Long headspace?

[CatShooter]

Someone is thinking way too hard about this!!! If common sense still prevailed in this country, this thread would NOT exist. For a chamber cut to SAAMI specifications, the bolt should CLOSE on the "GO" head space gauge,,,, the bolt should NOT CLOSE on the "NO-GO" head space gauge.

Don't cloud a good thread with logic and common sense!!!

You made me laugh out loud!

All you guys go here ( http://www.youtube.com/watch?v=B_KVS1hIbQg ) and look at 9:50 - it shows the use of "GO" and "NO GO" gauges.

I was a full time gun smith for seven years and have continued to build rifles after I left it (no money in it).. I would NEVER own a "go" or a "no-go" gauge.

They are for crude "accept - reject" measurements.

 

[firearmdoc1]

+1 shortgrass, every barrel I have ever chambered was done using BOTH a go and no-go gauge. At the risk of offending others on this forum, the use of" the scotch tape method" is purely lazy and cheap. How much does a gauge cost? 40 bucks or less. If you are being paid to perform a job by a customer you should be using the appropriate tools for the job. How consistant do you really think the tolerances are on tape? Tape can be compessed where a properly made gauge cannot. If I were to speak with a gunsmith and found out they were using tape to headspace my chamber I would politely thank them for their time and find someone who was willing to use the proper tools. If you are chambering your own barrel, you are free to do as you want. This is just my opinion and I welcome any comments I may get from this.

 

[CatShooter]

The whole theory of headspace is that, if it is more than allowed, the base of the factory cartridge slams against the bolt head with a hammer-like blow which, over time, can cause the lugs to crack and eventually fail. By keeping the fit of the round in the chamber within specs you make the loading and unloading of the bolt lugs a much more smooth action without the hammer-like impact.

This is not true.

The "theory" behind headspace is so an industry that is made up of many independent companies can make firearms and ammunition that is interchangeable.

The allowable head space with a min 223 cartridge and a max chamber is 14 thou... that is a looong way from the head of the case to the bolt face.

Bolts on modern firearms like the Rem 700 and Win M-70 can withstand 100,000 pounds of force (real pounds, NOT psi) without even a whimper - the force of a case head varies between 3500 to 5500 pounds - the case NEVER threatens the integrity of the bolt.

Remember, this is a litigious society, and firearm companies will not allow equipment into the field that is capable of failing, and face $100,000,000 law suits - their lawyers won't allow it, and their insurance companies won't allow it.

 

[firearmdoc1]

[/quote]

Bolts on modern firearms like the Rem 700 and Win M-70 can withstand 100,000 pounds of force (real pounds, NOT psi) without even a whimper - the force of a case head varies between 3500 to 5500 pounds - the case NEVER threatens the integrity of the bolt.


[/quote]
I received a Remington 700 in the shop one time that the customer had removed the barrel from. His complaint was that he couldn't get the bolt open.
After removing the bolt, there was evidence of extreme pressure. The bolt nose was obturated, and the lugs showed signs of signifigant set back. The receiver lugs were also set back and the lower lug was cracked.
It seems to me that cracking a bolt lug would be nearly impossible. There are other parts of the bolt and receiver that would give way before the bolt lugs fail.
Needless to say I can't imagine what the pressure was.

 

[Erik Cortina]

+1 shortgrass, every barrel I have ever chambered was done using BOTH a go and no-go gauge. At the risk of offending others on this forum, the use of" the scotch tape method" is purely lazy and cheap. How much does a gauge cost? 40 bucks or less. If you are being paid to perform a job by a customer you should be using the appropriate tools for the job. How consistant do you really think the tolerances are on tape? Tape can be compessed where a properly made gauge cannot. If I were to speak with a gunsmith and found out they were using tape to headspace my chamber I would politely thank them for their time and find someone who was willing to use the proper tools. If you are chambering your own barrel, you are free to do as you want. This is just my opinion and I welcome any comments I may get from this.

I only use a go gauge to chamber barrels, if you know what you are doing there is no need for a no-go gauge. I DO NOT use tape either.

 

[firearmdoc1]

Erik, I agree that chambers can be properly cut without the use of a no-go gauge. It is just the way I do my chambers, and Yes I know what I am doing.
As for IF someone knows what they are doing, that's a big IF for a lot of so called gunsmiths out there.

 

[shortgrass]

Erik, I agree that chambers can be properly cut without the use of a no-go gauge. It is just the way I do my chambers, and Yes I know what I am doing.
As for IF someone knows what they are doing, that's a big IF for a lot of so called gunsmiths out there.

I agree. The proper use of a depth mic and a GO gauge can take you along ways. If a shim on the GO gauge is used I'd suggest steel shim stock stuck on the bolt face with a small dab of grease. The use of GO and NO-GO gauges, when working for customer is a must! It could give your lawyer a 'leg to stand on' when you get drug into court by some moron who reads too much on the interdnet! If you're doing for yourself, like mentioned before, have at it, do it any way you want. They're your eyes or the eyes of a family member. The weak point is the brass. Firing NEW brass in a long chamber stretches the brass at the head end, thinning it, thus weakening it. Re-sizing, without paying attention, will "over work" the cases, causing work hardening and a short case life. Chambering is nothing more than a machining operation. No magic, no mysteries, no voodoo. I've been a machinist for near 40 years, now. Been gunsmithing (after a formal 2 year education) for 20+ years (my shop is still open [on a part time basis, so I don't have to deal with idiots]and active and makes a buck or two!). Every machine shop that's machining something precision out of metal GAUGES what they're making. Either with micrometers (that have been checked with 'standards'), snap ring gauges (which have been set with gauge blocks), thread ring gauges which includes a GO and a NO-GO (which have been checked/set with standards), and pin or plug gauges for hole diameters, which include GO and a NO-GO gauges. You can't re-invent the wheel! This machining thing has been going on for over a century, now. Whatever you've come up with, between those ears, has already been tried by someone somewhere. If it was 'sound' practice it was adopted, if not sound, quickly abandon. A very good friend owns a precision machine shop. He uses certified gauges for all the work he does,,, and no tape!

 

[ebb]

I've done several chambers with Go and No go gages it IS NOT difficult to get it in between. Why anyone would believe a bolt is supposed to close on a No go gauge is beyond me. There may be lots of wiggle room with SAMMI but a custom gun is supposed to be better than SAMMI. If you've gone to the trouble of a match barrel and many top notch components why would you settle for a sloppy chamber. SAMMI is for manufacturers to send unsatisfied customers away.

 

[shortgrass]

I've done several chambers with Go and No go gages it IS NOT difficult to get it in between. Why anyone would believe a bolt is supposed to close on a No go gauge is beyond me. There may be lots of wiggle room with SAMMI but a custom gun is supposed to be better than SAMMI. If you've gone to the trouble of a match barrel and many top notch components why would you settle for a sloppy chamber. SAMMI is for manufacturers to send unsatisfied customers away.

Agreed, again. The 'game' the OP shoots in requires SAAMI spec. I'd expect it should be "GO" + .001 or .0015, not "NO-GO" + .005". Even if chambered right up to minimum, I still drop the "NO-GO" gauge in, just for safeties sake. Every human can make a mistake. I read, where when dialing in a barrel, that "it is checked and double checked" throughout the process. Does not final head space gauging deserve the same attention? In a machine shop the operator checks the dimentions he's cutting, then they're inspected again (usually by someone else) before they're shipped. Then, they're inspected again by the customer.

 

[Erik Cortina]

If the gunsmith made a mistake with headspace, I wonder what the rest of the chamber is like? :

 

[sailhertoo]

Mr. Gordy Gritters uses tape.

He is one of the country's top gunsmiths.

 

[shortgrass]

Mr. Gordy Gritters uses tape.

He is one of the country's top gunsmiths.

And he would be laughted out of any reputable machine shop in the country! Ya', he can shoot,, that doesn't make him a machinist. I've been driving since '69 and that doesn't make me a mechanic (especially on the newer makes). Wonder how that tape 'thing' would hold up in court?

 

[SDWhirlwind]

Ok. I understand where you guys are coming from. So long as my rifle is safe to shoot then I am not going to worry about it. I wont be going to nationals or any other high level matches, so I dont think it is a big deal. If it is not safe to shoot then I will have the barrel set back a touch to correct the headspace.

I read on another site that the bolt should not close on a NO GO gauge, but DRNewcomb say it can close on a NO GO but not on a FIELD gauge. Can anyone clarify?

You are talking about thousandths of an inch. The standard use of the three gages are that the GO gauge is used to tell the gunsmith that the chamber is too short and to keep turning the reamer. When the bolt will close on the GO gauge he slows down and starts using the NO GO gauge, as the bolt just begins to close on the NO GO gauge he will stop. The two gauges indicate the minimum and maximum dimensions for a new, factory chamber. After some shooting it is normal and safe for the bolt to close on a NO GO gauge. This does not indicate that the gun is unsafe. That job falls to the FIELD gauge, which indicates that the camber has grown to more than allowable specs. This only applies to factory ammo. If you are handloading and sizing your cases to shoot in this particular chamber the FIELD gauge does not indicate an unsafe condition by itself. However, if a factory rifle's bolt would close on a FIELD gauge, I would want to know why before shooting it, even with necksized reloads.

The whole theory of headspace is that, if it is more than allowed, the base of the factory cartridge slams against the bolt head with a hammer-like blow which, over time, can cause the lugs to crack and eventually fail. By keeping the fit of the round in the chamber within specs you make the loading and unloading of the bolt lugs a much more smooth action without the hammer-like impact.

Two of your 3 posts in this thread are ABSOLUTELY incorrect concerning determining 'correct' headspacing!! Part of the reasons I rarely anymore post on any internet forums is comments just like yours being blantantly incorrect and then having to argue as to why!!!

DRNewcomb, your interpretation of correct headspace is blantantly false and incorrect!!!!! Any 'custom' firearms builder that would let a rifle out the door with headspace that exceeds a NO GO isn't worth the title!!!! I build for myself and a few friends only and the rifle I finished last week, a 6XC has zero+ headspace! Personally I feel .002 is excessive and am disappointed if I error and exceed that! I won't/don't let anything leave my shop over that and strive for .001 maximum!

Over NO GO may be safe and acceptable as for liability and SAAMI but that is a poor excuse to use IMHO for a competent respectable gunsmith/machinist!

I realize my opinion however is totally worthless and usually results in bad mouthing and name calling on the net. Easy to do when you have the anonymity with a keyboard!

 

[jscandale]

Thanks gents. I have a custom 308 FT/R rifle that I had bult for me and the bolt closes on a NO GO gauge. When I first discovered that I was kind of freaking out about it. But, then I started thinking about the brass fireforming during the first firing and that Im only bumping the shoulders .002, so it should not be an issue now, untill I have to use new brass again. What I have, then, is essentially a long body 308 wildcat.

A NO GO gauge is use by gunsmiths to tell them when to stop reaming the chamber. The bolt actually should close on a NO GO gage. It should not close on a FIELD gauge. The three gauges are GO, NO GO and FIELD. The GO gauge says, "you need to ream some more". The FIELD gauge says the chamber is to long to shoot with factory ammo.

Slight correction. A "GO" gauge tells when to stop reaming. A "NO GO" says too far with the reamer. Most cartridges have about .003" from go to no go, some have .006".

The OP is correct about only having to size the shoulder back from the fire form and be just fine, but Erik has the right idea...if you paid to have the job done right, you should take it back and have it properly headspaced to the proper saami spec if that is what you paid for.

Just my $.02

JS

 

[jscandale]

Mr. Gordy Gritters uses tape.

He is one of the country's top gunsmiths.

Just out of curiosity, how does one earn the title of "one of the country's top gunsmiths"? Is there a reality show that I missed?

JS

 

[BillPa]

Just out of curiosity, how does one earn the title of "one of the country's top gunsmiths"? Is there a reality show that I missed?

JS

I never met the gentleman, but......

Builder of a number of custom rifles featured in Varmint Hunter Magazine

Builder of rifles winning the 2004 Heavy Gun, 2005, 2006, 2009, and 2010.
Overall 1000 Yard IBS National Championships, 2006, 2007 and 2012 IBS.
1000 yard "Shooter of the Year", and rifles winning 2003, 2004, 2005, 2006, 2007, 2008, and 2009 Iowa 1000 Yard club championships.

Builder of rifles that have set several new IBS 1000 Yard world records and numerous club records around the USA.

Builder of rifles winning multiple American F-Class regional and National championships, and Canadian F-Class Provincial championships, and rifles that have set F-Class world records

http://www.gordysgunsmithshop.com/gordysresume.html

Bill

 

[Taildrag15X]

My buddy Eric has nailed it, for the everyday home gunsmith checking a chamber job with a go & no go or screwing on a pre fit Savage is fine, but for a "Top level world leader gunsmith" to use tape on a go gauge is is foolish IMHO.

I'm no world renouned smith, have turned a few barrels and for myself but not to the level of Eric and I use these gauge sets:

http://www.forsterproducts.com/catalog.asp?prodid=700594&showprevnext=1

 

[sailhertoo]

Mr. Gordy Gritters uses tape.

He is one of the country's top gunsmiths.

And he would be laughted out of any reputable machine shop in the country! Ya', he can shoot,, that doesn't make him a machinist. I've been driving since '69 and that doesn't make me a mechanic (especially on the newer makes). Wonder how that tape 'thing' would hold up in court?

The very fact that you don't get it does not surprise me after this post. You have zero headspace or not. Weather you measure it with tape or a bottle of pixy dust.

(I would say you,sir, have zero headspace between your ears along with the rest of the couch potato rifle smiths on here)

If you people don't know what you're talking about (its obvious, yes), don't knock others methods.

Have a nice day.

 

[jscandale]

I think the fact that Gordy uses tape (as long as he knows the exact thicknes of the tape) is certainly an acceptable way to perform a final check on his reamer depth. If the tape measures .003", and the bolt does not close with minimal finger pressure, it's a positive indicator that the chamber is not beyond proper depth, provided that the bolt does close easily on a go gage. Is it an ideal labratory method? Probably not, but it works well and I don't know how a court room got into the mix. That's just internet forum "I'll show you" kinda talk.

I have never met Gordy (understand he is a very nice guy and certainly does not deserve to be bashed for his method) or most of the other gunsmiths on this forum, but I would suspect that most or all of them are able produce a job that is capable of producing documentable winning scores in any type of rifle competition. I don't say that because I have any particular knowledge of their work, I say it because I know from lots of experience that doing a good job just ain't that hard if you are willing to stick to the fundamentals of proper machining practice. No pixie dust, no chicken bones, just attention to detail and high quality measuring instruments.

Personally, I don't get into to much work for benchrest shooters because I don't participate in that type of shooting. I do however build lots of guns for high power competition which is quite demanding, particularly AR-15 match rifles. I will submit an observation...when I build a rifle for a seasoned high master competitor, the rifle seems to be very accurate all the time. When I build a rifle for a beginner or someone who thinks they ought to be a top level competitor if it wasn't for all of there equipment holding them back , the rifle is just never as accurate or is only accurate sometimes. Wonder why that is....?

Just my thoughts...

JS

 

[Scott Harris]

I took a 2-day class from Gordy. I've had a lot of "top" smiths do barrels for me. There are only two that have impressed me: Gordy and Warner Tool. The rest, whom I won't embarrass by naming, are not in the same league. Make no doubt about it, Gordy is amongst the very best, and is a true gentleman to boot. You wanna know how someone gets the name "one of the best smiths in the world?" His customers keep winning and winning and winning. I asked Gordy how long it takes him to chamber a barrel when nobody is pestering him: he said 8 hours. After spending two days with him and watching all the extra things he does that most smiths don't even think about....I get it. Too bad his wait list is over a year long...lol.