How to reduce COAL variation?

[IGOTGLOCKED]

I am reloading 9 on a 650 bolted securely (no strong mount) to a 2'x8' bench made with 2x6's all bolted together, no nails or screws. The bench is secured to the wall and bolted to the floor. I have rechecked all the bolts to be sure nothing is loose. The bench is rock solid! I can tell you since securing the bench to the wall and bolting the legs to the floor my 650 runs noticeably smoother. 

I am loading with mixed head stamps & hi-tek coated 145 gr rn.

I ran a hundred rounds yesterday and I have a variance of .010 between the very shortest and the very longest. The majority of which were probably at about .006/7 ish variance. Dillon mentioned in the manual .016 is ok however that really seems like a lot?

First how are my variances compared to really good numbers? Second, what am I able to look at to understand what might tighten my COAL variances?

Thanks from IGG!

[js1130146]

Well, the first place I'd look is bullet variance. If all the bullets aren't identical, then you will always have variance in OAL. In my experience coated bullets from the same lot can vary a decent amount in most dimensions. It might be enough when loaded in mixed brass to explain your variances.

[IGOTGLOCKED]

4 minutes ago, js1130146 said:

Well, the first place I'd look is bullet variance. If all the bullets aren't identical, then you will always have variance in OAL. In my experience coated bullets from the same lot can vary a decent amount in most dimensions. It might be enough when loaded in mixed brass to explain your variances.

Coated vary more than plated?

[jcc7x7]

1 hour ago, IGOTGLOCKED said:

Coated vary more than plated?

Yes and coated is all I shoot , Limited, SS and open

Try case lube it makes the machine run smoother and smoother is more constant, i.e less variation in oal

With mixed 9 brass that was the key for me and it's just easier to load with the Dillon spray lube than without it

Neil

[IGOTGLOCKED]

2 minutes ago, jcc7x7 said:

Yes and coated is all I shoot , Limited, SS and open

Try case lube it makes the machine run smoother and smoother is more constant, i.e less variation in oal

With mixed 9 brass that was the key for me and it's just easier to load with the Dillon spray lube than without it

Neil

Thanks, so no need to sort out all like head stamps?

[js1130146]

45 minutes ago, IGOTGLOCKED said:

Thanks, so no need to sort out all like head stamps?

I've never bothered even with 9 major. Just sort to cull the crap brass and start loading.

Sorting your brass (and bullets) will help reduce your inconsistencies and increase your accuracy. But IMO it's not worth the time investment for USPSA. YMMV

[glassblower]

Some factors to consider........

Is your OAL at the point where the bullet is contacting the rifling at the longest measured value? If the bullet is contacting the rifling, then you could be causing high pressure and you either need to shorten the OAL or lessen the variation. The point being is that some variation in OAL can be ok depending on your intended use. 

Check and clean your bullet seating die occasionally as the bullet coating can stick to the seating die and cause variation in subsequent rounds.

Verify that there is consistency in the bullet shape. I received some projectiles from a reputable manufacture that had several different lot numbers and there was enough variation in the profile to drive me crazy with OAL variation. Turned out they did have an issue in the manufacturing process and did replace the bad lots.

Sort some head stamps and set up your OAL using only the single heads stamps. Then you will know the variation and can work to reduce it with the single head stamp. When you've done that, you know whether mixed head stamps will fit your needs or temperament.

Make sure that the shell plate doesn't wobble, if it does it can induce OAL variation. There are a number of fixes to help reduce the shell plate wobble in the forums.

When I added a Mr Bullet Feeder to my 1050, I started getting smaller variations in my OAL and I "think" it was caused by the bullet feeder consistently placing the projectile in the same vertical position for every case. If doing it by hand you could introduce enough tilt in the projectile that the seating die may not be able to straighten. That means the die is pushing on a different point on the profile.

Oh, and I've done all those things and still sometimes get substantial variation depending on the weather, prayer, holding my mouth right, chewing gum, excess gas, or other random factors.

[Sarge]

IGG,

use case lube, sort by headstamp, make sure shell plate is not wobbly loose, run the press at normal speed, to see really tight numbers. 

Dry cases means the sizer die travels a little different distance every pull of the handle. Believe it or not nearly every brand of brass will yield a different oal with everything else being equal. Tight shell plates produce better results all around. I put the bearing kit on my press and it allows you to really tighten the plate down yet still turn freely. Lastly, the worst thing you can do is run the press one round, pull it out and measure, repeat, etc. I found if you start loading and pull the first few completed rounds out of the bin then just pull the handle 20 times or so at normal operating speed, THEN measure those 20, THAT is going to produce your real  average.

If none of the above appeals to you then by all means just make sure the longest rounds coming off the press fit your gun and mags and call it good!

I hope this helps. Feel free to on me anytime. I happen to like helping reloaders get the most out of their 650.

[resortboarder]

Consistency in your stroke is key. When combined with case lube, you'll get even better results.  Add in many of the other recommendations and you should be as consistent as the bullets will allow you to be.

I'm not interested in sorting my brass by headstamp and I only use one bullet weight and profile, but I've noticed that my COAL will increase if I slow down at the bottom of my stroke even a little bit. 

[JLeeCZ]

Different bullet lengths would affect seating depth variations more so than OAL. It's the stroke.

[Hi-Power Jack]

Is the large OAL affecting functioning or accuracy or PF?

I find that a normal amount of deviation in powder charge or OAL

usually doesn't have that much impact on short ranged pistol cartridges.     

[IGOTGLOCKED]

17 hours ago, jcc7x7 said:

Yes and coated is all I shoot , Limited, SS and open

Try case lube it makes the machine run smoother and smoother is more constant, i.e less variation in oal

With mixed 9 brass that was the key for me and it's just easier to load with the Dillon spray lube than without it

Neil

I have and always do lube my 9, thx!

[IGOTGLOCKED]

16 hours ago, glassblower said:

Some factors to consider........

Is your OAL at the point where the bullet is contacting the rifling at the longest measured value? If the bullet is contacting the rifling, then you could be causing high pressure and you either need to shorten the OAL or lessen the variation. The point being is that some variation in OAL can be ok depending on your intended use. 

Check and clean your bullet seating die occasionally as the bullet coating can stick to the seating die and cause variation in subsequent rounds.

Verify that there is consistency in the bullet shape. I received some projectiles from a reputable manufacture that had several different lot numbers and there was enough variation in the profile to drive me crazy with OAL variation. Turned out they did have an issue in the manufacturing process and did replace the bad lots.

Sort some head stamps and set up your OAL using only the single heads stamps. Then you will know the variation and can work to reduce it with the single head stamp. When you've done that, you know whether mixed head stamps will fit your needs or temperament.

Make sure that the shell plate doesn't wobble, if it does it can induce OAL variation. There are a number of fixes to help reduce the shell plate wobble in the forums.

When I added a Mr Bullet Feeder to my 1050, I started getting smaller variations in my OAL and I "think" it was caused by the bullet feeder consistently placing the projectile in the same vertical position for every case. If doing it by hand you could introduce enough tilt in the projectile that the seating die may not be able to straighten. That means the die is pushing on a different point on the profile.

Oh, and I've done all those things and still sometimes get substantial variation depending on the weather, prayer, holding my mouth right, chewing gum, excess gas, or other random factors.

Indeed I have done the "plunk & spin" so am good there.

Ironic that I just happened to clean my dies the night before I loaded the 100 test rounds. I soaked them in alcohol, blasted with my compressor and swabbed them out.

I will check bullet shape, didn't think of that.

As suggested I will sort some head stamps and run another test batch, that will be a great test.

Shell plat is solid, I have had that aftermarket bearing under the shell plate since it was new.

Would lubing the bullets help the seating die to better seat if bullet is slightly tilted?

Thanks for all the suggestions glassblower!

[mjmagee67]

Mixed cases is your major issue. What to you get when you use only one brand of brass? I only sort brass for major matched. With mixed brass I'm fine with +/- .006. for a range of .012 to .013. If I sort by head stamp like I do for major matches I get +/- .02 to .03 pretty regularly.

[amada8]

2 hours ago, IGOTGLOCKED said:

Shell plate is solid, I have had that aftermarket bearing under the shell plate since it was new.

Please tell us you wrote this incorrectly.

The bearing goes on top of the shell plate, under the head of the bolt.

 

From top to bottom:

1 Wire clip (to exit completed cartridges).  You probably need to tweak this part.

2 Bolt

3 Washer

4 Bearing

5 Washer

6 Shell plate

 

Edited January 4, 2017 by amada8

[IGOTGLOCKED]

1 hour ago, amada8 said:

Please tell us you wrote this incorrectly.

The bearing goes on top of the shell plate, under the head of the bolt.

 

From top to bottom:

1 Wire clip (to exit completed cartridges).  You probably need to tweak this part.

2 Bolt

3 Washer

4 Bearing

5 Washer

6 Shell plate

 

Thank you for catching this for confirmation. This was incorrectly stated, it is installed under the shell plate correctly.

[amada8]

Cmon IGG,,, the bearing goes on top.......

 

[IGOTGLOCKED]

6 minutes ago, amada8 said:

Cmon IGG,,, the bearing goes on top.......

 

I did it again! Sometimes I get in a hurry and I need to do a better job proofing what I type...

I swear it is installed correctly. It was actually installed by the distributor who I bought the 650 from... He said he sells them all with it specifically due to eliminating the powder spill experienced with out it.

Thx again!

[IGOTGLOCKED]

27 minutes ago, 57K said:

 

Good points here, particularly concerning your longer loads. I would advise making sure that there's at least .005" of free-bore with your longest loads regardless of the equipment one may be using. Actually, +/- .005" is not bad for progressive reloading.

Some foreign brands of brass are thicker. The extra friction when seating bullets in them will result in longer loads. Nickel cases will do the same. As far as WIN, REM, FED, SPEER, CCI (Not BLAZER) Starline, Hornady, Fiocchi & GFI and S&B are pretty close to the same case-wall thickness. Others that may be thicker, I cull them out and don't load nickel plated with brass.

Remember that every moving part in your reloading press can allow flex. Typically, the flex is offset somewhat by flexing the same amount if you maintain the same technique as has also been mentioned. I also like presses that have a top-dead-center feature, but so far no progressive press maker uses it and REDDING does not make a progressive. This might be a case where a competition seating die will help maintain consistent OACL.

 

I did the plunk & spin test then backed it off .015 from there.

I will sort the nickel and Blazer out.

Thank you for this!

[IGOTGLOCKED]

2 hours ago, mjmagee67 said:

Mixed cases is your major issue. What to you get when you use only one brand of brass? I only sort brass for major matched. With mixed brass I'm fine with +/- .006. for a range of .012 to .013. If I sort by head stamp like I do for major matches I get +/- .02 to .03 pretty regularly.

Then perhaps I am in the ball park? My variance on the majority is about 1.157/8 to 1.164.

All the input given seems logical and I am going to check/implement all the changes that have been discussed and see where it takes me from here.

Thx!

[bwikel]

2 hours ago, amada8 said:

From top to bottom:

1 Wire clip (to exit completed cartridges).  You probably need to tweak this part.

2 Bolt

3 Washer

4 Bearing

5 Washer

6 Shell plate

 

I omit #5, no real need for the washer under when the bearing can ride on the top of the shell plate. It also makes it easier to get the ejector wire in place without having to tweak it.

[Sarge]

Just now, bwikel said:

I omit #5, no real need for the washer under when the bearing can ride on the top of the shell plate. It also makes it easier to get the ejector wire in place without having to tweak it.

Yep. Washer on top only for me.

[IGOTGLOCKED]

1 hour ago, Sarge said:

Yep. Washer on top only for me.

This is all such great input thank you!

[IGOTGLOCKED]

20 hours ago, Sarge said:

IGG,

use case lube, sort by headstamp, make sure shell plate is not wobbly loose, run the press at normal speed, to see really tight numbers. 

Dry cases means the sizer die travels a little different distance every pull of the handle. Believe it or not nearly every brand of brass will yield a different oal with everything else being equal. Tight shell plates produce better results all around. I put the bearing kit on my press and it allows you to really tighten the plate down yet still turn freely. Lastly, the worst thing you can do is run the press one round, pull it out and measure, repeat, etc. I found if you start loading and pull the first few completed rounds out of the bin then just pull the handle 20 times or so at normal operating speed, THEN measure those 20, THAT is going to produce your real  average.

If none of the above appeals to you then by all means just make sure the longest rounds coming off the press fit your gun and mags and call it good!

I hope this helps. Feel free to on me anytime. I happen to like helping reloaders get the most out of their 650.

I have and do use case lube (One Shot)

I will sort by head stamp, which ones have you found out load best/worst?

I will recheck my shell plate. IF it requires adjusting I assume I will have to readjust my dies as a result - correct?

I will run a re-test and put aside the first few then check the next couple of dozen and report back with the results. This is really a great point and makes a lot of sense...

Lastly I am an engineer (code for OCD) I want to produce the best rounds I am able to at a reasonable budget. I can't afford to shoot all Starline. And obtaining "accepatble" results and calling it good is NOT me...

Thanks for patience and all your help over time Top!

 

[SOA1911]

IGG, like you, I am very thorough in my reloading style, and some may call me OCS too.

57K, I have come to the same conclusions concerning brass as you. In the case of 9x19 mm, I will cull a few headstamps (e.g. Blazer), but most are of good quality. Last week, I reloaded some mixed 9mm Luger brass, and I noticed an odd "feel" during my sizing and crimping process. So, I stopped and checked the cartridges' specs. Everything was good except for the crimp. Each were 0.003" off: 0.379" instead of my chosen crimp of 0.376". Each cartridge had a PMP headstamp, which is from South Africa. Very odd.