forster seating die rocks !!!!!!!!!!!!!!!

[black_ump]

I have the forster mic seating die and it rocks but iam curious about something. I dialed the die to 2.800 dead nuts, then the next one i seated was 2.7998 so i brought it back up .002 then the next one was seated at 2.8003, i have had a +/- .005 fluctuation.

Well i stopped and though about it, and i think trimming the meplat and then sorting bullets by length would yield better results but is their a better easier way ( i down own a meplat trimmer) ?

out side of that, I am loving this die, oh and I am shooting 308

 

[token5gtd]

Re: forster seating die rocks !!!!!!!!!!!!!!!

been a lurker for a while, and i have an answer for you!

look into buying a hornady or sinclair bullet comparator (the one that attaches to your calipers) it measures the OAL from the ogive instead of the tip.

i had your same problem when i started reloading pre-comparator... my OCD and i would fiddle with the seating depth of each bullet to get them exact, then discovered later that my groups were slightly tighter when i just left the seating die alone, since it seats from the ogive, not the tip.

other than going ahead and buying the comparator, just don't worry about it that much. set your first round where you want it, and check about every 5th after that. as long as you're within about .003", you can account the difference to the tip.

 

[MinorDamage]

Re: forster seating die rocks !!!!!!!!!!!!!!!

token is correct. The distance from Ogive to tip varies even on match bullets. Because the die is seating the bullet off the ogive, you will have the same base to ogive measurement for each round, but the COAL may differ based on variations in the ogive to tip measurement on the bullet.

Josh

 

[black_ump]

Re: forster seating die rocks !!!!!!!!!!!!!!!

thanks for the heads up, my "aero/space" machining skills take over when i work with things that i feel are "tight" tolerances. sorry about the "freak out".

any one have a link to the bullet comparator thing so i know what iam looking for

 

[dpreston]

Re: forster seating die rocks !!!!!!!!!!!!!!!

you ask and you shall recieve

http://www.sinclairintl.com/.aspx/pid=36535/Product/Hornady_LNL_Comparator_Body_w__14_Inserts

 

[Fuzzball]

Re: forster seating die rocks !!!!!!!!!!!!!!!

"It uses some place on the Ogive."

ALL seaters work off the ogive.

There hasn't been a rifle yet made that cares where a meplat hangs in empty space, all that matters is the bullet jump to contact the rifling and that doesn't matter within a few thou one way or the other.

 

[black_ump]

Re: forster seating die rocks !!!!!!!!!!!!!!!

so the 2.800 is measured off of the ogive then ? not the tip of the bullet correct ? just wanna make sure I am following you correctly

 

[black_ump]

Re: forster seating die rocks !!!!!!!!!!!!!!!

just checked out a video on this on youtube. my new question is the OAL for 308 is 2.8" is that 2.8 from the ogive ? I think it is and thats interesting how ever since iam loading for a semi auto 2.8 might be ( if from the ogive ) long since the round has to fit in a magazine, seems if i have to go from the ogive i will be seating the bullet in a little further.

I was confused but then just watched another video where their is an OAL and then their is a comparator OAL. so my question is, if the OAL is 2.8 on 308 what would that measure using a comparator ? I am guessing around 2.3 or 2.2 ish

 

[vman]

Re: forster seating die rocks !!!!!!!!!!!!!!!

ohhhh im not at home so cant double check so dont quote me... but i think I run my rounds at about 2.335 from head to ogive.

It may have changed as i have recently started kissing the lands so it might be a bit longer.

But in regards to the forster ultraseater... I love mine

 

[MinorDamage]

Re: forster seating die rocks !!!!!!!!!!!!!!!

NO! 2.80" will be the COAL. Most reloading manuals, if not all, list these numbers as a general guideline for length. As we discussed earlier, a COAL with some variation is fine. However, the seater is seating off the ogive. The bullet comparator will enable you to figure out the base to ogive dimension for a loaded case. Here is what you really need to do to make good ammo.

1. Get the Hornady Overall Length Gauge. Click Me! This allows you to figure out what the measurement is from the base of the case to the lands. You will insert whatever bullet you are planning to shoot into a modified casing, place it into the chamber, push the bullet forward until it contacts the rifling, remove, and measure.

2. Once you remove the OAL gauge, you could measure from the base to tip to get a COAL. Instead, use the bullet comparator on a caliper and you can obtain your base to ogive measurement. It should be somewhere in the 2.3-2.4 range or so. Each throat is different.

3. Once you have the base to ogive dimensions for YOUR rifle, you can then set up your dies and find out how far off the lands your bullet prefers to sit. Attempting to load 308 to 2.8" base to ogive would give a COAL in the neighborhood of 3.25". That is not correct. Again, base to ogive should be somewhere around 2.3-2.4". COAL will vary from there.

Good luck,
Josh

 

[black_ump]

Re: forster seating die rocks !!!!!!!!!!!!!!!

ok sounds good, I will write this info down in my book, thanks for the heads up

 

[black_ump]

Re: forster seating die rocks !!!!!!!!!!!!!!!

ok well since we are on this comparator question, you guys mention measuring the bullets before loading them. what should sierra 175 and 155 smk's normally measure and how much variance would you allow ? what about sierra 110 jhp's ?

 

[clmayfield]

Re: forster seating die rocks !!!!!!!!!!!!!!!

Here are some quick instructions:
http://blog.sinclairintl.com/2010/02/19/bullet-prep/

If you buy a bullet comparator, it should come with instructions as well.

 

[MinorDamage]

Re: forster seating die rocks !!!!!!!!!!!!!!!

black_ump,

My best advice is to find an experienced reloader somewhere in your area. Talk to people at the range and figure out who does this stuff for precision. Get up with them and have them help you with the basic process. I'd be open to doing so, but the trip from Cali to PA is a little prohibitive.

Josh

 

[black_ump]

Re: forster seating die rocks !!!!!!!!!!!!!!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MinorDamage</div><div class="ubbcode-body">black_ump,

My best advice is to find an experienced reloader somewhere in your area. Talk to people at the range and figure out who does this stuff for precision. Get up with them and have them help you with the basic process. I'd be open to doing so, but the trip from Cali to PA is a little prohibitive.

Josh </div></div>


ill have to gas up the private jet

 

[black_ump]

Re: forster seating die rocks !!!!!!!!!!!!!!!

so according to the diagram at this link the ogive to the back of the casing length should be 2.1835" correct ? I cannot seat to the lands because of my g3 rifle mags so I would like to stick to a 2.8" oal and then if need be play with it from their

http://en.wikipedia.org/wiki/File:Cartridge_308.PNG

 

[Placebo]

Re: forster seating die rocks !!!!!!!!!!!!!!!

Thanks everyone who chimed on here as I learned alot by reading through. I was still miffed about the comparator until i saw it connected to the calipers in that pic on the sinclair blog. Hit me like a brick, now I totally understand. A pic actually is worth a thousand words.
Thanks for helping me also with this thread

 

[MinorDamage]

Re: forster seating die rocks !!!!!!!!!!!!!!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: black_ump</div><div class="ubbcode-body">so according to the diagram at this link the ogive to the back of the casing length should be 2.1835" correct ? I cannot seat to the lands because of my g3 rifle mags so I would like to stick to a 2.8" oal and then if need be play with it from their

http://en.wikipedia.org/wiki/File:Cartridge_308.PNG </div></div>

Seriously, you should not be going off the diagram from wikipedia. It is strictly generic and you need to figure out what your rifle wants and can handle.

1. Get the OAL gauge
2. Figure out you base to ogive dimension
3. Start at the base to ogive seating depth than gives you around 2.8" COAL
4. Work from there until you hit max mag length or touch the lands, whichever is first.
5. Stop using generic diagrams from the internet
6. Invest in the proper tools to get the job done
7. Find a reloader to help you

Josh

 

[black_ump]

Re: forster seating die rocks !!!!!!!!!!!!!!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MinorDamage</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: black_ump</div><div class="ubbcode-body">so according to the diagram at this link the ogive to the back of the casing length should be 2.1835" correct ? I cannot seat to the lands because of my g3 rifle mags so I would like to stick to a 2.8" oal and then if need be play with it from their

http://en.wikipedia.org/wiki/File:Cartridge_308.PNG </div></div>

Seriously, you should not be going off the diagram from wikipedia. It is strictly generic and you need to figure out what your rifle wants and can handle.

1. Get the OAL gauge
2. Figure out you base to ogive dimension
3. Start at the base to ogive seating depth than gives you around 2.8" COAL
4. Work from there until you hit max mag length or touch the lands, whichever is first.
5. Stop using generic diagrams from the internet
6. Invest in the proper tools to get the job done
7. Find a reloader to help you

Josh </div></div>

or i could just save time and money and start buying fgmm ammo and be done with it.

all of this is just confusing and frustrating me to be honest seems like every time i turn around i need another and another and another tool.

And on top of that I dont even know if the dollar to accuracy ratio is even worth, all this money into all these little do dads for what ? .005 tighter groups ?

Dont mean to yell and i do enjoy your helpful info and tips I am just starting to get over whelmed with all this.

 

[vman]

Re: forster seating die rocks !!!!!!!!!!!!!!!

black_ump, believe me, starting out in reloading sux.

You could literally purchase a custom rifle with the cost of buying all of the tools and equipment to reload. But in saying that IF you did spend the money on it, as many of us here have you have to consider what is worth more to you...?

1) having an extra rifle in the safe... keep in mind you only hand two hands
2) spending the money on factory ammo which wont last you all that long
3) spending the money on the reloading equipment, which after a short amount of time quickly becomes absorbed after you have realised you can now load THE BEST ammo for your rifle for a fraction of factory costs.

Still stumped about seating dies and ogive lengths????

I will add my two cents...

The comparitor tool allows you attach a comparitor insert that matches the diameter of the bullet ogive you are interested in. In this case i will use the .30cal, or .308 example.

If you look at the anatomy of a projectile you will notice that the "bearing surface" or part of the bullet that is actually .308 in diameter, only makes up a portion of the bullet. The rest of the bullet consists of a boat tail (in some cases) and a nose portion. Now, without getting too technical there are two common types of "noses" on most match projectiles. The secant ogive and the tangent ogive... this just refers to the shape of the nose be it more rounded, or more triangular in shape. At the tip of the nose you have the smallest diameter, however at the back of the nose at its largest diameter you have the OGIVE, which in this case is a .308 ogive.

It is at the ogive where bullet seating occurs when you press that ram handle down. If you could look inside of a seating die you will notice that the seating stem is designed in a way that it allows the nose of the bullet to pass up, but stops the bullet from traveling up any further into the die once the ogive diameter of .308 meets the seating stem.

This means that regardless of the length of projectile be it a little longer or a little shorter, they are get seated from the same spot. So technically speaking if you had two 155 grain projectiles and one had a slightly longer bearing surface, that longer bearing surface would push back into the case neck and reduce the internal case volume. From the outside, both loaded rounds would look the same because they are seated at the same distance from the start of the ogive.

This is why its important to use a comparitor if your taking measurements and trying to be precise. The head to ogive length will rarely be that far off between measurements, however the projectiles themselves can sometimes be longer or shorter in the nose and if you take that into your measurements your more than certain to get measurements which are varied in length.

 

[black_ump]

Re: forster seating die rocks !!!!!!!!!!!!!!!

ok i understand that. so i need to measure both base to ogive and sort them that way and then when i seat bullets i need to measure from ogive to the back of the casing where the primer sits.

well now that i got all that seeping into my brain i would like to start my coal at 2.8 so what would that translate to measuring off the ogive ?

 

[MinorDamage]

Re: forster seating die rocks !!!!!!!!!!!!!!!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: black_ump</div><div class="ubbcode-body">well now that i got all that seeping into my brain i would like to start my coal at 2.8 so what would that translate to measuring off the ogive ? </div></div>

Not sure. It is based on the projectile you will be shooting. Some bullets have a longer ogive length (see pic below). You will have to determine where the ogive and bearing surface junction (the bullet's shoulder) needs to be to give you the correct length. Some projos have a short ogive length, others long. So, even if you seat to the same seater setting, a bullet with a longer ogive length is going to make a cartridge with a longer COAL.

Now that you understand the bullet anatomy, I made a picture for you (see below). Remember, the seater is going to push every bullet, no matter how long or short, to the same base to ogive length. Assume these three things:

1. You have your seater set to a base to ogive distance of 2.3"
2. You have some short fat bullets
3. You have some long sleek target bullets

If you seat both types of bullets to the same base to ogive length, the COAL for the short projos could be up to 0.1" shorter or more than the target loads. So, with base to ogive for both bullets being 2.3", the COAL for the short projos could be 2.75" and the target bullet COAL could be 2.9".

See how this varies? This is why everyone talks about never being able to tell you what will work exactly for each different rifle.

1. The OAL gauge and a bullet comparator we talked about will help you find the maximum base to ogive length for your chamber.
2. From there, you can use the bullet comparator to ensure your seating depths are consistent. It will give you the ability to measure loaded rounds from base to ogive which will give you the most consistent data.
3. Use the reloading manuals to start. Each bullet will specify a different initial COAL. short ones will naturally be shorter than VLDs. Once you find a powder node, you can then start to experiment with seating depth.

Josh

 

[black_ump]

Re: forster seating die rocks !!!!!!!!!!!!!!!

thanks for the heads up, i will be working with both 155 smk's and 175 smk's.

so according to this what it seems i need to do is load a 175 smk to 2.8 and then use the comparator to get the ogive measurement then do the same for the 155 and write those numbers in my book then

 

[Timo Turl]

Re: forster seating die rocks !!!!!!!!!!!!!!!

tag

 

[MinorDamage]

Re: forster seating die rocks !!!!!!!!!!!!!!!

Exactly.

Josh

 

[vman]

Re: forster seating die rocks !!!!!!!!!!!!!!!

black_ump to make things simple I go by the principle that if its near the lands it will shoot better than if it wasnt. For that reason I have set the micrometer on my Forster Ultra seater so that "0" reads my exact head-ogive shoulder length.

I did that by taking a reading in my rifle using the hornady tool and comparitor. I then write that number down.

Set up your die so that its screwed down and the micrometer is on zero and the ram height it at the top and you have the required tension on the sleeve (its a preference thing). I like to have my sleeve stick out a bit so that I get a good feel of the seating process. Back out the seater stem all the way by screwing it upwards. Put an empty case and projectile in the ram and put it in the seater die. Turn the seating stem back down until you feel it contact the projectile, which will lightly seat the projectile.

Measure that projectile and compare it to your "zero" reading you obtained from measuring your rifles OAL. Adjust the seater stem down and reseat that same round until it reaches the same value as your rifles OAL. Once this is down lock down the top of the seater stem, and your die is now zeroed. If the micrometer is reading on the line at zero you will seat projectiles that will meet the lands on your rifle. Doesnt matter what the projectile is as long as its got enough bearing surface to be seated out far enough to the lands, your die will put it in the right place.