Called Dillon today with a question......

[S8MS-01904]

Yes, called Big Blue to ask why my O.A.L. is fluctuating.

Here's the scoop: Loading 9mm with carbide Dillon dies on a 550B with SNS 147g RN coated bullets. Using Range pick-up brass that has been tumbled in corncob media.

Trying to set length at 1.1470 to 1.1475" using 3.1 /3.2grains of TiteGroup.

The problem I'm having is as I measure my completed bullets, I was getting lengths all over between 1.1420 to 1.1530 and no consistency. Also notice the bell disappearing. I can use the 1.1420's but would like to hold a consistent O.A.L.

And Big Blue's answer was it can't be done. I was told I can't load 147's with range brass and hold a consistent O.A.L.. They said I have to use one head stamp brass to be consistent. OK, but I ain't sorting that bucket of brass.

Thank You Big Blue.

I have sampled these on the Range, yes, they fire. My guess to continue is to go bigger on the bell and measure the rounds as they get completed. I have 5,000 of these to process.

Suggestions???

 

[BE Mike]

The short answer is that you don't need that kind of precision loading 9mm, even match ammo. COAL isn't that critical for good ammo. For good groups, you need a good bullet, with very good looking bases. A consistent powder throw is important. Matching the primer to the load can make a difference. Your coated bullets may or may not get you good accuracy, but probably not pristine accuracy. The pistol you are shooting the rounds in will be an important link in accuracy or lack thereof. Unless you need real precision groups, say 3" at 50 yards, you are probably good to go.

 

[King31]

+- 5 thousandths is pretty common from what I have found. It honestly isn't that difficult to separate the brass by headstamp. If you are wanting the precision of your ammo, then I would not think that one extra step is going to hurt. I definitely would be willing to give it a try for a smaller batch. Also, are you setting your dies with a full shellplate or with just one case, going die to die? I notice mine is different depending on how many cases are on the press getting loaded at the time. Slightly more friction to resize a case can result in very small fluctuations on other dies. God I hate that F word.

 

[S8MS-01904]

That's what I figured, just looking to hit the A-zone at 30 yards. Mostly Glock pistols of various barrel lengths to blast away.

 

[red_zr24x4]

Do the 1.1530 pass the plunk test?
If yes, give them a try

 

[Thegeek]

Can't be done? Case is indexed from the bottom, the bullet is indexed from the top. If the indexes don't change, how does the OAL change? I don't care what my case length is, I'm getting within .003" with my RCBS with Lee dies. The only thing that could change the length is an inconsistent seating die.

 

[BravoMike]

when I reload mixed head stamps it is not too uncommon to see +/- .005, so .011 difference from shortest to longest isn't unrealistic. Just chamber check them and if they pass they are fine. When I sort the brass by head stamps, I usually see much more consistent OAL at +/- .001.

 

[BravoMike]

Can't be done? Case is indexed from the bottom, the bullet is indexed from the top. If the indexes don't change, how does the OAL change? I don't care what my case length is, I'm getting within .003" with my RCBS with Lee dies. The only thing that could change the length is an inconsistent seating die.

I honestly don't know why I see a difference, but know that I do. The only theory I have is that it could be related to case length and/or case thickness and how easily the bullet seats. I'm using the Lee carbide dies.

 

[red_zr24x4]

Mic a sampling of the bullets

 

[hps]

I'm pretty sure you'll not get consistant OAL until you trim ur brass to the same length. Its not that important!!

 

[VERT]

My 9mm loads fluctuate in OAL more then I would like. But I have never found it to be problem. Different headstamps do load to a slightly different length.

I did find a 124 grain bullet that loads nice in mixed brass and if accurate. So I will run with those.

 

[ROLEXrifleman]

Don't forget that the actual tool head on a 550 moves. In addition there are 4 stations on the shell plate, that revolve around a steel baring under spring tension...... With all these variables you should be grateful your variances are so low.
for oal as tight as your looking to get a progressive just won't cut it

 

[Sniper 79]

When is the last time you cleaned the seater die?

 

[Leo]

I believe the op is way too picky. Most people do not shoot a rifle accurately enough to tell the difference on 10 12 thousandths of seating variance. Even if you own a ransom rest, you will ever be able to see that a difference in a target from a handgun.

If you get a stoney point gauge system and get a measurement from the bullet crown where the seater plug touches to the bullet tip you will see at least .010" variance bullet to bullet. Your barrel does not perceive bullet tip differences, diameter and bullet ogive to the start of the barrel lands is all that affects the relationship. Cast bullets are not like something precision turned on a a lathe, there is variance.

SAAMI spec for a round nose 9mm is 1.169 max OAL. Your stuff should work fine.

Sniper79 makes a good point, when you load cast bullets, bits of that waxy bullet lube sticks inside the die and changes as you reload. Good Luck

 

[RobbyMaQ]

I'm too new. But I'm assuming the proper RN vs HP end of die is being used. I've not seen this much variance in my 115gr 9mm (using 550 & dillon dies (I love their 'dial' adjustments)). But I'd have to check to see what actual variance I have. I just know I checked and rechecked often to make sure I wasn't out of spec. Guess I just don't understand how the weight of the bullet would affect this, with exception to the consistency in the shape of the bullet perhaps? Yeah I get brass can be inconsistent in the bell, but what am I missing that this variance is so much greater with 147gr over 115 gr?

 

[S8MS-01904]

Can't be done? Case is indexed from the bottom, the bullet is indexed from the top. If the indexes don't change, how does the OAL change? I don't care what my case length is, I'm getting within .003" with my RCBS with Lee dies. The only thing that could change the length is an inconsistent seating die.

Agreed, I think my OCD gets in the way with just make bullets. Seating dies are clean.

 

[Thegeek]

Don't forget that the actual tool head on a 550 moves. In addition there are 4 stations on the shell plate, that revolve around a steel baring under spring tension...... With all these variables you should be grateful your variances are so low.
for oal as tight as your looking to get a progressive just won't cut it

So the bottom index is fluctuating. For all the people saying it as to do with case length, please share your wisdom.

 

[Doublehelix]

I am also a total newbie, so take everything I say with a gallon of salt...

I read somewhere (oh, great!) that progressive presses will see more OAL variation than a single-stage press because the shell plate flexes slightly when sizing whereas with a single-stage press, the ram is fully supporting the shell holder and there is no (very little?) flex at the bottom of the holder.

I have no idea if this is true, it is just something that I have recently read as a part of my intensive reading!

 

[VERT]

I have no doubt there is variation in the progressive and turret presses. But I can also tell you with certainty that different headstamps also load differently and result in variation as well. I posed a similar question on INGO and people told me that wasn't possible, but it is. I don't know if it is because of the thickness of the brass or small variation in the rim. Also just because the headstamps matches does not mean the brass is the same. I load a lot of 9mm on a Dillon Square deal using range brass. COAL +/- 0.05. Powder drop will also vary slightly. Never been a problem. Only issues I have had have been primers not seating and once I had cartridge miss the final crimp station (probably because of a primer not seating earlier in the process)

 

[rvb]

mixed brass, floating tool heads ..... all that matters very little. I don't see what mixed brass or trim length has to do with it at ALL... maybe if you're trying to get under 1-2 thou variation.
IMO has to do with the bullet consistency in the point the bullet is pressed on by the die. HPs and flat points are usually a little more consistent as they are pressed at the same point you measure, the end. round nose is not usually as consistent as the die is pressing somewhere on the o-give. I usually see +/- 1-2 thou with the JHP I load. When I loaded FMJ I saw +/- 3-4 thou. you're seeing a variation of 11 thou, or +/- 0.0055 ... not a big deal.

This is where your chrono comes in. Who gives a crap about oal variance if you're getting single digit SD.

as for the bell "disappearing," I assume you mean sometimes the brass isn't getting belled? Or are you saying its' going away in the seating process? If the former, you aren't belling enough to make up for mixed brass variance (case length, wall thickness). If the later, you are belling too much that the seat die is having to smush it down. I like 15 thou min of bell. when I set the funnel depth I grab some mixed brass, size it, and set so the min is about 0.015" over the sized diameter. I use that for all calibers. Some say it's a little much, but it 1) makes setting the bullet in place easier and 2) gives more consistent powder throws if you ensure the mechanism is fully pushed up every time.

-rvb