7mm-08 140 TGK COAL?

[USAF Ret]

If anyone is shooting the 140 TGK from their 7MM-08, can you provide your COAL or a reference for suggested COAL? The Sierra app does not list it. Thanks.

 

[44hunter45]

Every rifle is different. Spend some time on Youtube looking at the various methods of determining COAL for that bullet in your rifle.

You do not need to spend a bunch of money on fancy modified shells and comparators. My method uses the seating die as the comparator. So when I find the lands and then back out my desired .005" - .020", I already have the die locked in and I'm ready to start making ammo.

 

[USAF Ret]

Every rifle is different. Spend some time on Youtube looking at the various methods of determining COAL for that bullet in your rifle.

You do not need to spend a bunch of money on fancy modified shells and comparators. My method uses the seating die as the comparator. So when I find the lands and then back out my desired .005" - .020", I already have the die locked in and I'm ready to start making ammo.

Copy that. Great idea. Waiting on the bullets to get here. I have the comparator, so it will be easy. Got a smoking deal on clearance at Midway. Not sure why, but a box of 500 @ $.18 a bullet. Planning on running it with RL-15 as that seems be getting good results for a lot of folks.

 

[44hunter45]

RL-15 will work great. If you find Varget, many shooters find it magic in 7mm-08.

Google "relative burn rate chart" Most folks are using the color coded one from Hodgdon. I find the one from loadata.com to be the most accurate. Look for powders in the burn rate range near RL-15 or Varget.

 

[USAF Ret]

RL-15 will work great. If you find Varget, many shooters find it magic in 7mm-08.

Google "relative burn rate chart" Most folks are using the color coded one from Hodgdon. I find the one from loadata.com to be the most accurate. Look for powders in the burn rate range near RL-15 or Varget.

I have about 8 lbs of Varget, haha. I am going through ladder testing with different powders right now. Big Game has been very good as well. I have that chart and will take a look. I appreciate the guidance. Been reloading for a few years, but sometimes the obvious slips through my learning.

 

[44hunter45]

It's my drug.

 

[USAF Ret]

It's my drug.

There are worse drugs, but it can be an expensive one. However, if another ammo shortage hits, I am truly not concerned at all. I am sure you aren't either.

 

[AckleyHunter]

I got the same deal, I think it was like .22/bullet. Gave the mailman a hernia putting them in the mailbox. Switched from Nosler BT. I run them with 41.5 gr Rel15 and make them as long as will fit/feed in the magazine. One hole groups. Rel 15 isn't the fastest, but always the most accurate in my 7-08.

 

[USAF Ret]

I got the same deal, I think it was like .22/bullet. Gave the mailman a hernia putting them in the mailbox. Switched from Nosler BT. I run them with 41.5 gr Rel15 and make them as long as will fit/feed in the magazine. One hole groups. Rel 15 isn't the fastest, but always the most accurate in my 7-08.

Great info. Thanks!

 

[N2TRKYS]

Big Game for 7-08. 2.80” has worked in every 7-08 that I’ve loaded for. I don’t know or care how far off the lands I am.

 

[std7mag]

One of the main reasons for handloading is to taylor the ammo to YOUR rifle.

Going the SAAMI 2.800" and calling it good, you may as well just buy factory ammo.

@USAF Ret.
Just remember that IF you run into issues, your comparator measurements will mean nothing to anyone else.

I use the KISS method. Keep It Simple Stupid.
Measuring COAL is usually going to be within about 0.005" give or take of anyone else measuring the same bullet.

In talking with people that make specialty bullets, they say that the hardest part is to make the ogive consistent.

Personally, I like a slower burning powder than Varget or RL15.
Yeah, they are accurate in many different cartridges. But for a hunting rifle I want velocity with that accuracy.
H4350, H414 (W760), Big Game burn rates work well for the 140gr bullet weight.

 

[USAF Ret]

Sierra came back and yes, agreed with y'all. 2.800.

 

[std7mag]

Sierra came back and yes, agreed with y'all. 2.800.

They said "2.800" because that is the SAAMI measurement.
It will fit in every rifle chambered in 7mm-08.
They will have no clue what the distance to the lands is in YOUR rifle. Or how much room you have in the magazine.

Also notice that Sierra told you COAL, not CBTO.

Luckily, Sierra's are known to be fairly jump tolerant.
Meaning they will shoot well at almost any distance from the lands.
But you can improve their accuracy by changing seating depth.
Usually 0.020" from the lands works best for my rifles.

That 0.020" off the lands in my rifle is 2.895" COAL.
0.005" off the lands for a 140gr Berger VLD is 2.898" COAL.

Find the distance to your lands, subtract 0.020".
Then make sure it fits in the magazine.

 

[USAF Ret]

One of the main reasons for handloading is to taylor the ammo to YOUR rifle.

Going the SAAMI 2.800" and calling it good, you may as well just buy factory ammo.

@USAF Ret.
Just remember that IF you run into issues, your comparator measurements will mean nothing to anyone else.

I use the KISS method. Keep It Simple Stupid.
Measuring COAL is usually going to be within about 0.005" give or take of anyone else measuring the same bullet.

In talking with people that make specialty bullets, they say that the hardest part is to make the ogive consistent.

Personally, I like a slower burning powder than Varget or RL15.
Yeah, they are accurate in many different cartridges. But for a hunting rifle I want velocity with that accuracy.
H4350, H414 (W760), Big Game burn rates work well for the 140gr bullet w

They said "2.800" because that is the SAAMI measurement.
It will fit in every rifle chambered in 7mm-08.
They will have no clue what the distance to the lands is in YOUR rifle. Or how much room you have in the magazine.

Also notice that Sierra told you COAL, not CBTO.

Luckily, Sierra's are known to be fairly jump tolerant.
Meaning they will shoot well at almost any distance from the lands.
But you can improve their accuracy by changing seating depth.
Usually 0.020" from the lands works best for my rifles.

That 0.020" off the lands in my rifle is 2.895" COAL.
0.005" off the lands for a 140gr Berger VLD is 2.898" COAL.

Find the distance to your lands, subtract 0.020".
Then make sure it fits in the magazine.

I will be measuring the chamber with the TGKs to see how much jump I have, I usually shoot a ladder test for velocity and then do group testing on any flat spots. If the groups are off the chart bad, I just dismiss. If they are decent, but not what I want them to be, I will work with seating depth.

Note: I do usually start with the SAAMI COAL and play from there. Probel with this bullet is that it was a release as part of the expansion of the Gamechanger line and does not have any load info.

 

[N2TRKYS]

Chasing the lands is a waste of time. I’ve never had to play with seating depth to get the velocity I want and accuracy.

COAL measurement is fine. BTO is cool and all, but not needed. It’s importance is grossly overrated.

 

[USAF Ret]

Chasing the lands is a waste of time. I’ve never had to play with seating depth to get the velocity I want and accuracy.

COAL measurement is fine. BTO is cool and all, but not needed. It’s importance is grossly overrated.

I have actually tightened up groups with seating depth changes. I have a rifle that likes a little more jump and gained me a good little bit in accuracy.

 

[antelopedundee]

I'd go to a store that sells ammo and if the have it, use a caliper and measure the COAL of however many brands they have. Or you can just contact Sierra.

 

[USAF Ret]

I'd go to a store that sells ammo and if the have it, use a caliper and measure the COAL of however many brands they have. Or you can just contact Sierra.

Already got info from Sierra. Posted above. Thanks.

 

[N2TRKYS]

I have actually tightened up groups with seating depth changes. I have a rifle that likes a little more jump and gained me a good little bit in accuracy.

That’s a bummer. I’ve never had to fool with loads that finicky that seating depth tighten up groups.

 

[USAF Ret]

That’s a bummer. I’ve never had to fool with loads that finicky that seating depth tighten up groups.

Not really finicky, just fine tuning. Fairly common practice.