Which bullet comparator?

[Lloyd90]

Looking to get a bullet comparator for measuring seating depth, options are;

 

Hornady comparator body and then the head space gauge or

Sinclair hex bullet comparator

 

Any recommendations?

[Savhmr]

Yes. Avoid the Sinclair and buy the Hornady.

[Lloyd90]

Yes. Avoid the Sinclair and buy the Hornady.

Ah I just read somewhere else the hex nut wasn't great,

 

My understanding is I need one of these in a D;

https://www.1967spud.com/shop/hornady/head-space-gauges-for-oal-gauge-system/?attribute_pa_headspace-gauges-inserts=d-400

 

And one of these

https://www.1967spud.com/shop/hornady/hornady-comparator-body/

 

Missed anything?

[team tractor]

Ah I just read somewhere else the hex nut wasn't great,

 

My understanding is I need one of these in a D;

https://www.1967spud.com/shop/hornady/head-space-gauges-for-oal-gauge-system/?attribute_pa_headspace-gauges-inserts=d-400

 

And one of these

https://www.1967spud.com/shop/hornady/hornady-comparator-body/

 

Missed anything?

I've been looking for one the past few weeks as I'm on a budget. The hornady seems the only one out there besides the nut

[Savhmr]

That's the one Lloyd. It pays to buy the seating depth comparator too, as well as the headspace comparator. There are one or two very expensive alternatives, but the Hornady one seems about the best for the money.

[old man]

Please tell me what is wrong with the Sinclair nut?

Unless you are a real fiddler, it's maybe all you need?

 

It's cheap, accurate and does what it should for a few quid?

[Dougy]

Please tell me what is wrong with the Sinclair nut?

Unless you are a real fiddler, it's maybe all you need?

 

It's cheap, accurate and does what it should for a few quid?

I agree, does it really matter what you measure it with as long as it's slightly above the point of the ogive. Consistency is the aim, I had someone from work turn me a piece of alli for measuring 260 loads. I later bought a hornady comparator insert, checking the seating depth of already loaded rounds and they were all the same to 0.0001.

[LeadWasp]

Yes. Avoid the Sinclair and buy the Hornady.

+1

 

Ah I just read somewhere else the hex nut wasn't great,

 

My understanding is I need one of these in a D;

https://www.1967spud.com/shop/hornady/head-space-gauges-for-oal-gauge-system/?attribute_pa_headspace-gauges-inserts=d-400

 

And one of these

https://www.1967spud.com/shop/hornady/hornady-comparator-body/

 

Missed anything?

no it isn't

 

I've been looking for one the past few weeks as I'm on a budget. The hornady seems the only one out there besides the nut

Nathan we went through all this on Sunday!

 

Please tell me what is wrong with the Sinclair nut?

Unless you are a real fiddler, it's maybe all you need?

 

It's cheap, accurate and does what it should for a few quid?

Repeatability issues. Although you have to use a repeatable pressure with the Hornady, it is easier to get a series of identical readings. I find the Sinclair doesn't give the this. Mine sits on the shelf unused.................

[LeadWasp]

Ah I just read somewhere else the hex nut wasn't great,

 

My understanding is I need one of these in a D;

https://www.1967spud.com/shop/hornady/head-space-gauges-for-oal-gauge-system/?attribute_pa_headspace-gauges-inserts=d-400

 

And one of these

https://www.1967spud.com/shop/hornady/hornady-comparator-body/

 

Missed anything?

For seating you actually need the insert shown in the photo on this page https://www.1967spud.com/shop/hornady/tools-for-oal-gauge-system-copy/ however he doesn't seem to do them individually. Try reloading solutions or Dauntsey guns.

Edited March 17, 2017 by LeadWasp

[Lloyd90]

For seating you actually need the insert shown in the photo on this page https://www.1967spud.com/shop/hornady/tools-for-oal-gauge-system-copy/ however he doesn't seem to do them individually. Try reloading solutions or Dauntsey guns.

 

Yes I think Savhmr said similar I'm just reading them now,

 

these reloading sites are alright but they're not great on their search options lol

[phaedra1106]

For something a bit better than the Hornady have a look at The Shooting Sheds products,

 

http://shootingshed.co.uk/oscom/index.php?cPath=38

[Lloyd90]

For something a bit better than the Hornady have a look at The Shooting Sheds products,

 

http://shootingshed.co.uk/oscom/index.php?cPath=38

Stop confusing me more 😂

[team tractor]

+1

 

no it isn't

 

Nathan we went through all this on Sunday!

 

Repeatability issues. Although you have to use a repeatable pressure with the Hornady, it is easier to get a series of identical readings. I find the Sinclair doesn't give the this. Mine sits on the shelf unused.................

That's why I ordered a hornady today mate

[Lloyd90]

That's why I ordered a hornady today mate

What caliber?

 

Anyone care to explain the different use of a seating comparator and a headspace comparator.

 

One measures seating depth? One measures head space?

[Lloyd90]

So its one of these

http://www.ebay.co.uk/itm/Hornady-L-N-L-Comparator-Insert-for-Comparator-Body-VARIOUS/252575073290?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D20140122125356%26meid%3D9ba0e5668aef4a8780cdcf8f23334ca2%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D252573379364

 

Any one of these

 

http://www.ebay.co.uk/itm/Hornady-Lock-N-Load-Comparator-Body-HORN-B2000/252573379364?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D20140122125356%26meid%3Db1e981eb778342ab83b1d49cf268670c%26pid%3D100005%26rk%3D3%26rkt%3D6%26sd%3D252575073290

[team tractor]

What caliber?

 

Anyone care to explain the different use of a seating comparator and a headspace comparator.

 

One measures seating depth? One measures head space?

From what I've been taught it measures the exact same place for each round as you can't measure from the point as it changes with every round

You need to measure where it touches the lands not the point.

[LeadWasp]

If you look at the original page of Spuds that we were talking about you see a longer silver coloured guage resting on the shoulder of the cartridge. This is a headspace gauge. Headspace is measured from a datum on the cartridge/chamber wall (typically the point that resists forward motion - i.e. the shoulder) to the bolt face. Think of it as a clearance that allows a cartridge, made to within certain upper and lower tolerance limtis, to fit into your chamber.

 

Too little headspace and your cartridgewon't fit, too much will allow the brass to expand back too far on firing and may rupture the case. One sign of high pressure with a load is a stiff bolt because although the cartridge has expanded onto the chamber walls. obturated and transferred some of the firing force via friction, the remainder has caused the brass to expand back towards the bolt face. You will also potentially see extractor marks or bolt marks worn onto the brass.

 

It is also possible to have a hard to chamber cartridge because normal brass growth has reduced your headspace over time, rather than acutely on a single firing. This is when you need to bump the shoulders back/full length resize.

 

Headspace is also a mental health App. Someone once warned me that reloading 'will drive you mad'. I may need this App before long.............

[LeadWasp]

This also opens up the shiny/not shiny brass argument. There was a thread on PW where someone grumped that saying that dull brass resisted pressure better was claptrap - or something like that.

 

I'm firmly in the claptrap camp in that to me a rougher material will have higher friction on the chamber wall than shiny/smooth. Dougy will attest that all my brass looks like one of Steptoe's fivers (maybe not as sticky). Additionally you will often see gunsmiths deliberately 'de-glaze' a freshly reamed chamber wall with a very fine abrasive such as a fine Scotchbrite grade.

 

For the civil engineers amongst you, think how piles work. They transfer a strong axial load to the pile hole wall (think chamber) via friction over a much greater surface area (think case wall) than the end of the pile (cartridge head).

[Lloyd90]

If you look at the original page of Spuds that we were talking about you see a longer silver coloured guage resting on the shoulder of the cartridge. This is a headspace gauge. Headspace is measured from a datum on the cartridge/chamber wall (typically the point that resists forward motion - i.e. the shoulder) to the bolt face. Think of it as a clearance that allows a cartridge, made to within certain upper and lower tolerance limtis, to fit into your chamber.

 

Too little headspace and your cartridgewon't fit, too much will allow the brass to expand back too far on firing and may rupture the case. One sign of high pressure with a load is a stiff bolt because although the cartridge has expanded onto the chamber walls. obturated and transferred some of the firing force via friction, the remainder has caused the brass to expand back towards the bolt face. You will also potentially see extractor marks or bolt marks worn onto the brass.

 

It is also possible to have a hard to chamber cartridge because normal brass growth has reduced your headspace over time, rather than acutely on a single firing. This is when you need to bump the shoulders back/full length resize.

 

Headspace is also a mental health App. Someone once warned me that reloading 'will drive you mad'. I may need this App before long.............

 

 

 

Right, so the first one I linked was the wrong piece for measuring the COAL.

 

NOW THEN! The two I linked from ebay are the right ones?

[LeadWasp]

Yes - you kneed both of those. If this is the eBay arm of http://www.cdsgltd.co.uk/ then they are good. I've bought some dies off them and the Lyman lube spray (ace stuff). They give good Cust Service generally but can be hard to reach on the phone (guess they're teaching shooting!).

 

You will also need the modified case AND the rod thingy.

 

With the rod, you just need to learn the 'feel' of it so that you use a consistent pressure with your single finger tip. It is easy to push a bullet a few thou into the lands early on.

 

Don't be afraid to experiment with jump. I have some bullets that like 90 thou! Every cartridge has a general sweetspot.

 

A lot of people say you don't need this kit and try putting ink on the bullet. I persevered but never got as consistent results as you do with the Hornady.

[Lloyd90]

Yes - you kneed both of those. If this is the eBay arm of http://www.cdsgltd.co.uk/ then they are good. I've bought some dies off them and the Lyman lube spray (ace stuff). They give good Cust Service generally but can be hard to reach on the phone (guess they're teaching shooting!).

 

You will also need the modified case AND the rod thingy.

 

With the rod, you just need to learn the 'feel' of it so that you use a consistent pressure with your single finger tip. It is easy to push a bullet a few thou into the lands early on.

 

Don't be afraid to experiment with jump. I have some bullets that like 90 thou! Every cartridge has a general sweetspot.

 

A lot of people say you don't need this kit and try putting ink on the bullet. I persevered but never got as consistent results as you do with the Hornady.

What do I need a modified case and the rod thingy for?

 

Thought I only need the comparator and the right insert to measure the ones I've loaded.

[LeadWasp]

If you've already loaded some ammunition there might be a bit of confusion. The OAL in a reloading book is usually a TOTAL length, head to tip...problem is the tip can be squashed if it's a lead bullet. Additionally the position of max diameter (calibre) can vary depending on the profile of the bullet. Hunting bullets have their max dia. quite a way forwards whereas a VLD has a long slim nose so the max dia. is back a bit in terms of the total bullet length.

 

The idea with the Hornady gauge is to use the modified case, with a bullet and the rod thingy to measure what the max ogive overall length (let's call it the OOAL) is. This is the maximum case+bullet length you can fit into the chamber where the bullet is just touching the lands. You take this value, subtract what you think will be a useful/accurate jump and use this to set your seating die to produce of a bullet of OOAL minus your jump in length.

 

Put simply you need to measure your OOAL BEFORE you load ammunition. If you've made rounds already you can at least now backwards check that what you have made is at least shorter than your max length. it will be safe but might be a bit pants.

 

So you screw the modified case onto the rod tool (I forget it's proper name). You then put your chosen bullet into the neck of the case and offer the whole assembly up to the chamber. You then very gently advance the rod through the case pushing the bullet up until you meet the SLIGHTEST resistance. At this point the bullet is just touching the lands. You then tighten the set screw on the rod device (carefully as it is easy to mess up the length) and withdraw the assembly. You then put the bullet comparator into the holder and mount this on one arm of your vernier calipers. You then offer the case+bullet+rod up to the comparator, putting the bullet into the comparator orifice and measure the case head to bullet ogive diamater in the caliper. I would do this at least 5 times until you get either a consistent result or a decent samplr from which to take an average. If your results are more than 5 thou different I would reject them and do it again. It is quite a subtle technique.

 

With some light small bullets such as varmint 40 grainers etc you might end up with less than a calibre's worth of bullet length in the neck. There is some evidence to suggest that at least a calibres worth of bullet needs to be seated for accuracy. i.e. a 22. CF bullet would require .224 of bullet in the neck. I would suggest obeying this rule initially so you might end up with a bullet that is OOAL minus jump, minus whatever else you need to seat a bullet 1 calibre deep.

Edited March 18, 2017 by LeadWasp

[Lloyd90]

Ah I read that I can do the same with a already fired case, bullet and a sharpie marker.

 

To measure the loaded case I can just use the two I linked from eBay?

[LeadWasp]

Hi Lloyd90 - yes you can use the sharpie marker method with an EMPTY case. To be honest I tried and tried with it but couldn't get acceptably repeatable results. By all means go ahead but if you can spare the dosh just get the full kit as it will save time and frustration. there will be many who have had success with the economical method. I failed miserably..............

 

 

You need an empty, once fired in your gun, case so the neck is expanded to calibre and the bullet will slide freely.

Edited March 19, 2017 by LeadWasp

[team tractor]

I used to think all this was boring but I've read ever comment so far

I'm actually understanding it all at last I think.

Dougy and leadwasp have been really patient with me at the range explaining .