Topic: odd issue with .308 handloads: round won't chamber

[mjmcmahon]

Hi all -

I loaded some ammo for a friend to use for a match at Parma yesterday and, unfortunately, we found out after we arrived that the rounds wouldn't chamber in his rifle (or mine, for that matter).  The only difference between the rounds I loaded for him and the rounds I loaded for me was the length I trimmed the brass to.  My brass was originally trimmed to around 1.985" - shorter than the spec by ~.02".  I trimmed his brass to spec: 2.005".  Could this additional length be causing the inability to chamber the round, even though it's within specification?

Also -

his rifle may have an extremely tight chamber - he has some factory Magtech .308 ammo that will commonly have difficulty extracting.  Getting the round to extract often requires hitting the butt of the rifle against the bench or floor while holding the bolt to the rear.

Any suggestions here would be greatly appreciated.  Needless to say, dragging my friend to a long-range competition on Sunday only to have him be unable to shoot because the ammo wouldn't chamber was extremely frustrating!

[Nomad]

 Could be that you need to pull the bullets and resize your brass. You may want to take and  could check the brass in the chamber before you load it.
 Also screw down your die until it starts to cam lock.
 You may need to get some small base dies for a tight chamber...Luck. Keep us posted..... 

[mjmcmahon]

The brass used was Lake City and was full-length sized before seating, so I don't think that's the issue.  The resizing die I used was a Hornady which, if I remember correctly, is small-base?

[2big2fail]

The brass used was Lake City and was full-length sized before seating, so I don't think that's the issue.  The resizing die I used was a Hornady which, if I remember correctly, is small-base?

Was your Lake city brass "once fired" or several times?  The reason I ask is because I've had on occasion tight fitting casings too, but not so tight that it would'nt chamber.  Anyhow, it turned out (to the best of our investigating the matter), that the heavy wall of the mil brass after multiple reloads became hardened.  Enough so, that pressing the same cartridge again and again without removing it, it still felt like a hard press.  Conclusion: once the brass reaches a certain hardness, it will re-expand right out of the die. Given, just a few mills, but enough to notice on a non NATO weapon.  Heat the brass to  800 degres or so, and that will re-soften it.  Especially, Mil brass.. 

[carharttfarmer]

did you adjust your seaing die between the to differnt lengths of brass? if not thats probable the problem

[mjmcmahon]

2big: it was 'once fired' purchased from a member here.  Some of the brass was difficult to size, but the Lee dies didn't have a problem with it after I applied some muscle.

Carhartt: No, I didn't adjust the seating die, but I mic'd the brass with a bullet comparator AND checked for OAL with a separate mic.  None of it was excessive length.

[mjmcmahon]

After doing a little more research, I'm wondering if this isn't a case of the FL sizing die not being properly adjusted for the shoulder.  Is there a downside to simply maxxing out the FL sizing die depth?  What I mean is, the die instructions say to screw the die in until it touches the top of the shell holder, lower the ram, and then rotate an additional 1/4 to 1/2 turn.  What would the downside be to rotating it the full 1/2 turn, rather than 1/4 or 1/3, assuming that after the initial FL size you'd be using a neck sizer only?

[2big2fail]

After doing a little more research, I'm wondering if this isn't a case of the FL sizing die not being properly adjusted for the shoulder.  Is there a downside to simply maxxing out the FL sizing die depth?  What I mean is, the die instructions say to screw the die in until it touches the top of the shell holder, lower the ram, and then rotate an additional 1/4 to 1/2 turn.  What would the downside be to rotating it the full 1/2 turn, rather than 1/4 or 1/3, assuming that after the initial FL size you'd be using a neck sizer only?

Once the shelholder and the die come into contact, you're not getting any more out of it.

[mjmcmahon]

doh....yeah, doesn't matter how much further you tighten it down, the brass isn't gonna go up any further!

Common sense for the win.  Thanks for not laughing 2big!

[Grumblecakes]

you could try pulling the powder and the primer and reseating the bullet. cover it in soot or dry erase or something and see where it is hanging up.

i had a round that wouldnt chamber the other day because of a tiny burr left over from trimming.

also depending on the bullet profile it may be contacting the rifling before being chambered. with my savage the almost every 165gr is almost on the lands at max coal and with amax they are pretty much on the lands.

[J Mack]

If you’re going to load for long distance shooting I recommend Redding small base dies and a Hornady HK66 LNL Head Space Kit w/Body.
PTG makes the reamers for the Redding dies and Dave tells me that the Redding small base dies will size the brass perfectly for his match chambers.
Forget about setting your sizing die by turning down a ¼ turn or whatever the instructions say and buy yourself the Hornady head space kit and just bump you case shoulders a thou or so.

[carharttfarmer]

Once the shelholder and the die come into contact, you're not getting any more out of it.

not just in contact press needs to cam over other wise you get problems trust its no fun to do 400+ cases over agin

asked about the seating die because depending on how hard you crimp the longer brass could buldge slightly at the shoulder not enough to notice by eyeballing it but enough to cause issues

mark one up with a sharpy drop it in the chamber and try closeing the bolt and you find out for sure just what is causeing it

[J Mack]

doh....yeah, doesn't matter how much further you tighten it down, the brass isn't gonna go up any further!

Common sense for the win.  Thanks for not laughing 2big!

I have had to machine .020 from more than one inexpensive sizing die just to get it to touch the shoulder.

[RGinIdaho]

Measure the cases from base to datum line on the neck. Adjust the die accordingly.

A lot of the time you can get by with screwing the die down until it touches the shoulder then lowering the ram and screwing the die in 1/4 turn. Usually over works the brass, I've seen it take shoulders back as much as .006" and not take the shoulder back enough for tight chambers...

[RGinIdaho]

.308 Win and 7.62x51 Nato

Identical cases, different pressure specs...

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[2big2fail]

.308 Win and 7.62x51 NATO

Identical cases, different pressure specs...

   The reason they opetrate at different pressure is because they are different.  In two ways, 1. thicker walls on the 7.62 leading to the above mentioned pressure difference.  Approx. 25 to 30 grn weight difference.  A volume fill comparison will show that, or weigh the cases.  2. the shoulders are tapered at a slightly flatter angle on the NATO brass after firing from any such NATO rifle. Then, (if the brass had been fired several times) as the hardened brass is extracted from the sizing die, it will "spring back" somewhat causing a feed issue.
     I had a long conversation about the NATO comparison with the ballistics engineer at the Nosler research and development facility in Bend Oregon (before it blew up)   Anyway, the class was very helpful and I hope this pays it foreward somewhat.  
   Here's a link that explains a little more about that:
 PS. apologies for the edit, fingers are broadband, brain is dial up    
 
http://www.303british.com/id36.html

[ballardw]

I didn't see this mentioned. With slightly longer cases was the bullet seater/crimp adjusted at all? A little longer brass with the same seat/crimp might cause a small bump in the neck that could prevent seating.

Please don't ask how I learned this one...

[broncovan]

Measure the cases from base to datum line on the neck. Adjust the die accordingly.

A lot of the time you can get by with screwing the die down until it touches the shoulder then lowering the ram and screwing the die in 1/4 turn. Usually over works the brass, I've seen it take shoulders back as much as .006" and not take the shoulder back enough for tight chambers...

DING DING DING.  We have a winner here. 

Ask me how I know.   300 rounds later.......... I had my die set to where it barely touched and after the second reload, I started having loading problems on my Rock River LAR-8.  Lake City, Remington, Winchester, didn't matter.  Measured the OAL after resizing, and all was correct.  After I bought a case guage, I found that although the OAL was good, the length from the base to the Datum line was a hair too long.  I screwed the die down to where it touched the shell plate, then did the 1/2 turn extra and all is well now.

PM me and we can get together so you can borrow my case guage.

[mjmcmahon]

awesome information guys!  I'll measure to the datum line on his cartridges and see what I come up with.

[broncovan]

Just to make sure you know where the datum line is, it's a spot that's .400 on the shoulder of the case.  Should be exactly half way between the bottom and top of the shoulder.  Gets pretty tough to measure when only a couple thou will cause you grief.  At least that's about what my guesstimate was when I discovered the problem for me.  Easiest way is to use a case guage, you see it right away.

[mjmcmahon]

ouch...yeah, that datum line is going to be difficult to find when it's half way up the shoulder.  I'll start with the following:

1. measure my buddy's chamber using the LNL OAL gauge...I may have the bullets seated too far out and they're engaging the rifling.

2. take an unloaded cartridge case and color it with a sharpie to see where the round is hanging up.

3. re-adjust my FL sizing die...this time, I'll try 1/2 turn and then try and chamber the case.

I'll report back once I know more.

Thanks again for all the advice guys!

Mike

[fj40mojo]

If you’re going to load for long distance shooting I recommend Redding small base dies and a Hornady HK66 LNL Head Space Kit w/Body.
PTG makes the reamers for the Redding dies and Dave tells me that the Redding small base dies will size the brass perfectly for his match chambers.
Forget about setting your sizing die by turning down a ¼ turn or whatever the instructions say and buy yourself the Hornady head space kit and just bump you case shoulders a thou or so.

Best advice. Buy the gear. You won't regret it. As far as I'm concerned this should be manditory equipment for reloading bottle neck cartridges. Don't know how I did without it for all those years-stupic dumb luck!

[RGinIdaho]

I can loan you tools and show you how to setup the correct shoulder "bump" if you have cases fired in your buddies rifle. You know where I'm at so come on by.

If not:

adjust the die until it touches the shell holder
resize a case
try it in the rifle - go then stop, no go continue
adjust the die down 1/8
resize the case
try it in the rifle - go then stop, no go continue
adjust down 1/8 turn
and so on

I wouldn't pass 1/2 turn by presses produce a lot of force and can be cracked.

Remember, as you resize a case, the length from base to shoulder will grow if the die is not set down enough to contact the shoulder. You can see this if you have something similar to the LNL tool.

[FALex]

all this help, for poor ol' me?! Hey folks, mjm is speaking about my rifle.  Unfortunately, I haven't had that great of an experience with it and I've taken a lot of time and money to build it to the way I wanted it, aesthetically, at least! I appreciate you guys helping my buddy - mjm out.  He's a hell of a friend and a hell of a help (if you couldn't tell). I don't know squat about loading except how to prep brass...you guys are speaking Mandarin to me, but I do appreciate the help.  I hope to know half as much as you all do right now in the near future.  Again, thank you much (you too, Mikey!)

[ida83704]

all this help, for poor ol' me?! Hey folks, mjm is speaking about my rifle.  Unfortunately, I haven't had that great of an experience with it and I've taken a lot of time and money to build it to the way I wanted it,

Is this the one
http://www.boiseshooters.com/index.php/topic,12433.msg78233.html#msg78233

have you tried other manufactures types of .308 ammo in it?
Federal, Remmington, etc?

[mjmcmahon]

All this turned out to be user error: the instructions for the Hornady FL sizing die indicated that you should screw it in so that it touches the shell holder and then adjust as necessary by testing each round in the chamber of the rifle you're loading for and making 1/8 - 1/4 turns.  Unfortunately, I put it in touching the shell holder and then never adjusted it.  Once I actually got hands-on with FALex's rifle, 1/4 turn was enough to get the cartridges seating normally.

I had another question while I have the experts on-hand: I discovered while getting setup for loading FALex's rifle that my Lee caselength gauge was allowing the brass to be trimmed MUCH lower than spec (minimum of .020", sometimes as much as .050"!).  I'm tempted, in the name of consistency, to trash a lot of this brass.  Most has been shot at least 5 times and some appears to be hardening because my chamfer tools are beginning to make irregular cuts in it.  Getting more brass isn't a huge deal, just wondering if I'm sweating the petty things.

Thanks again to everyone who shared their experience and advice!

Mike

[J Mack]

Your die should be 7/8” X 14 threads this means that it will move .071” per turn or .017” per ¼ turn. FYI most guys try to only bump the shoulders of their cases something a lot less than .017” 
I’m not sure it’s possible to get a .030” difference in case OAL with a properly set Lee caselength gauge, these are a few suggestions.
1)   Check to confirm your numbers.
2)   Are you trimming after sizing the brass and was all the brass sized the same?
3)   I’ve seen where the “mandrel” caselength gauge portion get pushed into the cutter portion after trimming dry cases “no oil on the necks” and this could cause the issue you describe but it should be obvious by looking at mandrel to see if it has cutter marks in the base and should have been a gradual change meaning your last case trimmed is shorter than your first and the ones in the middle should be just that.
4)   Trim then measure one case at a time and only note the cases that have had material removed, if these cases are under minimum by the amounts you describe and you have no cutter marks at the base of your mandrel return your Lee caselength gauge as you have one that is out of spec.
I think the Lee case trimmer is a good setup and I have trimmed many thousands of rounds with good success.   

[mjmcmahon]

J Mack -

the problem here is that the case length gauge wasn't correctly set from the outset...like a fool, I screwed the gauge all the way in (as they indicate in the instructions) and it was cutting too deep, sometimes as low as 1.945", although the majority are at 1.975-1.985.  All this brass has only been neck-sized after the original firing.  I've almost completely stopped using the mandrel case-length gauges now, choosing to go with an RCBS case length trimmer instead.  I'm trying to decide now whether to add the power module to that trimmer or replace it with another option (probably NOT a Giraud, though...$450 is a bit much!)