Used Mil brass sticking when chambered

[delzur]

Hello all,

I am hoping someone might be able to provide some info regarding a reloading issues I am fighting. I am reloading 308 mil brass and I am experiencing a problem with the cartridges jamming when they are loaded. If the round loads far enough, the gun will fire and eject the round fine, however, trying to cycle the cartridge out by hand is a futile task.

I have been through all the measurements multiple times and even seated the bullet as far down as 2.7 COAL without success. As a last resort I took some 220 grit sand paper and gave a cartridge that was sticking a once over. This allowed the cartridge to load and eject freely without being fired. I tried this again with a second cartridge with no success, however, with the newly roughed up brass I was more easily able to see where contact was occurring. It appears that the seating issue I am having is caused by the tapper at the neck.

With that said, I am using the Hornady 308 full length die set. The sizing die is set all the way down to the case holder.

Here are the measurements I am seeing (6 location from top to bottom):

Factory Reload Spec (Speers)
0.338 0.336 0.3435
0.341 0.3435 0.3435
0.4505 0.4501 0.454
0.4517 0.451 0.4553
0.4685 0.469 0.4703
0.468 0.471 0.473

Thanks....

 

[BobinNC]

Re: Used Mil brass sticking when chambered

You've probability got your sizing die set down way too far. You could be creating a bulge by forcing the shoulder back.

Or the once fired mil brass was fired in a rifle or machine gun, with a chamber too large for your FL die to successfully size down.

Or you have min spec. chamber and a max spec. die. Is your rifle a bolt or auto-loader? Factory or custom match barrel??

More info would be helpful.

 

[delzur]

Re: Used Mil brass sticking when chambered

The weapon system is a POF 308 with the factory barrel chambered for 7.62x51 NATO.

The hornady die set is item number 546358 (308 Win (.308) 2-Die Set). I see that they have a match grade full length die. However, I am fairly new to reloading so I am not sure how to tell a max vs min spec set.

 

[BobinNC]

Re: Used Mil brass sticking when chambered

Many semi-auto's require you to use small base dies to insure feeding. Consider buying a small base Fl die, and using new commercial, not used (once fired) mil brass.

Given the way autoloaders eat brass, I recommend new Winchester brass, as apposed to the more expensive Lapua.....

 

[delzur]

Re: Used Mil brass sticking when chambered

Ok, so my local sportsman's warehouse was open so I ran down and picked up a RCBS 308 FL SB sizinf die. I fashioned up another test round and it manually ejects fine.

Here are the numbers:
0.3365
0.339
0.447
0.451
0.469
0.470

I will have to run a couple more to make sure, but this seems to have corrected the issue I was having.

Thanks for the advice.

 

[shoot4fun]

Re: Used Mil brass sticking when chambered

You are on the right track now.

 

[Lumpy Grits]

Re: Used Mil brass sticking when chambered

Most if not all mil .308 today comes from a MG.
Also buy a Wilson Case gage for your .308 and learn to use it.
Cheers,
LG

 

[Hummer]

Re: Used Mil brass sticking when chambered

Your .469 dimension, is this measured .200 up from head of case at the web area? If so your die may be marked small base but it is not.

Commerical new brass head size (as above) is usually .465 in 308 for Rem, Fed, Win cases. For LC cases it is .468 on unfired cases. Thusly if you die is giving you sized cases at .469 you are no where near a new commercial case base size.

What is this dimension on fired cases you have? Based on your other dims you have a normal SAAMI chamber.

 

[delzur]

Re: Used Mil brass sticking when chambered

There are three columns of measurements.

The first set is from factory Federal 308 ammo.
The second set is full length resized 7.62 military ammo in a hornady die.
The third set is from the same batch of military ammo sized in a RCBS small base die.

The military ammo has not been fired through my POF 308 which is chambered for 7.62.

 

[Lumpy Grits]

Re: Used Mil brass sticking when chambered

Take that fed fact. rnd. and fire it, post the dims. of that case.
Redding seems to have a bit "tighter" SB dies than the rest.
Cheers,
LG

 

[Fuzzball]

Re: Used Mil brass sticking when chambered

IF your web is too large to easily chamber you need to try a small base sizer.

IF the neck/shoulder junction is too far forward you aren't FL sizing enough and need to turn the die down more, 1/16th turn (about 4.5 thou) should be plenty.

 

[delzur]

Re: Used Mil brass sticking when chambered

@ Fuzzball
I am doing a full size. The die is turned down all the way to the shell holder. Any further and the press would cam over.

@ lumpy grits
The following are the measurements taken from a once fire fed factory round the other night.
0.345
0.348
0.456
0.457
0.471
0.47

@ Hummer
Yes, the measurement was at 0.2 up.

The only difference I really see between the Hornady and the small base RCBS is at the neck and shoulder.

 

[Lumpy Grits]

Re: Used Mil brass sticking when chambered

What's your OAL after sizing?
LG

 

[Fuzzball]

Re: Used Mil brass sticking when chambered

"The die is turned down all the way to the shell holder. Any further and the press would cam over."

We "cam over" a press even without a die in it! All cam over means is the ram has lifted fully up and the lever toggle has rotated passed top dead center. At that point the ram reverses to start back down, slightly, until we hit the lever stop. We feel cam over as a reduction in lever effort because the ram pressure has decreased.

Turn your sizer down another 1/16 turn so the case shoulders can get pushed back properly.

 

[delzur]

Re: Used Mil brass sticking when chambered

I just got back into town after being gone for a week.

@ lumpy grits
The OAL on a sized 308 round is 2.0295.

@ Fuzzball
I have some new brass 308 and 7.62 that was fired through my rifle. Ill turn the die down when I size it later this week.

 

[RoosterShooter]

Re: Used Mil brass sticking when chambered

I did a lengthy write up on MILSURP brass not too long ago. I can't recall where it is located, but I will sum it up for you.

ALL 7.62 & 5.56 Lake City 'Standard' Milsurp brass has been fired from either the M240, M249, or M16 respectively.

Most 5.56 shooters do not have an issue with this, because, aside from a few barrel producers, most AR-15s chambered in 5.56 are built to Mil-Spec. Therefore, they have a little extra room in the throat and chamber for loose tolerances.

The problems mostly arise from bolt gun shooters who try and use the 7.62 LC brass to reload for their precision long range weapons. The M249 has a lot of extra chamber space incorporated into it's design to prevent jamming. This causes a lot of issues for the bolt gun shooter.

Basically, unless you want to spend a lot of time on 7.62 LC brass, you need to look for either 7.62 LC LR (long range), or 7.62 Match (scarce as hen's teethe). These two variants are ONLY fired in precision rifles, and do not have the extensive 'over-sized brass' issues associated with the standard 7.62 Lake City brass.

If you are looking for some 7.62 LC LR ..... let me know. I have plenty to spare, and will sell it cheaper than most dealers who occasionally get their hands on it.