Help me rescope and reload for Christensen Arms Summit Ti.

[robby denning]

N2, me either on the ogive measurement , but I'm happy to learn about this technique and see if it improves my accuracy.

Per Mikes recommendation, I just walked out of Sportsmans. you can either buy the entire kit with six caliber inserts, or just buy the body and the inserts as you need them. That's the route I went.

$21


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[N2TRKYS]

I do like the one that measures to the shoulders, though. I'll only full length size and this allows me to bump it back 2 thousandths. Very handy.

Can't wait to hear how they shoot.

 

[danmayland]

I only do COAL. I don't measure to the ogive and have never seen a reason to. I can get a better measurement that way verses to the ogive. But, like you stated, I'm not the sharpest, either. Lol

Measuring the ogive is the only true way to gauge distance to the lands and it's the only way to get consistent accurate readings on cartridge length. Bullets like Bergers are especially difficult to measure coal because of inconsistent bullet length due to the nose design.


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[N2TRKYS]

Measuring the ogive is the only true way to gauge distance to the lands and it's the only way to get consistent accurate readings on cartridge length. Bullets like Bergers are especially difficult to measure coal because of inconsistent bullet length due to the nose design.


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All of your bullets ogives are the same length?

 

[mcr-85]

All of your bullets ogives are the same length?

Measuring to the ogive will be far more consistent than the tip of the bullet. If there is a variance it will be a lot smaller than the variance you'll find in Berger meplats.

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[N2TRKYS]

Measuring to the ogive will be far more consistent than the tip of the bullet. If there is a variance it will be a lot smaller than the variance you'll find in Berger meplats.

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Most of my Bergers only vary about 3 thousandths at the most on bullet length. I haven't noticed that being enough to matter. I haven't noticed enough variance in the bullet length of my hunting bullets to matter. By the time you sort by bullet ogive length, bullet weight, and bullet total length, you'll hardly have any bullets to shoot. Lol

 

[mcr-85]

Most of my Bergers only vary about 3 thousandths at the most on bullet length. I haven't noticed that being enough to matter. I haven't noticed enough variance in the bullet length of my hunting bullets to matter. By the time you sort by bullet ogive length, bullet weight, and bullet total length, you'll hardly have any bullets to shoot. Lol

I don't sort em....I just shoot em. But I measure to the ogive

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[N2TRKYS]

I don't sort em....I just shoot em. But I measure to the ogive

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Good luck this hunting season.

 

[robby denning]

OK I think I have this process down, Mike's instructions that he showed on page 3 were better than Hornady's. Theirs were pretty good, but Mike is right in that you have to run your Comparator tool out to the end of your caliper jaws, make sure your cartridge measurement is taken perpendicular to the jaws, and you have to use a ramrod gently to unseat the bullet from the lands after you've taken the OAL gauge measurement.

It took me about an hour to grasp the entire concept and get consistent measurements.

Here are the pictures in the order that I took the measurements; you can see at first I was all over the place, with way too much variance in COAL (as much as 0.014 if I'm reading my caliper correctly)

But the last three pictures show that you can get this down to the nearest thousandth. I'm calling it at 3.234".

The Comparator is 1.00" so I have to subtract that, which puts my COAL really short, so I might not be explaining this right. I need to talk to Mike, or he'll chime in.

I'm learning so much from this. Now onto the next step.


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[HellsCanyon]

Man Robby we really need to get you a new set of calipers!
Looks like you're getting the hang of it.

I can't see anything to really improve upon, you're doing great. I typically at this point will go .020" off the lands, and run different powder charges to see where I hit pressure and where the flat spots in velocity is (velocity nodes). After finding your sweet spot for powder charge, tune your seating depth. I typically start with .020/30/40/50/60 off the lands and then bump up and down .005 from whichever depth shoots best to fine tune. I typically nail a load down in 3 trips to the range.

Mike


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[robby denning]

Yeah they're pretty bad, I think I got them when I was about 25.

So if I'm 3.234", do I subtract 1 inch for the gauge and then the 0.020 for my COAL, and set my seating die to get a COAL of 2.234-0.020= 2.214"?
Sounds totally wrong to me because the COAL factory rec is 2.860 for this caliber




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[HellsCanyon]

Yeah they're pretty bad, I think I got them when I was about 25.

So if I'm 3.234", do I subtract 1 inch for the gauge and then the 0.020 for my COAL, and set my seating die to get a COAL of 2.234-0.020= 2.214"?
Sounds totally wrong to me because the COAL factory rec is 2.860 for this caliber




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The gauge on my mitutoyo calipers ranges from 1.000-1.004" depending on the insert.

For the sake of simplicity, don't worry about subtracting 1" to get coal. Just know that when that gauge is in your calipers, that 3.234" is where your lands are. Your calipers could be off .100" or more but since you are always using THAT particular gauge, calipers and case, that is YOUR individual reference number. So subtract .020" and you'll have 3.214".

Something seems a bit off there on measurement.

I would seat a dummy round .030 LONGER than your 3.234", color the ogive with a sharpie, and chamber it. If it's truly .030" longer than the lands when you extract it, it'll have distinct marks from the lands on the ogive.

Two questions, how many rounds do you have down this barrel and how hard are you pushing the plunger on the hornady tool to push the bullets into the lands? I use a significant amount of pressure to make sure that bullet is seated firmly.

Mike


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[robby denning]

That makes sense on my personal measurement. i'll do the dummy round as suggested

On your questions...

1) gun has probably had 200 rounds through it

2) light to moderate pressure on the plunger, I feel it hit the lands snuggly. That was one thing I had to work on initially to make sure I was doing it consistently, once I did my measurements got closer together.


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[mcr-85]

Yeah they're pretty bad, I think I got them when I was about 25.

So if I'm 3.234", do I subtract 1 inch for the gauge and then the 0.020 for my COAL, and set my seating die to get a COAL of 2.234-0.020= 2.214"?
Sounds totally wrong to me because the COAL factory rec is 2.860 for this caliber




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Remember you are measuring to the ogive instead of the tip of the bullet. That will put your measurement "short" of what the book calls COAL.

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[robby denning]

Remember you are measuring to the ogive instead of the tip of the bullet. That will put your measurement "short" of what the book calls COAL.

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Oh yeah! The point of the entire exercise! I told you I'm not very sharp.


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[William Hanson (live2hunt)]

I'm just reading this thread now. Really informative!

Live2hunt custom shelters

 

[danmayland]

Remember you are measuring to the ogive instead of the tip of the bullet. That will put your measurement "short" of what the book calls COAL.

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I was about to mention that!! Good call


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[danmayland]

Robby. Do yourself a huge favor and pick up these awesome calipers. $26 and worth the weight in gold.

iGaging IP54 Electronic Digital Caliper 0-6" Display Inch/Metric/Fractions Stainless Steel Body: Amazon.com: Industrial & Scientific


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[HellsCanyon]

Remember you are measuring to the ogive instead of the tip of the bullet. That will put your measurement "short" of what the book calls COAL.

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Bingo! Way too easy to overlook the simple things (and I'm currently packing to go hunting for 2 days so my mind is on big deer ).

You're all set now Robby!

Mike


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[maninthemaze]

When writing down my measurements to keep track of things I differentiate between the two as COAL = cartridge over all length and BTO = base to ogive.

Just my 2 cents and worth the price charged.