Acceptable COAL tolerances?

[HuntHarder]

So I am fairly new to reloading, and I am curious as to what most think are acceptable COAL to maintain good accuracy. I have noticed that even measuring berger bullets, I can get anywhere from .000-.008 difference in overall length. So I did a little research online and found a Hornady comparator.

Do any of you use a comparator to achieve optimal accuracy? Most people say that measuring COAL is not near accurate enough and the use of comparator is needed to achieve accuracy. What are some of you more experienced reloaders using?

 

[muledeerarea33?]

Case volume is the biggest factor as well as bullet weight in my opinion. If your using a dedicated O.A.L, tool you shouldn't see more than .005 +-

as long as your arm is consistent on the press. Spitzers will give different measurements due to deformation of the lead tip. As will lead cast if you press too hard on your measuring device of choice. I try to load per case volume and bullet weight and then group by my oal.

[Chimichanga]

Try the hex nut bullet comparator from Sinclair intl or midway. Let's you take your measurement from the ogive. (It's the same idea as other bullet comparators). I haven't been reloading a long time but this is what I have gathered from hours and hours of reading forums and picking peoples brains.

[rcdinaz]

You didn't say if you were measuring the bullet at the ogive or not, assuming you were measuring to the tip then yes the bergers have a very small amount of difference due to the bullet jacket swag at the tip.

 

The Hornady or Stoney point gauge works well and measure from the ogive you will have to make sure you have the right gauge for your caliber. One other recommendation, if you are using VLD bullets you should have a VLD seating stem a standard seating stem will cause the bullet to rock to one side much of the time.

 

I often load all the rounds longer than desired and then go back and do final seating measuring to the required OAL and checking with my calipers. I do this even with a micrometer seating die. I would not do this with varmint loads but I do with final loads for big game.

[IA Born]

I don't load Bergers, but I use a Hornady gauge with the comparators for my Barnes TSX and TTSX bullets. I won't reload without it. Like others have said, it measures off the ogive of the bullet and gives you much more consistent measurements. Its not the true OAL since its from the ogive, but its far more consistent than the tips of bullets, which, as others have said, can be smashed if you use too much pressure on soft-nosed bullets. IMO and from my research and experience, seating depth plays just as much of a factor in customizing loads to get the most accuracy. I've tightened up various loads just by adjusting the seating depth of the bullet.

[rossislider]

I have noticed a pretty substantial difference between when I used COAL and now using the Hornady comparator. I also load with Bergers which I have found can be a bit tempermental when talking distance off the lands. Go with the comparator, you will improve you accuracy.

[DesertBull]

If you are trying to measure coal from the tip of the bullet you drive yourself batty. Get a comparator and the hornady overall Length guage. With modified case. This will allow you to measure where your bullet is in relationship to the lands of your barrel. Berger bullets tend to be most accurate very close to or into the lands.

[Nmhunter]

the ogive measurement will give you the true length for chambering the round ( hint: off, touching or into the lands of the the barrel). the OAL will give you the max measurement that can be used in the magazine of your gun. the OAL will not be useful or necessary l if you are shooting a single shot such as a ruger #1, XP-100 or encore.

nmhunter

[HuntHarder]

Thanks for all the info guys. Kind of what I was thinking most would say, but I recently started shooting longer range and notice that my reloading needs to be top notch in order to achieve my desired results.

 

So I use RCBS full length dies, and have a question regarding them. I set my seating depth, and have achieved accuracy to my standards without using a comparator ( current set is right at .50 MOA). Do most of you guys check your ogive measurement, then adjust your seating die every round? Seems like this is going to really lengthen my reloading time if this is the case.

 

Is the VLD seating stem a new stem I can replace the RCBS one with that came with my seating die?

 

I seated my bullets to my maximum magazine length, and my gun seems to love them. Just like most said, I was kinda going nutty doing a COAL measurement after I had loaded 50 rounds. My gun shoots great, but in the back of my mind, I know that my COAL is or can be .008 different than the previous round I just shot. I might be over thinking this....

 

In the past, my reloading has consisted of less than an inch @ 100, I am good with that. Now that I am into this long range stuff, I think I am over-thinking it..

Thanks guys,

[DesertBull]

I purposely seat my bullets a few thousandths long then measure, then adjust die down to get the exact seating depth I want. A micrometer seating die helps but not mandatory.

 

Yes I measure every round for seating depth. A typical shooting session for me is 15 or so rounds because I let the barrel cool between each shot so leading 15 rounds in this manner does not take too long.

[pwrguy]

I have been getting excellent results MOST of the time without messing with a comparator. Don't get hung up with coal. If you are using a good quality seating die you are going to get good results by setting the seating die to a proven coal and just loading the whole lot without measuring anything else if your seating die is hitting the same spot on the ogive for every bullet. Do make sure you keep your seating die nice and clean or you will get some shaky results.

[muledeerarea33?]

I have been getting excellent results MOST of the time without messing with a comparator. Don't get hung up with coal. If you are using a good quality seating die you are going to get good results by setting the seating die to a proven coal and just loading the whole lot without measuring anything else if your seating die is hitting the same spot on the ogive for every bullet. Do make sure you keep your seating die nice and clean or you will get some shaky results.

as long as your arm pressure is consistent this is a great and cheap alternative to buying all the other stuff. I still use a case length gauge though for my hunting and target stuff.

[HuntHarder]

Well I got my comparator, and checked my previously loaded rounds. I must have a consistent arm throw. Over 86 rounds, My deviation was .002. With about 70 being all the same. I do not know if .002 will really make a difference, but I am going to use those to practice with first, and use the ones that were all the same for hunting.

 

Here is another question for you guys. I ordered my new turret for my new load, and was curious what an acceptable deviation in Muzzle velocity was. Thru 16 rounds, I had an extreme spread of 26 fps and most were within 13fps of each other.