Of cannelures, ogives, lands, and OALs

[taliv]

yep, the inconsistency is on the very tip itself.

stoney point sells a popular reasonably priced tool to do that, slv. sinclair sells some pricier versions

this is the one i use
http://www.sinclairintl.com/cgi-bin/category.cgi?category=RESDTSD&item=59-4000&type=store
http://www.sinclairintl.com/cgi-bin/category.cgi?category=RESDTSD&item=09-4X&type=store

(edit: i don't know what's up with the "new style" "old style" crap... but mine looks like the combination of the two pictures you see there... the rod with two stops on it, and the nylon slider that goes over the rod and has the little metal shaft sticking out the side)

 

[USSR]

Cool tool, that comparator, but how do you get an exact measurement of your chamber from boltface to lands? You would have to know this in order to know your ideal measurement on the comparator. I had a friend tell me to seat a bullet by closing the chamber, but that seems somewhat crude.

Again:

<SLV>,

If you don't already have it, buy the Stoney Point/Hornady OAL Gauge and a modified case, and determine just exactly where your throat is. Having your bullet .010" to .015" off the lands is a good place to be.

Don

 

[redneck2]

Easy and cheap answer to "bullet on the lands"

1)..As mentioned, cut a case on each side of the neck down to the shoulder with a dremel.

2)..drill the flash hole out large enough so the blade of a pocket screwdrive fits thru it

3)..seat a bullet out too far out

4)..open the action and insert the round with your fingers

5)..using the screwdriver against the outside rim, push the case tight into the chamber, then put the screwdriver thru the hole and gently push the bullet forward to the lands

6)..remove the round with a cleaning rod

I put nail polish on it to lock the bullet in place. You now have a bullet that seated at .000". Use this to set your bullet seating die. (Check OAL to make sure the bullet doesn't move) . Keep this dummy bullet round for reference.

FWIW...there are a lot of useless toys for reloading. The Stoney Point gauge is one of the best investments I've made

 

[Khornet]

The Sinclair tool

is simple, reliable, repeatable. That plus one of their comparators will give you precisely loaded ammo. AND you don't have to get "specially modified" cases to do your measurement. Instead you use a case fired in YOUR rifle.

IMHO those tools are a basic necessity for those wanting to load rifle ammo. Not too spendy, and they last forever. Saves a lot of wasted time on trial and error.

As the years take their toll on my 03A3, I repeat this measurement from time to time, and have been able to see how erosion has slowly increased the length to touch the lands.

As for the soot-on-the-bullet trick, I've tried it several times on various guns and never found it to work.

 

[azar]

redneck2,

Thanks for sharing your method of measuring the o.a.l. without using an o.a.l. gauge. It's similar, but a little different (aren't they all), from others I've heard.


Khornet,

I'm glad I'm not the only one who hasn't gotten the soot / dry-erase marker trick to work! I felt pretty stupid after trying multiple times across a couple of different evenings.


For those of you who have bullet comparators and o.a.l. gauges. which one would you recommend? The Sinclair or the Hornady, and why?

 

[taliv]

seemed like khornet explained it pretty well. the sinclair tool does not require special cases, which means it works in any gun, any caliber with no fuss.

 

[azar]

taliv,

There's no difference in accuracy without the special cases? Sorry if that's a noob question...

 

[Bullet]

ny32182
Can I get an exact definition of ogive, meplat, and/or any other dimensions that might be useful to know about? A diagram, maybe?

From SAAMI’s Glossary -

OGIVE
The curved portion of a bullet forward of the bearing surface.

http://www.saami.org/Glossary/index.cfm

 

[Bullet]

While this is not what you asked for you might consider this (copied from another forum)-

“There are some pretty universal rules about seating a bullet. You first seat the bullet to a given depth and then work up with the charge. To do otherwise might lead to a pressure excursion. Do you know how to read pressure in a rifle case??? If the radius of the primer is gone,the bolt lifts hard,you can see the extrusion of brass back into the elector hole,see the machine marks on the bolt face in the brass or the primer flat falls out of the case the load may be a bit hot. BUT, this can and will happen regardless of where the bullet is seated if you tip the powder bottle too much. Here's a very easy way to develope a load:
1)-Set the bullet into the lands(if you can reach them) as much as the neck tension of the case will allow.
2)-Start with a minimum listed powder charge-10% for the bullet weight
3)-Work the powder charge up till the groups get as small as they will get.
This depends on the rifle.
4)-After getting as small a group as the rifle will shoot at the jam,back the bullet off.002/.003 at a time and see if the groups improve.Depending on the rifle they may or may not.
5)-If you decide on trying another bullet back the powder down and go back to the jam length and start again.
What this saves is guesswork. If the bullet is seated HARD into the lands then the only way to go with it is shorter. If the bullet is seated HARD into the lands and you have a safe working load pressures will NOT increase as the seating depth is shortened. If you, at any point,. get pressure signs, STOP. Back off the powder and start up again and see if it repeats. Be aware that a load shot at 70 degreesF. may not be a safe load at 100 degrees F.Back a load off when you change ANY part of that load including changing lots of the same brand of powder. Never assume anything;prove it to yourself. There is not really a lot of rocket science in rifles; experience is much more important”

 

[taliv]

2)-Start with a minimum listed powder charge-10% for the bullet weight

i've always started with the minimum OR the maximum -10%.

There's no difference in accuracy without the special cases?

dunno. with the sinclair tool, there's not really a question because you're using the brass you're going to be shooting.
with the stoney point tool, i guess there's a question but i've never heard anyone complain about it, so I really doubt there's an issue. afaik, like most things in reloading, it's ease of use vs cost

 

[Bullet]

2)-Start with a minimum listed powder charge-10% for the bullet weight

taliv
i've always started with the minimum OR the maximum -10%.

I believe that is what he meant. Probably should have said -

2)-Start with a minimum listed powder charge or -10% for the bullet weight

 

[Khornet]

For a $50 investment

in the Sinclair tool and comparator, you'll get a useful set of tools that you'll be able to use on multiple guns for decades. Very handy when changing bullets or guns. You can do just fine without it, but it really adds to the fun.

 

[USSR]

Here's a very easy way to develope a load:
1)-Set the bullet into the lands(if you can reach them) as much as the neck tension of the case will allow.

I realize that these are not your words, Bullet, but IMHO, starting out load development by jamming your bullet into the lands is downright dumb and potentially dangerous to someone who doesn't know what they are doing. There are basically two scenarios that you find in load development in rifles: 1. the throat is located beyond what the magazine length is (so load to an OAL to fit the magazine); and 2. the magazine is long enough to accomodate an OAL that will reach the throat (so play with OAL's that vary from .010" to .020" off the lands).

Don

 

[Bullet]

USSR
IMHO, starting out load development by jamming your bullet into the lands is downright dumb and potentially dangerous to someone who doesn't know what they are doing.

I don’t think working up a load from jam is dumb and that reloading could be potentially dangerous to someone who doesn't know what they are doing. But you still might have a valid concern. Maybe starting at jam should be left to experienced reloaders.

<SLV> and any other new reloaders reading this - I wish I had a place like THR to ask questions when I was starting to reload. If you’re not sure about something ask questions here. I’m sure you will get some good advice, and remember, there are no dumb questions.