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How much variation in bullet length is considered normal and acceptable


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I have begun reloading using synthetic coated bullets and encountered a issue with my loaded rounds that ended up with them  being to long that some great members here educated me and allowed me to figure out and solve my problem 

It got me to wondering just how much should a HG bullet vary in length before it becomes unacceptable 

I took 25 random 124 grain Hi-Tek coated RN bullets from a bag of 500 and measured them all I don't recall their exact lengths but I do recall 21 were +/- withiin 0.0015 and 0.002 in length but 4 varied up to 0.0006-0.007 in length

How much difference in bullet length is normal and acceptable?

 

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Just load em up and go shoot.

It’s in our nature but we OFTEN tend to make reloading way more complicated than it needs to be.

If you’re shooting a rifle at a 1000 yards or more then by all means measure away. Measure everything.

But for 99% of pistol applications you’re wasting time you could be shooting.

One of my very good friends tends to obsess over minute often inconsequential reloading details and tell him the same thing.


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That’s pretty good very acceptable, there’s no way to get them much closer unless you was using some type of match bullet with new brass of all the same head stamp. My guns shoot just fine with a higher deviation in oal then yours.

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I have come across the same issue, I don't call it a problem yet, but I have to work around this. From your earlier post on the cartridge hanging up or at least requiring more than normal force to pull the slide back. These issues are related. A question is "How to get close, less variation, in COAL". I have tried multiple seating dies and I still have some variation I don't care for. 

Too much? I would be happy with 5 or less thou, I am trying different dies and always pulling the lever the same. The problem is the worst with the coated bullets I have tried, I won't say any names. I got frustrated and grabbed a trusted bag of 115 FMJ's and the variation is back under 4 thou, .004". It is easy to say so what, that is not why I reload, this is a technical hobby and often a problem solving exercise. I you every tool I can to make good ammo, by that I mean ammo that works correctly in correctly manufactured and assembled guns. I try to make ammo to SAAMI specs, I go by SAAMI specs, I assume the guns are to spec. I recently found a close friends pistol to be out of spec.  The 9mm is the popular guy and lots of mods are done every day, some good some maybe not so much.

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30 minutes ago, AverageJoeShooting said:

just get a redding competition seating die. Has a micrometer ontop so you set it once and it loads to the same length each time 

If you use the Redding Micrometer Seating Die, and check the COAL to .000", there will be variations regardless of what press we're using.  One thing that will shrink variances with the Redding Die is to remove the internal spring when seating pistol calibers.  Also, when setting the micrometer, make sure the shellplate is full then do final, fine adjustments.

 

My RL1100 is sporting a complete set of Redding Competition Pro Dies, and they always produce first class ammo!

 

👍

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In 9mm your going to have as much as +or- 10 thou. You can cut that down quite a bit by loading same headstamp. Another problem is that your seat dies work off the ogive of the bullet. Because of the variation in the bullets themselves your not seating off the same place on the bullet everytime,, however the part of the bullet in the case is pretty close. If you were to seat off the bullet tip then your oal would be spot on, but you length of bullet in the case would vary. Jacketed bullets are going have the least variation, but I have measured them and they are off also. It’s all a combination of variables that you as the reloader have no control over. Just load and shoot.

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19 hours ago, iflyskyhigh said:

Just load em up and go shoot.

It’s in our nature but we OFTEN tend to make reloading way more complicated than it needs to be.

If you’re shooting a rifle at a 1000 yards or more then by all means measure away. Measure everything.

But for 99% of pistol applications you’re wasting time you could be shooting.

 

+1

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Hogrider.

You mention removing the spring, I had not thought of that, thanks for the tip. I will try and see if it helps. You also mentioned to make sure the shell plate is full and then final adj?? Do you mean I should bottom the die against the shell holder, I am using a single station press for this operation. Does the shell plate do the same thing in a progressive loader. I picked up on that from another contributor a couple of weeks ago, maybe it's helping I can't tell yet. Back to the spring, if I am seating a jacketed bullet FMJ or JHP the Redding die seems to work it's best. The real issue, the issue that got me here for help, is with coated bullets. When I seated coated bullets I had my greatest variation in COAL. The problem didn't stop there, every once in a while, 8 or 10 cartridges the seat die would make a loud snapping noise, as if the coating had a "Sticky" property to it. My bullets don't feel sticky but I also remember the feeling of the slide being harder to pull back with a coated bullet sometimes. My guess is there is a variation in the thickness of the coating on the ogive of the bullet. I can't measure much difference on the diameter, .0005+- with a really good mic. I don't think it has to do with dia. it seems like the ogive. All I see to do is seat deeper for a safety margin and watch the powder charge because of the deeper seating. Thanks for any ideas.

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On a progessive press, somewhere between .005”-.010” is expected.

 

Most of that is due to variances in brass tension / mouth thicknes / mouth diameter... and often neglected? Variations in bullet profile. They’re seated off the ogive (shoulder) and yet we measure our OAL at the tip.

 

If I set my 1050 up for 1.130” OAL, I’ll see coated bullet mixed brass loads from 1.127” - 1.135” most of the time. Perhaps more, perhaps less. 

What is normal for a newer ammoloader to do? Why, go googling away for widgets and CNC-Machined shellplates to tighten the press up!

 

First thing I’ll do having learned my lesson, 15 years later? I’ll take that ammo and go chono it. Then shoot groups with it. If it’s the powerfactor I desire and it shoots a tight group relative to that bullet’s capability in that weapon? We’re done here. Load thousands and leave it alone. If it’s accurate and it feeds flawlessly, it doesn’t matter what your calipers say.

 

Edited by MemphisMechanic
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MemphisMechanic,

Thanks for the input, I suspected a large variation would be the case in a progressive press, and if I can get a grip on some of these little nit picks I will set up a progressive and run batches of proven loads. I don't load mixed brass, yeah, I know, I sit there and sort the damn stuff, by brand and by head stamp variation. My issue is I really like to make good ammo, I know if it goes bang and hits the paper close that is often all that is needed. I am loading for 14 different 9mm pistols. My close friend has a dozen and I handload. With just my 2 life is easy, the extra 12 make it interesting. I want to be able to load safe accurate ammo that feeds correctly, ejects and returns to battery. I am watching components getting hard to get and coated bullets seem to be the way to go. Thirty years ago I bought my brand name bullets, went to the reloading manual by the same manufacture and picked a load. I read the specs on the page and go by the data and it always worked. Today we can buy bullets with no or minimal load data, maybe a close COAL, so it needs to be developed. I do use a chronograph, I am trying to get my coated bullet loads at least close to jacketed bullet ammo. I am trying to get input from you folks that have done more volume 9mm than I have. I hate having a sheepish look and wondering why a load works in my 2 pistols and 10 0r 11 of my friends. Sometimes its simple, "Has this ever been cleaned?" Thanks for the tips!

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1 hour ago, DryHeat said:

Hogrider.

You mention removing the spring, I had not thought of that, thanks for the tip. I will try and see if it helps. You also mentioned to make sure the shell plate is full and then final adj?? Do you mean I should bottom the die against the shell holder, I am using a single station press for this operation. Does the shell plate do the same thing in a progressive loader. I picked up on that from another contributor a couple of weeks ago, maybe it's helping I can't tell yet. Back to the spring, if I am seating a jacketed bullet FMJ or JHP the Redding die seems to work it's best. The real issue, the issue that got me here for help, is with coated bullets. When I seated coated bullets I had my greatest variation in COAL. The problem didn't stop there, every once in a while, 8 or 10 cartridges the seat die would make a loud snapping noise, as if the coating had a "Sticky" property to it. My bullets don't feel sticky but I also remember the feeling of the slide being harder to pull back with a coated bullet sometimes. My guess is there is a variation in the thickness of the coating on the ogive of the bullet. I can't measure much difference on the diameter, .0005+- with a really good mic. I don't think it has to do with dia. it seems like the ogive. All I see to do is seat deeper for a safety margin and watch the powder charge because of the deeper seating. Thanks for any ideas.

Dry:

I took it for granted you were on a progressive!  Sorry, but if you using a single station press for this op as you stated, then simply use the setup instructions that came with your die.  There's also a .pdf for setup on Redding's website.

 

After loading thousands of coated bullets, I have never had any "sticking" issue with the various brands I have used.  I'm assuming the snapping noise happens when the seated round just begins to exit the seating die?  IMO, if you had sticking/snapping caused strictly by the bullet, there would be some sort of markings/indentions on the ogive!  Only time I have felt resistance in the seating die was either due to over-belling the case mouth which causes the outer case edge to rub against the inside of the seating die body.  Or, there was not enough expansion of the case mouth to allow the bullet a smooth transition into the case body while seating.  Make up a few dummy rounds (no primer or powder) then knock the bullet out of the case and look for scarring/scraping of the coating away from the lead core.  Also, take a permanent marker and blacken the walls of the case to see if anything is contacting the brass.

 

What diameter coated bullets are your loading?  Definitely makes a difference...........

 

If your trying to load for 12 different pistols, your off to an extremely challenging process!  My recommendation is to find a load that shoots well in YOUR TWO PISTOLS and document/test for a common load that shoots well in both.  DO NOT seat deeper for a "safety margin"!  Use this information to find a COAL that fits and functions in BOTH YOUR GUNS:

 

https://czfirearms.us/index.php?topic=34225.msg189131#msg189131

 

Then while checking and double checking the info for your particular powder, primer, and bullet combo at your DESIRED COAL, load up a sufficient number of test rounds and follow Memphis Mechanic's advise and TEST THOSE LOADS!

 

Make sure you use a QUALITY case gauge and/or YOUR PRIMARY gun barrel to check each and every round until you get these issues resolved.

 

Once you've developed loads that work just as you desire in YOUR PISTOLS, use what you've learned and develop loads for the "other 10 pistols"................

 

Good luck!

 

 

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Hogrider

Thanks for the detailed input and the link to a very good explanation for seating depth and COAL. It's about the same as I used the keep the bullets just off the rifling loading a 220 Swift.  The seating die does make the noise when I reverse the lever, come off of full seating depth. I am new with this type of die, I was hoping for a cure in COAL variation, not the case, in fact it got worse. I understand variation in bullet length, measure for that on a per batch basis, I usually grab 50 out of 750 or 1000 and set down and measure and record, if I use a seat die that pushes on the nose and not the ogive the difference is inside the case in theory and most of the time in practice. I have picked SWC seat stems that only touch the nose of the Truncated Cone 9mm bullets. I have used the barrel from my pistols as a gage, but only to confirm that I hadn't gone mad yet. I use 3 gages, a Dillon case gage, a Wilson Pistol Max gage, more on that later, and an EGW 7 cartridge gage. I use a PTG GO-NO Go field set to check the pistols, all but one passed. I think the bullet diameter is ok enough, I buy the .356 dia. bullets as suggested for lead over the years. The coated bullet I am working with on this load measures .3565 +.0000 -.0005. I think they are as good as I can get in a lead cast bullet. I think a die formed cup and core bullet is better, but it costs a lot more. I would like to be cranking out 12 to 15 hundred rounds a week, it was a regular week with jacketed bullets. My real issue haunts my loading bench with the coated bullets. When I bell the case mouths I have walked around the barn a couple of times, I bell only enough to get a good straight start for the seating process. I typically load up 3 or 4 dummy rounds for checking later. I use a separate taper crimp die and I only use enough crimp to straighten the case wall, if it isn't good the EGW cartridge checker will show it up. On my dummy rounds I use a kinetic puller and check for over crimp and damage to the coating. I learned in the late 90's I think about too much crimp on plated bullets in the 9mm, too much crimp and it seemed like they left the barrel sideways. I thank you for your thoughtful help. I think you know what my goal is, if the factories can do it, so can I. Stay on two wheels and thanks for the help.

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Competition pistol rounds are not PRS rifle rounds.  Variation is normal.  For reference, my loads are 1.130-1-135.  As long as you gun likes them, shoot them.  Did you plunk test your barrel to determine the longest OAL?  Your gun will be the judge of what it likes.

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