Comparators pro/cons

[Red98422]

I posted a thread earlier asking for basic tools that one should have to load bottle neck and one of the things mentioned by more than one member here was a Comparator.

Reading further about it, I'm more confused than ever. If my understanding is correct it measures to the Ogive of your cartridges, which seems to come into play to take out the "jump" of a bullet to the grooves.

It can also measure your shoulder. Which is said to be handy when neck sizing and just bumping back to a set distance. I can see this being handy for dialing in a new rifle.

Maybe I'm a bit overwhelmed with all these new measurements I have to deal with now, but can someone point me to a good...entry level explanation of how these tools can be used by someone not chasing 1k yards?

I guess I'm a decent enough shot (USMC expert and all 10 hits in the 500) but nowhere near what the guys here are capable of. And a lot of it seems to go over my head. I completely get why the tool was suggested I'm just trying to figure out how its used at my level

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[DizzyJ]

Comparators are simply put, a way to measure your work. You don't need to be a 1,000 yd marksman in order to need or use one. They are a way of checking your work so you don't get yourself into trouble loading rifle cartridges.

They can help you make sure your cartridge functions reliably in your gun without overworking the brass, or accidentally jamming a bullet into the lands, which could cause a kaboom if you're not careful.

Get the Hornady headspace gauge and bullet inserts for whatever caliber you're going to be loading for.

Too much shoulder bump overworks your brass and can lead to less accurate ammo and lessens the life of the brass. Too little shoulder bump and you can have issues with your cartridge not wanting to chamber.

 

[DizzyJ]

 

[Red98422]

Comparators are simply put, a way to measure your work. You don't need to be a 1,000 yd marksman in order to need or use one. They are a way of checking your work so you don't get yourself into trouble loading rifle cartridges.

They can help you make sure your cartridge functions reliably in your gun without overworking the brass, or accidentally jamming a bullet into the lands, which could cause a kaboom if you're not careful.

Get the Hornady headspace gauge and bullet inserts for whatever caliber you're going to be loading for.

Too much shoulder bump overworks your brass and can lead to less accurate ammo and lessens the life of the brass. Too little shoulder bump and you can have issues with your cartridge not wanting to chamber.

Thank you for putting it into layman's terms. I kinda grasped the importance of it, but reading online a lot of the information is written by folks way more advanced than me and they're usually discussing things in terms of 1/4moa

Thanks again for the break down to my level!

 

[DizzyJ]

 

[DizzyJ]

Thank you for putting it into layman's terms. I kinda grasped the importance of it, but reading online a lot of the information is written by folks way more advanced than me and they're usually discussing things in terms of 1/4moa

Thanks again for the break down to my level!

I didn't immediately understand the entirety of it myself when I was first introduced to it. Just take your time, absorb what you can. The rest of the understanding will come naturally with time.

Take little bites at a time. Read, watch videos, ask questions. Lots of knowledgable people here to help you out.

 

[Certaindeaf]

When it's too long to fit in the magazine one a them comparators is particularly invaluable.

 

[Stomper]

OK, y'all are using too many big words and cluttering up the issue.... he's a Marine after all.








But I think he's got it now.

 

[Red98422]

OK, y'all are using too many big words and cluttering up the issue.... he's a Marine after all.








But I think he's got it now.

And all I wanted to do was send rounds downrange and now they're trying to educate me




Yeah I got it now, the thing helps make sure all your rounds fit in the hole good!!....Coulda used something like that at last call a few times in the past ......


All kidding asside thanks @DizzyJ for the breakdown

 

[2A2Dend]

Great topic.

 

[Steel Head]

Simply put you use them to compare your fired brass to your sized brass.
I also use them to compare my head space gauges to new brass when setting headspace on my barrels to ensure minimal expansion on first shot.
You can obviously use the to compare bullet position in the case as well.

OK, y'all are using too many big words and cluttering up the issue.... he's a Marine after all.








But I think he's got it now.

 

[Whisky Tahoe]

Magazine size can determine the maximum length of a cartridge called COAL: Cartridge Overall Length
Chamber, throat, lands sometimes need a different measurement. CBTO: Cartridge Base To Ogive.
The bullet point on many low drag bullets will end up deep in the barrel before the ogive or first part of the bullet bearing surface starts to contact the lands.

Cartridges with bullets seated into the lands are said to be "Jammed" . Best left to benchrest shooters as pressures can rise and if you open the bolt after putting a cartridge in the chamber and closing the bolt, bullets can be pulled and that spills powder everywhere.

Cartridges with bullets off the lands are said to be "jumped" as they have to travel forward to get into the lands.

Comparators can refer to tools that measure the ogive (Sinclair comparator), or tools that measure parts of the chamber, (hornady, stoney point).

There is a youtube video by wheeler accuracy that will tell you how to "find the lands" or the exact seating depth.
The problem with Hornady, Sinclair or any other system that pushes bullets into the rifling is it is very easy to get into the lands and that results in measurements that aren't very accurate.

That said, if you use a particular method and use it consistently, while you might be off, you can remain consistent if that measurement is repeatable. I can't use the Hornady system and get repeatable results so I rely on the method where you remove the firing pin and ejector spring then test bullet seating depths till you can't detect the grab of the lands. This sounds like a lot of work however knowing where the lands are means everything when bullets need a specific seating depth to obtain their accuracy potential.

 

[atakawow]

The only con is that you spend $30 for the tool and $7 per cartridge you reload for.

 

[Steel Head]

The only con is that you spend $30 for the tool and $7 per cartridge you reload for.

I actually make my own inserts and tools now.
pretty easy with lathe.

 

[DizzyJ]

I actually make my own inserts and tools now.
pretty easy with lathe.

View attachment 675133

How much did the lathe and tooling cost?

 

[Steel Head]

How much did the lathe and tooling cost?

Nothing
We have a few lathes at work.

 

[DizzyJ]

Nothing
We have a few lathes at work.

That works out pretty well then!