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How to reduce COAL variation?


IGOTGLOCKED

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8 hours ago, 57K said:

Good job! When max possible OACL is established and you have a tolerance of +/- .005", your longest loads will be .010" off the lands and that is not too much. One reason I mention OACL in increments of .25mm is because it is very close to .010".

As far as I've been able to tell, SPEER and CCI brass may be identical. That is not the case with Blazer, however, which is a bit puzzling. But I guess when your loading cartridges in lots as large as they do, some engineer has determined through value engineering that the lower cost is significant enough to warrant the practice. And the cases you do end up culling from the rest work just fine for blasting ammo, or if you have enough, set OACL appropriate with those cases to get the same OACL.

Looks like I have my work cut out for me, all the advice is much appreciated!

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6 hours ago, 57K said:

IGG, range pickups are kinda based on economics, but there are still plenty of folks shooting Whitebox (WIN) and UMC (REM) ammo. Others can be reloaded but I think you'll find that they differ in the case of Aguila and PPU. I load brands like Fiocchi and GFI that is also Fiocchi along with S&B just as I would Rem and Win. I will mention though that the S&B brass have tight primer pockets and can be problematic for some with progressive presses. I do not and it's been a long time since I bought virgin brass. If I had to I would try to get S&B followed by StarLine, Win & Rem. The only real reason that 9mm brass gets retired is because of loose primer pockets, so I have no problem with S&B and I load semi-progressive with a LEE Classic Turret press.

I never heard this regarding the primer pockets. What are the warning signs they are beginning to loosen up I need to watch for?

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And like 57K mentioned, the S&B brass tends to have a bit tighter primer pockets, and it is excellent brass. One other brand that I personally like is Magtech, Both their ammo and brass is very good. 

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Sounds like a huge mess! What is your desired tolerance?

 

Going back to plated will certainly get the variance down. Might want to look at a comparator as well. I've noticed the coating or "nipple" can be uneven or jagged on the tip of a coated bullet giving false readings.

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  • 4 weeks later...

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As many of you know I have been on a mission to reduce my oacl. Consequently my next step in oacl variance reduction was to sort head stamps, which I did this weekend. This was pretty successful at least 90% of my rounds were within .003. A bunch were within .002. The extreme variance was was still about .005/6, perhaps a half dozen however that was my average prior to sorting head stamps. 

IGG

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1 minute ago, 57K said:

 

IGG, if your loading on a progressive, it really don't get better than that! .005/.006 isn't that bad either if that's kind of out of the norm. I bet nobody here could guess that I'm a bit anal about handloading. Even today, I don't have 1 single 50 round box of ammo where I haven't checked at least 10 cartridges for OACL variation, and some of that is to get an idea about bullet consistency, pistol or revolver loads. I start at 1 corner and move diagonally. When I get to one side I go up 1 row and go diagonally in the other direction. I like looking at my work!!!LOL!

Yes, progressive - Dillon 650. I case gauge of every round (always have) in the chamber of the gun I loading for... 

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1 minute ago, 57K said:

 

Are you using a competition seating die?

I started another post to ask however how am I able to stabilize my tool head. I believe if this can be accomplished I can still reduce my oacl if this is possible!

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7 minutes ago, 57K said:

 

No, I'm just asking, buddy. I use REDDING dies on my Classic Turret along with an RCBS Uniflow powder measure. That's so I can feel things by touch like thick or thin cases. Case-neck tension and primer pocket condition. With good quality bullets I can pretty much hold a tolerance of +/- .002". Not always and it is bullet dependent. I load 124 gr. Golden Sabers in defense loads and they won't typically be as tight while the old standard Rem 124 gr. JHP will along with a number of others. The last bullets I ordered were from SNS and I bought some 158 gr. .358s (polycoated) and I'm exceptionally pleased with their overall comsistency. They will maintian an OACL tolerance of +/- .002". About the only way I can do is on my REDDING single-stage!

 

Long story short, if you can get +/- .003" or better, I don't know that I would spend the xtra $ for a comp seating die. I'd probably buy bullets instead. But, if you're curious, yes, what I would buy would be REDDING.

Redding "Pro" or "Pro Competition"? 

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I just got the Redding Pro because my Redding micrometer die was giving me oal's with a variance from -.005 to .006.  I loaded my first hundred with the Pro die and got down to -.003 to +.003 and thought I had a huge improvement.  Today I switched from pd jhp to mg cmjand I was back to the larger variance again.  So I went over to the Redding site and found a post that talked about how the micrometer die worked.  It seats on the ogive of the bullet instead of the tip.  So that if your bullets are different in length your oal will be different but the base of the bullet inside the case should be pretty accurate.  I also found another post where somebody measured mg cmj bullets and there was a pretty good difference.  If you have a die that seats on the tip then your oal measurement measured with calipers should be pretty close.  To measure a bullet that seats by the ogive you need a bullet comparator.  I went back to my competition die because according to Redding it's made to seat the bullet straight.  Anyway I have a Pro die for sale if anybody is interested.

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Last I checked 100 rounds, I got +- .001 with Zero JHP and Starline brass. Seated with a Hornady seating die via Ammobot automated 1050.


Single headstamp is the best way to reduce variation. After that, stroke variation plays a big part also. Making the same stroke on the press every time is hard.


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18 hours ago, rooster said:

I just got the Redding Pro because my Redding micrometer die was giving me oal's with a variance from -.005 to .006.  I loaded my first hundred with the Pro die and got down to -.003 to +.003 and thought I had a huge improvement.  Today I switched from pd jhp to mg cmjand I was back to the larger variance again.  So I went over to the Redding site and found a post that talked about how the micrometer die worked.  It seats on the ogive of the bullet instead of the tip.  So that if your bullets are different in length your oal will be different but the base of the bullet inside the case should be pretty accurate.  I also found another post where somebody measured mg cmj bullets and there was a pretty good difference.  If you have a die that seats on the tip then your oal measurement measured with calipers should be pretty close.  To measure a bullet that seats by the ogive you need a bullet comparator.  I went back to my competition die because according to Redding it's made to seat the bullet straight.  Anyway I have a Pro die for sale if anybody is interested.

Thanks! A Redding tech told me the inside of the Comp is made at a tighter tolerance than the Pro. One would obviously assume then it aligns and seats the projectile straighter in the case...

However to confirm does the Redding Pro & Comp die seat on the ogive?

IGG

 

 

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There's a guy on you tube his handle is knowledgetoyou.  Or do a search on setting up a Redding micrometer die and he should come up.  He does a thorough setting up process better than the instructions by Redding.  I set my die up his way, but only got to load a few rounds but they were closer than anything else so far.  He explains setting up the bell so that the case is held in straight alignment with the bullet.  I don't know how to copy the video or I would've posted it here.

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17 hours ago, rooster said:

There's a guy on you tube his handle is knowledgetoyou.  Or do a search on setting up a Redding micrometer die and he should come up.  He does a thorough setting up process better than the instructions by Redding.  I set my die up his way, but only got to load a few rounds but they were closer than anything else so far.  He explains setting up the bell so that the case is held in straight alignment with the bullet.  I don't know how to copy the video or I would've posted it here.

Thank you!

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Only read the first couple replies...

 

thay said, the thing I have found to really get that last little bit out was to have the does lock but loose, run the shell plate into the tool head (while it's full, just like loading) and then tighten your jam/lock nuts down. That was the final piece to the puzzle for me. 

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Thanks for the video. I have been using the competition die for a couple years and set it up using the Redding instructions. I had no idea about the bell test though. I'll be checking my set up this evening.


Sent from my iPad using Tapatalk

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