What's the best way for someone new to reloading to go with reference to buying headspace gages for chamber measurement. I was looking in midway, heard Tubbs talking about them on dvd and have seen it mentioned here in the past. Which brand is the ones to get?

An RCBS Precision Mic(cartridge family specific) is what you need to check your fired brass fro headspace & to set up your sizing die for correct shoulder set back.

headspace is unlikely to change in a civilian situation, short of gross abuse .. take the gun to a gunsmith and have him check the headspace ..

headspace gauges are designed as"go" (zero slack) no go (generally .005 long) field (no real standard, .008-.01) and reject - anything longer .. these gauges, on a mounted barrel, tell you the range the rifle falls in.

if you want to know exactly how long the chamber is, a gunsmith can do several things, which doesn't include scotch tape.

quote:

Originally posted by Zhurh:
What's the best way for someone new to reloading to go with reference to buying headspace gages for chamber measurement. I was looking in midway, heard Tubbs talking about them on dvd and have seen it mentioned here in the past. Which brand is the ones to get?

Be ready to get lambasted about this question. I asked a similar question and apparently most people on here do not believe in headspace issues. Their solution seems to be just work your handloads to fit the chamber and it will take care of itself.

I took my gun to a gunsmith and for $10 he checked it for me. Some will do it for free, just call around.

quote:

if you want to know exactly how long the chamber is, a gunsmith can do several things, which doesn't include scotch tape.

Appreciate the info. Last year, bought ultramag press, scale, all the other equipment, dies for all my calibers, 10K primers (6K 215's, don't plan on my grandkids running out), 50 lb powder, all kinds of brass & bullets from midway. I figured screw big "O" I'll make sure I never run out in my life time. Dang, no joke, spent over 5 gran on everything.

So then I figure, I'll get my guns all with the best loads, ha; kinda hasn't worked out that way so far but I'm sure I'll get there someday. We live rural in Alaska, road closed for the winter, no gun smiths and all the locals here don't know anymore than myself concerning reloading I do believe.

I loaded up 50 7 mags (5 diff loads IMR 4350 57-60 grains) and the pattern didn't change dramatically, all were right around an inch to inch & a half. I must have been looking at pictures of targets on web sites too long; mine didn't solve much shooting off sand bag on my T bench on back porch. I have to try it again once it warms up also.

Somebody mentioned that headspace is another parameter that affects accuracy besides load. So I figured that before I start reloading more shells, maybe I should get gages for my calibers and some more seating dies with micro dial on top. I might be way off track too, chasing something unattainable ha; but you know, I have friends who have sub moa guns, cover a dime and I have shot them myself.

So anyway, appreciate the heads up on what equipment I should pick up to cover my quest on getting these guns shooting better through reloading my own ammo, ha ha. What's funny is this one 7 mag I started with has killed over 100 caribou and close to 20 moose but I need more accuracy of course.

So back to the ABC's of reloading, any ideas on equipment I should order greatly appreciated.

quote:

Originally posted by Zhurh:
What's the best way for someone new to reloading to go with reference to buying headspace gages for chamber measurement. I was looking in midway, heard Tubbs talking about them on dvd and have seen it mentioned here in the past. Which brand is the ones to get?

Zhurh:
Maybe I'm wrong but I think what you're really asking about is the "Head & Shoulders" cartridge headspace gauge. Stony Point used to have them but now, I understand that Hornady sells that stuff.
If this is what you're looking for, you need the proper gauge along with the holder. For your 7mm Mag., the gauge is the "E" - 0.420. There are a total of 5 different gauges fitting most if not all of the common cartridges. I used mine to set up my die to PFLR my .270 WSM. I think they're a handy tool.
I think but don't know for sure that I've seen them at Sportsmans Warehouse here in Fairtown. You should be able to order them thru Cabela's or another online retailer. Hope this helps some & good luck.
Bear in Fairbanks

As commonly used and understood, headspace gages are used to set headspace when installing and/or chambering a barrel. I think what you want is a tool with which you can measure the chamber of your rifle? RCBS makes what they call a precision mic that will measure base to shoulder length of fired cases which will give you an idea of how to set your FL sizing die. It will also measure the base to ogive length which will give you a starting point for bullet seating. Redding also markets their "instant indicator" which, IMHO, is not as "instant" as the RCBS. I have and use both.

Throat erosion will change the leade of a chamber, which the base to ogive measure will reveal over time.

Zhurh:
Is this what you're looking for?
B.I.F.

http://www.midwayusa.com/viewp...productnumber=479704

Hey Zhurh

Bear's link is the one I use. Technically it can be said to measure the headspace on an unbelted case but not on a belted one like your 7 mag. But it will give you the information you need the most which is how much your case is expanding and when and at what measurement the case has expanded fully to fit your chamber.

For instance, in your 7 mag you may have perfectly acceptable headspace of .004" but your case shoulder may expand as much as .025" forward until it fits your chamber. Now that explanation may be confusing but you need to understand that headspace if defined by the dimension you case is allowed to move forward in your chamber before it is stopped. The belt stops the movement so that headspace may be small. On an unbelted case the case shoulder contacting the chamber shoulder is what stops the forward movement so cases need to be closer to SAAMI specs.

Perhaps some pics

You put the proper insert from Bear's link on your caliper and rezero


the insert will hit on the shoulder of the case


then you can take a measurement on a new case


and a fired case


to see how much your case is expanding. Notice in the previous 2 pics that this Winchester 264 win mag had an expansion of .038" on the first firing! This same gun may have had "headspace" that was perfectly acceptable at .004" or so but the real problem is the excessive expansion at the shoulder which causes thinning at the pressure ring and can lead to case head separations.

So on a belted magnum a go-no-go-field gauge may say you are within SAAMI specs and fine when your chamber has a problem.

I don't know if the Precision Mic's will give you the information on shoulder position or not since I have never used one. But you do have to buy one for each caliber you use and they ain't cheap.

Great post by the last member - thanks.

Check this out too...http://www.6mmbr.com/catalog/item/1433308/977259.htm

Cartridge headspacing, "brass"A light loading may not expand the brass shoulder to the chamber on firing. This will give a false cartridge headspace measurement. When the body moves outward, the shoulder/neck moves back. On FL sizing, it moves forward again.

Thanks to everybody for the response. I feel like I'm the complete beginner reloading idiot; talking to all you who have been reloading 30-40 years. I'm overwhelmed at how much more there is to reloading than I ever figured; my heads a spinnin.

So anyway, This simpleton was wrong once again. I'm not looking for headspace gage, but for overall length gage, ha; but now I'm starting to learn a little more than I ever knew until the pictures & post; thanks again.

I was under the impression that how deep the bullet was seated with relevance to rifling, had as much a factor in accuracy as load weight. Probably a hundred factors I don't even know about as of yet. I guess I should just read more on this site before I ask anymore questions, ha ha.

So, I'm going to order that Hornady overall length gage and some modified cases. Will have to get that Hornady bullet comparator & headpspace gage bushing set I think.

I called a back east buddy who has been up hunting with me over the years and he mentioned how I could make a dummy round, then back seating bullet by .030 I think he said but I think I might just wait till I get everything from midway.

Thanks again for all the help.

Hey Zhurh

You need to realize that the modified case you will be getting will be like a new case, it will not be as large as a case fire formed to your chamber. So like in the pics above you will need to calculate how much "headspace" (I know it's not headspace on a belted case so don't anyone jump me) you have on the modified case and add that to your bullet jump.

For example, take a measurement with the Hornady Headspace insert on the shoulder of the modified case and it is 4.092" like in the pic above on the new case. Then take the measurement on a fired case and it is 4.129" like in the pic above. The difference is .037". So when you take the OAL measurement with the OAL tool using the modified case you will have to add that .037" to your calculation of how deep you are seating your bullet.

For example if you get a measurement of 3.745" with the OAL tool (measured on the ogive of the bullet with a comparator)


and want to seat your bullet .030" deep then the math would be 3.745"-.030"=3.715", but you need to realize that the modified case headspace would put your seating depth at .030"+.037"=.067"

Big difference

Complicated I know but it becomes clearer once you play around with the "thingy's" a little and the complete picture emerges (never has for HC but that is another story )

"...the test would look much like the pics above ...But I ain't sure," : Woods, 2011

I use cartridge headspace gages virtually every time I size a rimless rifle case. I have a bunch of Wilson gages as they are $15.00 or so. Not bank busters.

So many of the people on this forum load for bolt rifles that they engage in reloading practices that are sloppy to say the least. They get away with it because bolt rifles have large cams and a lot of leverage with which they crunch cases to the chamber.

My ammunition has to function flawlessly in gas guns, and I don’t like beating a bolt handle down in sitting/prone rapid fire. My cases are all full length resized and I control the amount of shoulder set back by using these gages.

I set up my dies with these cartridge headspace gages. Brass of difference work hardness, different thickness, all springback differently after sizing. Because of this, I usually have one of these gages on the bench and make slight die adjustments if I notice inconsistency in sizing length.

If your rifle is properly headspaced from the factory than ammunition sized to gage minimum in a Wilson gage is safe. It is better to drop a fired case in the Wilson gage and get a very good measurement of the actual headspace of the chamber. From there I recommend pushing the shoulder back about .003”. When you ask cases to expand .006” you are just at the safe limits of case stretching. Beyond that and the case is likely to rupture.



Given that this tiny distance, on the gage, is the difference between “Go” and “No Go”, I don’t see how anyone sizes their cases correctly without using gages to set up their dies.

Before, when I was setting up my dies following the factory dimensions, I thought my ammunition was correctly sized. Then I got gages and found just how far off I was.

There are those who don't use gages and don't think they are useful. But evaluate their opinion in the same context as a blind man giving advice on color coordination.