Measuring OAL

[andybrock]

What method / tool would you say is the most accurate way of measuring OAL from the case base to the bullet ogive?

 

I've been using a Sinclair nut but I'm sure there must be some thing more accurate.

 

Cheers Andy

[1967spud]

the hornady oal gauge is what i se and i finfd it good and repeatable

[Jagged 77]

Agree with Spud, the Hornady Lock n' Load with a good set of callipers is very repeatable and easy to use.

[Jamie]

I have the Hornady gauge. But I have to say I was disgusted that the inner grey shaft is plastic!

Works ok, but a right rip-off at £35-£40!

[tony]

I have the Hornady gauge. But I have to say I was disgusted that the inner grey shaft is plastic!

Works ok, but a right rip-off at £35-£40!

I agree with you mate, a metal shaft would be more suitable I recon

[Hatzi]

Had you considered a polymer shaft encourages a little more delicacy and less damage to the bullet? You are after all driving a soft copper jacket into a sharp rifled bore and pushing too hard is not very helpful.

[MJR]

You don't have to ram the bullet home, just use a delicate touch to 'feel' the bullet find the start of the rifling. One word of caution. I have found the same calibre size insert to vary very slightly in I.d. Obviously this will give varying readings so make sure you stick to one insert for measuring oal to ogive.

[shooter79]

You don't have to ram the bullet home, just use a delicate touch to 'feel' the bullet find the start of the rifling. One word of caution. I have found the same calibre size insert to vary very slightly in I.d. Obviously this will give varying readings so make sure you stick to one insert for measuring oal to ogive.

Like MJR said, the kit isn't meant to be thrashed, just guild it home slowly and apply light pressure to find the contact point.

[DaveT]

You don't have to ram the bullet home, just use a delicate touch to 'feel' the bullet find the start of the rifling. One word of caution. I have found the same calibre size insert to vary very slightly in I.d. Obviously this will give varying readings so make sure you stick to one insert for measuring oal to ogive.

+1 on the calibre insert variances.... really 'threw' me when I thought I was being clever in getting a spare in case I lost the original!!!

 

Shooting Shed do a meaningful upgrade on the Hornady toolset.........especially on the gauges which align better than the Hornady comparator and anvil set which seldom sit properly square on the calipers and so can give inconsistent readings.

[Jamie]

If I had known about the "Shooting Shed" comparator and anvil set, I would have bought there's instead. That's presuming they work as well as they look!

Oh well, you live and learn....

[Jamie]

If I had known about the "Shooting Shed" comparator and anvil set, I would have bought there's instead. That's presuming they work as well as they look!

Oh well, you live and learn....

 

Hatzi, yours is a fair point, but it's more the principle. I very much doubt Hornady were thinking about their customers when they decided on a plastic rod. Highly likely to do with profit margins....

Having said that, I do like Hornady "kit" in general, in fact I use their custom dies, along with Redding.

On another note I need a new vernier gauge, and I'm thinking about the Hornady one. But that's for another post for other users recommendations....

[alpha1]

The shooting sheds is hard to beat I have one for my 308. Good kit.

[MJR]

You can measure oal length with a cleaning rod if you make up a couple of adjustable collars that fit the rod. Check the chambers empty and close the bolt . Slide the rod carefully down the barrel from the muzzle end until it contacts the bolt face. Slide both collars down the rod until they touch the muzzle and lock them in position. Now remove the bolt and gently push a bullet up the chamber until it contacts the rifling. Slide the cleaning rod back down the barrel, very gently until you'd feel it touch the bullet. When touching slide the collar closest to the muzzle down to touch the muzzle and lock it in place. The distance between the two collars is your COAL. Now load a dummy case, no primer,no powder and adjust your die to seat the same bullet used in the measuring to your COAL. When set your dies are set to load a round to touch the rifling and you can record that position and COAL for future use.

[alpha1]

The shooting sheds is a lot easier and about as accurate as you can get they are widely used by benchrest shooters.

[The Gun Pimp]

The shooting sheds is a lot easier and about as accurate as you can get they are widely used by benchrest shooters.

Comp2.jpg

 

I don't know any benchrest shooters who use this device - enlighten me.

 

Personally, as a benchrest shooter, I can't really see the point of a 'comparator'. Except maybe if you bought a new seating die, you could use the comparator to set it up.

[Dunc]

You can measure oal length with a cleaning rod if you make up a couple of adjustable collars that fit the rod. Check the chambers empty and close the bolt . Slide the rod carefully down the barrel from the muzzle end until it contacts the bolt face. Slide both collars down the rod until they touch the muzzle and lock them in position. Now remove the bolt and gently push a bullet up the chamber until it contacts the rifling. Slide the cleaning rod back down the barrel, very gently until you'd feel it touch the bullet. When touching slide the collar closest to the muzzle down to touch the muzzle and lock it in place. The distance between the two collars is your COAL. Now load a dummy case, no primer,no powder and adjust your die to seat the same bullet used in the measuring to your COAL. When set your dies are set to load a round to touch the rifling and you can record that position and COAL for future use.

 

Excellent. Thanks for this.

[The Gun Pimp]

Plus 1 for MJR's method - exactly what I use and 'widely used by benchrest shooters........' The important thing is to establish a 'starting point' - everything else is trial and error - to find what YOUR rifle likes.

[alpha1]

You can measure oal length with a cleaning rod if you make up a couple of adjustable collars that fit the rod. Check the chambers empty and close the bolt . Slide the rod carefully down the barrel from the muzzle end until it contacts the bolt face. Slide both collars down the rod until they touch the muzzle and lock them in position. Now remove the bolt and gently push a bullet up the chamber until it contacts the rifling. Slide the cleaning rod back down the barrel, very gently until you'd feel it touch the bullet. When touching slide the collar closest to the muzzle down to touch the muzzle and lock it in place. The distance between the two collars is your COAL. Now load a dummy case, no primer,no powder and adjust your die to seat the same bullet used in the measuring to your COAL. When set your dies are set to load a round to touch the rifling and you can record that position and COAL for future use.

 

That's how precision benchrest shooters measure COAL.

[garyw]

You can measure oal length with a cleaning rod if you make up a couple of adjustable collars that fit the rod. Check the chambers empty and close the bolt . Slide the rod carefully down the barrel from the muzzle end until it contacts the bolt face. Slide both collars down the rod until they touch the muzzle and lock them in position. Now remove the bolt and gently push a bullet up the chamber until it contacts the rifling. Slide the cleaning rod back down the barrel, very gently until you'd feel it touch the bullet. When touching slide the collar closest to the muzzle down to touch the muzzle and lock it in place. The distance between the two collars is your COAL. Now load a dummy case, no primer,no powder and adjust your die to seat the same bullet used in the measuring to your COAL. When set your dies are set to load a round to touch the rifling and you can record that position and COAL for future use.

 

That's how precision benchrest shooters measure COAL.

same post as MJR- in fact word for word!

and i dont know any one who shoots br that measures coal that way.i think mr pimp needs to tell it like it is.

[onehole]

In addition to all above one should use a threaded and fired case from your rifle.Just using an unfired modified case of the shelf can tell porkies.If you are using a standard modified case and attempting to run "close" to lands then make up a dummy round and check !!!you may well be in them!! unless of course thats where your going.If planning to run well out of lands then a standard modified case will probably be ok.Take care,,,,,,,,,,Onehole.

[MJR]

Onehole, its late and I've had a couple of sherbets but I don't understand your post. In the first instance you warn of using a std modified case as you may be in the lands then go on to say a std modified case will probably be ok if you plan to run out of the lands? Apologies if I'm miss interpreting your post.

Either way the cleaning rod method removes any doubt as you measure a given COAL with that particular bullet.

[gbal]

I don't know any benchrest shooters who use this device - enlighten me.

 

Personally, as a benchrest shooter, I can't really see the point of a 'comparator'. Except maybe if you bought a new seating die, you could use the comparator to set it up.

Vince,it looks a bit like the Davidson seating depth checker,which is at least in the Sinclair catalog....which might be used by....

[andybrock]

Using the cleaning rod method..... when you've got the measurement between the two stops on the rod are you taking your measurement from the tip of the bullet rather than the bullet ogive?

 

So lets say the distance between the stops on the rod measures for arguments sake measures 2.250 inches, you then then make your dummy round, do you make this to 2.250 inches measuring from the base of the cartridge to the tip of the bullet?

[onehole]

Onehole, its late and I've had a couple of sherbets but I don't understand your post. In the first instance you warn of using a std modified case as you may be in the lands then go on to say a std modified case will probably be ok if you plan to run out of the lands? Apologies if I'm miss interpreting your post.

Either way the cleaning rod method removes any doubt as you measure a given COAL with that particular bullet.

 

Hi,,,,,,,I did say if your planning to run "well out" on my post ,,,, if you seek 25 to 30 thou off then an off the shelf modified case will measure and take you safely away from the lands.If you want to run close to land ie just 3 to 5 thou off then in my experience using a standard modified case can give you incorrect positions and again from my experience and using a standard off the shelf modified case I was actually ending up in the lands instead of an intended 5 thou off.As you know a fired case is pretty much as close as your going to get to the actual shape of your chamber and will give you best chance of getting it right whether you use COL or OG based measurements taken from whichever method ,,,cleaning rod,,stony point type device etc.Firmly believe one should work with ogives and check and batch every bullet in the box especially from Hornady!!

I know Spud or Baldie run a case threading service for a small fee ,,,others too I expect,,,,,pretty much guarantee one would take completley differrent measurements with a fired case,,,,Take care,,,Onehole.

[The Gun Pimp]

Using the cleaning rod method..... when you've got the measurement between the two stops on the rod are you taking your measurement from the tip of the bullet rather than the bullet ogive?

 

So lets say the distance between the stops on the rod measures for arguments sake measures 2.250 inches, you then then make your dummy round, do you make this to 2.250 inches measuring from the base of the cartridge to the tip of the bullet?

Yes - using the same bullet. But, what you now have is a 'starting point'.

 

Because the meplat measurement is only accurate to perhaps five thou., my first test would be this measurement MINUS five thou. In other words - just off the lands.

 

I'd then try different powder loads until I got the best three-shot group. Then you can experiment with seating depth - ten thou. off the lands, 20 thou. off and then go forward - into the lands in five thou. increments. Find what works best - but only after you have a good load off the lands.

 

Benchresters often use the 'jam' method - and work back from there but only because we already have a pretty good idea what works with the 6PPC.