I'm trying to figure out what the max COAL is on my Savage.  I've got a bullet in a once fired case with just a little bit of tension on the neck.  I put the cartridge in the chamber, close the bolt, then open it, and I measure the OAL off the ogive.  I'm getting wildly different lengths each time I try it.  I'm not sure what I'm doing wrong.  I'm not sure if I need more tension on the neck, or if I'm going about this all wrong?

What do you guys think?

Try using a marker and painting the bullet, hand load it in the chamber and close the bolt. When you extract it you should see marks from the lands in the barrel.

Not sure why you are measuring off the ogive if you want cartridge overall length.  Measure the COAL.  

https://www.nosler.com/blog/news-and-articles/2017/3/29/how-to-determine-proper-bullet-seating-depth-for-your-gun

The tips on these AMAXs don't seem very consistent.  I was seeing a +/- .010-.015" difference in my COAL when trying to measure off the tip.  I was hoping measuring off the ogive would be more consistent.

If you want an accurate reading, you're going to have to get an Hornady Comparator.

COAL is important when you are trying to figure out how far out you can seat a bullet and have the cartridge still fit in the magazine.

You are correct that measuring off the ogive is much more consistent in your search to find the seating depth that gives the optimum distance the bullet 'jumps' to engage the rifling in the barrel.

For that, you will need bullet comparators from someone such as Hornady or Sinclair.

Sorry, yes I meant seating depth.  This is new to me, I've only loaded pistols in the past.

Using the method from the Nosler link I'm getting (from the ogive) 2.200 to 2.225".  It's not exact because I'm having to push the bullet back to the mark

So I'm assuming I should start with a seating depth about 0.015-0.02" under that 2.200"?

Bullets may be sticking on the rifling and pulling it from the case as you extract. Too much tension on the bullet will make it stick sometimes.  Also if you aren't snap the case under the extractor and hold the cartridge straight when chambering. I slit the neck of a case to hold the bullet so that it only very lightly holds the bullet. Also hold the case straight when extracting.  Seems I find that factory loads are often .050" off the rifling in my factory bolt actions. I'd start at .050" and work down in .010" at a time looking for best groups. For a hunting rifle it's not recommended seating to touch or jammed into the lands. Couple of my bolt rifles for some reason like .025-.030" off.

How are you measuring to the ogive?

Also,

Not sure I understand what you mean by "push the bullet back to the mark"?

You're new, so here are recommendations to you.


1.  Buy the Hornady gages and do it "right".  That is to say, do it more easily.  Learn to use these to set the resizing die and bullet seating dies.


2.  Stick with magazine length loadings until you can out-shoot them; until the ammo is holding you back.

I noticed the rifling was pulling the bullet out of the case a little during extraction.  I was putting the case as far into the chamber as I could by hand then gingerly closing the bolt.

I have calipers and a Hornady comparator.  The rifling is grabbing the bullet during extraction, so I can see where the case scrapes off the marker on the bullet.  I then have to seat the bullet to where the scrape marks are visually.

You only want just enough tension on the bullet that it won't move when you extract the case. Any more tension and it will hang up in the barrel. Repeat a few times until you get some consistent measurements.

For what purpose?

Why are you not just using the COAL published in the manual for the load?

Are you trying to seat the bullet out far enough that it comes in contact with the lands of the rifling in your barrel?  If so, why?  And do you understand the consequences of firing a cartridge in that configuration?

I got all kind of varying results when attempting to find out what the max OAL was for my particular gun/bullet.   One variable causing this was bullet run-out - it will cause the bullet to touch the rifling sooner than if run-out was very little.   I had 2 loaded cartridges with same OAL - one would pass the plunk test - the other would not.  After I corrected run-out that resulted in more consistency between rounds.   I bought a Hornady Lock-N-Load Concentricity Gauge to check run-out - it seems to do the job.   The Hornady verified the issue - and I purchased a Redding competition seating die that fixed it.       I'm also new at this hobby - so someone with more knowledge probably could have resolved my run-out issue without the new toys I purchased.  If you don't have a case gauge buy one.   I recommend Wilson.  You will find that different case gauges will vary among the different manufactures as far as what they will pass.  I've had better luck with Wilson but YMMV.

Yes. Once you are satisfied that you are getting good measurements start about .020" off the lands. Mark your first full neck tension round or better yet make a full neck tension dummy and confirm that you are off the lands.

Even when I shot single load competition I stayed .010" off just to soak up inconsistencies.

My match load was not a hot load and I never saw any signs of pressure spikes. Just to give you an idea of the amount of rounds fired, I used well over 100 pounds of powder during my relatively short rifle competition shooting career.

Motor

Thanks rg1, I'll try that.

HDwhit: as I said earlier, I'm looking more for the seating depth than the actual overall length.  Yes, I know what it means to be right on the lands, and no I don't want to do that.

Actually there is nothing wrong with being "on the lands" as long as you worked your load up that way.

A lot of guys load touching the lands but once in a while it will bite you and I've seen this occur. There is a ceasefire called and someone will eject a casing with powder spilling out of it because the bullet stayed in the lands.

Just a gentle bump with a cleaning rod and it's out but still annoying. That's another reason why I stayed .010" off. I've never left one sticking in the lands.

Motor

That is definately something I'd like to avoid.

Ok, so I'm back at it again tonight.  I'm still not sure what to do for seating depth.  Should I just load to a COAL of 2.800" listed in my manuals and work from there?

Edit: I have about two dozen rounds at 2.795" ORAL.  I'm trying the OCW method, so wish me luck on that.

Try to find possum hollow cleaning rod stops. They are plastic donuts with a plastic finger screw that tightens up against your cleaning rod.

You'll need 2 of them. They are not expensive. You'll also need a blunt tip jag.

You put both rod stops on your cleaning rod.

Put the bolt in the rifle and close it.

Slide the rod into the barrel until the blunt tip jag is sitting against the bolt face.

At the same time hold the rod stops against the end of the barrel and tighten the stop nearest to the handle end of the cleaning rod.

Remove the bolt from the rifle. Drop a bullet into the throat of the chamber. Hold it in place with a suitable rod (a pencil or similar) against the lands.

Slide the cleaning rod back in until the blunt tip jag contacts the tip of the bullet.

(I'll let the rod and bullet move together back and forth a little to make sure they are touching and the bullet is against the lands).

While holding everything together slide the inner rod stop down against the end of the barrel and tighten it.

The inside distance between the two rod stops is the OAL at which you'll have ZERO bullet jump.

This may be an inexpensive more consistent way for you to establish what you seek. I use an old stainless steel cleaning rod that someone broke and gave me. I also machined aluminium blocks to use instead of the rod stops.

It works fine. Most of my load card files has the ZERO jump OAL listed on them. Over 90% of the time it's just there as a reference but at least the information is there if I need it.

Motor

Here's my results:






I'm kind of thinking i need to try a few lower charges.

I had a similar experience recently.

My son's 7mm Mag shoots the 150gr Sierra BTSP excellently using their "accuracy load" which is up around 63gr.

We tried some 150gr Combined Technology ballistic silver tips. I started at 61 and worked up. Didn't show any excessive pressure signs but the groups got larger with the powder charges.

Tried again starting at Nosler's start load (used Nosler's data from the start with these, they are one of the makes). The start load is 59gr. The rifle liked the start load the best.

I haven't had the chance to compare the velocity between the Sierra's and these yet. Sometimes a coated jacket makes less pressure and less velocity but no until I shoot them both over the chronograph I won't know.

They shoot the same POI elevation wise at 100 but the CT shoot 1 1/4" right compared to the Sierra's.

Motor

That group using 44.9 gr looks decent to me.  It looks to be in the 0.7 MOA range and is round-ish.

What was the wind like during firing?

That's interesting, the Hornady data shows a max of 44gr, while everywhere else shows a max of 47gr.  Maybe I should have just gone with Hornady's days from the start.

The wind was awful.  It never stayed steady from any one direction.  My phone said it was 2mph gusting to 4mph, but I think it was more like 5-10mph gusts of 15-20mph.  My sighter group was almost as tight as that 44.9gr group.

I use a cleaning rod that I cut the end off, so no tapped hole and a nice fitting rod for the size barrel I am doing this on, 223, 308 etc., but instead of the

rod stops you use , I use small black O-rings, found at any auto parts store or archery shop, they fit tight and will not move on their own. Same deal as yours but

different, I found out when using my .17rem the lands were getting farther away from the bolt face, because I also marked the measurements down, but no

problem using the rod method I found out quick that I could kick out my 25gr v-max a little more making up for barrel wear.