Quick question for folks who have been reloading/shooting the 300 win mag for a while...

I had a 300 win mag case separate on me yesterday during extraction. I am shooting a T/C encore and after the second shot, I opened the action and pulled out the case bottom..it completely separated just beyond the belt. Had the belt in hand and the rest of the case in the chamber. Great.

The cases are Remington and I have fired them 4 previous times with F/L resize. Load was 68 gr of IMR 4350 under 180 gr Hornady and CCI 250 primer. Had intended to shoot a ladder of 4350 and this was my starting load.

The barrel is at the 'smith's now to get the remains of the case extracted. I thought I had the headspace sorted out correctly, but he will measure the chamber..His feeling is that deep chambers are quite common in T/C barrels...could be stretching the cases too much.

I didn't think 4 re-loads was too much for this brass. My 7mm mag and 338 mag brass have been re-loaded a lot more than 4 times...of course, they are in bolt guns..not break open.

Any thoughts/ suggestions much appreciated.

Next time you can remove the case yourself.

Put your cleaning rod in the bore from the muzzle end with nothing on it. When it protrudes from the chamber, screw on a bronze brush for a shotgun or one that is bigger than the chamber and pull the rod into the case that's left. Now, push the rod back toward the chamber to remove the rest of the case. You can do it from the chamber end too with the handle section of a 3 piece rod but by pulling.

To avoid this in the future, after you fire your brass once in your chamber, do not full length resize it again till it starts to chamber with too much resistence. Neck size or PFLR only.

You can do a search here on the site for info on proper techniques for sizing.

Good luck.

Tried the cleaning rod trick...no joy...ran out of ideas and airspeed at the same time..so off to the gunsmith I went.

PFLR or neck size produce misfires in this rifle...not uncommon to the encore especially with the belted cases.

Thanks for the tips though.

Cheers

quote:

Originally posted by kreyten:
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PFLR or neck size produce misfires in this rifle...not uncommon to the encore especially with the belted cases.



Cheers

I'd love to know the reason for that!

Grumulkin posted this on 24 hour. He posts here as well. You may want to check with him.

quote:

I've only had 2 or 3 dozen Encore and Contender barrels so take this for what it's worth:

1. I mostly use handloads and when they're to be fired in the same chamber I only neck size.

2. In those instances where a case is slightly oversized and the action has to be closed firmly, I've noticed no decrease in accuracy.

Regardless of whether a chamber is belted or rimless, pushing the shoulder of the fired bottleneck case back so that it stretches again on each firing will quickly (in this case, on the fourth shot) cause a head separation.

Forget the belt. It is there for decoration. You should set your resizing dies so that the cartridge properly headspaces off of the shoulder.

Unfortunately, many factories and gunsmiths measure only the belt recess to determine headspace, leaving the chamber somewhat sloppy (excessivly long). Since the dimensions of the belt on the brass and the belt recess of the chamber can be widely at variance and remain within "specs", this results in a situation where your brass, if sized excessively, can also stretch excessively.

I can't even imagine what might cause a misfire with a neck-sized or PFLS case as compared to a FL-sized case, but rest assured, you should resize your case only as much as required to get it to re-enter the chamber and allow the action to close without undue force.

By the way, you might want to start over with a "real" rifle. The one you are shooting is a converted handgun, which was in turn adapted from a shotgun action. It's a piss poor way to design a gun, particularly one that can fire only one shot at a time and even then it takes both loading and manually cocking the hammer to accomplish that. Disregarding the fact that the contraption has more in common with a barn door hinge than with a rifle action, it is butt ugly as well. Most game shot with such a gun probably dies from its ugliness rather than the effects of trauma inflicted by the projectile.

Gentlemen..for your reading enjoyment:

http://www.bellmtcs.com/store/index.php?cid=172

quote:

By the way, you might want to start over with a "real" rifle. The one you are shooting is a converted handgun, which was in turn adapted from a shotgun action. It's a piss poor way to design a gun, particularly one that can fire only one shot at a time and even then it takes both loading and manually cocking the hammer to accomplish that. Disregarding the fact that the contraption has more in common with a barn door hinge than with a rifle action, it is butt ugly as well. Most game shot with such a gun probably dies from its ugliness rather than the effects of trauma inflicted by the projectile.

From your link:

quote:

This is what it should be. .001" BETWEEN THE CASE HEAD AND THE BREECHFACE.

I would think that your Encore would close with some noticable force or resistance with a cartridge in the chamber with this. I also think that if you continue to FL resize your brass, you will have a lot more than .001" headspace. I also think that if your chamber is that oversized and you continue to fire then FL resize your brass, you will continue to have case head separation.


Why don't you just size a little at a time and try them in the rifle? Just size until they just chamber with little effort ie....PFLR

quote:

Originally posted by rcamuglia:
...Just size until they just chamber with little effort ie....PFLR

Agree. If you are having mis-fires with P-FLR, the FLRing the Case would make the problem worse.

The Contender chambered for the 35Rem used to be a real stickler for this(long ago) even with Factory Ammo. Back then T/C recommended using Cases with Starting Loads and the Bullets Jamed into the Lands in order to Fire Form for the Chamber. Then subsequent Reloads were to be "Sized only enough to allow the Barrel to Snap-Shut with a small amount of effort." Or basically P-FLRing the cases.

I'd recommend you go from the "0.001" Headspace so it is -0.001" to -0.002" Headspace. Your problem will either no longer exist, or the Trigger Assembly needs cleaning.

Headspace on the shoulder, NOT the belt. http://www.brownells.com/.aspx...pace_and_Maximum_COL

Kreyton: The link you posted is relavent to RIMMED cartridges only. Neither the rimless case nor a bottlenecked belted case headspace the way a rimmed cartridge does. Rather, they properly headspace on the shoulder. The mistake many people make is believing that a belted case can consistently headspace on the belt -- it will not and should not.

Really doesn't matter what kind of head it has, if it's a bottle neck round resize it so the shoulder to head length is just snug or you'll get head seperations pretty quick. Springy actions just make it worse.

The photo show a head separation I had in my Encore. Being a scrounger, I couldn't resist picking up some fired cases I found in a dump in Alaska. One of them worked OK though the bright ring above the web indicates that if I tried loading it again it would probably separate. I could have avoided the problem if I had just used the bent wire trick on the case to feel for the groove that starts before a head separation occurs but I was an idiot. Both pieces of the case, by the way, were easily removed without the services of a gunsmith.

By all means, divest yourself of your Encore. They're ugly and just don't shoot worth anything. You need something capable of "minute of deer."

Different cartridges have different case lives depending on the design thereof and how hot they're loaded. If you resize barely enough so they're chamber in your gun they'll last the longest but eventually they tend to thin above the web and then a head separation occurs. If you have to trim a case, rest assured that the case has stretched.

By the way, after having shot at least 20 or 30 different Encore and Contender barrels on 6 different frames, I have yet to experience a headspace "issue." I frequently full length resize brass for these guns and accept the fact case life won't be as long as if I only neck sized.

This is an illustration on brass stretch from my Weatherby MK V 7 MM Rem

You should measure your brass at the shoulder datum for proper headspace.

Excessive headspace could cause a misfire. Neck sizing and partial sizing will not create excessive headspace or misfires.

Your case failed because of a combination of two things. Excessive headspace and a full length resize...it happens. Solve this by unscrewing your die until you achieve the proper headspace for your rifle.

My 7 mag die does not contact the shell holder by .023 to give me a .002 shoulder push back. I know this because I measure my brass.

This is a fired peice of brass from my 7 mag


This is a new piece of brass from the same lot # look at the amount of stretch WOW!!

Thanks for all the responses..will continue to work up the barrel...

Grumulkin..I just checked my brass and several have the shinny ring ahead of the belt..into the trash they go...

There is nothing wrong with a shinny ring just ahead of the belt. Most all brass will show this ring, belted or not.

I have several Encores and have had a number of case separations particularly in the 25-06 caliber. I had tried neck sizing, full length ,etc. When I called the custom shop at Thompson, they said that 3-4 loadings was about all I should expect in case life for their barrels. I just toss the brass after the third firing now.

It's the FL sizing. With any belted case, FL sizing oftens sets back the shoulder too far & the case stretches waaay to much. After you get the case out, try neck sizing or what I do w/ belted is partial FL size.
Back your die out & size until the case just chambers w/ slight finger pressure. Lock it off & load with that. Your brass will last at least twice as long.