Bolt won't close on reloads .308

[LawnMM]

Buy a headspace gauge. Every problem like this starts with "I screwed the die down till it touched then backed off x amount of a turn"

This is a game measured to the third decimal point, fractions of a turn aren't the way to go. Even if it works chances are great you are over working the brass.

 

[Darkside-Six]

Buy a headspace gauge. Every problem like this starts with "I screwed the die down till it touched then backed off x amount of a turn"

This is a game measured to the third decimal point, fractions of a turn aren't the way to go. Even if it works chances are great you are over working the brass.

I got one of those coming too I had a Wilson one before but lost it. that's how I wound up in this mess.

 

[Thump_rrr]

No two resizing dies are the same, you could have several dies in the same caliber and each one would bump the shoulder back a different amount, we also live in a plus and minus manufacturing world. Meaning you might have a "plus" resizing die and a "plus" shell holder, the simple fix for this is to lap the top shell holder on some sandpaper and remove a few thousandths. You also have military brass "fire formed" in a different chamber and when this brass is resized it tries to "spring back" to its original shape. You can try and adjust your dies to make hard contact with the shell holder with the press reaching cam over and pausing at the top of the ram stroke. Pausing at the top of the ram stroke for three seconds or more reduces the amount of brass spring back. This will also give you more uniform and consistent shoulder bump measurements, pausing lets the brass know who is the boss and to stay put after sizing.

Second you can try small base dies, every piece of once fired military brass I get my hands on is resized once with a small base die to bring the brass back to minimum dimensions. This is because military chambers are larger in diameter and longer in headspace than standard SAAMI chambers. But remember a small base die is "NOT" shorter in cartridge headspace length and is only smaller in base diameter and sizes further down the case. Meaning you need to find out if your cases are too fat or too long and work from there.

Third, get the Hornady cartridge case headspace gauge, it fits all calibers and you only need to buy "ONE" case gauge and not one for each caliber. Until you get a micrometer and vernier calipers you will not have accurate means of checking your fired and resized cases.

Below for comparison are .308 and a 7.62 Nato chamber measurements for a M14 rifle, and remember a machine gun will be even larger in diameter and longer in head space and this effects the spring back rate when resized.

If you want uniformity and accuracy then buy one brand of brass and only fire it in "YOUR" chamber, each brand/type of brass will have different internal case capacities and mixed brass will give you "mixed" accuracy results. If your going to use once fired military brass or range pickup brass then you will have "mixed" resizing results and varying internal case capacities. (Meaning good for short range blasting ammo in rifles like the AR15)

Below a fired case from my AR15 carbine.

And below is the same case that has been full length resized with .003 shoulder bump.

Get yourself a set of vernier calipers and the Hornady gauge, and stop guessing at your problems.

We live in a plus and minus world and each of the .223/5.56 dies below will bump the shoulder of the case back a different amount and squeeze the case to a different diameter after sizing. When you start using mixed once fired brass then all bets are off on what you will end up with.

My Wilson case gauges were retired after getting the Hornady gauge.

I only use them now for paper weights and pen holders. (engaging humor)

Don't put any trust in your Hornady headspace gauge if you are measuring absolute numbers.
To give you an example I have a Springfield Armory M1A National Match whose headspace dimension is 1.631".
When measured using the Hornady headspace gauge it measures out at 1.638".
The reason is that the Hornady gauge is made of aluminum and the ring where it touches the datum line of the case wears out very quickly. There are plenty of threads in reloading forums relating to this.
One solution is to only use the gauge to compare dimensions with other dimensions taken with the same gauge.
The other is to spend the money on the Sinclair comparator which has stainless inserts.

Drop in case gauges have their place such as for checking completed rounds to ensure they will chamber. When producing ammo in bulk you may run into a few cases that are out of spec for one reason or another.
It is the easiest way to catch them before it bites you in the rear during a competition.

 

[Darkside-Six]

Well i got the redding small base die today and that fixed everything. All the cases that i had trouble with fit perfectly into a headspace gage so it wasn't the shoulder. The Redding die fixed everrything so problem solved!

 

[FLIGHT762]

Don't put any trust in your Hornady headspace gauge if you are measuring absolute numbers.
To give you an example I have a Springfield Armory M1A National Match whose headspace dimension is 1.631".
When measured using the Hornady headspace gauge it measures out at 1.638".
The reason is that the Hornady gauge is made of aluminum and the ring where it touches the datum line of the case wears out very quickly. There are plenty of threads in reloading forums relating to this.
One solution is to only use the gauge to compare dimensions with other dimensions taken with the same gauge.
The other is to spend the money on the Sinclair comparator which has stainless inserts.

Drop in case gauges have their place such as for checking completed rounds to ensure they will chamber. When producing ammo in bulk you may run into a few cases that are out of spec for one reason or another.
It is the easiest way to catch them before it bites you in the rear during a competition.

My Hornady .400 gauge reads 1.611" on a 1.630" Go Head Space gauge. That indicates, my gauge has a .019" chamfer on it. Same thing on my .223 Remington .330 insert. When I measure a .223 Rem. 1.464" Go gauge, I get a reading of 1.455", indicating a .009" chamfer. Now, on my .375 insert for 30/06 when I use a 1.940" Go gauge, I get a reading of 2.037" which is a + of .097". Fired cases in my .270 are around 2.039", so the numbers are good.


Here's a video on it :


https://www.youtube.com/watch?v=e0lylBTf7Cw


And it is explained here: http://www.snipershide.com/shooting...5-help-headspace-measurement.html#post2490582



If I need to relate my numbers on fired cases or resized cases to the SAAMI 1.630" go dimensions, I just add .019". Fired cases out of most of my 308 Win. my rifles will measure 1.612" / 1.613". I do like the gauge as it has been very repeatable. I bought my gauge a few years ago when it was Stoney point. I have not found the gauge to wear.

 

[SniperLapua338]

If you don't already have one - get an RCBS Precision Mic.

RCBS PRECISION MIC CARTRIDGE HEADSPACE TOOL | Sinclair Intl

Buy a box of factory ammo with brass cases, fire them in your bolt gun. Save the cases and record their measurements from the Precision Mic. Now run the die down and then run a piece of your LC brass through and mic it. This will give you baseline. You need to use a fresh piece of brass every time you make an adjustment to the die. Once you think you're matched up, run 10 pieces and check the average.

I would like to add to what Mike is saying about buying a box of factory ammo with brass cases and to a suggestion that someone made earlier is to not only use the same brass maufacturer every time you reload but make sure you start by using the best manufacture's brass. This takes some research homework on the web to determine who manufacturers the best brass. One thing I shortly became aware of when I started reloading my Lapua and tracking my shots at least 200 yards is that my reloads using Lapua brass were 100% non-problematic in terms of chambering the round into the rifle and the conisistentcy of the groupings on the target.

After doing my research and talking to some folks more familair with both companies than I was, I discovered that Lapua makes the best .338 Lapua brass casings whereas Hornady makes the worst. Lapua's brass casings are designed with a thicker walling and with a sturdier more robust internal matrix which results in a brass casing that is stronger and stiffer which better handles the kinds of pressures acting on the case when the round is fired. On the other hand, Hornady uses a thinner walled brass so the internal matrix of their brass is significantly soft and therefore its reaction to the pressures is much more dynamic and variant. Grouping on target are spread and sometimes just plain all over the map. I love Hornady maufactured brass for handgun use but I keep their brass away from the reloading bench for long-range rifle reloading. Now I reload using Lapua made brass and in doing so the chambering and accuracy issues I was experiencing using the Hornady brass visrtually disappeared.

Just my $0.02 worth for this being my first posting.....

Cheers!

 

[FLIGHT762]

Well i got the redding small base die today and that fixed everything. All the cases that i had trouble with fit perfectly into a headspace gage so it wasn't the shoulder. The Redding die fixed everrything so problem solved!

Good to hear. I had a SSG 69 that needed that Redding S/B die to size the base to .468.5. or less to get ammo to chamber. A head space gauge like the Hornady or Sinclair used with a good pair of calipers will tell you exactly what is going on with your brass.

You'll find a lot of good uses for that die. I've repaired under sized loaded ammo with that die without having to disassemble the ammo. I have them in 308 Win. and .223 Rem.