View Full Version : Seating Depth Inconsistencys
I have recently started reloading. The machine is an older dillon, 450 upgraged to 550. With the exception of the frame. I have been loading 55fmj with no issues. I acquired some 75gr hornady bthp's. I can't seem to get a consistent oal with them. I'm using rcbs dies, full length sizer and the seater/crimp die. Ocassionally the bullet seems very hard to insert into the seat/crimp station. It does go, with extra force, although the OAL is varying. I've made several attempts at adjusting. I seem to be chasing my tail. Too long, too short, well, you get the picture. Would I be better served with a seperate seater and crimp station? Is the ogive difference causing my problem? Any suggestions would be greatly appreciated.
First, I think you'd be much better served with a seperate seating/crimping arrangement,For a progressive press it's the only way to fly.Set up this way, you only need to adjust you crimping die once, and the seating die does just that, seat..it's now easliy adjusted for different bullet weights, and you don't have to fool around getting the crimp and seating at the same time. You can also run into trouble trying to get a OAL measurement using the tip of the bullet..Usually, with BTHP's the hole in the bullet has a small burr on it, this can throw off your measurements. I believe there are tools you can buy to trim this burr. I use a bullet comparetor(SP?) (stoney ridge) it simply clamps onto you calipers and has a collet in it that is the same size as the caliber you're loading. This measures from the ogive of the bullet, and is usually more accurate. I'm sure either Sinclair or Midway has all these tools..
Other things to check..are the cases the same OAL?
What kind of crimping die do you have, and how much crimp are you using? Usually, with BTHP's you don't need much, you could try backing it off a little..
The case OAL is consistant. The combination, seat and crimp die is an RCBS. I think I'll take your advise and get seperate stations set up for each step. One other thing I've noticed is a slight ring in the bullet, where the seater contacts it. It can be felt with your fingernail. This seems like it would affect accuracy? This isn't a precision AR. But, I do try my best to produce good quality ammo. Would continuing to use the die I have to seat and getting a seperate crimp die be a good option, or should I get a die dedicated to seating only?
Sounds like inconsistent neck tension. Are you using mixed brass and does your sizer die have the expander button?
I load on a Dillon 1050 using all IMI brass or all LC brass in a given batch - mixed years, but not mixed brass. OAL is not perfect - variances run +/- .003" for most, but a few will vary more than that.
The best consistency is when all loading stations are populated and I maintain a firm down-stroke, (plus I resize on a single stage press). I don't use the seater die for crimping, which might be part of your problem.
The case OAL is consistant. The combination, seat and crimp die is an RCBS. I think I'll take your advise and get seperate stations set up for each step. One other thing I've noticed is a slight ring in the bullet, where the seater contacts it. It can be felt with your fingernail. This seems like it would affect accuracy? This isn't a precision AR. But, I do try my best to produce good quality ammo. Would continuing to use the die I have to seat and getting a seperate crimp die be a good option, or should I get a die dedicated to seating only?
I'd use the die you have to seat..That should'nt be a problem,You can get a crimping die from Dillon, or the Lee factory crimp die also works well and is inexpensive.. As I said before, the BTHP's should'nt need much crimp.The seater should'nt be leaving any marks on the bullet itself.You might want to take your calipers and start checking the I.D. of the case mouth.Shootist also touched on possible problem..You could seperate your brass by manfacturer,and run them through that way..Have you noticed what kind brass causes these problems?? your OAL's should'nt vary by more than + -.003 as shootist said
I have two stupid questions:
Are you lubing your brass?
Are all your stations full when you're measuring the seat depth?
especially with unlubed brass some will put more upward pressure on the tool head than other and can cause a little bit of variation.
and when you're setting the seating die, make sure all your stations are full because they will put the same amount upward pressure on the tool head as you'd get with a long run.
and yes, separate setting and crimp will do wonders for consistency.
The brass gets lubed when ful length sizing. All stations aren't full. I generally prime all brass first, then charge and seat/crimp in the dillon. I just finished loading 50, 55fmj rounds and never a hickup. All rounds were within .005(+/-.002-.003) Just wondering if there are other factors at work here. I'm going to pick-up a crimp die, and try the 75gr hornady's again. Something just doesn't jive. I've been doing the 55 with zero issues??????? I appreciate all the advice. The brass is LC-08. All like headstamps. I'm anal enough to even sort by weight, don't know why. The 6920 will never know the difference. I was just looking for some heavier rounds to tinker with, and opened up a real can of worms.
A variance in overall length with hollow point match bullets is normal. Just make sure that the longest ones are short enough to fit in your mags and you will be fine.
The brass gets lubed when ful length sizing. All stations aren't full. I generally prime all brass first, then charge and seat/crimp in the dillon. I just finished loading 50, 55fmj rounds and never a hickup. All rounds were within .005(+/-.002-.003) Just wondering if there are other factors at work here. I'm going to pick-up a crimp die, and try the 75gr hornady's again. Something just doesn't jive. I've been doing the 55 with zero issues??????? I appreciate all the advice. The brass is LC-08. All like headstamps. I'm anal enough to even sort by weight, don't know why. The 6920 will never know the difference. I was just looking for some heavier rounds to tinker with, and opened up a real can of worms.
If you're within .005 I really would'nt worry about it..Alot of what you're seeing is because of the burr on the bullet tip itself.. Buy yourself a bullet comparetor that clamps onto your calipers,measures from the bullets ogive, and you'll find out you're really much closer than that. Still,seperate your seating and crimping operations.It's much easier to deal with that way..
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.