New to reloading 308

[Skasdi1]

Hi all
Sorry if this is posted in the wrong section or if the subject has already been covered, new to forums and not sure how it all works just yet.
I recently purchased and M&P10 and had problems right out the box. I purchased some federal 180 gr walmart rounds and the gun fired 5 fine and on the sixth round it just clicked. I inspected the gun and the case fully loaded but the charging handle was stuck. After mortaring the gun i was able to get the case out. Went back the next day and it never fired again, only got stuck. I sent the gun back to smith and wesson and it arrived today. They honed the chamber and replaced the firing pin spring and test fired 20 rounds. I took the gun to the range and also fired 20 rounds without issue.
Then I had some reloads I worked up and the first round loaded but just clicked and no boom and the charging handle was stuck. So not sure if this is another issue with the gun or if it is the reloads.
Here is what I loaded up. Trimmed cases to 2.005. COAL 2.800. Used 43 gr of 8208 XBR and a 150 gr fmj hornady bullet. I use a LE Wilson case gauge and all rounds gauge just fine. I have been reloading for a few years now in 223, 40, 9mm and 45 without issue but this one has me baffled. I have tried different COAL and the gun still jams locking the charging handle and never fires.
Before going to the range I brought the gun home and broke it down completely and then oiled it up in the right places. I have 4 new pmags and I tried all 4 mags as well.
If anymore info is needed I will be glad to provide it and any input would be greatly appreciated.

 

[NuJudge]

What rifle are you trying to fire the .308 ammo in? From your terminology, it seems to be a semi-auto. Many semi-autos have little camping power in the bolt closing, and if a case is just a little large, the bolt may look closed, even when it is not quite closed. I have several .308 rifles that have really tight chambers, and ammo for them really has to be prepared with a Full Length Small base die. If you are using military surplus brass, most of it has been fired in Machine-guns, which have really loose headspace, and really strong efforts have to be made to get it back in spec.

A better gauge for your brass would be the chamber in your rifle. I believe the gauge you are using is one that measures whether the Headspace on the case is correct, and probably case length also. There are other measurements that are important.

Particularly for .308 Garand and M1A rifles, they have the reputation of having an increased chance of out-of-battery firing when a insufficiently sized case is used in a handload.

How does this rifle do with factory commercial or military ammo?

 

[scooter123]

The rifle in question is a Smith & Wesson M&P 10, S&W's interpretation of that AR10 in 308 Winchester.

From the description of what is happening it sounds like a Headspace issue. The first thing I would suggest is that you use a straight edge across the base of a sized case when it's in your Cartridge Gage. If that straight edge shows some "daylight" between the case head and the rear surface of the gage your cases should be under the maximum allowable Headspace dimension. Which means that they should chamber properly in a chamber that is to SAAMI specification.

Unfortunately, if your chamber doesn't have adequate headspace it can get rather complicated to sort out the exact cause. Because that Chamber dimension is a result of multiple features. First there is the relation ship between the Thrust Face of the Bolt and the rear surface of the Locking Lugs on the bolt. Next that is the depth of the chamber in the barrel itself. Finally there is the fitment of the Barrel Extension that has the fingers that lock the bolt. If the stackup of all these dimensions adds up to a short chamber condition what will happen is exactly what you have observed.

So, what to do about your rifle.

First, make good and sure that you are sizing your cases correctly. Generally I try and set my Headspace so that it is as close to halfway between the minimum and maximum as I can get it. Note, I am not suggesting a mistake on your part, I'm simply suggesting a second look to confirm you are sizing the cases properly.

Once that confirmed it then places all of the blame on a rifle that has a chamber that is not to specification. IMO it is under warranty and I believe that you should be talking to S&W again. If you can identify a particular Commercial ammunition that you are fairly certain will cause a bolt jam and make note of the Lot Number. That way you can tell S&W that such and such ammunition is jamming the bolt and when you checked that ammunition with a cartridge gage borrowed from a friend that ammunition is to specification. My hunch is that the Barrel Extension wasn't properly fitted and because these are pretty much permanently installed they will probably need to replace the barrel on your rifle.

 

[growr]

I am also wondering about the die not setting the shoulder back far enough....if your condition is more prevalent with your reloads and NOT with military or commercial fresh ammo this could be a problem.

With my M1a Supermatch I ended up buying an RCBS Case Micrometer to ensure that the shoulder was indeed in the correct spot.

Using my Dillon drop in gauge the ammo looked fine....however the shoulder was not in the right spot which is critical in an M1A. Having a shoulder in the wrong place CAN lead to a out of battery firing...RARE but it CAN happen!

I never had a problem using my Dillon .308 dies....but my RCBS die was a different story. The RCBS needed to have some material turned off with a lathe to get it correct.

Just a thought....

Randy

 

[Skasdi1]

Sorry for the delayed response. I was out testing more rounds before I responded to any of your questions.
NuJudge: I am using a full length RCBS .308 Win die set that I picked up on Midway. Am also using once fired 7.62x51 brass. The LE Wilson case gauge is checking exactly what you said. Since I posted earlier I ran to Walmart and bought every brand the gun would take. I have fired factory Winchester 180 gr 308 win, federal 150 gr 308 win and even super cheap ZQ 147 gr fmj 7.62x51 without issues. So it is definitely the my reloads.
Scooter123: I did exactly what you said and I sized some dummy loads tonight at COAL 2.700, 2.750 and 2.800. All three still hung up.
Growr: The gun is cycling both factory and military ammo without issues so I believe something is wrong in the die setting. After I read your post I ordered the RCBS Micrometer for 308. Eyeballing it with my RCBS digital caliper everything was to specification. But eyeballing it will not cut it in reloading, learned that long ago. This evening I reset my dies. I cranked the sizing die in to touch the shell holder than turned 1/8 turn out and locked down. I had both 308 win and 7.62 brass on hand so I ran both through sizing, then trimmed to 2.005 and loaded up dummy rounds of each and both jammed up the gun.

 

[Skasdi1]

Oh and thanks to everyone for responding.

 

[Skasdi1]

One other note tomorrow I am heading to the reloading store for more powder so I am going to throw my die, gun and some of the rounds I loaded up and swing by there. I have been going there for sometime and they are always glad to take a look. So I will post if they come up with anything.

 

[bbqncigars]

You may have to trim some off the bottom of the die if the shellholder is firm against the die after press cam-over. I use an RCBS X die to feed my two FALs and match Garand. No problems in my AP press or guns, but the initial setup took a while.

 

[Skasdi1]

After resetting both dies I grabbed a few 308 win cases and sized and set a bullet and those are feeding fine through the gun now. I did 5 the same way with the 7.62x51 cases and they are still jamming up the gun.

 

[growr]

When you get your case mic. take a measurement on a new unfired round of military or factory to use as your reference.

I found this tool to be invaluable to me in die set up....perhaps you will as well.

Randy

PS. If you can find it IMR4895 is OUTSTANDING for the .308......Has been used by the military for many years....everything that can be known IS known....especially if you are replicating M80 Ball, M118, or M852.
If your bullets have a cannelure, simply seat to the groove.....

Last thing, make sure that you are trimming to length AFTER you full length size......

 

[scooter123]

I use Dillon Dies for full length sizing my 308 cases and with theses dies I had to crank the die until it was contacting the shell holder. Fortunately my 308 is a Bolt Rifle so it was rather easy to set the die to the point where the Bolt Lift just started to get light. BTW, I used an empty case at this stage because I wanted to test for shoulder position only without the bullet muddying up the feel.

Note, it can be a bit tricky to chamber an empty case in an AR but it can be done. What you have to do is hook the case head behind the extractor and push against the ejector spring to hold the case straight. Then push the bolt forward until the case is into the chamber. Once there you can then push the bolt carrier fully closed.

Because you are loading for an AR10 it may be better to start with the shoulder set back as far as your Sizing Die will allow, a "short case" condition. BTW, if you need to get the Die down just a bit more I would suggest sanding down the top of your Shell Holder on a belt sander. Once you have the shoulder head spacing for a free release of the bolt then SLOWLY start edging that shoulder a bit towards the "long" side until you first start feeling some additional drag on the bolt when you pull on the charging handle. Then go shorter by just a tiny little bit.

Tips. First, I mark all of my dies with a Sharpie marker to indicate the perfect "indexing" of the die with a mark at 12 o'clock. Yeah, that mark will rub off but when I see htat starting I just refresh that mark. Second, the thread on our dies is a 7/8-14 thread, so one full rotation of the die is 1/14 inch or 0.071 inch. This means that your 1/8 turn out shifted the shoulder on your cases back by 0.071/8, nearly 0.009 inch. For Head Spacing that distance is a LOT. in fact it exceeds the total tolerance for Shoulder position which is 0.007 inch.

Finally, in an ideal setup you would see the shoulder shifted by only 0.002 to 0.004 inch by a firing cycle. Getting to this point requires taking the time to "tune" your head spacing for your specific rifle. By doing this you will cut down on how much "case growth" is seen at each firing and potentially extend the life of your cases. In theory doing this will also improve accuracy. Finally, you can do this tuning even for a rifle that has a chamber that is a bit "out of spec". However, when you tune head spacing for a specific rifle you do need to make sure that you keep that ammunition identified for that specific rifle.

PS; for my bolt gun I'll Fire Form my cases and then just Neck Size the cases. Generally I can get 2 to 3 firing cycles before the bolt lift gets so heavy that I need to do a full length size. Unfortunately that isn't possible with a semi so I try and set my sizing die up so that the fit in my chamber allows a free turning bolt but close enough to the maximum condition to minimize case stretch.

 

[MichiganScott]

Once fired 7.62x51 brass most likely was fired in a full auto weapon. Although I've never used a small base die to reload for any military type semi-auto from the Garand through the M1A and AR15, you most likely need one to size the mil-surp brass enough to chamber.

Scooter123 is correct about setting your dies for most reloading. However, in your circumstance, screw the sizing die in enough for the press to cam over center. That will size your cases to the absolute minimum with your dies. If they still stick, spend the money on small base dies.

You're right about the problem being your reloads and not the gun.

 

[Collo Rosso]

I had the same problem in my M1a and my first 308 reloads. A L.E. Wilson case gauge revealed I wasn't sizing down to the base. As others have said adjusting my sizing die to cam-over had the cases dropping in the case gauge just fine. A second function of the case gauge I like is once dropped in you run your finger over the mouth end and can determine which ones need trimming for length. I haven't had a problem since.

 

[Skasdi1]

Update: Purchased a small base die like some have suggested and my problems are solved. Thanks to everyone for the great advice, I learned a lot on reloading the 308 and truly appreciate it.

 

[growr]

...what manufacturers dies were causing your problems anyway?

Mine were RCBS which have normally been outstanding...I had to have a machinist friend of mine chuck mine up in his lathe and remove either 3 or 5 thousandths from the bottom of the die...don't remember which.

I decided just to use my Dillon dies which never caused any problems ever.

Glad you found the REAL source of your problem though....I immediately thought the die was somehow the culprit.

Randy

 

[ewmn]

Very interesting, as I'm planning on reloading my first 308 rounds. 1fired lc nato brass. My mp10 works well with factory ammo. I did know to use a small base die. So I bought a set of rcbs black case ar series dies. And a wilson gauge. I'm going to use imr 8208 xbr with hornady 168 gr.hpbt.

 

[DWalt]

About the only thing it could be is the FL die setting. I used to reload A LOT for .308 using military brass, for use in both a Remington 740 semi-auto and a Model 70 bolt action. I used RCBS standard (not SB) dies, never a problem with headspace or bolt lockup..

 

[MasterTech1960]

Very interesting, as I'm planning on reloading my first 308 rounds. 1fired lc nato brass. My mp10 works well with factory ammo. I did know to use a small base die. So I bought a set of rcbs black case ar series dies. And a wilson gauge.

I have been using the RCBS AR series black box dies and have not had a single problem loading for the M&P 10. They work well and were easy to set up. You should not have an issue.

 

[catgunguy]

When I first started hand loading, using used Lake City brass. I also was sticking reloads. Started using a micrometer to measure the bases and found my regular sizing die was not reducing the bases enough to fit my chamber. I also had to go to a small base die to get the bases to chamber.

 

[rwsmith]

This is....

This is one HECK of a thread. I'm going to have to chew through it to get more understanding. I've had some kinky things happen with chambering 30-06 reloads. Weird things. Strange things. Unexplainable things.......