Author Topic: Head Space (Read 1177 times)

brasskeeper · « **on:** March 24, 2005, 07:24:29 AM »

Is there a way to check the head space on a springfield 03 30-06 using a empty case with a bullet seated at a ceratin length?
If not what procedure short of a trip to the smithy?

lefty o · « **Reply #1 on:** March 24, 2005, 07:50:27 AM »

no, you need a set of headspace guages.

Racepres · « **Reply #2 on:** March 24, 2005, 11:32:30 AM »

Remember that headspace has nothing to do w/ the bullet... on the '06 headspace is determined from the datum line of the shoulder to the bolt (breach) face... Nothing that I know of except a headspace gauge can give you an accurate check.... Marty

BS · « **Reply #3 on:** March 28, 2005, 12:29:13 PM »

Why do you want to check the headspace?

Cut out two 7/16" diameter pcs from a side wall of a pop can. They should be .004, super glue and press one onto the primer of a live, unfired case. You should be able to close the bolt. Add another, and you shouldn't be able to close it. Use a small dot of glue on the primer and push hard, to keep it tight!

Foil on a disposable pie plat is .003

Might work?
BS

lefty o · « **Reply #4 on:** March 28, 2005, 06:20:54 PM »

the above method is not a decent indicator of headspace.

gunnut69 · « **Reply #5 on:** March 29, 2005, 05:23:52 AM »

Cases are made to 'tolerances' and the variance along with the relatively soft nature of cases makes them unacceptable as gauges. Headspace is a serious matter. If it is off and allowed to continue really bad things can happen... Take the rifle to a smith and get it checked.

BS · « **Reply #6 on:** March 29, 2005, 02:38:06 PM »

I just checked the difference between a go-gage and a factory round of 308, how much space do you think there is?

.003-.004, so a bit of grease on a pc. of pop can would work just fine for a go gage..........if you have nothing else, and want to check, why wouldn't it work? Two can thicknesses should be fine, for a no-go and if three fit, it needs some help!

NO-BS

Want to see a picture of my adjustable Mag Go, No-Go gage?
One gage does it all. 6.5, 350 to 458 size cases, also have one for 240 Weatherby. BE KIND!

lefty o · « **Reply #7 on:** March 29, 2005, 06:26:36 PM »

i dont really want to argue, but you give bad advice.

Headache · « **Reply #8 on:** March 30, 2005, 07:04:29 AM »

You can not check headspace using factory ammo and adding shims.

The gage point on factory ammo is 2.0526"-.0070". The chamber headspace is 2.0487"+.0100". Per design, you can have from .0039" of crush to .0131" of clearance.

The only way to check your headspace is to use headspace gages because you do not know where in the tolerance band your ammo may be.

Good luck,
Headache

PA-Joe · « **Reply #9 on:** March 30, 2005, 08:17:30 AM »

Brasskeeper - What are you trying to do?

If you have brass shot from that gun you can adjust your dies by sizing a case just a little. Set up your dies and back the die out 1 or 2 turns then size a case. See if it fits. Turn the die down and size again. Keep doing this until the case fits. This will give you a pretty good idea of what the headspace is.

Kiwi Rob · « **Reply #10 on:** May 25, 2005, 06:56:52 PM »

Hi , since" brass keeper" did not say why he wanted to head space his gun the avice he is getting could be a bit off ... If he has had a problem with his rifle or if he has decided that this is something he would like to know then we have 2 different ball games ..It is possible to use unfired cartridges to safely check head space , this will tell you if your gun is in safe condition or not , using the cartidges at your disposal , what it will not tell you is whether it is in factory new condition or up to saami specis , another way to check head space is to take an unfired case , prime it and fire it ,this will cause the primer to back out ,the same as happens when you fire a live cartridge and you can measure how much the primer protrudes ..As an aside flatted primers always thought to indicate high pressure can also indicate a head space problem ,primer backs out, case grabs chamber wall , case comes back and flattens primer ,you can check this out by deliberately sizing a case so it is short and fire it with a standard load and you will get a flattened primer ..Don't ask how I know this ..Rob

gunnut69 · « **Reply #11 on:** May 25, 2005, 07:43:35 PM »

Using a cartridge case does NOT determine headspace. It determines the fit of THAT cartridge in your chamber. Headspace is the relationship of your chamber to a set of specifiecations. Who cares? You will if the right set of circumstances occur. A case head seperation on some rifles can leaave you with a face full of high pressure gas.. The key to safety is to keep the 2 measurement ranges(one for the chamber and one for the cartridge) in a safe interface. Use guages,,although it is your sight you're gambling with..

Kiwi Rob · « **Reply #12 on:** May 26, 2005, 11:58:06 AM »

Hi , I do not disagree wht the premiss that proper gauges are the only way to check whether or not a firearm meets an industry standard or not
But as was mentioned by other contributors it is quite acceptable to check whether or not your ammunition is safe to fire in your rifle using any of the several methods posted ..My I dare to ask how the proper headspace measurements were arrived at for the many wild cat cartridges that are being used without incedent if one of the methods mentioned and condemed as being totally unsafe were not used .. It is no trick to provide ammo which will fit the chamber of a rifle that is a long way out of what would be regarded as proper headspace measurement for that rifle but which will allow it to be used safely ...
Rob

gunnut69 · « **Reply #13 on:** May 27, 2005, 06:19:27 AM »

Wildcatters are quite safe as they understand the need for proper headspace. The guages for wildcats are arrived at several ways. A set of measurements can be sent to a reamer maker and they can provide reamers for the chamber in question as well as reamers to create sizing dies. Headspace guages can be ordered by submission of a fired case or cerrosafe casting of the chamber or the specs provided to the reamer manf. Saying you can check to be sure the ammo on hand is safe in the rifle overlooks another important fact. If the rifle is out of headspace spec, WHY? In some rifles the lugs may have set back from high pressure loads. Continued use of these rifles will worsen the situation rapidly and a case head seperation will occur. In other rifles there are other possiblilites.. Cases cannot be depended on to give reliable headspace measurements as they can be litterally swaged or sized by the bolt actions camming force. Some guages are simple(rimmed and belted rounds) while others are more complex. For safety always use a headspace guage, anything else can lead to disaster. Another side bar - It is not advisable to put grease or oil on a primer as it could penetrate the primer/primer pocket interface and cause failure. Factory ammo may or may not be sealed, handloads almost never are sealed.

Kiwi Rob · « **Reply #14 on:** May 27, 2005, 12:15:23 PM »

Hi , do I understand from what you are saying that as a wildcatter I understand something about the need to have a properly headspaced firearm and the methods I use to accomplish this should not be recommended for use by inexperienced casual shooters ... If so I agree ,but it also seems that you are saying that a person with the proper knowlege and skills can safely headspace a firearm without having a factory made headspace guage ..As you say damage to a firearm which would cause a change in headspace would usually cause the firearm to be unserviceable , and again as you say , there are several reasons why the need to check the length of a chamber from mid point on the shoulder , to bolt face is needed and a heaspace guage will not give you this measurement but any of the alternate methods will ..Rob

gunnut69 · « **Reply #15 on:** May 27, 2005, 06:04:56 PM »

Actually I didn't say that you new what you are doing at all. I said that a headspace guage could be had in a number of ways. At no time did I even hint that what you have advocated would even resmble checking the headspace.. You are simply checking the fit of a single round in a chamber. I suppose were you to check each round there would be some benefit.. but a simple check with a guage will tell you whether the weapon is in spec and that is what was asked. Can you check the headspace with a cartridge,, The simple answer is no.. I don't know you at all but what you are advocating is dangerous.. Someone may actually trust a rifle checked with a cartridge and a piece of soda can. The headspace of a rifle is a range of measurements that are measureable. headspace guages are the easiest way to check that range.. There are other ways but they do NOT include a cartridge and a piece of aluminum can!!

Kiwi Rob · « **Reply #16 on:** May 28, 2005, 01:08:21 PM »

Hi , you did write " wildcatters are quite safe as they understand the need for proper headspace " , this to me implies that as a widlcatter I understand the need for proper headspace and how to achieve it.. It would seem that we are becoming involved in a debate without a referee , and it would seem that we are coming from different directions on this question.. Now as a practising gunsmith of more that 60 years experience , I see more than enough results of shooters do it yourself , repairs and modifications, and I am not advocating that individuals start up in business using a big hammer and a bunch of soda cans nor wish to be seen as giving advice to this end .. what I am saying is that using the methods stated previously the safe working headspace of a rifle can be arrived at .. I have studied the Chapter on headspace In Roy Dunlaps book "Gunsmithing " and also the chapter on headspace in " Hatchers note book" and refer you to these writings and offer them as the authority for my remarks .. It is not uncommon in the trade for a competition rifle to be headspaced using the cases that will be loaded and used specifically in that rifle... Rob

gunnut69 · « **Reply #17 on:** May 30, 2005, 10:20:28 AM »

I too have the books and have read them. It seems I did make a mistake, all wildcatters are not safe. I've even seen the sad results of some of their fantasies. Fitting a case to a chamber is a common reloading practice. It is an acceptable way to make belted and rimmed cases last long and rifles shoot more accurately. It does NOT measure headspace. There are several ways to measure headspace but a brass case is not the correct way. iIt is not even a fairly good way. They are much too easily deformed and the measurements are NOT accurate.. The only correct way is with a properly utilized headspace guage..

Kiwi Rob · « **Reply #18 on:** May 30, 2005, 06:01:07 PM »

Hi, The use of go and no go guages does not measure head space ,ni the meaning of the word measure that is to meassure the distance between the datum poimt on the shoulder and the face of the bolt ,this is another matter all together and seem to be the sticking point between us .. I agree it does establish that the firearm should be safe to use with cartrdges made by any reputable manufacturer ,I think we both agree on this point..
you say there are several ways to measure headspace .I assume you mean the actual measurement from datum on the shoulder to the face to the bolt , I would be happy for you to instruct me in this matter..
Having read and understood , what Mr Roy Dunlap , has to say about using cartridges to safely headspace rifles , and who I quoted as my authority for my remarks , I think it is a bit over the top for you to say that what I am advocating is dangerous .. I agree that using guages is the easiest way to check headspace I have not said otherwise just that it is not the only way and if I can include Mr Dunlap I am not alone in this belief ..
I note your remarks regading wildcatters , and assume that when you imply that I dont know what I am doing , you are just being a bit careless in your choice of words , and not trying to insult me personally..
In making fitted cartridges , the use of headspace guages is not as important as establishing the point which arrests the movement of cartridge into the chamber , and the face of the bolt ,the methods I use establish this measurement exactly and produce a safely heads spaced rifle .. Rob

gunnut69 · « **Reply #19 on:** May 31, 2005, 11:14:26 AM »

Hello! Went back a re-read dunlap. I suggest you re-read yours. Mine is a second edition and on page 212, 1st line of the 3rd paragraph, 'many small gunbuilders do not have a full supply of gages, and use cartridges to check headspace, which is, of course, a poor practice.'. He does say that a barrel can be set up initially but warns that cartridges from all makers must be used to be sure of satisfactory function. Also he recommends a 'large number of cartridges are necessary' in order to get a satisfactory job. He did not say headspace could be checked with cartridges.. If you check a rifle's heaspace with a cartridge you have NOT checked the headspace, just the fit of that round.. Guages are relatively cheap with most calibers available under $20 a piece. Most gunsmiths will have common calibers and a check on a bolt rifle is fairly straight foreward and ecconomical. Oh by the way headspace guages do measure chambers. They are normally fixed so they simply tell us where that chamber is in the range of tolerances for that particular caliber. There are adjustable guages available that will allow an accurate measurement of a chamber. Their application is so limited that they are fairly uncommon(and there is the cost). Sizing a case to a chamber doesn't require a guage, it semply requires reloading equipment. Chambersd should be built to specifications for the cartridge of choice. Headpsace guages will tell us where we are in that range. Ammuniction will then be tailored to the rifle..

Kiwi Rob · « **Reply #20 on:** May 31, 2005, 03:02:36 PM »

Hi , In quoting Mr Dunlap I assume that you are accepting him as a reasonably safe operator who would not recomend unsafe practices ..

Therefore I wonder why you choose to take portions of his writing out of context , and NOT quote the passage , which I am reading as I type this saying " IT IS POSSIBLE to obtain a SAFE AND SATIFACTORY headspacing BY MEANS OF CARTRIDGES but a large number of cartidges is necessary , trying ALL FOUR MAKES , Peters,Western,Remington and Winchester" which is what he ACTUALLY wrote .. This is all I have said , but which you have vehemently denied ..

As a practising gunsmith of 50 years experience I have guages for all of the popular rimless cases from .222 to .30.06including the field guages for the military 7 mm, 8 mm , 06 and.308 cartridges ..

Since I think you have drawn attention to the exact point I have been trying make all along , I would like to think that you would be big enough to concede that what Mr Dunlap wrote is not dangerous rubbish , however I would like to quote one more anonymous auther " A man convinced agianst his will is of the same opinion still " At which point , convinced as I am that you are one of these latter persons I will leave you to your private thoughts except that

I reserve the right to express my humble opinon about other matters in forums in GBO..Yours in shooting kiwi rob

gunnut69 · « **Reply #21 on:** May 31, 2005, 06:52:49 PM »

Sir you can disagree all you wish with me but Dunlaps words remain. Checking headspace, what the original poster spoke of, with cartridges is poor practice. What he is suggesting in the next sentences is setting headspace, and he even says that many cartridges have to be used from all makers, to get a reasonable setting. With the numbers of companies making ammo today that would get pricey indeed, as well ass time consuming. He in no place says it's OK to check headspace with cartridges.,. You are surely entitled to your opinion but practicing for whatever number of years doesn't make you always right. It simply means you've been at it a long time. Not really a guage of anything, but time and perhaps luck.