Not getting consistant OAL

IamArmed · December 21, 2014, 07:58 PM

I'm finding it very hard to maintain a consistant OAL when I seat bullets. I have a Lee breechlock single stage O loader and use Lee Carbide 9mm dies. The range varies randomly as much as .009 mm. As an example, when trying for a .980 OAL, I may end up with .976 - .985. Any suggestions?

chris in va · December 21, 2014, 08:26 PM

I reload 9mm using home cast lead bullets and they tend to vary that much as well, using my Lee hand press.

You can try using brass of the same headstamp as I've noticed some cases are much softer than others. Federal is like tissue paper while S&B is more like steel.

Bart B. · December 21, 2014, 08:30 PM

I'd shoot them. That much spread in OAL is trivial. And about what I get with 9mm reloads for my a Browing Hi Power. They're very accurate.

Years ago, when I shot bullseye pistol matches, I thought their match ammo had to be perfect. I was given a box of commercial .45 ACP wadcutter match ammo and a dial caliper to measure their OAL. Spread was .008". It shot almost 2 inches at 50 yards from a match M1911 clamped in a machine rest. A box of LC match ball ammo was about the same. It shot about 3 inches at 50 yards.

Wreck-n-Crew · December 21, 2014, 08:55 PM

Even though I don't see the small variance as an issue with function anything over .05" variance is usually due to inconsistent stroke on that particular press.

Check your primers to be sure they are properly seated. Also rotate the round and check the OAL again or as you go. Sometimes it is the alignment with the calipers when measuring. Finally check the OAL of the bullet itself. The ogive can vary on some bullets and though seating depth may be the same the OAL can vary. If your loading a real soft tipped lead round for rifle it may be flattening slightly when seating and your OAL will vary too.

berettaprofessor · December 21, 2014, 09:07 PM

I don't normally see variation like that with either my Lee single stage or turret. In fact, in a batch of 50 9mm, I don't see variation of 0.002, let alone 0.009. Almost all rounds are spot on. I do batches with the same brass, so I can't speak to varied brass in the same lot of cartridges.

How long has it been since you cleaned your dies? Any chance some grease is gunking it up. Are you making consistent strokes with the press, pushing hard at the bottom?

Wreck-n-Crew · December 21, 2014, 09:28 PM

Quote:

How long has it been since you cleaned your dies? Any chance some grease is gunking it up.

Forgot about that one !

**Unclenick** · December 21, 2014, 10:17 PM

A lot of this depends on the bullet. If you have a bullet comparator attachment for your caliper, try zeroing on the length of one of your bullets by moving it of to the side of the hole in the comparator so the bullet nose presses against the flat part of the insert next to the hole. Then measure with the bullet entering the hole normally and record the difference. Do that with a dozen bullets and see if what you measure doesn't account for what you see in the loaded rounds. Other batches of other bullets can be more consistent.

Also, look at your cases where the bullet base bulges the brass slightly. Ideally you want that brass even all around. Otherwise the bullets are tilting on their way into the cases. Using a Lyman M type expander (doesn't have to Lyman brand, but I mean one that puts a small step in the case mouth) to get bullets started upright will help considerably with that.

I've had .30 cal match rifle bullets vary 0.011" in length out of the same box, though the comparator's ogive-to-base measurements varied more like a third of that. In any case, whether from mold for from forming die, bullets are not perfectly identical. Bryan Litz said he's measured 3% variation in B.C., bullet-to-bullet at firing. Mostly these variations are below the radar as far as precision on paper is concerned, with other error terms being far more significant.

Only God is perfect. People get variations.

Barnacle Brad · December 21, 2014, 10:44 PM

I used to wonder about the deviation in oal, but once I was made aware that the seater plug was locating on the ogive and not the nose I was measuring to, it made more sense. Especially with soft point bullets, you are measuring any deformation in the point of the bullet. (Realize there are different seater plugs for different bullet profiles)
I dont have a comparator, but if I did I am sure it would remove most of the deviation I see. I pay no heed to .005 to .015 spread with soft points. For ballistic tips .005 is better, or more to expectations. But I just load hunting rounds...

When in doubt, listen to Uncnlenick.

Bart B. · December 22, 2014, 12:25 PM

Deleted

IamArmed · December 30, 2014, 07:01 PM

Thank you one and all for your time and efforts. I sorted my cases by head stamps and that appears to have solved the problem. Maximum variance is now just .001 or less. Thanks again.

Wreck-n-Crew · December 30, 2014, 07:24 PM

Quote:

Thank you one and all for your time and efforts. I sorted my cases by head stamps and that appears to have solved the problem. Maximum variance is now just .001 or less. Thanks again.

Not sure how case head stamps have to do with OAL other than maybe tight primer pockets causing problems with primer seating depth.

Either way doesn't matter if problems desist's i recon. keep checking and congrats!

MarkGlazer · December 30, 2014, 08:49 PM

Consistency in components is most likely the issue here and you have already determined that by sorting by headstamp. I find variations in the size of cases all the time, depends upon the manufacturer and yes, it is a bit frustrating. The same is true with the bullet. The primer only becomes an issue if you haven't seated it flush, and you should of course.

As stated by the contributors, precise OAL is not completely relevant. I'm a bit out of my depth here because I do not compete nor do I hunt at this time. There are those who can wax on about the need for precision in these areas. For my own purposes, the question is whether or not the round properly chambers and fires and whether or not you have loaded it within safe ranges, adjusting for the fact the OAL will vary.

PS - I do like and appreciate the person who commented about a clean die. Lead cast bullets are going to shed (for lack of a better description) and removing the plug, cleaning and coating with gun oil will go a long way towards consistency, not to mention keeping rust away.

Good luck. Be safe.

December 21, 2014, 07:58 PM	#1
IamArmed Junior Member Join Date: November 8, 2014 Posts: 10	Not getting consistant OAL I'm finding it very hard to maintain a consistant OAL when I seat bullets. I have a Lee breechlock single stage O loader and use Lee Carbide 9mm dies. The range varies randomly as much as .009 mm. As an example, when trying for a .980 OAL, I may end up with .976 - .985. Any suggestions?

December 21, 2014, 08:55 PM	#4
Wreck-n-Crew Senior Member Join Date: March 8, 2013 Location: Ohio Posts: 1,820	Even though I don't see the small variance as an issue with function anything over .05" variance is usually due to inconsistent stroke on that particular press. Check your primers to be sure they are properly seated. Also rotate the round and check the OAL again or as you go. Sometimes it is the alignment with the calipers when measuring. Finally check the OAL of the bullet itself. The ogive can vary on some bullets and though seating depth may be the same the OAL can vary. If your loading a real soft tipped lead round for rifle it may be flattening slightly when seating and your OAL will vary too. __________________ If you ever have to use a firearm, *you don't get to pick the scenario!*

December 21, 2014, 10:17 PM	#7
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	A lot of this depends on the bullet. If you have a bullet comparator attachment for your caliper, try zeroing on the length of one of your bullets by moving it of to the side of the hole in the comparator so the bullet nose presses against the flat part of the insert next to the hole. Then measure with the bullet entering the hole normally and record the difference. Do that with a dozen bullets and see if what you measure doesn't account for what you see in the loaded rounds. Other batches of other bullets can be more consistent. Also, look at your cases where the bullet base bulges the brass slightly. Ideally you want that brass even all around. Otherwise the bullets are tilting on their way into the cases. Using a Lyman M type expander (doesn't have to Lyman brand, but I mean one that puts a small step in the case mouth) to get bullets started upright will help considerably with that. I've had .30 cal match rifle bullets vary 0.011" in length out of the same box, though the comparator's ogive-to-base measurements varied more like a third of that. In any case, whether from mold for from forming die, bullets are not perfectly identical. Bryan Litz said he's measured 3% variation in B.C., bullet-to-bullet at firing. Mostly these variations are below the radar as far as precision on paper is concerned, with other error terms being far more significant. Only God is perfect. People get variations. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

December 21, 2014, 10:44 PM	#8
Barnacle Brad Senior Member Join Date: March 12, 2009 Location: Greybull, Wyoming Posts: 416	I used to wonder about the deviation in oal, but once I was made aware that the seater plug was locating on the ogive and not the nose I was measuring to, it made more sense. Especially with soft point bullets, you are measuring any deformation in the point of the bullet. (Realize there are different seater plugs for different bullet profiles) I dont have a comparator, but if I did I am sure it would remove most of the deviation I see. I pay no heed to .005 to .015 spread with soft points. For ballistic tips .005 is better, or more to expectations. But I just load hunting rounds... When in doubt, listen to Uncnlenick. __________________ Brad

December 22, 2014, 12:25 PM	#9
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Deleted Deleted Last edited by Bart B.; December 22, 2014 at 12:37 PM.

December 21, 2014, 08:26 PM	#2
chris in va Senior Member Join Date: December 26, 2004 Location: Louisville KY Posts: 13,806	I reload 9mm using home cast lead bullets and they tend to vary that much as well, using my Lee hand press. You can try using brass of the same headstamp as I've noticed some cases are much softer than others. Federal is like tissue paper while S&B is more like steel.

December 21, 2014, 08:30 PM	#3
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	I'd shoot them. That much spread in OAL is trivial. And about what I get with 9mm reloads for my a Browing Hi Power. They're very accurate. Years ago, when I shot bullseye pistol matches, I thought their match ammo had to be perfect. I was given a box of commercial .45 ACP wadcutter match ammo and a dial caliper to measure their OAL. Spread was .008". It shot almost 2 inches at 50 yards from a match M1911 clamped in a machine rest. A box of LC match ball ammo was about the same. It shot about 3 inches at 50 yards.

December 21, 2014, 09:07 PM	#5
berettaprofessor Senior Member Join Date: November 23, 2008 Posts: 1,091	I don't normally see variation like that with either my Lee single stage or turret. In fact, in a batch of 50 9mm, I don't see variation of 0.002, let alone 0.009. Almost all rounds are spot on. I do batches with the same brass, so I can't speak to varied brass in the same lot of cartridges. How long has it been since you cleaned your dies? Any chance some grease is gunking it up. Are you making consistent strokes with the press, pushing hard at the bottom?

December 30, 2014, 07:01 PM	#10
IamArmed Junior Member Join Date: November 8, 2014 Posts: 10	Variance minimalized Thank you one and all for your time and efforts. I sorted my cases by head stamps and that appears to have solved the problem. Maximum variance is now just .001 or less. Thanks again.

December 30, 2014, 08:49 PM	#12
MarkGlazer Senior Member Join Date: February 19, 2013 Location: Atlanta, Ga Posts: 329	Consistency in components is most likely the issue here and you have already determined that by sorting by headstamp. I find variations in the size of cases all the time, depends upon the manufacturer and yes, it is a bit frustrating. The same is true with the bullet. The primer only becomes an issue if you haven't seated it flush, and you should of course. As stated by the contributors, precise OAL is not completely relevant. I'm a bit out of my depth here because I do not compete nor do I hunt at this time. There are those who can wax on about the need for precision in these areas. For my own purposes, the question is whether or not the round properly chambers and fires and whether or not you have loaded it within safe ranges, adjusting for the fact the OAL will vary. PS - I do like and appreciate the person who commented about a clean die. Lead cast bullets are going to shed (for lack of a better description) and removing the plug, cleaning and coating with gun oil will go a long way towards consistency, not to mention keeping rust away. Good luck. Be safe. __________________ non ministrari sed ministrare