Homemade headspace gauge

[BuckRub]

I seen a clip and a man took like a 40 caliber casing and put it on like a 30-06 FireFormed case just to get a general measurement and then when sizing that same case you start out long and slightly keep going in with your die then remeasure until you find your .002 that you pushed your shoulder back or whatever you're looking for. I haven't tried this but seems like it can pretty much get you going in that direction. What do you guys/girls think ?

[Bart B.]

That'll work. So will a metal bushing about 5/8 inch long with inside diameter 3/8 or 4/10 inch inside diameter. Ace Hardware has several that'll do just fine.

[BuckRub]

I haven't ever played around with shoulder bumping but sounds like something I may start playing around with. Either try this and get good results or go ahead and buy something made specifically for this. And thanks for the tip Bart B.

[BuckRub]

I shot about 8 rds of 30-06 about 5 days ago. I also shot about a box of 38 specials yesterday. Both were laying right beside me. I picked up one of each and tried to stick the 38 around the 30-06 and it fits snug as a bug. I got my calipers and got a measurement. Next case and then next and all my 30-06 cases were perfect length. Perfect length meaning they were all the same. Tomorrow just for grins I'm taking that measurement then getting my 30-06 sizer die and running it down till I touch shell holder and backing off about 2 turns and start adjusting and measuring until I get my .002 shoulder setback. Then gonna resize all and check. Once I get things set I will lock my set screw down on my die and should be good to go for future resizing. (Only for my gun I know) but right now I only have one 30-06. Try it, it works like a charm.
For those who have been wanting an RCBS precision mic but haven't got one yet get in contact with me and for a 30-06 I'll send you a 38 special case right now for only $39.99 plus shipping of course. Hahaha

[F. Guffey]

“I seen a clip and a man took like a 40 caliber casing and put it on like a 30-06 FireFormed case just to get a general measurement.......”

It would appear the man that made the clip was rather limited in knowledge and skill, in my opinion he wasted your time. After watching the clip there should have been no questions. He should have made it clear there was an objective, he should have made it clear what the purpose of the demonstration was going to illustrate. He could have started with: “After watching this video clip you will be able to measure etc., and understand why and or how”

A general measurement? And, that is all you need to know? It appears that is all the man that made the clip knew about the subject.

And then Bart B. says all you have to do is go to ACE Hardware. Others suggest HOME DEPOT and or LOWE’S.

F. Guffey

[BuckRub]

YouTube - Mail Call Monday # 25
It is only a measurement. A measurement that I need for a starting point then I need one for where I want to go ( .002 smaller ). It told me that and I'll find the .002 smaller on the bench. Isn't that what store bought gadgets do the same thing. They tell us a measurement of a FireFormed brass and then you find the .002 smaller and its only $50.00 plus tax
I don't know what else you want the store bought to do for me??? But thanks for your encouraging words though.
F Guffey-same thing you basically said in "Head space and FL Sizing" in your post #34. You stated that you could do the same thing with a set of feeler gauges as Redding does with their fancy tool and it would save you $40.00. Hmmmmm

[steve4102]

[BuckRub]

Yep that's what I'm talking about. I took 8- 30-06s and put the 38 over the necks and they were all 3.204" or 3.2035". Worked like a champ just like your feeler gauges did.

[243winxb]

A 40 S&W case at .400" works for me on 243win.

[F. Guffey]

243winxb, could that be because the datum/round hole for the 308 W and 243 Win is .400"?

I have the option of using a datum that is larger in diameter than the neck and smaller in diameter than the case body/shoulder juncture.

I make datums, I collect datums and on occasions I purchase datums, the datums I purchase are never recognized as datums, they always look like something else.

F. Guffey

[44 AMP]

I've been reloading for over 40 years, and currently reload for over 30 different cartridges, rifle and pistol. This thread is confusing the hell out of me.

I do not understand what it is that you are talking about doing, or why.

Am I correct in assuming you are taking a case, or a piece of tubing, checking to see that its ID is the diameter of the .30-06 case at the "datum line", measuring the total length, and subtracting the pistol case length to get the distance from the rifle case head to the datum line point?


or is it something else?

[Bart B.]

44AMP, you're right.

Things with datums more precicely round and hard are better than case mouths, but only when sub thousandths inch measurements are needed. Steel ones keep their shape and won't slowly get larger like brass cases do. Gently used, any straight walled short case whose mouth fits the bottleneck case shoulder at some point is usually good enough.

People minimally size their bottleneck cases so they don't stretch too much when fired and cause cracks at the pressure ring; case life is much longer this way. And accuracy improves, too, as there's less case movement in the chamber when pressure builds up and doesn't cause any significant vibrations to cause the muzzle axis to point at different places for each shot for a given point of aim.

[BuckRub]

Ok, so I just tried to get my .002 under. My size was 3.210" I lubed a few and started. Man nothing happens for awhile and then all at once. So when I mic'd first it was done at 3.205 so I set that one aside and next one I got perfect (3.208) I then went to .209 and tightened locknut down. It actually went back to .207 so I redone with another case and finally 3.208 while tightened. It really works great. Done 2-3 more just to make sure, Perfect !!! So there ya go. Now mine is 3.208 but you use a nother case or a different caliber it won't be the same. This measurement is just for me to tell where my shoulder is, yours is more than likely be different depending on where your small case sits on your shoulder or the length of the smaller case. Again your before and after length is just your shoulder as a reference. Also once you use that smaller case use the same one for all, don't use different ones. And make sure the cases your seeing on or adjusting is all FireFormed by the same gun. If not you're wasting your time. Also label these rounds as that may only function in same gun they were FireFormed from.
Oh yea- and just for grins I set die up as usual and per instructions and resized some just to see and they were .008 under my FireFormed brass. The only thing is I have about 100 reloaded cases all set to where they punch a nice ragged hole. Now my new brass I'm not mixing or adjusting but it now has slightly more capacity, if I loaded same amount of powder should be timy less cup pressure I would assume. Enough to see, maybe - maybe not. But after I need more 30-06s I'll shoot new brass to see if it still hits perfect or if I need to slightly add tiny bit more powder.

[Bart B.]

Backrub's observation:

Oh yea- and just for grins I set die up as usual and per instructions and resized some just to see and they were .008 under my FireFormed brass.

Now you know the value of simple tools and their use to ensure you're not sizing your bottleneck cases too much.

Note the dimension differences are what's important. The exact case headspace and chamber headspace numbers are not important. Size your fired cases accordingly and you'll be doing all the right stuff.

[Brian Pfleuger]

Originally Posted by BuckRub

So when I mic'd first it was done at 3.205 so I set that one aside and next one I got perfect (3.208) I then went to .209 and tightened locknut down. It actually went back to .207 so I redone with another case and finally 3.208 while tightened. It really works great.

You can solve the problem with the slight change when tightening the locknut by doing it while the case is in the die. That makes sure that everything stays in the position that gave you the size you wanted.

[BuckRub]

It was. I know this too when tightening a lock nut they'll usually lose .001 or so that's why I went .001 over but it actually lost .002 that's why I had to re-do. Thanks

[F. Guffey]

AMP 44 said:

“I do not understand what it is that you are talking about doing, or why”

In post #5 I suggested the video, without a link, was rather limited on information. the first 4 responders had an opportunity to fill in some blanks or additional information.

“Talking about doing, or why: A – B = C . BuckRub said:

“Yep that's what I'm talking about. I took 8- 30-06s and put the 38 over the necks and they were all 3.204" or 3.2035". Worked like a champ just like your feeler gauges did”. The 3,204 +/- reading is the ‘A’ factor, he does not have a ‘C’ factor, if he measured the length of the 38 Special case from the mouth of the case to the head of the case he would have factor ‘B’. After measuring the length of the case he could subtract the length of the case from the from his measurement of 3.204” to get the length of the case from the shoulder/datum to the head of the case.

Infatuation with #head space and making head space gages, placing a 38 Special case over the neck of a 30/06 case does not make a head space gage. Larry Willis. Sinclair and Hornady have insisted on labeling their equipment as ‘HEAD SPACE gages, I have insisted from the beginning the gages being sold were not head space gages, I have insisted the gages were comparators. BuckRub is measuring case length from a point on the shoulder to the head of the case, not a problem but he is omitting the comparator part, if he measured the case before he fired the case and again after he would be comparing the case length before firing and again after firing. He is measuring the case length after firing, not a problem, then he is sizing the the case by reducing the length of the case by .002” using a method of trail and error, he is adjusting the die down in increments.

My feeler gages? One thought at a time, not complicated but it helps if a reloader can keep up with more than one thought at a time. I use comparators, I make comparators, using a comparator is a way to determine how to transfer a measurement from one place to another, when transferring a dimension from the chamber to the die, press and shell holder a reloader can use wild guestimates, or they can transfer the dimensions with a feeler gage. I do not insist on securing the lock ting to the die, I secure the die to the press with the lock ring, because I adjust the die in the press every time. I have no fear of loosing the adjustment.

Case length: When measured from the shoulder/datum to the case head in the perfect world depends on using the correct datum, as in measured from, when dealing when dealing with the 30/06 the datum is .375”, When using a comparator a round hole of any dimeter will work as long as the same round hole is used.

http://www.saami.org/PubResources/CC...pringfield.pdf

For years I have said I make datums, I collect datums and I purchase datums, when using a comparator nn the shoulder of the 30/06 I can use a datum/round hole of less than .441” down to a diameter that is larger in diameter than .339”, meaning when pocking a round hole/datum I have choices that have a spread of less than .441 to larger in diameter than .339”, I can not miss, I have at least 95 choices. For years it has been insisted the datum was located half way between the case body/shoulder juncture and the shoulder/neck juncture, and I have always asked, “How can that be?” The 25/06 has a longer shoulder than the 30/06, both use a datum of .375”, meaning both datums can not be half way between the two junctures.

F. Guffey