Headspace measurement and control

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Getting into reloading, I am spending a lot of time reading up on reloading topics and watching all kinds of how-to videos. I see a lot of semi-conflicting information, most of which I can reason through to a "good" answer.

As a preface, I am specifically looking to reload 308 Win for my FAL, which is a DSA SA-58 and has a 308 chamber. It is only a 2-3 moa rifle by design, but I do want to learn good practices. I do have a nice bolt rile (Sako-85) on my wish list.

The issue of headspace seems to be all over the map. The only things of agreement are that firing a cartridge out of battery is a very bad thing and that cases that are too short can overextend and crack/separate. Some (FAL files forums) even claim that it is a waste of time to tune casing headspace in a FAL, which beats ammunition into submission. In terms of measuring headspace, people vary from go/no-go gauges to layers of tape on a cartridge head. A couple (rare) people seem to use an obvious, yet simple, solution - keep resizing the brass by 0.001 to 0.002 increments until the bolt closes with little/no force - that is the chamber headspace. Then take off another 0.002 for resizing brass. You can dump all kinds of money into 0.001 incremented headspace gauges, but why? Why even buy the GO and NO-GO gauges when a single tool will do? Some people seem unworried if the brass exceeds the chamber headspace and rely on the FAL action to smash the cartridge into place.

My current thinking is to do incremental brass resizing and then use a caliper and a $28 Wilson 308 headspace gauge to measure the headspace. The Wilson can also give an easy quick check against SAAMI specs for each reload.

There is the secondary question of how to control shoulder push-back. I bought the Redding premium die set. Their process seems to be to use their competition shell holders that are stepped in 0.002 offsets. Basically put in the new shell holder and push to the die. Given that the shell holders do not support the case wall, why use them? Why not just back off the die seating depth? There will be a tiny gap between the shell holder and the die, but is this any different than using a deeper shell holder that closes that gap? $25 isn't that much except I have already spent more than I'd like on gear. It's time to spend money on bullets, powder, and primers.

Re: Headspace measurement and control

2
For a semi-auto, just get a full length resizing die and be done with it. Neck sizing, light shoulder bumps, concentricity and all the other obsessive stuff is best saved for a bolt action that you are working to get down to 1/4" groups on. With a semi, seek to get better than bulk performance (which is easy to do) by finding the right bullet and powder combo.

The Wilson gauge is a great thing to have on hand for an easy check to make sure you are in spec and didn't screw up part of the process (sizing die not down far enough ect.)

Can't help you on the Redding shellholder setup. I use regular shell holders and adjust things with the dies.
“Do the best you can until you know better. Then when you know better, do better.”
- Maya Angelou

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Re: Headspace measurement and control

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Shin's got it all right, except I have used a shoulder bump gauge to measure how much I'm sizing for the semi auto that I sold him. No need to do that. I think the Wilson case gauge (or the Lyman equivalent) is an excellent check for setting up dies for semi-auto rifles. I use one for the bulk 30-06 for Garands that I load to share with a friend. Definitely just adjust your dies and skip the special shellholders.

For the bolt gun in your future, if you want primo accuracy, you'll reload differently, with more care and tricks and specific to the gun. You won't want to share that ammo you've put more work in to with the FAL and you'll probably not shoot the FAL junk in your precision gun (but you could).
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Re: Headspace measurement and control

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I'll just reiterate that for a semi-auto (I have an AR10 in .308) just full-length resize. You can buy a gauge but if you follow the die instructions you should be fine.

For measuring the accuracy of your reloads, check out http://taran.ptosis.ch/taran.html. It's a free program that gives a pretty good idea how precise your loads/gun/you are. I like to pay attention to the R50 measurement of a 20-30 shot composite. It doesn't sound as impressive as saying "I shot a 1/2 MOA group" but it's a whole lot more meaningful. While nothing overly impressive. I've been around R50 of .60 MOA for some of my loads for my AR10. In plain English that means 50% of my shots should hit within a circle with a radius of .60 MOA.

Re: Headspace measurement and control

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I have FALs. I shoot FALs. Personally, I don't reload, good surplus is cheap & life's too short.

I've built many a FAL and the two layers of masking tape always makes a FAL run just fine. Extraction & Ejection good, cases look fine. Don't expect too much from the basic design, but my current ones do just fine on 100m Tannerite and 300m steel.

Buying ammo there in MA might be touchy, but the surplus NATO Hirtenburger fodder places the bullet where it is supposed to go every time.

S u b R o s a
"Oozing charm from every pore, he oiled his way around the floor."

Re: Headspace measurement and control

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Following up, I am finally resizing my first cases and decided to measure my Wilson headspace gage. The difference between min/max headspace measures at 0.005 and for case length it is 0.010. Those are significantly off the 0.007 and 0.020 SAMMI specs.WTF? If they are off that much, why should I have any confidence that the gage is any good? Anyone else have a headspace gage that they have measured?

Re: Headspace measurement and control

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Measuring headspace by fired brass is iffy. Measure the chamber in whatever gun you are using via go/no go gauges.

Trim fired cases to spec, then reload those that don't exhibit faults.

Battle rifles aren't too picky by design, as long as the bolt closes OK, choot 'em. Just don't run steel case stuff in a FAL, proven to give wholesale misery.

For the pleasure of shooting one in the manner intended, just buy good surplus NATO from Germany, Austria, Malaysia, S. Korea, S. Africa, England, eTc. Nix on Indian and Pakistani. Gather the Berdan brass up, recycle it, donate the $ to a good cause.

SR
"Oozing charm from every pore, he oiled his way around the floor."

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