What am I missing.

I sized and trimmed a bunch of .243 cases for my brother's ruger 77 .243 Win. rifle. Then I chambered each case to make sure it would chamber. All of them chambered with ease. I am using 6 mm. Gameking bullets. I started out with a load of 41 grains of Reloader 19 powder with Winchester primers. I seated the bullets for an overall length of 2.710, which is what is recommended in the Nosler book.

None of the rounds will chamber and I have to knock the bolt back with a hammer to get them out.

What?

Make sure the bullets are really 6mm. I recently heard of a new sealed box of .30 caliber bullets that where really 8mm.

Also, different manufacturer's bullets have different profiles. The Game King is not a Nosler product, so if the profile of the bullet is different, you could be shoving the bullet into the rifling. (maybe) Do you have rifling marks on the bullet when you knock it out of the gun?

There are a lot of variables here.

2.710 is slightly longer than the specs for the 243.

But, on;y very slightly and should not have caused the problem you have described.

I see some lids on the Internet are longer than this .

Some go over 2.800!!

tried 2.705 - no go. tried 2.7 - no go. bullets are .244 on my calipers.

I seat Sierra game kings in my Brno.

Cases 2.035 trim

100 gn 2.650" 85gn 2.620" oal

Hodgdon data. jc

Stop guessing and determine for sure your allowable OAL; partially size a case so it will allow a bullet to be pushed back and carefully measure it. You an also use a cleaning rod but that method takes more time and measuring.

Stop guessing and determine for sure your allowable OAL


The magic number turns out to be 2.657

thank you all.

check that your not hitting the crimp in the seater die.
this can cause a bulge right below that point and it can also push the shoulder of the case out a titch stopping the round from chambering.

in the case of the second event you can pull the punch out of your 308 size die and run the loaded cases in there to push the shoulder back in place enough to chamber.
Lube them.

quote:

The magic number turns out to be 2.55

That doesn't sound quite right for a factory rifle.
The Sierra manual lists the recommended OAL of 2.65", usually the recommended OAL is similar to factory ammo.

The process I use for all rifles I load for is #1 check the overall magazine length in the rifle.
#2 check the length to the lands using the bullet you intend to load for (various methods available to do this but I chamber a bullet in a case method)
With those 2 measurements you can then start.


Update: Apparently you changed the "magic number" after I posted to 2.657"

quote:

Originally posted by Lamar:
check that your not hitting the crimp in the seater die.
this can cause a bulge right below that point and it can also push the shoulder of the case out a titch stopping the round from chambering.

in the case of the second event you can pull the punch out of your 308 size die and run the loaded cases in there to push the shoulder back in place enough to chamber.
Lube them.

That's the first thing I'd check: something happened during the seating process. I think Lamar is spot-on. Pull a bullet and see if the case will chamber. If so, that would rule out a deformed case.

If your doing a crimp on the seating stroke you can have this problem.

Raise your die up and put a case on the shellholder and lever the case to the top. Now screw the die back down to make sure it does not touch the case.

I set my seating die to where the die just touches the case and then back it off half a turn.

OP said up front that he made sure the sized brass would chamber. So it it either crimp buckling, or bullet jam into the throat.
And he now has his max allowable OAL so if they don't chamber now, yes, check the crimp. I rarely use any....maybe a little.
I'm sure he is good now.

quote:

Originally posted by dpcd:
OP said up front that he made sure the sized brass would chamber. So it it either crimp buckling, or bullet jam into the throat.
And he now has his max allowable OAL so if they don't chamber now, yes, check the crimp. I rarely use any....maybe a little.
I'm sure he is good now.

I'd be surprised if it were bullet jam: he had to knock the bolt back with a hammer to extract the round.

If bullet-jam were the problem, I'd expect he'd have filled his action with powder and had to knock the bullet out of the barrel.

I am thinking crimp buckling.

I would suspect crimp buckling BUT that should be obvious having some kind of very noticeable shoulder bulging/crinkling PLUS he must have NOT noticed the difficulty in closing the bolt...having to use a hammer to open the bolt again...or maybe he didn't look hard enough???...

I couldn't discern from the posts IF he actually did find/solve the problem.????...I would like to know.

Good Hunting

quote:

Originally posted by dpcd:
OP said up front that he made sure the sized brass would chamber. So it it either crimp buckling, or bullet jam into the throat.
And he now has his max allowable OAL so if they don't chamber now, yes, check the crimp. I rarely use any....maybe a little.
I'm sure he is good now.

No crimp . All is well.

Was it crimping that was the problem?

quote:

Originally posted by RMiller:
Was it crimping that was the problem?

I was using OAL data from Nosler for a Sierra bullet without realizing it. Bullets were seated too long. No crimping involved.

Interesting, thanks.