I'm wondering if there's a general-purpose tool for checking the shoulder-length (headspace) of bottle-neck rifle cases? Here's the situation. I own several old military bolt-action rifles. I'd like to check the headspace but don't want to buy a half-dozen headspace gages. For .223 and .308 I have case length gages that can measure the size of a fired case, which is a pretty good judge of headspace for all normal purposes. I also have an ogive gage, which is like a 1" hex nut with holes of different diameters drilled into the flats. I was wondering if anyone had something similar that could be slipped over neck of a rifle case and used with a caliper to get an idea of how much a case expands on firing? Sorry if this question is not exactly clear.
General-purpose way of checking case length?
- Thread starter DRNewcomb
- Start date
jepp2
Gold $$ Contributor
Sounds like you need to get the Hornady Lock-N-Load set. That is what I use.
https://www.midwayusa.com/product/4...headspace-gauge-5-bushing-set-with-comparator
https://www.midwayusa.com/product/4...headspace-gauge-5-bushing-set-with-comparator
That looks like it would do the job, even though the calibers I'm thinking of are not included. (i.e. 6.5x54MS, 7.5 Swiss, 6.5x55) It could probably be used well enough.
+1 Keep in mind that any cylindrical object large enough to slip over the case neck and contact the shoulder can act as a cartridge HS gauge. It helps if the cylinder is cut squarely & de-burred. In the past I've used empty pistol and/or rifle cartridges (de-primed, trimmed & de-burred) for this purpose with excellent results. Though I have a .223 Rem. Hornady HS gauge I just checked and found a 7BR rem case would slip over a .223 rem neck and make shoulder contact w/o interfering with the case mouth. Voila'
The added benefit ? ........... Sometimes you can find these "gauges" at the range for FREE! ............. Just a thought. Knock the used primers out of the cases used for H/S gauges for a more consistent and exacting reading.The inserts are not 'caliber specific' in that you use the one that sets on the shoulder somewhere above the shoulder/body junction and below the neck/shoulder junction...the exact location is not critical. It is a comparator; it does not measure an absolute headspace. It will give you a measurement of the difference between a fired and unfired case dimension. If the case is stretching excessively, it will be revealed in your measurement. I use a 0.400" (diam) insert for 6.5 Creedmoor case measurement and 6.5 x55 measurements. I could also use the 0.375" insert for either case.
The Innovative Technologies headspace gauge will let you adjust to most any case,and requires no caliber specific bushings.
A friend had an issue with a .223 chambering which seemed overlong. we quickly compared a fired case with a factory new one using one of his .30 calibre bushings.
LOL it sounds like we need a new forum for "thrifty reloading tricks"
Brians356
Gold $$ Contributor
It does not measure headspace of the chamber, true. But it can measure the length of the datum on the case at a diameter specified (for many cartridges) by SAAMI, and the comparator sizes available are intended for that purpose, and so are generally "caliber specific". For example, the 270 Win is measured at the .375" diameter on the shoulder, and Hornady sells that comparator.
However, the cartridges the OP specified are all European and the Hornady bushings do not correlate directly to the datum diameters for most of those. So as you point out, for comparative purposes, any bushing diameter that contacts the straight slope of the shoulder somewhere will work for that.
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I make general case length gages, I do not make one for case head space because my cases do not have head space. I also make chamber length gages. I know; there are those that say it can not be done. And then there are gages that can be modified, I modified a few gages before I was told it can not be done.
And then there are plates with holes that are used for measuring wire diameter and bolt diameter etc..
F. Guffey
There is no such tool as a Technology head space gage because the case does not have head space, and then there are reloaders with limited shop skills. The tool your are referring to as being a head space gage is a comparator. With minimum shop skills a reloader can make a comparator with a drill and bit if they can drill a hole that is perpendicular.
And then there is the datum, a reloader with a basic understanding of 'the datum' already has all of this stuff sorted out.
F. Guffey
Guffey, Thanks for clearing up this issue for us................. Don't know what we'd do without you.
I have no fewer than 20 8mm57 Mausers and enough parts to build 15 more, three of them are 8mm06s. Among other things I am a case former and I am a reloader. I am the fan of form first then fire; most other reloaders fire to form.
There was a shooter, collector/reloader in the Huntsville, Alabama area that had 18 Mausers in his collection; he wanted to check the length of his chambers so he went to his local gun smith. I did not agree with the advise he was given and I could not go along with the part about one of the head space gages did not exist. No matter what head space gage he purchased after using it he would not know the length of the chamber from the shoulder of the chamber to the bolt face.
Anyhow, I made him a set of gages; I instructed him to start chambering gages until the he could feel the bolt close. After felt resistance I suggested he read the number on the gage. He had two Commission rifles he decided to hang on the wall because one of the chambers was .018" longer than a minimum length full length sized case from the shoulder to the case head and another that was .023" longer.
I sent him 26 gages, I told him I could do all of that with one gage.
F. Guffey
Might also consider using a Wilson Case Gauge, or RCBS Precision Mic. The Wilson tool requires calipers. The RCBS tool works like a micrometer with a -0- to 50 thousandths index scribed on the tool. The RCBS reads relative, iow it is NOT calibrated to some saami specific, but you can use it to measure your gear with precision.
Read and record the length of an unfired round, then do same for your fired round. Allow .001-.0013 for springback and you have your oal chamber dimension. Record these for each rifle. Your fired brass can serve as a gauge, once you know its oal from base to shoulder. Probably should trim any necks to max oal should they exceed that, if using as a gauge.
Read and record the length of an unfired round, then do same for your fired round. Allow .001-.0013 for springback and you have your oal chamber dimension. Record these for each rifle. Your fired brass can serve as a gauge, once you know its oal from base to shoulder. Probably should trim any necks to max oal should they exceed that, if using as a gauge.
Hard to beat the simplicity and cost of the Harrell's bump gauge.
https://www.google.com/url?sa=t&sou...play=1&usg=AFQjCNElKRLTd3fvK5hX7h4spQ1oWTazmQ
https://www.google.com/url?sa=t&sou...play=1&usg=AFQjCNElKRLTd3fvK5hX7h4spQ1oWTazmQ
I actually make my own, all chamber drawings note the diameter the headspace datum is taken at, ie, 30-06 and ALL derivatives are at a point on the shoulder at .375" wide, all belted mags are at .400" wide, etc etc.
I take inch round ally solid bar, part it off at an inch long, brake all sharp edges, and drill undersize then hone or turn to correct diameter.
These sit on the case neck comfortably, and all you do is place one in the caliper, and zero it in place, then slip it over your case shoulder and take a measurement of a fired case, and adjust your die until you get .002"-.003" bump and you're done.
I did this today on once fired cases in my 300WM, all of them were different by a few thou, so more fire forming is needed.
Cheers.
I take inch round ally solid bar, part it off at an inch long, brake all sharp edges, and drill undersize then hone or turn to correct diameter.
These sit on the case neck comfortably, and all you do is place one in the caliper, and zero it in place, then slip it over your case shoulder and take a measurement of a fired case, and adjust your die until you get .002"-.003" bump and you're done.
I did this today on once fired cases in my 300WM, all of them were different by a few thou, so more fire forming is needed.
Cheers.
Or; the reloader can follow 60+ year old instructions. Wilson suggest the reloader use a straight edge. They went to the trouble to furnish directions for finding a straight edge. They explained to the reloader the small rule carried in the top left shirt pocket was a straight edge. For me it was no reach when going from the straight edge to the feeler gage, rather than making wild guestimates or measuring distance with light or thumb nail I went straight for the feeler gage when using the Wilson case gage as a comparator.
And then there is the flat surface; a reloader can stand the case on a flat furnace then place the Wilson case gage over the case; if the gage is supported on the shoulder of the case there will be a gap between the base of the gage and flat surface. If the reloader can figure out how to measure the gap between the gage and flat surface they can determine the length of the case from the shoulder to the case head. It should not come as a surprise the Wilson case gage is a datum based tool. The difference between Wilson's datum in their case gage and my datums is Wilson uses a radius on their datum.
If a reloader is going to stand the Wilson case gage upside down to read the case head protrusion I suggest they place the case neck over a hole in a flat surface; rational, without the hole the flat surface will be supporting the case, not the gage.
F. Guffey
I won’t call “the chamber’s full up” with a fire formed or otherwise manipulated case until, having first removed the firing pin and ejector, I see the bolt handle is all but full down at the same time that I’m just beginning to feel some resistance to the bolt’s closure because, from bolt face to the chamber’s shoulder, it’s slap full of bottleneck case. From there, measure and record for all future, the case head to case shoulder reference length for zero headspace, and adjust the dies to bump ‘um, or not, to whatever amount shorter.
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