COAL .308 got me stuck

[cruze82]

ok went and purchased a hornady coal gauge with modified case today and iv hit a huge wall

here is the issue, the way I have been measuring overall length before was with a cleaning rod down the barrel so it touches the closed bolt face then I would mark the cleaning rod then I would select the projectile (168g sierra) and use a pencil and push it in till it touches the lands and mark the cleaning rod again.
this gave me a measurement of 2.8020 so I think to myself its 20 thow over recommend seating length as the reloading manual tells me

so today I get home and try out my new hornady gauge I follow the instructions and watch some youtube videos and I get a really long oal 2.982 now at this length the bullet barley seats into the case mouth where has all this gone wrong ?

BTW this is in my Remington 700 sps varmint

[Chronos]

hey cruze, i use the hornady gauge with my own fireformed cases.

first question, you are using your cleaning rod which is a method i've never seen used and one i'd say isnt very accurate. do you thin the point of the bullet is going into the threaded hole in the end of the cleaning rod giving you the difference between your two methods?

if i were you i'd buy a sinclair bullet comparator nut so you can measure the cartridge length to the lands which is where the bullet touches the rifling. measuring to the bullet tip is pointless unless you are trying to get them to magazine length. also if you use vernier calipers to measure as it sounds like you're doing already, remember to zero them on your comparator nut first

let us now how you go but i'll grab some of my ammo and get my measurements to help you out

Chronos

edit: what bullet are you using?

[Apollo]

For a start measuring from the Bolt Face is not a great idea, you will have some Headspace and a Cartridge Case does not necessarily sit back against the Bolt Face.

You have an error marking with a pencil, especially if the Barrel Muzzle Crown in not perfectly flat. Pretty hard to get an accurate measurement.

If you purchased a factory made Modified Case it will not necessarily be the same length as a case fired in your own chamber so another source of error. You can adjust for this if you have the Hornady OAL Gauge and measure both cases then make an adjustment to the measurements. Make sure the Modified case is sitting firm against the chamber shoulder. You can soot the shoulder to check that it is touching and where.

Are you measuring to the bullet tip and not the Ogive, another error especially if you change bullets or the tip is not perfectly even.

I don't have a .308W, yet alone a Remington so I can't even guess which dimension is close.

Using the Hornady gear it is normal to take a few different measurement attempts and make sure the readings are consistant. If you don't believe the longer measurement then seat a bullet in a case at that distance and see if the dummy round will chamber and you can close the bolt. If it closes then you are close, soot the bullet and chamber again. Be careful extracting and try to not let the bullet touch any part of the chamber on the way out, see if there are "land marks" on the bullet ogive.

If you are using a Magazine Feed you may not be able to load long cartridges anyway.

[cruze82]

AHH mate you hit the nail on the head the bullet tip is going into the tip of the cleaning rod so I just measured how much is going into the tip of the cleaning rod and added the measurement to my original measurement and it comes out to 2.982 the same as the hornady gauge

how did I miss this what a FAIL

I have a hornady bullet comparator as of today so will be measuring from the ogive from now on as the bullet tip method is very crude as they vary so much

but is the bullet sitting that far out of the case mouth ok it seems like it barley seats in

[Chronos]

AHH mate you hit the nail on the head the bullet tip is going into the tip of the cleaning rod so I just measured how much is going into the tip of the cleaning rod and added the measurement to my original measurement and it comes out to 2.982 the same as the hornady gauge

how did I miss this what a FAIL

I have a hornady bullet comparator as of today so will be measuring from the ogive from now on as the bullet tip method is very crude as they vary so much

but is the bullet sitting that far out of the case mouth ok it seems like it barley seats in

yeah that's a factor of the way the throats are cut compared to the sammi spec and the bullet you use

with a 150gr nosler BT in my .308 the COAL with the bullet touching the lands is 2.966" (a bit less than your measurement so your remmington may have a longer throat than my Tikka) and just .165" of the bullets parallel section in the neck, probably not enough to keep the bullet straight in the case during chambering. i load to my magazine max COAL of 2.810 leaving .156" jump to the lands. the advantage is at ADI 2208 max loads there's no sign of excessive pressure

Chronos

[Apollo]

Probably my most accurate rifle is a Stolle 6.5x47 Lapua using 130gr Berger VLD's and they aren't seated in the case mouth very far either but how far is not very far. When the rifle shoots better than 1/8 MOA I'm not complaining. I also use very little neck tension with bushing dies, about 0.0015" and you can push the bullet in by hand if you try.

Hope this photo is clear enough. My seating depth. The Bullet Bearing Surface Length into the Case Neck is 0.150" .

[Chronos]

Probably my most accurate rifle is a Stolle 6.5x47 Lapua using 130gr Berger VLD's and they aren't seated in the case mouth very far either but how far is not very far. When the rifle shoots better than 1/8 MOA I'm not complaining. I also use very little neck tension with bushing dies, about 0.0015" and you can push the bullet in by hand if you try.

Hope this photo is clear enough. My seating depth.

yeah but those are being carried around loose in your pocket, jammed into a magazine and pushed from the magazine uop into the chamber where thay may sit .020" off the lands. i believe if the OP is loading these for a hunting rifle then need to be more securely held. a couple of my rifles are the same but they're single loaded (6BR and .284W)

Chronos

[cruze82]

AHH mate you hit the nail on the head the bullet tip is going into the tip of the cleaning rod so I just measured how much is going into the tip of the cleaning rod and added the measurement to my original measurement and it comes out to 2.982 the same as the hornady gauge

how did I miss this what a FAIL

I have a hornady bullet comparator as of today so will be measuring from the ogive from now on as the bullet tip method is very crude as they vary so much

but is the bullet sitting that far out of the case mouth ok it seems like it barley seats in

yeah that's a factor of the way the throats are cut compared to the sammi spec and the bullet you use

with a 150gr nosler BT in my .308 the COAL with the bullet touching the lands is 2.966" (a bit less than your measurement so your remmington may have a longer throat than my Tikka) and just .165" of the bullets parallel section in the neck, probably not enough to keep the bullet straight in the case during chambering. i load to my magazine max COAL of 2.810 leaving .156" jump to the lands. the advantage is at ADI 2208 max loads there's no sign of excessive pressure

Chronos

That was my main concern it not seating deep enough to control bullet runout
I have loaded all my rounds to 2.810 with ADI 2208 at max load of 46grains and had no pressure signs at all, and at that load was the best accuracy I have seen in this gun just under .5moa
but I was wanting to play with bullet seating to see if any more accuracy could be squeezed out of this gun

I will have to get in the reloading room and make up a couple of dummy rounds !


Appoll - you made a very valid point that the modified case is not to the same spec as a once fired case so I gave them a measure to the sholder and they are identical
I have had a go nogo gauge in this gun and it was a tight chamber so kind of expected them to be similar
witch makes things much easier on the maths side

[Apollo]

The point was that the likes of 0.150" is sufficient to hold a bullet straight in the case neck. In fact it'a near half the full length of the case neck. They are 0.002" off the lands and if they were used for hunting loose in your pocket then all they would require is a tad more neck tension, maybe up to 0.0025-0.003". A tube magazine might be a different story.

My .243W Tikka Varmint with a number of different bullets that are used in it's magazine have even less bullet bearing length in the case neck, just a tad more neck tension. Other calibres like .223R or 204R might be even less again, all hunting rifles.

Plenty of times they have carried loose and jammed into a magazine.

[Apollo]

Controlling Bullet Runout might be a different story and in my view starts with the case itself and case preparation. Then seating methods and neck tension.

I don't bother measuring bullet runout in any case until after they have been once fired and prep work done again.

[Chronos]

The point was that the likes of 0.150" is sufficient to hold a bullet straight in the case neck. In fact it'a near half the full length of the case neck. They are 0.002" off the lands and if they were used for hunting loose in your pocket then all they would require is a tad more neck tension, maybe up to 0.0025-0.003". A tube magazine might be a different story.

My .243W Tikka Varmint with a number of different bullets that are used in it's magazine have even less bullet bearing length in the case neck, just a tad more neck tension. Other calibres like .223R or 204R might be even less again, all hunting rifles.

Plenty of times they have carried loose and jammed into a magazine.

i'd be careful loading a bullet with less than half the caliber dimension (say .150" for a .308) of bearing surface in the case neck but that's just my opinion

as you say it may be less for smaller calibers but i'd say a similar percentage of the caliber, might only be .150" for a .204 but thats a lot more than 50%

Chronos

[cruze82]

ok same pic to show how deep in the neck it is

[Chronos]

ok same pic to show how deep in the neck it is

or isn't

Chronos

[Apollo]

Now that IS a shallow seating depth and in my opinion not usable.

Think I'd go a bit further but not much, depends on your purpose. The way you are describing things it sounds like it's more target than anything else. If target then all you need is to hold that bullet at the seating depth off or in the lands that provides the best accuracy. Concentricity then becomes a matter of achieving the best consistant accuracy amoungst other sorting practises.

The only .308 I have is a 30BR and they are 115gr Flat Base, seating depth of bearing surface is about 0.120" and in the USA these are used for hunting. They are seated to jam but only just, if I seat say 0.040" jam all that happens is the bullet is pushed back into the case neck to my original seating depth which is a 0.010" jam. BTW, tried many and none stick in the lands.

[Warrigul]

ok same pic to show how deep in the neck it is

I have come across this twice with Remington chambers, the chamber is nice and tight but the throat is comparatively deep. This does allow you to use round nosers if you ever want to but is a pain for some HPBTs. I know of one bloke who had the barrel set back and rechambered simply to get around this issue(which really isn't an issue in the big scheme of things, especially hunting).

There was minimal difference in running the projectile .040" off the lands so we ran the cases close to max length and seated them a bit deeper to give .040" jump and it looked much better.

At the time the 155 grain Dyers were a slightly better fit and out performed the 168 grain sierras out to 600 but the owner wanted the 168 grainers(he had a few).

For the second rifle as it was only an occaisonal target rifle and mainly a hunter I ended up "LEE factory crimping" the round at a proper depth down the neck and it was more than accurate enough to be competitive in out local comp. The Lee factory crimp will often give the same consistant pressure start that being seated close to the lands does, without all the fiddling.

Bewary of land jam if hunting, one day you will get a sticker to ruin your trip. They may not jam in the lands when checked on the bench but with a bit of heat and some fouling in the barrel it is a different story.

[cruze82]

Your right this is a target load i'm playing with and all will be single fed and none of these rounds will be floating around in my pocket

I think i'm just going to have to work my way out from 2.810 in 0.020 increments and find a accuracy node with a decent amount of bearing surface

I hate load development so many trips to the range !!!

[Apollo]

I hate load development so many trips to the range !!!

Your too far away to offer to borrow mine, it's just outside the front door....

Point noted "Warrigul" and I don't ever jam bullets but this is an experiment with load development and to the same point the reason I'm even trying an extra 0.002" neck tension. The reason here is that I'm getting a flyer ever half dozen shots and have not isolated the reason. It's not the rifle and I'm pretty sure it's not me but something with this new barrel. I'm talking 200m Benchrest Score Shooting where I get that ocassional shot that strays about 2-3mm off target.

Like the point about the Lee Factory Crimp Die and I have several. Best example I have is how much it improved accuracy with a .22 Hornet giving that pressure boost that you can't get with any extra neck tension and these thin necked cases.

[on_one_wheel]

ok went and purchased a hornady coal gauge with modified case today and iv hit a huge wall

here is the issue, the way I have been measuring overall length before was with a cleaning rod down the barrel so it touches the closed bolt face then I would mark the cleaning rod then I would select the projectile (168g sierra) and use a pencil and push it in till it touches the lands and mark the cleaning rod again.
this gave me a measurement of 2.8020 so I think to myself its 20 thow over recommend seating length as the reloading manual tells me

so today I get home and try out my new hornady gauge I follow the instructions and watch some youtube videos and I get a really long oal 2.982 now at this length the bullet barley seats into the case mouth where has all this gone wrong ?

BTW this is in my Remington 700 sps varmint

On the topic of COAL...

By no means am I a expert in the field of reloading but in the absence of any precision measuring equipment made specifically for measuring your JTL ? ( just touching lands ) I used this technique,

Take a fired shell ( from your own rifle ) and put a small depression in the top of the neck opening making a very slight D shape.

Put the type of projectile you are going to use just inside the neck and "smoke" it over a candle till the whole projectile is neatly covered in black soot.

Carefully chamber the round with the bolt fully closed being careful not to rub off any soot in the process, then gently lift the bolt handle and slowly extract the round making sure you grab it by the brass on the way out not to mark the soot or disturb the projectile.

Inspect the projectile, you should be able to see the 5 or so marks made by the start of the rifling around the projectile where it touched the lands. Look at where the projectile meets the brass neck and make sure there is not a clean mark where the projectile has been pulled forward by being slightly stuck in the lands.

If there is no whiteness mark left from the projectile being pulled forward, and you can clearly see the marks left by the lands take your vernier calipers and measure your COAL

Repeat the process many times, I did it about 20 times, re smoking the projectile every time and recording your measurement each time. You will see a pattern appear with some measurements coming up time and time again, and the odd one plus or minus a fanny hair or two.

I am confident this method gave me a very accurate measurement of my COAL @ JTL

With my currant choice of projectile, my JTL is 68.1 mm, I originally pressed my projectiles in to give me a jump of 0.2mm but later opted for a safer jump ( greater margin for error ) of 0.5mm making my cartridge over all length 67.6mm

[Gregg]

they aren't seated in the case mouth very far either but how far is not very far. When the rifle shoots better than 1/8 MOA I'm not complaining.

I've met a bloke or two in my time that was adamant you had to have the whole neck contacting the bearing surface, makes the COAL very short obviously. No where near the lands.

Couldn't convince them otherwise, even though there accuracy was pretty ordinary no interest in trying anything longer. "hunting accurate" was the defence.

Rubbish IMO.

[Lorgar]

On the topic of COAL...

By no means am I a expert in the field of reloading but in the absence of any precision measuring equipment made specifically for measuring your JTL ? ( just touching lands ) I used this technique...

Why I like my Tikka... The "right" seating depth is what will fit in the mag, no testing required

I hate load testing these days

[Apollo]

I bet you hate "load testing" especially when you see them all land in that same little hole. Bummer, where did the rest of them go....

The best value piece of reloading gear I bought would have to be the Hornady OAL Depth Seating Gauge, especially when I found out the neighbour had a nice small precision Lathe to make my own Threaded Custom Gauge Cases with.

[cruze82]

ok the more research I do the more I find out that most rems have a long thought like warrigul was saying, its so they can take round nose rounds

So I have cracked the sh&#! and its going into the gunsmith!
it was already booked in for blueprinting in 2 months time but I can see some more work being done

before I get "why don't you just buy a Tikka" its one of those Holden Porch things I like to roll up to the lights and let my old HQ blow the fancy car away! no matter what I had to spend but they don't have to know that
I just love my Remington's

[Chronos]

ok the more research I do the more I find out that most rems have a long thought like warrigul was saying, its so they can take round nose rounds

So I have cracked the sh&#! and its going into the gunsmith!
it was already booked in for blueprinting in 2 months time but I can see some more work being done

before I get "why don't you just buy a Tikka" its one of those Holden Porch things I like to roll up to the lights and let my old HQ blow the fancy car away! no matter what I had to spend but they don't have to know that
I just love my Remington's

LOL like you could ever compare a modern Remington to a HQ :p

A tip, supply a dummy round to your gunsmith made up using your preferred billet and have the smith cut the throat to suit.

Good luck with it.

Chronos

[Apollo]

I think the big fingers, spell check got that one...