, onto the "official" hard rubber mat from shoulder height may not have done it much good, either.

A few years back, one of my sons was working for a company making fittings for the oil and gas exploration biz. All his calipers and micrometers, analogue and digital, had to go to the local RAAF base instrument lab for ANNUAL certification, as did all the company-owned metrology toys. 200Km round trip! Some gear was on a six-month test schedule.

As some Roman bloke once asked: "Quis custodiet ipsos custodes?" See also: "Nil illegitemus carborundum".

[RC20]

What is being lost here is that this is a cock on close action.

It therefore does not act the same as a cock on open action.

As head space is going to be defined when the bolt is engage and closed, you pull the striker out of the bolt and that gets rid of the cam action (which is very powerful)

This system also was never set up for SAMMI and it did not exist nor would they have cared. It was a comb at rifle with looser tolerance to ensure it kept functioning in cobat.

As the ammo was once fired, no one care what it did to the case.

You don't want to cram in a head space gauge and raunch it down, the system will try to give.

If the lugs are worn, then that will be reflected in a easy close on a field reject gauges.

If its the lugs you have an issue as those will be hammered and shear in X number of fired shots.

Most parts in the 1917 do interchange, P14 no as they did not insist on it.

All my 1917s show very little hard use though parts are mixed.