OAL at Ogive something not right

This is whats going on may run a little long. I sacraficed a 7mmSAUM case to seat a bullet into for getting the OAL of a loaded round. Well I did that a couple of times with the same bullet and I kept coming up with the same measurement which im guessing is good because it was consistant. So then I proceed to my Forstner Ultra Micrometer bullet seating Die at which point I pull the bullet out of the modified case just a bit and make adjustments to the die until it reads the same seating debth as it did after being pulled out of the action. Heres where the confusion comes in. When I take a primed, powdered case and try to seat a bullet in there it comes up .010 longer .050 shorter almost every single time (never exactly the same as the test round). Im not sure if the brass is that "springy". I am no where near a compressed load with 59.5 grains of 4831. Im kinda lost on this thing. All measurements are at the ogive. As a matter if fact some of the measurements are slightly under or over the measurements that were aquired using the modified case setup, even though the cases are a 1.20 a piece lol. Any advice would be very welcome and greatly appreciated. Id like to get out shooting this weekend but I dont want to be flinging rounds down range for no reason other than feeling recoil.....Thank you again.


Very Respectfully Submitted

Semper Fidelis

Just for some clarification...when you say "it comes up .010 longer .050 shorter almost every single time" do you mean every bullet loaded "falls within a range of being .010 longer to .050 shorter than the factory load that you "want" it to be at?

The seating die is probably contacting the bullet at a different spot along the ogive. See if you can adjust the seating die to replicate the length you measure with your comparator. (Don't worry bout the specific number you need to dial into the micrometer die. )Then see if that measurement is repeatable. (in other words, if you always seat using measurement x on the micrometer seating die, it always measures Y with your calipers and the comparator). If the bullets are consistent, hopefully, you should be able to make a direct correlation.

Yes Sir it comes up different lengths I am thinking it may be bottoming out on the powder or maybe I need to tighten up the neck on my cases. Ill fiddle more with it tonight if I have time its kinda frustrating...i have not measured the bullets individually to insure they are all the same from ogive to base...I dont even know if that would make a difference in the measurement from ogive to base from the same batch of bullets.....TOO MUCH MATH HEAD ABOUT TO POP

If your using polymer tipped bullets, make sure the tip is not hitting the plunger

keeki makes a good point....

I like to loose my sanity before I figured out it was the poly tip getting a little squished and giving variable lengths.

I measure all of my Noslers & Hornady's from the copper below the poly tip. It isn't perfect but it's a heckuva lot more consistant that using the bullet tip. Same goes for lead. If the bullet tip is getting pushed in by the lead tip, forget about accurate, consistant measurements.

Something else that drove me batty. Hornady XTP's for my 9mm & the 'lil woman's .380. Some brass fits a little more snug than others. When it does, it tends to squash the hollow point of the bullet. I got away from using Remington brass for pistols for that reason. Federal, Starline, Magtek and on rare occasion Win. brass for pistol loads.

Now I have to ask the question, unless you're shooting competition or BR, do you really need the COL to be that "spot on"? Will a few thousandths make that much difference or affect your accuracy that adversly?

Y'all have aroused my curiosity a bit. I don't pay that much attention to COL. Ammo ends up being + or - .005" , maybe even a little less. I don't see any ill affect to my results.

Whatcha think?

Frank in Fla..

Heck all this time I thought it all had to be within .001 no kidding....I mean I pull whats left of my hair out trying to perfect these rounds and make them identical in every way. Just so I know Im on the correct path here Ive been measuring at the Ogive with the tool that attaches to the micrometer heck I even use that specific micrometer for that reason only so's to not move the part that attaches to the micrometer at all. My cases are all trimmed to the exact length Im just cornfused about this Ogive to shell base thing, its really got me stumped how it can change even a little bit. My test case is a fully prepped case with 2 cuts in the neck to allow the bullet to slide in and out and I (think) its pretty darn accurate. If Im over thinking this bullet seating depth thing to much someone please let me know so I can go shoot this POS lol. I just dont wanna load up a bunch of rounds and not know what my rifle likes or dislikes....Thanks in advance for any advice..


Very Respectfully Submitted

Semper Fidelis

Let me throw this at ya, Chesty...

I seat 2... maybe 3 bullets & check the OAL from the case head to the copper tip of the bullet (not the plastic tip). I use a Lee dead length seater, which I believe are much better than Lee's regular seating die.

I seat long & adjust to length or use a bullet of the same weight, caliber, etc to set the die. When I reach the COL that has been working for that particular bullet, I fill 'em & seat 'em. I think I started checking each & every one when I first started reloading but found that set 'em & forget 'em works just fine. On a 100yd line, even a 200 yd line, I sure as heck can't tell the difference. Neither can the target. I shoot a 400yd line once in a while but I don't have enough time on the line & the guy tutoring me isn't available as often as I'd like. Some BS story about work or job & kids or something... I don't know. But I have been able to use my home rolled ammo on a 400 yd line & still hit the target consistantly, once I figure out the elevation adjust & wait for the wind to stop.....

Trial & error. After you're content with the brass & bullet you're shooting, then make adjustments to your COL and note the differences.

Have fun, y'all... Off to bed. Heavy day tomorrow & rain on the way.

Frank in Fla.

I figured it out almost too ashamed to post the truth.....Here goes.....These darn dies confused me for one....for two the little set screw on top of the micrometer MUST be tight lol....if not the micrometer will move up and down making erratic adjustments to the seating stem....I tightened that set screw for the bullet seating stem and whammy all is well and the little notches are pretty darn accurate on the micrometer.....I apologize for my ignorance on this I swear I learn something scary new every single day....I wasnt gonna shoot until I had this figured out....these dies hardly give an ounce of runout also....pretty darn nice...Thank you all again and I apologize if I wasted anyones time....


Very Respectfully Submitted

Semper Fi

I am sure you are not the only one that has had that problem, ask my how I know ;D
Posting questions so others can and WILL help is what I really enjoy about this forum
Glad you got it worked out
Jack

lol. When the numbers don't add up. It usually is something silly like this. Check, check everything.

CFP......There is never such a thing as a stupid question when it comes to anything firearm related. Or for that matter.....women related. Because at least with firearms, you can generally fix 'em. If not...you can at least trade 'em in for another for a reasonable cost. (You know...not lose your entire life savings) ;D

I'm never embarrassed to ask any firearm related question...no matter how "dumb" I may think it is or others may think it is. Hey.....better to be safe....keep your eyesight, and have all your fingers than "what could happen."

Dave

The number 1 rule I use for troubleshooting almost ANYTHING - Look for the obvious first. 90% of the time, you'll find it right there. I had a mentor of sorts that I trained under as a journeyman electrician. Now that I'm a Master Electrician & State Registered Electrical contractor, I still use that rule and it always comes up right.


Ya see now Chesty.... You had all of us racking our brains trying to help resolve your issue. Heck... I even lost 2 nights sleep over it, worried to death..... sitting in my office at 2am wondering....Geezzz. I hope everythings alright with Chesty.

Now you gotta take us all out for lunch & a cold one. ;D We'll meet at your place.

Frank in Fla

Chesty, No harm, no foul. You are among friends. Thanks for sharing your problems.
Hopefully we can learn from your mistakes and you will learn from ours. Together, we will become a lot smarter (with respect to firearms...still up in the air whether or not men can ever be smarter about women!)

I wont even get into women holy crap....My wife has been through 5 combat deployments shes the toughest woman alive and she put up with my sorry A&&...lol...But seriously thank you gentlemen for the kind words and patience I mean that...Ill get to shoot the 7MMSAUM Ive been trying to build for months FINALLY. I think all im lacking is batteries for my chrono "the one i didnt shoot" and the printer and ill be a posting some results later tomorrow night with load and build data for anyone else shooting that fine rediculously overpriced round I did no real research on before I ordered the barrel...


Very Respectfully Submitted

Semper Fi

If I were you, I would be grateful to even hit the berm with that mismatch of parts ;D

LOL the parts are good its the shooter im worried about lol...I actually bought a go gauge instead of using a case this time not sure if that will help accuracy any but cant hurt right lol//

Just some Chrony advice.....(don't ask me how I know ::) ) But the next time your at a hardware store, pick up some wooden dowel rods that are the same size as the metal sun shield one's. That way....should your bullet hit the rod....instead of the metal rod sending shock waves thru your chrony, the wooden one's just snap as if nothing ever happen.

Of course....this only works when you use the sun screens and hit the rod part.

I like the hell out the wooden dowel idea for one the new chrono I have has two piece rods drives me crazy, i can barely tie my show much less deal with eight rods and 3 piece diffuser.....I know where ill be tomorrow and ill let ya know how it went and thank you very very much for the advice


Very Respectfully Submitted

Semper Fidelis

The wooden dowel idea is a good idea. Those two piece rods can be difficult sometimes. And wiping out my cronie would definitely ruin my day. Do the wooden dowels have enough (backbone) to hold the sunscreen securely?

Quote:

---

Originally Posted by Johnny Savage

Do the wooden dowels have enough (backbone) to hold the sunscreen securely?

---

Yeah, they work just fine. Just get the right size....don't get 'em to skinny.