More headspace understanding needed
- Thread starter Lead hammer
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You can also do a good job of setting up your sizing die by feel. When you run a fireformed case only part of the way into the sizing die, it will actually change it’s dimension and make it hard to or impossible to chamber. Squeezing the case walls down causes the case to lengthen and gets too long for the chamber. When I set up a Redding body die or a full length die I will remove the firing pin assembly and the ejector plunger and spring so there is no interference with the feel. Then I adjust the die in small increments and keep sizing a case until the bolt handle falls all the way closed under its own weight. All the way; meaning the bolt handle hits metal stop at the bottom with no resistance. Then rotate that case around in the chamber to make sure it works in all positions. This method doesn’t tell you exactly how much clearance you have, but if you take your time it will be minimal. I use a Redding body die with Lee collet die and I have great brass life doing this with consistent easy chambering.
A little added experience:
I have a Sinclair concentricity gauge and a Hornady concentricity gauge and used them to figure out which steps were causing runout. Resizing with FL die w expander ball was a big cause and very inconsistent depending on lube inside the neck. Once I switched to Redding body die and Lee collet it solved that but I was still getting inconsistent results during the bullet seating step(using rcbs, Redding and Lee seating dies). Jerry and others recommended the Forster BR seating die and that solved the rest of the problem. Now I would just recommend for most purposes to skip buying die sets and just start with these dies. I don’t even really use the concentricity gauges anymore.
A little added experience:
I have a Sinclair concentricity gauge and a Hornady concentricity gauge and used them to figure out which steps were causing runout. Resizing with FL die w expander ball was a big cause and very inconsistent depending on lube inside the neck. Once I switched to Redding body die and Lee collet it solved that but I was still getting inconsistent results during the bullet seating step(using rcbs, Redding and Lee seating dies). Jerry and others recommended the Forster BR seating die and that solved the rest of the problem. Now I would just recommend for most purposes to skip buying die sets and just start with these dies. I don’t even really use the concentricity gauges anymore.
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I enjoyed reading this. Gave me another something to try to size my brass with, instead of the 2 thou bump, i could go by feel.
As i have sinclairs concentricity gauge, Redding body, Lee collet, and Forster BR NM seating die.
I now live the same thing, as in not needing the concentricity gauge. Everything clocks within 1 thou runout.
Yessir - For those of us that cant be bothered with all those fancy metrological devices, adjusting your sizing die by feel has been standard operating procedure for years. For a given batch of brass, you can even record the die position for future sizings.
Yes, it seems either Redding body die/Lee collet neck die or Redding FL S die and neck turn. I will probably just stick with the first combo.
Or just use new brass forever lol ......... not
What i am using now can do 1/2 moa out to 600 with sized new brass, and did a 4 shot 0.358" 100 group, it must work ok, but I need case life and hopefully even better accuracy when I start bumping.
Or just use new brass forever lol ......... not
What i am using now can do 1/2 moa out to 600 with sized new brass, and did a 4 shot 0.358" 100 group, it must work ok, but I need case life and hopefully even better accuracy when I start bumping.
Mystic Precision
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It is not a right or wrong answer... it is a what fits your chamber the best. I continue to be surprised that the internet hasn't understood that a type of die simply indicates the function the manf suggests it will do. It does not fix the dimensions!!!!
Like Headspace, there is a range and manfs produce to whatever they feel is best... and that may also change with time or batches of dies.
For precision work, the goal is to create a "proper" fit to the rifle and application. How you get there will vary depending on where on the spec range your rifle ends up.
With custom rifles, gunsmiths use reamers that are usually, at the min side of the spec so many FL sizers could work. With factory chambers, the dimensions may be closer to the max.... here a min spec FL sizer may actually create more problems then it solves.
There are size 10 shoes and then there are size 10 shoes. Does every shoe fit every foot?
Use the dies that create the ammo that suit your particular rifle and its intended useage. Got a bunch of info on how to sort this out on my facebook page tech articles. Find me at mystic precision inc.
Jerry
Ya sometimes we can get a little lost in the equipment and the exacting measurements and possibly misunderstand what we are trying to accomplish, especially when dealing with our hunting and factory rifles. If a person has a good understanding of what they’re trying to accomplish, it makes the process and tool selection easier. In the case of headspace I'm mostly trying to build ammo that has full clearance for easy, reliable chambering, but minimum full clearance to improve brass life.
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Then try a Forster full length benchrest die with its high mounted floating expander. The neck of the case is still held and centered in the neck of the die when the expander enters the case neck.
Meaning these Forster dies will not pull your case necks off center and induce neck runout.
You can also try the Redding competition shell holders and just bump the shoulder back the minimum amount from its fired length. Meaning not take the bolt apart and go by feel, the five competition shell holders allow you to bump the shoulder back in .002 increments and never touch the die during bump adjustment. The competition shell holders allow the die to make hard contact with the die with press cam over.
Example below
Again below is a fired 5.56 case from my AR15 at 1.4675 and to bump the shoulder back .003 I used the +.004 competition shell holder. This shell holder pushes the case into the die .004 "less" than a standard shell holder and makes hard contact with the die. This takes any slop out of the press and makes your shoulder location more constant. And if the standard shell holder had been used the shoulder would have been pushed back .007 if the die made hard contact with the shell holder.
To bump the shoulder the same amount with a standard shell holder you would need to put feeler gauges between the shell holder and die and have a air gap between the shell holder and die. The problem with this method is the shell holder and die do not make contact and any flex in the press causes variations in shoulder location.
Bottom line the advantage to using Forster benchrest dies are you only size the case in one operation with no "speed bumps" on the case neck from using the Lee collet die. This means you can check case neck runout "before" seating a bullet and know if you have a problem case. And not have speed bumps on the case neck and not have accurate readings.
There are many reloaders using the Lee collet die and a body die and are very happy campers. I just prefer using the Forster dies over the Lee collet die and the bullet runout figures are the same. So remember using the dies expander is not the end of the world as long as the expander is centered and the inside of the case neck is lubed.
Biged
Speed bumps are user error
If you dry tumble, and resize using this technique: resize neck, pull back slightly, rotate casing 1/8 turn, resize neck 2nd time
There shouldn’t be any bump marks or streak marks or whatever people call them, it’s in the LEE instructions
These redding match shell holders look great, I’ll probably buy some.
I remember with my Lee setup, i had to shave a shellholder to allow 2 thou bump as die would contact shellholder before bump was made.
I am not saying forster FLS is bad and will even buy one in 2018 to experiment a limited batch of ammo with.
Just making sure there’s no misconceptions on lee collet die, as it doesn’t make speed bumps if used right
Speed bumps are user error
If you dry tumble, and resize using this technique: resize neck, pull back slightly, rotate casing 1/8 turn, resize neck 2nd time
There shouldn’t be any bump marks or streak marks or whatever people call them, it’s in the LEE instructions
These redding match shell holders look great, I’ll probably buy some.
I remember with my Lee setup, i had to shave a shellholder to allow 2 thou bump as die would contact shellholder before bump was made.
I am not saying forster FLS is bad and will even buy one in 2018 to experiment a limited batch of ammo with.
Just making sure there’s no misconceptions on lee collet die, as it doesn’t make speed bumps if used right
There are lots of great tools for us to use while handloading and I’m not against using any of them. The only point I wanted to make with my previous post, is that a handloader can still get great results even if they don’t have some of the more specialized tools. Just takes some understanding of what you’re trying to achieve with the tools.
Then try a Forster full length benchrest die with its high mounted floating expander. The neck of the case is still held and centered in the neck of the die when the expander enters the case neck.
Meaning these Forster dies will not pull your case necks off center and induce neck runout.
You can also try the Redding competition shell holders and just bump the shoulder back the minimum amount from its fired length. Meaning not take the bolt apart and go by feel, the five competition shell holders allow you to bump the shoulder back in .002 increments and never touch the die during bump adjustment. The competition shell holders allow the die to make hard contact with the die with press cam over.
Example below
Again below is a fired 5.56 case from my AR15 at 1.4675 and to bump the shoulder back .003 I used the +.004 competition shell holder. This shell holder pushes the case into the die .004 "less" than a standard shell holder and makes hard contact with the die. This takes any slop out of the press and makes your shoulder location more constant. And if the standard shell holder had been used the shoulder would have been pushed back .007 if the die made hard contact with the shell holder.
To bump the shoulder the same amount with a standard shell holder you would need to put feeler gauges between the shell holder and die and have a air gap between the shell holder and die. The problem with this method is the shell holder and die do not make contact and any flex in the press causes variations in shoulder location.
Bottom line the advantage to using Forster benchrest dies are you only size the case in one operation with no "speed bumps" on the case neck from using the Lee collet die. This means you can check case neck runout "before" seating a bullet and know if you have a problem case. And not have speed bumps on the case neck and not have accurate readings.
There are many reloaders using the Lee collet die and a body die and are very happy campers. I just prefer using the Forster dies over the Lee collet die and the bullet runout figures are the same. So remember using the dies expander is not the end of the world as long as the expander is centered and the inside of the case neck is lubed.
I’m a greenhorn Reloader but have been finding yours and Jerry’s posts very informative.
I’m about to order the Forster FL die. Will it work with standard shell holders? I currently have RCBS holders.
That is something that is still a mystery to me, neck tension
If it is measured by caliper or by some sort of torque spec while seating, unsolved mystery
I’d probably find the answer if i’d search it
What i can tell, the neck opening is 305 and bullets are 308
Would that be considered a 3 thou neck tension?
If it is measured by caliper or by some sort of torque spec while seating, unsolved mystery
I’d probably find the answer if i’d search it
What i can tell, the neck opening is 305 and bullets are 308
Would that be considered a 3 thou neck tension?
These have worked for myself. Neck turning only brought on by necessity due to inconsistent neck seating, seating forces and cutting my teeth on crappy brass. Purchased a system from Jerry. I don't think you will be disappointed.
I brought down the diameter of the collet die mandrel a couple of thou to give me the desired neck tension. This for two different calibers.
Just got two. Trying them out tonight. Test seating results appear better, and dialing in for different bullets will be a breeze.
Now I don't need a concentricity gauge Marty.
I have been watching your posts and seeing the progression. You are where I was a short while back, but without the fancier rifles and with a different objective in mind with the rifles we have here. 
It's not taking you long and the questions you present are pretty well scripted for you to obtain the answers you are looking for. Nice work.You will like the competition shell holders. Great for bumping the same caliber for two different rifles as well. Learned that one from Dogleg.
This forum's been really good for me. I learned from Ed and Jerry that there are multiple ways to achieve the same result. I found one way easier to understand and could put it into practice a little better than the other. Never looked back and over time getting better.
Regards
Ronr
I agree completely, this forum and others like it are great. I'm always picking up new ideas and learning as well.
Thanks RonR,
This is a purpose i had never imagined for the shell holders, load for different rifles by adjusting shell holder, smart!
As when i was going to purchase 2nd 308, i was going to get 2nd body die, i'll save money and trouble.
My rifle is not too fancy, but i got a fancy barrel on order on the way from Jerry.
It will help eliminate if the barrel is a factor in my groups not being where i want.
If barrel doesn't help, I could chalk it down to shooter and/or reloads.
On a target sheet, I can place 25 shots, 5 shots x 5 groups.
Biggest group is 0.7 moa and smallest is 0.4 moa.
Sure, if I'd go for an only 3 shot group i could claim my rifle is quarter moa, being honest with myself involves having many rounds shot before actually claiming certain accuracies (or inaccuracies).
Really hoping for steady sub 0.5 moa accuracy with this barrel, then i'll stop d***ing around with reloads and just shoot.
This is a purpose i had never imagined for the shell holders, load for different rifles by adjusting shell holder, smart!
As when i was going to purchase 2nd 308, i was going to get 2nd body die, i'll save money and trouble.
My rifle is not too fancy, but i got a fancy barrel on order on the way from Jerry.
It will help eliminate if the barrel is a factor in my groups not being where i want.
If barrel doesn't help, I could chalk it down to shooter and/or reloads.
On a target sheet, I can place 25 shots, 5 shots x 5 groups.
Biggest group is 0.7 moa and smallest is 0.4 moa.
Sure, if I'd go for an only 3 shot group i could claim my rifle is quarter moa, being honest with myself involves having many rounds shot before actually claiming certain accuracies (or inaccuracies).
Really hoping for steady sub 0.5 moa accuracy with this barrel, then i'll stop d***ing around with reloads and just shoot.
Loaded neck dimension minus unloaded dimension = neck tension.
RonR, how did you remove material from the mandrel? Hand held drill and fine sandpaper? Lathe?
Thanks will check this out soon.
Got the specs on recommended neck tension?
Or is it something proprietary to each rifle setup?
I am not at my notes, but I think I set 0.002" and have not had any problems, even when dropping rounds on the ground. I will go measure some 6.5, just a sec.......
edit: yep 0.290 and 0.288
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