.308 1st time fail...help please

[30Cal]

If they're shorter than the chamber and they won't fit, then you need an SB die. Some people will claim that the Dillon FL die is the same, but it's not. I know that for a fact.

[G-forceJunkie]

The key points have been made:
1) Why are you crimping match bullets that don't have a Cannelure?
2) load to 2.800 for reliable function. Its already jumping alot, .010" less wont matter.
3) Size the brass more. Set up your press so it is touching the shell holder, then give it another 1/8 or 1/4 turn. You want that sucker to really size down all the way. Depending on how fat the base of your brass is after firing, you may need to use "small base" dies.
4)Check your sized brass after sizing in the chamber, but before reloading. Then try again after loading. Find out if your problem is the sizing, or if your deforming the case upon reloading. Do this by removing the upper (and firing pin if you want) and slide the carrier home by hand. The bolt should rotate closed with no pressure (other then typical drag from friction.) If you have to force it, its too tight.
5) Is your chamber clean? A match chamber in aan autoloader need to be kept really clean.

[Fyathyrio]

Looks like you need to bump the shoulder back a bit. Do you have a drop in case gauge?

They drop in just fine...but I can bump it back a couple more maybe. I'm already at 0.004" from fire formed size. Maybe I'm just lucky and it's a tight chamber.

[Gunsrruss]

Good advice here

The key points have been made:
1) Why are you crimping match bullets that don't have a Cannelure?
2) load to 2.800 for reliable function. Its already jumping alot, .010" less wont matter.
3) Size the brass more. Set up your press so it is touching the shell holder, then give it another 1/8 or 1/4 turn. You want that sucker to really size down all the way. Depending on how fat the base of your brass is after firing, you may need to use "small base" dies.
4)Check your sized brass after sizing in the chamber, but before reloading. Then try again after loading. Find out if your problem is the sizing, or if your deforming the case upon reloading. Do this by removing the upper (and firing pin if you want) and slide the carrier home by hand. The bolt should rotate closed with no pressure (other then typical drag from friction.) If you have to force it, its too tight.
5) Is your chamber clean? A match chamber in aan autoloader need to be kept really clean.

You need the small base dies and you need to turn down that die the 1/4 to 1/2 turn after the die hits the shell plate. I pulled down a couple thousand rounds before I learned this

[Fyathyrio]

The key points have been made:
1) Why are you crimping match bullets that don't have a Cannelure?
I thought this was required for AR actions to prevent bullet setback...am I wrong?

2) load to 2.800 for reliable function. Its already jumping alot, .010" less wont matter.
Yup, hopefully that's the main prob as it's an easy fix.

3) Size the brass more. Set up your press so it is touching the shell holder, then give it another 1/8 or 1/4 turn. You want that sucker to really size down all the way. Depending on how fat the base of your brass is after firing, you may need to use "small base" dies.
I'll try this tomorrow also, I was trying to minimize how much the brass was worked, I set the die IAW Dillon instructions and it's not touching the shell holder, so there's plenty more adjustment here. If it still won't chamber, which brand small base die do you recommend?

4)Check your sized brass after sizing in the chamber, but before reloading. Then try again after loading. Find out if your problem is the sizing, or if your deforming the case upon reloading. Do this by removing the upper (and firing pin if you want) and slide the carrier home by hand. The bolt should rotate closed with no pressure (other then typical drag from friction.) If you have to force it, its too tight.
I'll do this also in the morn with a couple dummy rounds...I'll go through the tips one at a time to find the culprit.

5) Is your chamber clean? A match chamber in aan autoloader need to be kept really clean.
The chamber wasn't fresh, maybe 60 rnds, I'll make sure it's freshly cleaned before next trip.

Thanks again! I'll update once I find the problem(s) and report back so others hopefully won't feel my pain.

[G-forceJunkie]

You don't crimp bullets that are not designed for it. It will deform them and hurt accuracy. You just need to size the necks so you have enough neck tension to keep them from setting back. I use Redding type S match dies because you can set the neck tension with different diameter neck bushings. Every brand of brass has a different neck wall thickness, so you will need to buy several to fine tune the neck size with whatever brass you are using. Size the neck down so the I.D. is several thousandth of an inch smaller than your bullets. .001 to .002 is typical with bolt guns, semis you probably want to go a bit tighter (but i don't know exactaly, I dont load match ammo for gas guns.) Measure the expander ball in your dillion dies, its probably around .306" One thing you havent mentiond, is what barrel/chamber you have. Is it a tight match chamber? Don't worry about "minimizing working the brass" with an autoloader, its going to beat the brass up anyways. You probably will get half as many loading before they are junk than you would with a bolt gun. Reliability is key, does it matter if you get 8 instead 4 loads per brass if it doesnt function? Good luck.

[EL_NinO619]

You don't crimp bullets that are not designed for it. It will deform them and hurt accuracy. You just need to size the necks so you have enough neck tension to keep them from setting back. I use Redding type S match dies because you can set the neck tension with different diameter neck bushings. Every brand of brass has a different neck wall thickness, so you will need to buy several to fine tune the neck size with whatever brass you are using. Size the neck down so the I.D. is several thousandth of an inch smaller than your bullets. .001 to .002 is typical with bolt guns, semis you probably want to go a bit tighter (but i don't know exactaly, I dont load match ammo for gas guns.) Measure the expander ball in your dillion dies, its probably around .306" One thing you havent mentiond, is what barrel/chamber you have. Is it a tight match chamber? Don't worry about "minimizing working the brass" with an autoloader, its going to beat the brass up anyways. You probably will get half as many loading before they are junk than you would with a bolt gun. Reliability is key, does it matter if you get 8 instead 4 loads per brass if it doesnt function? Good luck.

I agree with you but not 100%, you can hurt accuracy when you over crimp. But with a light crimp and a Auto loader I see no problem, its safer to have a little crimp than the possibility of set back. With a AR platform I don't see him reaching Bolt action accuracy. So do a light Crimp.

Also OP you might wanna try RCBS small base die..

[robert101]

It seems you have a tight chamber. Here are my few notes on 308 loading for my DPMS TAC20:
1. Keep round length less than 2.80. I typically don't load longer than 2.75".
2. Full length resize. I usually turn the die to 1/8 turn below bottom out of die and shell holder.
3. Keep neck size to about .340. Some factory rounds are acutally less than this number.
4. I don't crimp and seat bullet in same operation. I do apply a very light crimp after bullet seating. I do mean light as I believe that only removing the bell is better than crimping a non-cannalure bullet.

You can slightly decrease your OAL in your prior loaded ammo if you haven't crimped to heavy. Look at the bullet to make sure you haven't deformed it too much.

[Fyathyrio]

Well, it's been a good morning playing with gun stuff with my morning coffee. I've also learned a lot and should be able to solve my problem.

First, I tried loading sized unloaded brass, and it seemed to go in OK. Then I tried the loaded rounds and they were still a little tight with a clean weapon. I seated the bullets down to 2.791 OAL and they fed better. After doing that I tried the marker trick and I did not see any clear areas where the marker was rubbed off, and the entire shoulder area seemed to have seated in the chamber. Additionally there are no marks on the body, so the brass was properly sized for my weapon/chamber, but with no room for error. Finally, I pulled one of the rounds that I had seated deeper, there's no ring on the bullet from the initial crimp, and the seating did not scrape any copper off. Only visible marks are the light striations from seating.

The only issue I've not been able to resolve is what style chamber I have. The guys at JD Machine are all off at a gun show in AZ this weekend. I'll find out Monday if it's a match chamber or not.

What I've learned...
OAL is important!
My sizing method placed the brass in the middle of the go/no go steps on the case gauge, looks like I need to bump the shoulder a bit more to get reliability. These would be perfect if this was for a bolt gun.
My light crimp is light.
Playing with guns and reloading stuff is fun!
CalGuns is awesome, thanks for all the help!

So, it appears that I'll at least be able to seat these a bit deeper and fire them, which sounds like a lot more fun then taking them apart.

[problemchild]

Do yourself one HUGE favor and buy a JP case gauge.

http://www.youtube.com/watch?v=uhgWqrvdzrU

[Gunsrruss]

Die

RCBS small base die. Of course there will be those who will say it ain't so. Trust me I pulled down rounds until I was smoking mad, but I learned my lesson. Don't worry about the brass being over worked. I full length the brass each time. You will get between 4-6 reloads before it starts to come apart. Yes, you will need a case gauge also. I have Wilson.

[Fyathyrio]

Do yourself one HUGE favor and buy a JP case gauge.

http://www.youtube.com/watch?v=uhgWqrvdzrU

Looks like it works and reads same as my Dillon case gauge...what's the difference?

Gunsrruss, thanks for the die recommendation, I'll go that route if adjusting my die further down doesn't work out.

[gau17]

Looking at your picture, make sure you are seating your primers below the flush line. You dont want to risk having a slam fire.

It might just be the angle on the picture. Just making sure.

[huckberry668]

I just notice there are shiny rings in the middle of the necks and 1/4" below the shoulders of the reloaded rounds. I believe that's where it's over sized and come in contact with the chamber preventing it from chambering.

use a dial caliper and measure the diameter of the shiny rings and compare to factory rounds. I'm betting if you blacken the rounds entirely and try loading them again those are the areas contacting.

Do these reloaded rounds chamber in other 308 guns? what kind & condition of sizing die are you using?

[Fyathyrio]

The rings on the body and neck are from the trimming process where the Possum Hollow trimmer rubbed the case.

I don't have any other .308 guns to try these in, but I'm willing to accept donations! I'm using a brand new Dillon die set, cases were individually lubed with Imperial Sizing Die Wax to ensure smooth operation.