Here's a Q for the experienced out there....

MadMarty

MadMarty

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The following is something I decided to work on this afternoon, with some time on my hands as my daughter is napping.
I have been told by some respected shooters in person and on forums that finding the OAL to the ojive is a waste of time, yadda yadda.
Ive been told by other respected shooters in person and on forums that its a great way to tune handloads, this way I can start experimenting with jump to the lands or maybe a little jam.
This post is not to determine whether its useful or a waste of time.......

40g Vmax
Hornady LnL Gauge
.223 Modified case.
Savage 12 BVSS - SINGLE SHOT (dont need to worry about magazine COAL)

I had attempted prior in the year to get a measurement to the ojive of 3 different bullets. Unfortunately the Savage thwarted both mine and two other respected and knowledgeable shooters' attempts to do so.
I used the Hornady LNL, the Frankford arsenal OAL gauge, and both smoking/felt on a bullet with a case fired in my rifle.
None allowed any reasonable length to be chosen as initial measurements varied across all attempts by approx .040 to .070. So its winter here now, and I found myself with some time to attempt this again. Heres what I found with the 40g VMAX and the Hornady LnL tool :

I started by measuring 8 times. After the 8 I noticed that when measuring on my calipers it wasnt square so I re-setup and went for another 10.
First 8 measurements:
1.814
1.824
1.827
1.814
1.819
1.818
1.813
1.822
Then I re-setup and made things sit flat on the calipers. I did 10 more measurements.
1.820
1.813
1.824
1.824
1.813
1.868*
1.859*
1.816
1.822
1.825
Now the two measurements that have a * by them..... I put the same tension on everytime I measure, but on the 1.868 as I was about to tighten the rod, I felt a little give and pushed a touch harder. Felt the bullet release and then touch/jam again and did my measurement. Same with the next one. In did not feel that jam/release/jam feeling again, even when I pushed hard after all this.

SO! The first measurements totalled 14.551, with 1.818 being the average.
Measurement set number two WITHOUT the two anomalies measured 14.557, with 1.819 being the average.
Measurement set number two WITH the two anomalies measured 18.284, with 1.828 being the average.
Adding Measurement One and Two WITHOUT the two anomalies measured 29.108, with 1.819 being the average.
Adding Measurement One and Two WITH the two anomalies measured 32.835, with 1.824 being the average.


Heres a question and the point of this post...... Seeing as I now have a much nicer average with measurements, should I begin experimenting using the 1.819? Or are the measurements still fluctuating too much? Also is the difference between 1.819 and say 1.850 a big deal or negligeable?

Ive put about 200 or so 55g pills through this barrel since I first attempted. Maybe this is why Im getting better averages.
as a side note I noticed that a 1.819 measurement to the ojive means Im seating the 40g VMAX almost all the way into the case, which takes room for powder or will compress loads that maybe shouldnt be. Concerning to be sure, as the 50G SPSX and the 60G VMAX will take up much more space.

The rifle is to be a medium range paper/steel puncher and gopher/coyote eliminator if that helps anyone as to purpose.

Im absolutely in love with all the knowledge and science, the measurements and the precision behind this sport, and as such I dont mind taking the time to do this another two times!

Thanks all!
 
I would start with 1.819. They wouldn't be fluctuating too much for me, but that is going to be up to you. I would say you have a good average there for a starting point! just my opinion. Like many of things to do with reloading, its all how specific you want to get and if you are happy with your results.
 
30 thou difference is enough to make a difference but you'll find out by making a few loads at different lengths.

I wonder if some of the variation in your oal measurements could be due to using a fired round round instead of a modified case?
Is the neck loose enough to allow some cant on the bullet when it's in the neck? The modified cases have a little tension in the neck to help make sure the bullet is held straight when pushed forward to touch the lands. Just a thought.

If you can't get a consistent measurement off the ogive don't worry too much. Your dies will seat the bullets off the ogive very time anyway. When you do find what it likes make sure to get that measurement off the ogive and not the bullet tip though in case your dies get moved off that adjustment in the future.

I load with a jump to find the approximate velocity I want first then adjust seating depth for accuracy. Just beware that if your close to pressure with a jump and keep that powder charge with a oal that puts you on or into the lands pressure will rise.
 
Here's a Q for you; are you using the same bullet or grabbing a new one for each measurement? By function of the tool and differences in base to ogive from one bullet to another you will get different measurements with different bullets of the same lot. At any rate I would load a couple dummy rounds starting just before touching the lands, according to your measurements, and seat progressively longer until you reach the lands when chambering. Smoke the bullets of course. When trying a bunch of jumps you're going to find a winner anyways so unless you're just trying to avoid jamming then its not critical to know exactly where your leade is so long as you're close.
 
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Who told you OAL to OGIVE measurement was bunk? That's one constant measurement regardless of bullet type/weight compared to COAL measurement.
 
.284 said:
30 thou difference is enough to make a difference but you'll find out by making a few loads at different lengths.

I wonder if some of the variation in your oal measurements could be due to using a fired round round instead of a modified case?
Is the neck loose enough to allow some cant on the bullet when it's in the neck? The modified cases have a little tension in the neck to help make sure the bullet is held straight when pushed forward to touch the lands. Just a thought.

If you can't get a consistent measurement off the ogive don't worry too much. Your dies will seat the bullets off the ogive very time anyway. When you do find what it likes make sure to get that measurement off the ogive and not the bullet tip though in case your dies get moved off that adjustment in the future.

I load with a jump to find the approximate velocity I want first then adjust seating depth for accuracy. Just beware that if your close to pressure with a jump and keep that powder charge with a oal that puts you on or into the lands pressure will rise.
Click to expand...

In this latest round of measuring I used the modified case as is needed with the Hornady LnL tool. I dont have any measurements on hand from when I used a fired case.

supernova said:
Here's a Q for you; are you using the same bullet or several? By function of the tool and differences in base to ogive from one bullet to another you will get different measurements with different bullets of the same lot. At any rate I would load a couple dummy rounds starting just before touching the lands, according to your measurements, and seat progressively longer until you reach the lands when chambering. Smoke the bullets of course. When trying a bunch of jumps you're going to find a winner anyways so unless you're just trying to avoid jamming then its not critical to know exactly where your leade is so long as you're close.
Click to expand...

I always use the same bullet.I started taking some quick measurements of my 60g Vmax's and the measurements are all different again :mad:
Ill try loading some dummy rounds and seat to different ojive lengths like you suggest. Well, once i make my indoor loading bench I will!

Trinimon said:
Who told you OAL to OGIVE measurement was bunk? That's one constant measurement regardless of bullet type/weight compared to COAL measurement.
Click to expand...

A couple F-class shooters, one of which owns a bullet making company here in Canada. I wont list names, but it was disheartening to be told Im wasting my time etc etc.
 
Just to be clear, and I'll edit my post, when I say different bullets I mean all the same type i.e. your 40 gr VMAX not other weights, types or brands. My question should have read: are you using just one 40 gr VMAX to measure or are you grabbing a new one for each measurement? At any rate even with the same bullet being used and a few numbers out to lunch I see a close enough trend in your numbers for you to base off of. These OAL guages are a little finicky to get consistent numbers with so I'd say you're ready to start. Whether you try dummy rounds or go straight to loaded rounds I'd be comfortable starting where you're at.
 
supernova said:
Just to be clear, and I'll edit my post, when I say different bullets I mean all the same type i.e. your 40 gr VMAX not other weights, types or brands. My question should have read: are you using just one 40 gr VMAX to measure or are you grabbing a new one for each measurement? At any rate even with the same bullet being used and a few numbers out to lunch I see a close enough trend in your numbers for you to base off of. These OAL guages are a little finicky to get consistent numbers with so I'd say you're ready to start. Whether you try dummy rounds or go straight to loaded rounds I'd be comfortable starting where you're at.
Click to expand...

I am using one 40g vmax for all the measurements, to avoid any minute change in jacketing etc.
 
MadMarty said:
A couple F-class shooters, one of which owns a bullet making company here in Canada. I wont list names, but it was disheartening to be told Im wasting my time etc etc.
Click to expand...

So COAL is more important than CBTO? I've been wasting my time and money on comparator gauges for nothing. Damn it... could've bought powder or bullets instead.
 
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I've been using the Hornady LNL gauge for several months now (also in a Savage 12 BVSS - good choice!), and it definitely works better with some bullets than with others.

It's given very consistent readings with Sierra 69gn MatchKings, but lighter bullets (Lake City 55gn) have been all over the map. Haven't tried with the 40gn VMax yet - sounds like it may be in the same bucket as the LC.

Good luck!
 
Thanks for the encouragement! I tried doing some measurements with the 60gVMAX but they were all over the place. I got frustrated and decided to leave it for a bit lol
 
Unless I missed it, a good way to get an accurate measurement using the LNL gauge is to use a cleaning rod (dewey) in conjunction with the gauge. You can push the bullet back and forward lightly untill you can absolutely feel that it is seated squarly in the lands. I can usually recreate measurments within .003" using different bullets from the same box ie, 5 different 175grn Hornady AMAX.
 
slowly insert the dowel or rod untill you touch the bullet on the comparator. Then just wiggle the comparator with the dowel touching on the other end untill you can feel the sweetspot. Once you shove the rod down the barrel you will instantly know how it works.
 
since you will be working loads for each bullet weight/make, set your seating die at 1.800 for the 40 gr v-max bullets which should be roughly 20 thou of the lands. I started working loads for my 222 I got the seating die set so the 50gr bullets were off the lands by 20 thou. I had good accuracy so when I switched to the 55 and 45 grain bullet I left the seating die the same and got comparable accuracy just with a different powder charge.
 
deadeyes40 said:
since you will be working loads for each bullet weight/make, set your seating die at 1.800 for the 40 gr v-max bullets which should be roughly 20 thou of the lands. I started working loads for my 222 I got the seating die set so the 50gr bullets were off the lands by 20 thou. I had good accuracy so when I switched to the 55 and 45 grain bullet I left the seating die the same and got comparable accuracy just with a different powder charge.
Click to expand...

No offence, but I wouldn't recommend somebody a seating depth number when every chamber is different among the same brand, and wildly different between different companies when you are talking about 0.020". MadMarty has some excellent tools at his disposal and it would be better for him to learn how to use them properly and get an accurate measurement of his own from his own chamber than referencing a fellow reloaders pet load. You also referenced the 222, which is very different from the 223.
 
You're getting excited over something that isn't terribly important. OAL measurements are normally for magazine fed rifles and don't apply too much to a single shot. You're more interested in the chamber length as it applies to where the rifling starts. Establish that lenghth and set your calipre to it for use as a guage.
"...wasting my time and money on comparator gauges..." Yep. They're made to separate you from your money. A good vernier calipre, preferably digital, is the only thing you need.
 
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