Inconsistent COAL in LEE 300AAC dies is it the die or am I asking too much.

[adanymous]

Not trying to brag. But some backstory. I had a rem 700 300AAC. It was a ***. bbl said 1-7 but was 1-10. Didnt shoot heavy subs for anything. Was a baffle striking SOB. Buddy of mine loved it with supers and offered to buy it, which was an opportunity to build what I wanted. I figured I could build a savage 111 for the $1200 ish I got for the rifle (wasnt a stock 700). $5000 later I have a blueprinted sav 111 in a yankee hill chassis with an air gauged to .0001 bore dia criterion 10" stainless bbl VLTOR stock, blah blah blah grips and bolt handles and other such with a .30 harvester can. On top of that I put a Leupold MkIV 4.5-14 with their amazing TMR reticle. I know thats a ridiculous scope for this application, but I have 3 of em in a drawer and the MK II I put on it originally ran out of elevation. Dont judge me :lol:

I know this is an incredibly stupid gun. I have a 300AAC AR thats way more reasonable. Ill probably rebarrel this in the future to something else less stupid. HOWEVER. My brother made fun of me for spending a gazillion dollars making a glorified 100 yd gun. Im not taking any of his guff so Im trying to REALLY push the limits of a 300AAC shooting heavy subs. And its super fun to shoot, set the rifle down, wait several seconds, and then hear the ping of the bullet striking steel. I had a doe on the range I was shooting at the other day and she only left when she got bored. I had to stop shooting when she got too close to my bullets flight path.


I worked up a subsonic load with 311-247s by chrony to be slightly short (most of the time) of 1100 fps. Im trying to toe the line on sub sonic. So I cannot vary my powder charge to attain accuracy. What I am doing is the F-class guys method of varying COAL decreasing from on the lands to mid accuracy node by .003 per test group of cartridges to find my accuracy node. Ive shot over 100 rounds working up velocity and COAL once I found the proper velocity. I take a journal to the range and take tons of notes on each 5 shot group every time a variable changes. I draw maps of targets with which variable was shot at which target and what the group looked like. So you can imagine how much time I have into figuring this out. I went to the range yesterday and shot a 4 shot group within about 1.5 caliber @ 100yd @ 2.230 COAL and 11gr 4198 (I dont have AA1680, I am aware its awesome). The best node I have is .006 wide. I was planning on setting up my die at the longest COAL and id have .006 for erosion wear before I have to reconfigure the load (not that a sub bullet will erode the rifling to any degree), but thats the method and I was trying to stick to it.

My Lee bullet seating die is varying seating depth +- 6 or 7 thousandths. I cant even stay in my node without measuring every bullet and readjusting the seating depth every dang time. On the long side of the node I was shooting like 1.5 inches, not calibers. So massive difference in accuracy.

1 does anyone understand all that garbage?

2 Is there a die I can buy that will give me better consistency in COAL? The lee seating adjuster on the die visibly moves on seating. Ive not seen any micrometer 300AAC dies.

3 Am I just asking too much from a powder coated cast boolit? Is this variation from variation in the coating?

4 Do you think I should seek psychiatric help for trying to shoot a 247gr cast lead boolit 500 yd?

[kungfustyle]

Measure your boolits, just the leads not the loaded cartridge, see if there is some discrepancy there. https://www.midwayusa.com/product/1022385148?pid=982380 this might help. I appreciate the love that you are putting into it, but, you may be trying to make a silk purse from a sow's ear. If you enjoy what your doing, go for it, if not your energy and $$ could find better uses. Good luck.

[M-Tecs]

Measure your boolits, just the leads not the loaded cartridge, see if there is some discrepancy there. https://www.midwayusa.com/product/1022385148?pid=982380 this might help. I appreciate the love that you are putting into it, but, you may be trying to make a silk purse from a sow's ear. If you enjoy what your doing, go for it, if not your energy and $$ could find better uses. Good luck.

Any idea how well it holds neck runout? Interesting design.

[Waleone]

1. Yes, I understand you are a meticulous, detail oriented person.
2. L. E. Wilson makes a micrometer seating die for 300 AAC BLK for use with an arbor press. I have one and had to modify it to allow for the larger diameter of cast bullets to fully enter the die before beginning to seat into the case. I took a 1 degree tapered reamer, miked and marked the desired diameter, ground off the larger diameter flutes of the reamer (being careful not to overheat the reamer) and reaming from the chamber end of the die slowly by hand and constantly checking depth with the desired bullet until both the bullet and case can be fully inserted into the die before the bullet begins to seat into the case.
3. I have very little experience with powder coating bullets, none with rifle bullets. Could the seating die be gunked up? I'm not sure of your practices, but usually we use minimal neck tension for cast bullets, it does not take much to for the bullet to stick to the seating stem. Besides building up to change seating depth, it could be creating suction and pulling the bullet back out a bit after seating. Could there be build up of bullet lube from previous use with lubed bullets?
4. There are times I believe all of us (including myself) who chase utmost accuracy with cast bullets need professional help! This game is mad science and voodoo with an exorcism or two mixed in!

BTW, have you tried minimally neck sizing your cases and loading to an excess overall length, then single feeding into the rifle and finish seating the bullet in the chamber when the bolt is closed and the bullet makes contact? Not very useful if you want to feed from the magazine, but I find in bolt guns that many times it gives me the best accuracy.

[jmorris]

There is a lot of information in the OP but I don’t see what bullet you are using.

It isn’t uncommon for some to not have consistent OAL (the projectile itself), the very tip is the culprit. SMK’s are notorious for this despite shooting well.

You need to measure off the ogive, there are a number of ways you can do this. These are a one size fits most solution.

http://www.thegunmag.com/wp-content/uploads/2017/03/HL-comp-cal-768x569.jpg

You can also get them that stay on the caliper or even remove the bullet seating stem from the die and set it on top, like it was seating the bullet and measure the OAL of the round and seater.

[Dusty Bannister]

If you are powder coating a cast bullet, you are randomly changing the contact area on the nose of the bullet so seating will be based upon the thickness of the PC.

[adanymous]

That comparator is genius! Im going looking for one!

[adanymous]

If you are powder coating a cast bullet, you are randomly changing the contact area on the nose of the bullet so seating will be based upon the thickness of the PC.

youre probably right honestly

[adanymous]

Waleone, That method of loading is sometimes called "chasing the lands" there are some great youtube videos regarding the method i am using. Search "Stop chasing the lands" and you should find it. It changed my methodology for the better.

[adanymous]

Did some more searching and found lyman now makes a pro Mic Seating die....just bought that.

[jmorris]

That comparator is genius! Im going looking for one!

https://www.midwayusa.com/product/101273351

https://www.brownells.com/reloading/measuring-tools/bullet-comparators/sinclair-hex-style-bullet-comparators/

Are two but you really just need a “datum” (diameter that is less than bore and more than tip, it is what you make it) drill a hole in anything that is flat and square and you just made a tool.

[BK7saum]

Did some more searching and found lyman now makes a pro Mic Seating die....just bought that.

The problem is not your seating die but powder coating thickness on the ogive/nose of the bullet. The powder coating thickness will vary and affect the seating depth of your bullets as you have seen.

Jacketed bullets, especially hollow points vary in length but measurements to the ogive are usually much more uniform. OAL is not as consistent as base-to-ogive measurements on loaded cartridges.

PC cast boolits are less uniform after PC, one artifact of this is varying seating depths of boolits seated with tapered nose seating stems.

If you double-seated your bullets and used a flat nose stem or punch to just finish the last few thousandths, that would get your OALs exact, but might hide another issue.

I hope the Lyman die works better fir you, but am skeptical that it will. It will make it easier to adjust individual cartridge lengths, though.

[jeff423]

I use the Redding Competition seating die. The micrometer gives me very consistent results. I also use a comparator.

[DougGuy]

Did some more searching and found lyman now makes a pro Mic Seating die....just bought that.

How did the pro mic seating die work out? I'm soon to be loading the 300 but only duping the Remington 220g sub so loading with Barnes 220g boattail jhp.

[Winger Ed.]

, the very tip is the culprit.
You need to measure off the ogive, there are a number of ways you can do this. These are a one size fits most solution.
.


This has been my experience with seating stems that grip on the ogive.
A flat point boolit with a flat seating stem tends not to do this.

[jmorris]

Yeah, I was assuming he wasn’t loading wadcutters in the 300blk but he didn’t state that as fact. Why I noted that in the first sentence of my first post.