Headspace. ? On 6.5cm proof ss zermatt origin prefit

[JRBullock1987]

My proof research SS 6.5 creedmoor zermatt origin action prefit barrel gave me a headspace/datum line measurement of 1.534" on fireformed brass yet my brand new alpha brass had a measurement of 1.5345" and im not sure if this is usual? this is my first bolt gun and new brass typically has a much shorter headspace measurement than once fired. After installing the barrel i checked the go which it closed on and no go which is failed to close on so the barrel passed them but it just seems a little strange that my once fired has the same datum line measurement as brand new brass thats usually on the shorter side of datum line measuremens. Can anyone explain if this is normal. If not is it bad? I contacted proof and they basically said it's fine but idk it feels strange to me. What is usually what ppl experience in fireformed brass datum line headspacing growth from new brass?
(Picture is of my rifle)

 

[D̷e̷v̷i̷l̷D̷o̷c̷A̷Z̷]

How did your calipers gain an extra decimal space?

As a DIY gunsmiff myself I recommend more 5 axis dremmel for the fix.

You contacted Proof and they said it was not a concern. Clearly they don’t know anything, good thing you came to the internet where we have a reputation of being helpful.

Oh I know. It prob needs a covid shot.

Welcome to the hide. What does this have to do with reloading?

 

[Sum Ting Wong]

I’ve seen this multiple times with left handed actions.

 

[Aftermath]

How do it shoot the shots?

 

[JRBullock1987]

How did your calipers gain an extra decimal space?

As a DIY gunsmiff myself I recommend more 5 axis dremmel for the fix.

You contacted Proof and they said it was not a concern. Clearly they don’t know anything, good thing you came to the internet where we have a reputation of being helpful.

Oh I know. It prob needs a covid shot.

Welcome to the hide. What does this have to do with reloading?

Eat that lol. I dont fckn know I didn't know where to put it. I reload so I figured it had to do with resizing and reloading fireformed brass.....I asked bc they didn't go into details and thought and see if some turd burglars on the interwebs could expound on the subject.

 

[JRBullock1987]

I’ve seen this multiple times with left handed actions.

Joking or seriously?

 

[Sum Ting Wong]

I was joking. As a machinist, calipers are only trusted down to a thou(.001), even with my half thou Mitutoyo pair. Anything under that and you need a micrometer. I definitely wouldn’t trust that Chinese pair you’re using.

If the rifle shoots good, don’t worry about it.

 

[JRBullock1987]

I was joking. As a machinist, calipers are only trusted down to a thou(.001), even with my half thou Mitutoyo pair. Anything under that and you need a micrometer. I definitely wouldn’t trust that Chinese pair you’re using.

If the rifle shoots good, don’t worry about it.

I'm just stressed it's on the very short side so if I end up bumping my shoulder a bit more than 2 thou I'll be pushing it on the short side of headspace? I'm just not exactly sure when the small side of the shoulder datum measurement is pushing smaller than it's supposed to be with 6.5cm. I'm new to bolt actions and custom actions and 6.5cm so I know very little about it and don't want to go and start shooting my face off thinking I'm still in spec when my brass is oversized if that makes sense? I know you were joking bro im not a sensitive Susie lol.

 

[Sum Ting Wong]

How much resistance was there on the go gauge? Could just have a tight chamber.

 

[JRBullock1987]

None it closed like it does without but what's confusing me us the Saami spec min is 1.541 and my fired brass is at 1.534. Isn't that smaller than it should be by a shit ton? Fuck me I'm so confused lol. I knew I should have finished college.

 

[D̷e̷v̷i̷l̷D̷o̷c̷A̷Z̷]

Eat that lol. I dont fckn know I didn't know where to put it. I reload so I figured it had to do with resizing and reloading fireformed brass.....I asked bc they didn't go into details and thought and see if some turd burglars on the interwebs could expound on the subject.

So you used trash tools, called the manufacturer, got an answer you didn’t like so you asked the internet.

And you posted up $40 pair of calipers and tell ME to eat it.

I like you already.

Just shoot the darn rifle already*











*this is not professional guidance. I don’t even clean my rifles so what do I know.

 

[Evintos]

None it closed like it does without but what's confusing me us the Saami spec min is 1.541 and my fired brass is at 1.534. Isn't that smaller than it should be by a shit ton? Fuck me I'm so confused lol. I knew I should have finished college.

That's because a headspace comparator generally doesn't measure the headspace in the exact spot that's indicated in the SAAMI print.

Use your headspace comparator, measure your headspace gauges (both go and no-go gauge) and tell us your results. Then compare it with your brass measurements.

Edit - Your headspace comparator is referencing a spot that's in between the two highlighted dimensions.

 

[JRBullock1987]

That's because a headspace comparator generally doesn't measure the headspace in the exact spot that's indicated in the SAAMI print.

Use your headspace comparator, measure your headspace gauges (both go and no-go gauge) and tell us your results. Then compare it with your brass measurements.

Edit - Your headspace comparator is referencing a spot that's in between the two highlighted dimensions.
View attachment 8532364

So my forster no-go on my forster dual datum comparator is 1.539" and my forster go guage on it is 1.534". So that doesn't really leave me the ability to bump the shoulder back bc it'll be under the go guage aka min. headspace correct? Is that that a barrel chamber thing only or can the action play a role in that?

 

[Evintos]

So my forster no-go on my forster dual datum comparator is 1.539" and my forster go guage on it is 1.534". So that doesn't really leave me the ability to bump the shoulder back bc it'll be under the go guage aka min. headspace correct? Is that that a barrel chamber thing only or can the action play a role in that?

Absolutely incorrect. If you wanted to bump the shoulder 2 thou for example, you take your comparator, adjust your die until your brass case measured (with the comparator) measures 1.532"

This is a comparator measurement thing. Comparators are made to be mostly universal (within a range of cartridges per bushing) Your headspace 99.99% within SAAMI spec. Your comparator is not measuring the exact SAAMI specified point for 6.5 creedmoor.

Refer to the picture for a visual representation (the red line) where your comparator is sitting (which is 1.534" based on your actual measurement of both the headspace gauge and brass).

In order for your comparator to measure the same spot as a SAAMI print, you would need a custom bushing (specifically for a cartridge, in your case 6.5 creedmoor) that would have to rest on the green line.

Basically, you're not doing anything wrong other than interpreting the measurements you've obtained incorrectly.

 

[JRBullock1987]

Absolutely incorrect. If you wanted to bump the shoulder 2 thou for example, you take your comparator, adjust your die until your brass case measured (with the comparator) measures 1.532"

This is a comparator measurement thing. Comparators are made to be mostly universal (within a range of cartridges per bushing) Your headspace 99.99% within SAAMI spec. Your comparator is not measuring the exact SAAMI specified point for 6.5 creedmoor.

Refer to the picture for a visual representation (the red line) where your comparator is sitting (which is 1.534" based on your actual measurement of both the headspace gauge and brass).

In order for your comparator to measure the same spot as a SAAMI print, you would need a custom bushing (specifically for whatever cartridge, in your case 6.5 creedmoor) that would have to rest on the green line.

Basically, you're not doing anything wrong other than interpreting the measurements you've obtained incorrectly.

I guess I'm not understand the point of the go guage being the min and to no go being the max and it being ok to be shorter than the go but not bigger than the no go?. Aren't you supposed to be between the go and no-go guage comparator measurements? Sorry if im making it feel like pulling teeth lol. So if I bump the shoulder say 2 thou I would be out of the go/no go guage range right? Wouldn't that be a bad thing since that's what they are used for? Fuck brother I'm sorry this is probably making you bald prematurely lol

 

[JRBullock1987]

So you used trash tools, called the manufacturer, got an answer you didn’t like so you asked the internet.

And you posted up $40 pair of calipers and tell ME to eat it.

I like you already.

Just shoot the darn rifle already*











*this is not professional guidance. I don’t even clean my rifles so what do I know.

Haha. And fuck you I like my Chinese measurement stick. I only have to zero it every time I turn it off then on again unless I want to add a 1 to all my measurements haha. But I like to think of it as it keeps me on my game since we'll....you know.....I know exactly what I'm doing once you sobs on the internet tell me WTF I'm doing ahahaha

 

[D̷e̷v̷i̷l̷D̷o̷c̷A̷Z̷]

Haha. And fuck you I like my Chinese measurement stick. I only have to zero it every time I turn it off then on again unless I want to add a 1 to all my measurements haha. But I like to think of it as it keeps me on my game since we'll....you know.....I know exactly what I'm doing once you sobs on the internet tell me WTF I'm doing ahahaha

I’m still trying to figure out what you are doing.

your concern was +0.0005 on crap calipers. A machinist said he trusts GOOD calipers to 0.001 and the manufacturer said shoot the darn thing.


So how does it shoot?

For real. How does it shoot?

 

[JRBullock1987]

I’m still trying to figure out what you are doing.

your concern was +0.0005 on crap calipers. A machinist said he trusts GOOD calipers to 0.001 and the manufacturer said shoot the darn thing.


So how does it shoot?

For real. How does it shoot?

Haha. I've only put 20 rds through it so far and i was getting about .5" with a couple of groups i shot after zeroing it with hornady 140 gr eld match. Im hoping once the barrels broke in a little bit i can get some hand loads in the .25s reguarlarly. We will see. This is the first bolt action I've ever shot and the first time using 6.5cm so im still getting used to it.

 

[D̷e̷v̷i̷l̷D̷o̷c̷A̷Z̷]

As far as telling you how to you your comparator and how much you should bump you brass.

Here’s a real KISS
-set on “shoulder” wherever that fucker lands
-hit “zero”
DONT FIGHT ME KEEP READING
-bump shoulder
-accept “-0.003”

There. I just save you the trouble of learning to extract a separated case head. A whole thread on how it happened. 16 opinions on how to fix it. A lot of wasted brass.

Prob 18 months - 12 years depending how often you shoot.

 

[JRBullock1987]

As far as telling you how to you your comparator and how much you should bump you brass.

Here’s a real KISS
-set on “shoulder” wherever that fucker lands
-hit “zero”
DONT FIGHT ME KEEP READING
-bump shoulder
-accept “-0.003”

There. I just save you the trouble of learning to extract a separated case head. A whole thread on how it happened. 16 opinions on how to fix it. A lot of wasted brass.

Prob 18 months - 12 years depending how often you shoot.

Lol

 

[JRBullock1987]

As far as telling you how to you your comparator and how much you should bump you brass.

Here’s a real KISS
-set on “shoulder” wherever that fucker lands
-hit “zero”
DONT FIGHT ME KEEP READING
-bump shoulder
-accept “-0.003”

There. I just save you the trouble of learning to extract a separated case head. A whole thread on how it happened. 16 opinions on how to fix it. A lot of wasted brass.

Prob 18 months - 12 years depending how often you shoot.

I'm lucky enough to be able to walk out my back door and shoot at 100 yards any time so I shoot as much as I can afford to. One of the reasons I just built a custom rifle instead of buying a bunch of off the shelf rifles and upgrades amd wasting money. I wanted to get a good foundation rifle, and be able to not have to keep buying more and more stuff and being able to focus on reloading costs instead lol.

 

[Evintos]

I guess I'm not understand the point of the go guage being the min and to no go being the max and it being ok to be shorter than the go but not bigger than the no go?. Aren't you supposed to be between the go and no-go guage comparator measurements? Not necessarily, your comparator doesn't rest on the exact spot that the blueprint calls for, which is why I told you to go measure your Go-Gauge with the comparator to see what the difference is. Sorry if im making it feel like pulling teeth lol. So if I bump the shoulder say 2 thou I would be out of the go/no go guage range right? Yes Wouldn't that be a bad thing since that's what they are used for? Not really as long as it's above SAAMI cartridge minimum spec. Fuck brother I'm sorry this is probably making you bald prematurely lol LOL, of all the things I deal with, if this causes me to go bald, I'm quitting the internet after doing research on hair transplant surgery.

Headspace gauges - Go Gauge is supposed to be made to SAAMI or CIP specified minimum chamber blueprint specifications. No-Go is some arbitrary number usually in the middle between blueprint minimum and maximum spec. A field gauge should be at blueprint maximum spec. The SAAMI specs is to establish safety dimensions for factory rifles with factory ammunition in a mass production scale, so for a cartridge, there is both the SAAMI cartridge and SAAMI chamber spec.

When you're sizing your cases, you want it to be smaller than your chamber (but not excessively smaller) in order for you to be able to chamber the round smoothly without issue. This would be under your chamber size. So if your chamber is at min spec, then your loaded cartridge needs to be smaller than chamber min but not smaller than SAAMI cartridge min spec.

The SAAMI cartridge specifications are designed so that the minimum sized cartridge spec will fire safely in a maximum SAAMI sized chamber without blowing up. Cartridge spec normally has a max spec that will still feed reliably in a min chamber even with a tiny bit of fouling. 6.5cm cartridge headspace is 1.5438 (max) and 1.5368" SAAMI min cartridge headspace.

Based on your comparator measurements of the 6.5cm headspace gauges, your comparator bushing is giving you a relative measurement of the headspace that is around 0.007" lower. When you're trying to compare SAAMI spec to what you measured with your comparator, you need to subtract 0.007" from the SAAMI blueprint numbers.

Use -0.007 and apply it to SAAMI min cartridge spec to obtain relative measurement (what you should see with your comparator). So for 6.5cm, 1.5368 (SAAMI cartridge min) - 0.007 = 1.5298"

1.5298" is the dimension for min limit sized ammo (measured using your comparator) that is still safe to fire in a SAAMI max chamber.

As a handloader, you don't have to follow SAAMI cartridge spec exactly since you can load to a specific barrel chamber. Since you have a min SAAMI chamber, you can even go below SAAMI cartridge min as long as you never shoot that handload in a chamber larger than SAAMI min.

SAAMI Max chamber (1.551) minus SAAMI min cartridge (1.5368) = 0.0142" difference. You use this number to maintain the same relationship with min chamber spec.

1.534" (your headspace gauge/chamber spec using comparator) - 0.0142" = 1.5198" is the shortest your case should measure with that comparator otherwise you blow up. In other words, plenty of room to bump the shoulder back without issue.

 

[JRBullock1987]

Headspace gauges - Go Gauge is supposed to be made to SAAMI or CIP specified minimum chamber blueprint specifications. No-Go is some arbitrary number usually in the middle between blueprint minimum and maximum spec. A field gauge should be at blueprint maximum spec. The SAAMI specs is to establish safety dimensions for factory rifles with factory ammunition in a mass production scale, so for a cartridge, there is both the SAAMI cartridge and SAAMI chamber spec.

When you're sizing your cases, you want it to be smaller than your chamber (but not excessively smaller) in order for you to be able to chamber the round smoothly without issue. This would be under your chamber size. So if your chamber is at min spec, then your loaded cartridge needs to be smaller than chamber min but not smaller than SAAMI cartridge min spec.

The SAAMI cartridge specifications are designed so that the minimum sized cartridge spec will fire safely in a maximum SAAMI sized chamber without blowing up. Cartridge spec normally has a max spec that will still feed reliably in a min chamber even with a tiny bit of fouling. 6.5cm cartridge headspace is 1.5438 (max) and 1.5368" SAAMI min cartridge headspace.

Based on your comparator measurements of the 6.5cm headspace gauges, your comparator bushing is giving you a relative measurement of the headspace that is around 0.007" lower. When you're trying to compare SAAMI spec to what you measured with your comparator, you need to subtract 0.007" from the SAAMI blueprint numbers.

Use -0.007 and apply it to SAAMI min cartridge spec to obtain relative measurement (what you should see with your comparator). So for 6.5cm, 1.5368 (SAAMI cartridge min) - 0.007 = 1.5298"

1.5298" is the dimension for min limit sized ammo (measured using your comparator) that is still safe to fire in a SAAMI max chamber.

As a handloader, you don't have to follow SAAMI cartridge spec exactly since you can load to a specific barrel chamber. Since you have a min SAAMI chamber, you can even go below SAAMI cartridge min as long as you never shoot that handload in a chamber larger than SAAMI min.

SAAMI Max chamber (1.551) minus SAAMI min cartridge (1.5368) = 0.0142" difference. You use this number to maintain the same relationship with min chamber spec.

1.534" (your headspace gauge/chamber spec using comparator) - 0.0142" = 1.5198" is the shortest your case should measure with that comparator otherwise you blow up. In other words, plenty of room to bump the shoulder back without issue.

View attachment 8532406

DUDE.....God bless you!!! Thank you for taking the time to explain this... I'm seeing what you're putting down. Is there a comparator set out there that isn't way off like my forster is? Or are they all, all over the place? I need to get some new bullet comparator anyways and might as well find a good set of both. My bullet comparator in 6.5mm has a very sharp edge and when I use it to get my cbto it leaves a pretty deep ring cut around the bullet even with the lightest of pressure. The .223 one isn't too bad but I can't use the 6.5mm one..sucks but might as well find a set that is closer to actual measurements

 

[918v]

You can’t analyze your situation if you don’t have exact numbers. Your tool and method of measuring is not that precise. But, you also have feel. And that is just as valuable as precise measurement.

How does the bolt close on your cases? The bolt can tell you a lot. Sako likes to cut their chambers the same way and you often feel the bolt drag on factory ammo. But understand that factory brass varies too. I have measured new premium brass whose shoulder length varied by .007” and it was basically +.002/-.005” for my chamber. With the + ones I could feel the bolt drag slightly. Now, you don’t have a Sako but the same thing applies.

It’s normal.

 

[JRBullock1987]

You can’t analyze your situation if you don’t have exact numbers. Your tool and method of measuring is not that precise. But, you also have feel. And that is just as valuable as precise measurement.

How does the bolt close on your cases? The bolt can tell you a lot. Sako likes to cut their chambers the same way and you often feel the bolt drag on factory ammo. But understand that factory brass varies too. I have measured new premium brass whose shoulder length varied by .007” and it was basically +.002/-.005” for my chamber. With the + ones I could feel the bolt drag slightly. Now, you don’t have a Sako but the same thing applies.

It’s normal.

I think it feels ok. Not a big struggle but im not sure if it's supposed to be a little harder than running the bolt it's empty or if it's supposed to feel like there's nothing in there

 

[Aftermath]

How do it shoot the shots?

I’m still trying to figure out what you are doing.

your concern was +0.0005 on crap calipers. A machinist said he trusts GOOD calipers to 0.001 and the manufacturer said shoot the darn thing.


So how does it shoot?

For real. How does it shoot?

Haha. I've only put 20 rds through it so far and i was getting about .5" with a couple of groups i shot after zeroing it with hornady 140 gr eld match. Im hoping once the barrels broke in a little bit i can get some hand loads in the .25s reguarlarly. We will see. This is the first bolt action I've ever shot and the first time using 6.5cm so im still getting used to it.

Dude...
You have your first bolt gun, doing your first reloading and are getting a 0.5" group at 100 yards.
You are doing well, even though you are using 6.5CM.
The only way to get better at shooting is to shoot more often and try to be better more often.
Realize that the reloading can be as addicting as shooting for some folks and they get all wrapped up and spend thousands of dollars on gear. Meanwhile, other guys use just the basic gear and make very accurate ammunition.
If you want to shoot better, shoot early and shoot often. Focus on doing it better and better.
If you want to make ammunition, spend your money and focus your time on that.

 

[JRBullock1987]

Dude...
You have your first bolt gun, doing your first reloading and are getting a 0.5" group at 100 yards.
You are doing well, even though you are using 6.5CM.
The only way to get better at shooting is to shoot more often and try to be better more often.
Realize that the reloading can be as addicting as shooting for some folks and they get all wrapped up and spend thousands of dollars on gear. Meanwhile, other guys use just the basic gear and make very accurate ammunition.
If you want to shoot better, shoot early and shoot often. Focus on doing it better and better.
If you want to make ammunition, spend your money and focus your time on that.

I've been reloading for a little over a year now for a precision ar15 and usually get between .3 to .5 regularly. But it's all the barrel lol cause I have zero skills with shooting. I started shooting 0recision at the same time I starting shooting precision ar amd just fell in love with it. I love the reloading as much as the shooting and am very particular and ocd about reloading and being as precise as I'm capable of being. I def splurged with this rifle but I didn't want to have to buy multiple rifles as I got better so I figured I'd build the most expensive basic custom rifle I could afford and then use it for as long as it still works and I'll get d8fferent barrels when I need to. But I'm not gunna be buying multiple actions and have 4 different rifles lol. Im a one and done kinda guy haha. I have this weird thing with my shooting where I get double groups sometimes. Like a 5 shot group will be more like a 2 and a 3 shot group really close together... it's sooo annoying. Idk if it's me, my optic or what. I'm self taught which isn't saying much considering I have no clue what I'm doing and just kinda do what feels natural.

 

[Aftermath]

I've been reloading for a little over a year now for a precision ar15 and usually get between .3 to .5 regularly. But it's all the barrel lol cause I have zero skills with shooting. I started shooting 0recision at the same time I starting shooting precision ar amd just fell in love with it. I love the reloading as much as the shooting and am very particular and ocd about reloading and being as precise as I'm capable of being. I def splurged with this rifle but I didn't want to have to buy multiple rifles as I got better so I figured I'd build the most expensive basic custom rifle I could afford and then use it for as long as it still works and I'll get d8fferent barrels when I need to. But I'm not gunna be buying multiple actions and have 4 different rifles lol. Im a one and done kinda guy haha. I have this weird thing with my shooting where I get double groups sometimes. Like a 5 shot group will be more like a 2 and a 3 shot group really close together... it's sooo annoying. Idk if it's me, my optic or what. I'm self taught which isn't saying much considering I have no clue what I'm doing and just kinda do what feels natural.

That is not that uncommon to have the 2 or even 3 different tight groups that are part of a big loose group. In my own experiences, I have seen it be a sort of cloverleaf more often than not. I was never able to convince myself that it was me being so consistently wrong in 3 different places and decided that I needed to work on the load development some more.

As far as doing what feels natural. Natural might feel good and might very well get the job done but getting some good instruction is definitely worth it. If nothing else, you can be confirmed that you are doing it quite well.

 

[918v]

I think it feels ok. Not a big struggle but im not sure if it's supposed to be a little harder than running the bolt it's empty or if it's supposed to feel like there's nothing in there

If you have .002” clearance then it should feel like there’s nothing in there. If you have zero clearance the bolt will feel snug. Picture the case in the chamber with the case’s shoulder pressing against the chamber’s shoulder and the case head pressing against the bolt face. If the case is slightly too long the bolt will press hard against the case head using the camming force of the action as leverage. It will make the case fit and will push the shoulder back like a sizing die. You’ll be able to feel it.

 

[JRBullock1987]

If you have .002” clearance then it should feel like there’s nothing in there. If you have zero clearance the bolt will feel snug. Picture the case in the chamber with the case’s shoulder pressing against the chamber’s shoulder and the case head pressing against the bolt face. If the case is slightly too long the bolt will press hard against the case head using the camming force of the action as leverage. It will make the case fit and will push the shoulder back like a sizing die. You’ll be able to feel it.

I'm actually resizing the 20 rds I sighted the rifle in with right now. I annealed and im having to cam over a bit on my forster to get 1 thou shoulder bump. I checked it in the chamber and it feels like nothing other than when the extractor pops over the base. So my question is if I emailed and talked to someone at proof and they he says they make all their prefits the same. Does that make the short chamber an action thing? Or did someone cutting the barrel chamber just screw up somehow? Does this kinda thing have to be the barrels problem so to speak or is the action also possibly to blame?

 

[JRBullock1987]

It’s not a short chamber.

What makes you think that? I'm honestly curious cause I don't have anything to compare it to. Just to bump 1 thou bumping back my shoulder im shorter than the go gauge. The other guy explained it to me and I'll think I get it then completely not understand it lol. I'm also named over pretty hard just to get 1 thou bump on the coax and I've never had to cam over this hard to get so little sizing before. Obviously it was a difference cal (5.56) but I would think the same thing applies right? I freaking hate that i do this sport alone cause I don't have anyone to really explain and show me this stuff. I'm a visual Lerner so just reading stuff on the interwebs doesn't always get through my thick ass brain haha

 

[918v]

I'm actually resizing the 20 rds I sighted the rifle in with right now. I annealed and im having to cam over a bit on my forster to get 1 thou shoulder bump. I checked it in the chamber and it feels like nothing other than when the extractor pops over the base. So my question is if I emailed and talked to someone at proof and they he says they make all their prefits the same. Does that make the short chamber an action thing? Or did someone cutting the barrel chamber just screw up somehow? Does this kinda thing have to be the barrels problem so to speak or is the action also possibly to blame?

It’s a tolerance stacking thing. The chamber is plus/minus as are the bolt face, your sizing die, etc. The case lube also affects how much your die bumps the shoulder. It’s not an issue unless you are having problems closing the bolt on factory ammo. Your brass will live longer.

 

[Evintos]

DUDE.....God bless you!!! Thank you for taking the time to explain this... I'm seeing what you're putting down. Is there a comparator set out there that isn't way off like my forster is? Or are they all, all over the place? I need to get some new bullet comparator anyways and might as well find a good set of both. My bullet comparator in 6.5mm has a very sharp edge and when I use it to get my cbto it leaves a pretty deep ring cut around the bullet even with the lightest of pressure. The .223 one isn't too bad but I can't use the 6.5mm one..sucks but might as well find a set that is closer to actual measurements

They're all off because they measure relative headspace. They'll never be exact unless you just happen to get lucky. I like the Derraco Headspace comparator set, lots of bushing and bullet inserts for around $50.

 

[JRBullock1987]

It’s a tolerance stacking thing. The chamber is plus/minus as are the bolt face, your sizing die, etc. The case lube also affects how much your die bumps the shoulder. It’s not an issue unless you are having problems closing the bolt on factory ammo. Your brass will live longer.

It's not super hard but there def a little resistance compared to bumping the resized brass back 1 thou and there's zero resistance on them and maybe a 3 out of 10 resistance on factory brass. When I shot the hornady the headspace literally didn't change at all. It stayed exactly the same.

 

[JRBullock1987]

They're all off because they measure relative headspace. They'll never be exact unless you just happen to get lucky. I like the Derraco Headspace comparator set, lots of bushing and bullet inserts for around $50.

Cool thanks

 

[918v]

It's not super hard but there def a little resistance compared to bumping the resized brass back 1 thou and there's zero resistance on them and maybe a 3 out of 10 resistance on factory brass. When I shot the hornady the headspace literally didn't change at all. It stayed exactly the same.

It’s just like every one of my Sako rifles. I wouldn’t worry about it. Just wait till everything wears in after a couple thousand rounds.

 

[JRBullock1987]

It’s just like every one of my Sako rifles. I wouldn’t worry about it. Just wait till everything wears in after a couple thousand rounds.

For sure. Do you know ow if when using something like a coax that does have the ability built in to have a cam over but you have to screw the sizing die down far enough that it cams over a little bit. Would that fuck up the brass holder shell clampy thingymajigger. It's not super hard but there's def a little cam over

 

[vh20]

Is there a comparator set out there that isn't way off like my forster is? Or are they all, all over the place? I need to get some new bullet comparator anyways and might as well find a good set of both. My bullet comparator in 6.5mm has a very sharp edge and when I use it to get my cbto it leaves a pretty deep ring cut around the bullet even with the lightest of pressure. The .223 one isn't too bad but I can't use the 6.5mm one..sucks but might as well find a set that is closer to actual measurements

It's on the expensive side, but I have really enjoyed the Area 419 bullet and headspace comparator set, paired with their stand for it (but it requires you use Mitutoyo calipers - which would be a great idea for you to do anyway.
The Area 419 set isn't going to give you an exact industry-standard measurement (neither are any of the other brands), BUT they did design them so they are very consistent from set to set, so that if someone else across the country has the same set, the measurements you compare will be consistent with each other. Most sets don't maintain that consistency set to set, at least I'm not aware of any other set that is made this way, which is why its often hard to compare measurements with each other.
The stand they make for the unit is REALLY cool, because it allows you to measure in a stable manner (almost one-handed) and use gravity as a consistent pressure for every measurement you make. Set the case or cartridge in, allow gravity to close the calipers on the shoulder or bullet ogive, then give the case a slight wiggle until the numbers stop getting smaller. The force applied (by gravity) is the same every time. It is especially helpful when measuring bullet seating depth, as it keeps the edge of the comparator from being forced against the ogive with a different pressure each time, keeping the measurements more consistent.

 

[918v]

For sure. Do you know ow if when using something like a coax that does have the ability built in to have a cam over but you have to screw the sizing die down far enough that it cams over a little bit. Would that fuck up the brass holder shell clampy thingymajigger. It's not super hard but there's def a little cam over

It won’t. Those jaws are super hard. I use a shell holder conversion on mine and have the die adjusted to act as a hard stop for the mechanism. Just have to screw the die in deeper, way past the cam over point.

 

[JRBullock1987]

It's on the expensive side, but I have really enjoyed the Area 419 bullet and headspace comparator set, paired with their stand for it (but it requires you use Mitutoyo calipers - which would be a great idea for you to do anyway.
The Area 419 set isn't going to give you an exact industry-standard measurement (neither are any of the other brands), BUT they did design them so they are very consistent from set to set, so that if someone else across the country has the same set, the measurements you compare will be consistent with each other. Most sets don't maintain that consistency set to set, at least I'm not aware of any other set that is made this way, which is why its often hard to compare measurements with each other.
The stand they make for the unit is REALLY cool, because it allows you to measure in a stable manner (almost one-handed) and use gravity as a consistent pressure for every measurement you make. Set the case or cartridge in, allow gravity to close the calipers on the shoulder or bullet ogive, then give the case a slight wiggle until the numbers stop getting smaller. The force applied (by gravity) is the same every time. It is especially helpful when measuring bullet seating depth, as it keeps the edge of the comparator from being forced against the ogive with a different pressure each time, keeping the measurements more consistent.

I was actually looking at their sets earlier this morning but got a little confused on the angle stuff for the caps. Are you supposed to use the 30° angle comparator bushings for 6.5cm?

 

[JRBullock1987]

It won’t. Those jaws are super hard. I use a shell holder conversion on mine and have the die adjusted to act as a hard stop for the mechanism. Just have to screw the die in deeper, way past the cam over point.

I've seen those conversations. How do you like using the regular shell holder compared to the coax jaws? The reg shell holders can't self center like the jaws huh?

 

[vh20]

I was actually looking at their sets earlier this morning but got a little confused on the angle stuff for the caps. Are you supposed to use the 30° angle comparator bushings for 6.5cm?

Not sure about the 30 deg angle you referenced. The 6.5CM uses the .400" dia. bushing according to the chart on their product page (scroll down to it):

Area 419 ZERO Headspace and Ogive Measurement Gauge Kit

NEED CALIPERS? ORDER MITUTOYO CALIPERS HERE.

www.area419.com

 

[JRBullock1987]

Not sure about the 30 deg angle you referenced. The 6.5CM uses the .400" dia. bushing according to the chart on their product page (scroll down to it):

Area 419 ZERO Headspace and Ogive Measurement Gauge Kit

NEED CALIPERS? ORDER MITUTOYO CALIPERS HERE.

www.area419.com

Nvm im thinking of sac comparator kits.

 

[JRBullock1987]

Not sure about the 30 deg angle you referenced. The 6.5CM uses the .400" dia. bushing according to the chart on their product page (scroll down to it):

Area 419 ZERO Headspace and Ogive Measurement Gauge Kit

NEED CALIPERS? ORDER MITUTOYO CALIPERS HERE.

www.area419.com

Damn you weren't kidding that's awesome looking. Smart how they stick a flat platform for the base instead of having to index of the calipers small shelf

 

[Ex E6]

Eat that lol. I dont fckn know I didn't know where to put it. I reload so I figured it had to do with resizing and reloading fireformed brass.....I asked bc they didn't go into details and thought and see if some turd burglars on the interwebs could expound on the subject.

Resolution doesn't indicate accuracy ( + or - 0.0001) Next question ?

 

[JRBullock1987]

Resolution doesn't indicate accuracy ( + or - 0.0001) Next question ?

Lol

 

[918v]

I've seen those conversations. How do you like using the regular shell holder compared to the coax jaws? The reg shell holders can't self center like the jaws huh?

No it can’t but everything aligns well and there aren’t any runout issues with the ammo. But I can use competition shell holders to control shoulder length better than without.

 

[JRBullock1987]

Do you see a more consistency with the comp shell holders than with anything else?

 

[Rob01]

If all you need is a headspace gauge then the Hornady works fine. Been using it for many years with the 6.5 Creedmoor and no issues and give me my measurements needed. All you need is to get the fired measurement and bump it .001-.002" when sizing. No need to spend $300+.

Hornady Lock-N-Load Headspace Ga 5 Bushing Set Comparator

The Hornady Lock-N-Load Headspace Gauge is a great tool for increasing the accuracy of your loaded ammunition. The Headspace gauge measures from the...

www.midwayusa.com

It's nice to have the headspace shorter than longer so I would not worry at all about your set up.

 

[vh20]

Damn you weren't kidding that's awesome looking. Smart how they stick a flat platform for the base instead of having to index of the calipers small shelf

ALSO, and I didn't notice it when I first got it, that flat base has a hole in it just slightly larger than a large primer pocket, so you don't have to deprime your fired cases before you measure their headspace. That's a requirement when using the caliper jaws for the base, and just adds another step if you aren't already depriving as a separate operation (I don't). This one indexes the case off the entire face of the head EXCEPT where the primer goes. Pretty cool idea.