Your thoughts on OAL

[FireNHole]

At the moment I am having to deal with a Lee Turret press. Will be getting a RL 550b in a few months. In the mean time I am having some difficulty getting consistent OAL lengths on my 9mm loads. I have sorted my brass so that I am loading my preferred ones ( FC, WIN, PMC, Blazer, RP ). Today I was loading up a sample pack of 147GR FN rounds from Blue Bullets. I have heard nothing but good stuff about them so I wanted to give them a try. After loading up a few different loads I was going to head to the range and chrono them later today but out of curiosity sake I was checking each round with my digital calipers. My first two or three were right on where I wanted them at 1.150 / 1.151. The next 8 rounds were anywhere from 1.142 to 1.158. I might be making a big deal out of nothing but seeing as I barely passed my last chrono at my first major match with a 125.8 PF I would like to get a better handle on my loads. Are those OAL differences acceptable or should I be looking at doing something else to be more consistent. When I load up on my friends Dillon 550 the OAL length is typically with 1.149 and 1.151.

[Hi-Power Jack]

If your velocity and accuracy are good, I wouldn't worry too much.

When you "sort your preferred brass" does that mean that they are all on headstamp in a batch?

Or could they be any one of the five mfgrs you mentioned?

Sorting brass, usually means using only one single headstamp at a time, to keep

everything as consistent as possible.

[cecil]

my Dillon 650 does not load to consistent AOL... I think its because I use mixed brass and my 650 shell plate is not 100%... .010 variance is normal for my 9mm loads.. my shell plate bolt is as tight as it will allow to let it turn and the set screw under the shell plate is tight.. but my STI Steel Masters eat my reloads..

[SilverBolt]

My 650 is new. Somewhere around 5k rounds so far. My OAL is pretty consistent. My target OAL is 1.150. My results are 1.146-1.150. You are seeing a .016 variance. That has to be affecting your FPS.

[sarge863]

On my hornady lnl, i seem to get more variance with fp versus rn. Always seem to get fliers with fp but rn is always spot on.

[FireNHole]

If your velocity and accuracy are good, I wouldn't worry too much.

When you "sort your preferred brass" does that mean that they are all on headstamp in a batch?

Or could they be any one of the five mfgrs you mentioned?

Sorting brass, usually means using only one single headstamp at a time, to keep

everything as consistent as possible.

You would be correct as I am have all of those in a bucket labeled match brass. I guess to get even more detailed would be to separate them completely by head stamp. For the most part I would assume that all brass labeled WIN would be consistently be the same, just as PMC, etc. I imagine there would be some difference especially if its been loaded up before. I just went over to my friends and loaded up on his 550. We had a low of 1.145 and a high of 1.149. This was with mixed brass.

[Sandbagger123]

lubed the cases and see if it helps.

[AlphaSeeker]

I just set up my LNL for my first reloading run. Have read numerous AOL numbers in the forums , from 1.12 to 1.15. The spec for 9mm is 1.165. Measuring factory ammo, I get 1.163. This is confusing.

Even more interesting, my Xtreme RN are much longer than factory FMJ heads.

Perhaps the length that makes the difference is the internal chamber length of the round? Anyone have those dimensions?

[FireNHole]

lubed the cases and see if it helps.

Didn't think about that =)

[Butterpuc]

what seating die are you using? and are you seating and crimping with the same die? I have been told with the moly/coated bullets you should seat and crimp separate.

Earlier someone recommended using the same headstamp, I agree for your situation, try that on the next batch since you are having issues. You might want to try some weaker Loctite (blue or purple) on the seating threads, maybe it is moving... or try to invert the seating cone inside the die. I haven't had to do that, but have had friends who have.

I do not load my 9mm by "sorted" brass, unless the brass is bad, I use whatever I pickup at the range. I experimented with only running Win brass, then Rem brass, then Fed brass, etc... to see if i could see any measurable differences. I didn't (I loaded 50-100 rounds of each and shot them through a chrono). Where I did notice a difference was loading to different OALs. Shooting a 147gr FP moly bullet using a Lee seating / crimp die (with the crimp backed out all the way, crimping with a Redding taper crimp die in station 5) I normally only get +/- 0.002" OAL spread. I loaded 20 rounds each at different OALs starting at 1.100" through 1.150" in 0.005" increments, and by far the best accuracy and standard deviation was at 1.135" with an SD of 2fps.

[Laughingdog]

my Dillon 650 does not load to consistent AOL... I think its because I use mixed brass and my 650 shell plate is not 100%... .010 variance is normal for my 9mm loads.. my shell plate bolt is as tight as it will allow to let it turn and the set screw under the shell plate is tight.. but my STI Steel Masters eat my reloads..

Shell plate play should have no effect on OAL. When pressing up, the brass is being pushed down against the base of the press, not pulled up against the shell plate. Play in the toolhead is what would affect OAL.

[Desmo412]

I just set up my LNL for my first reloading run. Have read numerous AOL numbers in the forums , from 1.12 to 1.15. The spec for 9mm is 1.165. Measuring factory ammo, I get 1.163. This is confusing.

Even more interesting, my Xtreme RN are much longer than factory FMJ heads.

Perhaps the length that makes the difference is the internal chamber length of the round? Anyone have those dimensions?

You really need to take some time to do a lot more reading before shooting any of those reloads. The LNL is a great press and I have loaded many thousands of 9-major loads that have worked flawlessly on mine, but please take the time to learn as much as possible first. Your cartride OAL will be determined by the chamber of the gun you are loading for. Typically this is anywhere from 1.10 to 1.165. Many people load as long as possible with the thought of keeping the pressure down....others try several different lengths in search of the best accuracy. As long as the rounds fit in your mags and don't engage the rifling when chambered, you will be good to go.

[AlphaSeeker]

I just set up my LNL for my first reloading run. Have read numerous AOL numbers in the forums , from 1.12 to 1.15. The spec for 9mm is 1.165. Measuring factory ammo, I get 1.163. This is confusing.

Even more interesting, my Xtreme RN are much longer than factory FMJ heads.

Perhaps the length that makes the difference is the internal chamber length of the round? Anyone have those dimensions?

You really need to take some time to do a lot more reading before shooting any of those reloads. The LNL is a great press and I have loaded many thousands of 9-major loads that have worked flawlessly on mine, but please take the time to learn as much as possible first. Your cartride OAL will be determined by the chamber of the gun you are loading for. Typically this is anywhere from 1.10 to 1.165. Many people load as long as possible with the thought of keeping the pressure down....others try several different lengths in search of the best accuracy. As long as the rounds fit in your mags and don't engage the rifling when chambered, you will be good to go.

Desmo,

First, I apologize if my question has diverted the thread but I think the question is in line with what the OP is seeking.

Although I am completely new to reloading for myself, I've dealt with similar issues in other industries.

I understand the relationship of barrel chamber length to OAL. Produced a few custom barrels in my machine shop days.

Mag size parameters are a given as well.

Powder Mfr. load data addresses safe OAL for specific bullet models, without providing the physical dimensions of these heads.

If the OAL of a bullet in known, it can be subtracted from the OAL of the cartridge, providing the chamber length [including case base].

If the powder chamber is reduced in volume, pressure will rise and may rise catastrophically at a certain minimum volume for a given powder.

It may be advisable to note the internal chamber length in evaluating load results. If a different bullet length is used, the starting[safe] OAL could be readily determined from chamber length previously established and tested for the same powder.

The minimum AOL given for a powder charge may be unsafe if my bullet is .100 longer - as is the case with the Xtreme 147gr which are .100 longer than factory heads I pulled.

Evaluating loads with different bullets and same C.OAL would produce very different results if the length of the heads is different.

A person might assume that one is better than the other when the real difference is the powder chamber size and associated pressure.

Sorry for the long post. Hope the OP finds this helpful.

[rtp]

I just set up my LNL for my first reloading run. Have read numerous AOL numbers in the forums , from 1.12 to 1.15. The spec for 9mm is 1.165. Measuring factory ammo, I get 1.163. This is confusing.

Even more interesting, my Xtreme RN are much longer than factory FMJ heads.

Perhaps the length that makes the difference is the internal chamber length of the round? Anyone have those dimensions?

Not sure where you're coming up with this?

Max OAL per SAAMI for 8mm is 1.169" - that may or may not feed in your specific mags and/or gun's chamber, depending on the projectile.

Go here for how to learn the Max OAL your gun barrel/chamber can be loaded to with a given projectile:

http://www.czfirearms.us/index.php?topic=34225.0

Most factory FMJ loads run around 1.15", and many factory hollow points are ~ 1.10"

Your comment about a different bullet length is why people work up loads - different profiles, which include the length as well as cartridge OAL, jacketed vs plated vs lead, sizing, all play a part in how effectively/fast a bullet goes through a given barrel with a specific charge. Shorter OAL on the same bullet will reduce the free space, and raise pressure/velocity. A longer length FMJ compared to a 'shorter' one set at the same OAL will have more pressure than the shorter one.

[rtp]

Powder Mfr. load data addresses safe OAL for specific bullet models, without providing the physical dimensions of these heads.

If the OAL of a bullet in known, it can be subtracted from the OAL of the cartridge, providing the chamber length [including case base].

If the powder chamber is reduced in volume, pressure will rise and may rise catastrophically at a certain minimum volume for a given powder.

It may be advisable to note the internal chamber length in evaluating load results. If a different bullet length is used, the starting[safe] OAL could be readily determined from chamber length previously established and tested for the same powder.

The minimum AOL given for a powder charge may be unsafe if my bullet is .100 longer - as is the case with the Xtreme 147gr which are .100 longer than factory heads I pulled.

Evaluating loads with different bullets and same C.OAL would produce very different results if the length of the heads is different.

A person might assume that one is better than the other when the real difference is the powder chamber size and associated pressure.

This is correct, along with different materials and bullet widths (e.g. .355 vs .356, .357, .358..), coatings, etc., also having an effect, but.. I don't think this should be a routine part of reloading calculations, however.

If you have a near max load of a like type and weight bullet (e.g. both FMJ or very thick plated, same weight) and intend to load them both at the same cartridge OAL, I think it's a reasonable assumption to assume the longer bullet should be downloaded vs the shorter if not working up a load from minimum published load data.

Edited March 31, 2014 by rtp

[Canine582]

if I give my 550 a little girl pull vs a big boy pull I get inconsistent COAL all the time.

be a "big boy"

[danman00]

I see inconsistencies as well using a Lyman turret press and what I think i have found in my case (again I think) is when I'm placing the bullet on top of the belled case during the seating process, sometimes it's not sitting perfectly straight (vertically). Sometimes its sitting crooked 10 - 15 degrees (i'm guessing) one way or another. The seating die straightens it out as it seats it down into the case but I'm wondering if that "off" angle is throwing it off - seating it deeper or shallower by a few thousandths. Maybe its the profile of the inside of my Lee seating die. Again, Im not sure but I've found that if the bullets are sitting perfectly straight on the top of the case, my OAL inconsistancies are alot less. Just my two cents.

Edited March 31, 2014 by danman00

[levellinebrad]

Some of the inconsistencies could also be coming from the seating die insert. If you have lee dies, you can send them a bullet and they will make an insert for that specific bullet.

Sent from my SCH-I605 using Tapatalk

[Briank]

Go here for how to learn the Max OAL your gun barrel/chamber can be loaded to with a given projectile:

http://www.czfirearms.us/index.php?topic=34225.0

That technique looks great and makes sense, but when I try it, the bullet stays lodged in the chamber. I can push it out fairly readily with a cleaning rod but I can't get the "dummy" case out with it in place to measure it. What am I doing wrong?

[BeerBaron]

the inconsistency is no doubt due to the flat point pullets. a very small change in the shape of that nose and how it contacts the seating insert is changing the OAL. all you can do is either send a bullet to lee and get a custom seating stem made, or switch to RN bullets. think about how a round nose shape seater is contacting the top of a FP. then consider how the slight shape of the nose changes. any variance in that tip and it changes the OAL. it's not the problem with the press.

also a tip. if you have the 4 station turret run it set up as: size+ deprime in 1, then reprime, then flare + powder in 2, then seat only in 3 (wind the crimp completely off the seat and crimp die) and the put a factory crimp die in station 4 and use that to crimp and post-size. makes for a much better round and better seating and better crimping.

[SevoTT]

I'm not sure what dies you are using, but I found that when I used plated bullets, a dead length type seating die (with the proper seating stem), and an EGW U-die, that the seating die would actually deform the bullet tip a little producing a flat spot, which would lead to different OAL's. This was using mixed brass with varying wall thicknesses which I think lead to different bullet seating force. I improved this by getting a "custom" seating stem and ditching the U-die for the softer plated bullets.