Off the lands question

[Placebo]

Here is my question. I am trimming Hornady brass case to 2.010 for my Rem 700 VTR in 308. CCI BR2 primer and 42.4 varget to push 168 gr AMAX. COAL is 2.824.

Well i have been reading how to find your COAL when jammed to the lands. Well i barely seated a amax bullet in casing and put it in my rifle locking the chamber. I extracted the round and it measured 2.934. So i assume this is the length to the lands. If i load the Amax at 2.924 it would be .010 off the lands. I guess my question is do these numbers sound extreme or right on for the Amax due to the plastic tip.

Thanks in advance.
P

 

[McLarenross]

Re: Off the lands question

Im not sure with the 168 A-Max but in my factory Remington chamber with 178 A-Maxs touching the lands is 2.960". Factory Remingtons are long throated generally.

 

[Placebo]

Re: Off the lands question

Thanks. So do you load with a COAL of 2.95?

 

[MitchAlsup]

Re: Off the lands question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Placebo</div><div class="ubbcode-body"> Well i have been reading how to find your COAL when jammed to the lands. Well i barely seated a amax bullet in casing and put it in my rifle locking the chamber. I extracted the round and it measured 2.934. So i assume this is the length to the lands. If i load the Amax at 2.924 it would be .010 off the lands. I guess my question is do these numbers sound extreme or right on for the Amax due to the plastic tip.</div></div>

If the measurement can be repeated with 0.002 accuracy at least three times, then its a good measurement.

2.934 sound about right for a 308 Remmy. In my case I measure 2.963 for a 155 Scenar, and load then to 2.948 to give a 0.015 jump.

 

[MinorDamage]

Re: Off the lands question

Taking a COAL measurement is asking for trouble. Bullets vary from ogive to tip and you may end up loading them closer or farther away than you think. Mitch is correct about doing it a couple times and make sure you are within .002 (although I contend you need a micrometer for this. Caliper measurements can be off).

So, get a bullet comparator like Hornady's LnL type. That will allow you to meaure base of cartridge to ogive. With that info, you can load different bullets and never have to wonder if they will touch the lands, be jammed, etc. Remember, the ogive is what is going to contact the lands, not the tip. Take the measurement off the ogive and thank yourself later.

Josh

 

[Tripwire]

Re: Off the lands question

Black Magic Marker....and skip the guessing part.

 

[Placebo]

Re: Off the lands question

Thanks everyone for chiming in. I really appreciate it.

 

[Tripwire]

Re: Off the lands question

Paint that bullet black with a marker, then back the COAL off until you SEE it just barely contacting the lands.

There's your starting point. With micrometer comp dies it's a no brainer to then set your seating depth wherever you want. If you don't want the micrometer comp dies then you need a comparator.

Forget about using the COAL, whatever it ends up being, as your set-in-stone reference point, the true measurement is where the ogive contacts the lands minus whatever jump you end up with.

You'll drive yourself batshit measuring off of bullet tips.....

 

[1969GTOnut]

Re: Off the lands question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MinorDamage</div><div class="ubbcode-body">Taking a COAL measurement is asking for trouble. Bullets vary from ogive to tip and you may end up loading them closer or farther away than you think. Mitch is correct about doing it a couple times and make sure you are within .002 (although I contend you need a micrometer for this. Caliper measurements can be off).

So, get a bullet comparator like Hornady's LnL type. That will allow you to meaure base of cartridge to ogive. With that info, you can load different bullets and never have to wonder if they will touch the lands, be jammed, etc. Remember, the ogive is what is going to contact the lands, not the tip. Take the measurement off the ogive and thank yourself later.

Josh</div></div>

I agree. Get a Hornady bullet comparator and OAL gauge and measure only from the ogive.

 

[Placebo]

Re: Off the lands question

will do. Thanks for the great advice everyone. I learned so much from this forum. Tomorrow i will learn even more. Much appreciated.

 

[Bayou]

Re: Off the lands question

In my 700P OAL for a 168 gr Amax just touching the lands, the OAL is 2.965". For a Nosler CC 168 gr its 2.966". These are averages of 5 measurements using different bullets and the Stoney Point gauge with modified cases.

 

[sniperaviator]

Re: Off the lands question

I'm in the same boat. 2.94" with Lapua Scenars and its as long as I can load. I have to single feed. Longest my AI mags will load is 2.875". Anyone have a magazine that can feed these long bullets?

 

[MinorDamage]

Re: Off the lands question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sniperaviator</div><div class="ubbcode-body">I'm in the same boat. 2.94" with Lapua Scenars and its as long as I can load. I have to single feed. Longest my AI mags will load is 2.875". Anyone have a magazine that can feed these long bullets? </div></div>

I have a Sako TRG and the mag is 2.95".

Josh

 

[Country]

Re: Off the lands question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tripwire</div><div class="ubbcode-body">Paint that bullet black with a marker, then back the COAL off until you SEE it just barely contacting the lands.

There's your starting point. With micrometer comp dies it's a no brainer to then set your seating depth wherever you want. If you don't want the micrometer comp dies then you need a comparator.

Forget about using the COAL, whatever it ends up being, as your set-in-stone reference point, the true measurement is where the ogive contacts the lands minus whatever jump you end up with.

You'll drive yourself batshit measuring off of bullet tips..... </div></div>
110 % Correct.

 

[sniperaviator]

Re: Off the lands question

Anyone have a rifle that has a magazine that will hold the longest round that will fit in the chamber? So if the OAL of a round with a Berger bullet is 2.9", and you have a 2.92" magazine (or some such) you can be loaded jammed to the lands and still fit in the magazine.

 

[prosise]

Re: Off the lands question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MinorDamage</div><div class="ubbcode-body">Taking a COAL measurement is asking for trouble. Bullets vary from ogive to tip and you may end up loading them closer or farther away than you think. Mitch is correct about doing it a couple times and make sure you are within .002 (although I contend you need a micrometer for this. Caliper measurements can be off).

So, get a bullet comparator like Hornady's LnL type. That will allow you to meaure base of cartridge to ogive. With that info, you can load different bullets and never have to wonder if they will touch the lands, be jammed, etc. Remember, the ogive is what is going to contact the lands, not the tip. Take the measurement off the ogive and thank yourself later.

Josh </div></div>


Highly second this response. Very well said.

Prosise

 

[Headgear]

Re: Off the lands question

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Taking a COAL measurement is asking for trouble. Bullets vary from ogive to tip and you may end up loading them closer or farther away than you think. Mitch is correct about doing it a couple times and make sure you are within .002 (although I contend you need a micrometer for this. Caliper measurements can be off).

So, get a bullet comparator like Hornady's LnL type. That will allow you to meaure base of cartridge to ogive. With that info, you can load different bullets and never have to wonder if they will touch the lands, be jammed, etc. Remember, the ogive is what is going to contact the lands, not the tip. Take the measurement off the ogive and thank yourself later.</div></div>

Isn't that the truth!

When you get a comparator, just look at the difference between a SMK vs. an Amax of the same weight.