300 wsm sizing problem

Mar 2, 2002
the last time out shooting i watched my buddy bulldog'n the bolt closed and thought he had the bullets out to far.so when he reloaded i checked the bullet-land spacing and had the bullet set .030 off the lands.today at the range i shot his 300 wsm and the bolt was closing very hard on his loads.so i suggested after wrestling the bolt closed that his cases must be to long.some were a little long, after trimming and chambering without a bullet in the case it was still tight,i set the rcbs fl die all the way down to full size and it is still to tight.i neck size all my stuff and never had this come up before.what do you feel is going on? it doesn't matter if the cases are once fired factory or low to hot loads.his rifle is a win. factory.the stock rounds feel just fine chambering.and handloads are printing .5" groups at 100yds.

Many times the factory chambers are not as straight as they should be. If that's the problem and you didn't index the reloaded case to go back into the chamber the SAME way is was extracted out when fired, it will go in hard.

If it's a factory die, it will not (in most cases) resize the web area of the case which has probably expanded also.

The overall case length of ANY reloads should be trimmed back .010" to start with. This allows for case stretching. The lower the shoulder angle, the more stretching and brass flow will occur. A 17 degree will stretch more then say a 35 degree in most cases.

Check your die also for a build up of grease and dirt. If that happens, the case will be sized off angle. Clean your dies often.

Set the die (as a last resort) to over cam when the ram comes up. This will bump the shoulder back very slightly. Don't overcam by more then .001" or .002".

I would suggest firing factory rounds and marking the base of the case with a felt marker as to a certain point on the action. This will index them and then after reloading, put them back in the SAME way they came out.

If that don't solve the problem, check the die for dirt and also make sure the case length is proper.

If it's expanding in the web, a custom die that comes further down the case may have to be considered.

I think the indexing may just solve it though?

Let us know how you make out.

Factory chambers are many times the problem.
Darryl Cassel

PS--As an ad on here, check the Ojive of the bullets used. If you changed bullets from one firing to the next, the Ojive can be off by more then the .030" you say your off the lands. Even in the same bullet brand and weight, I have seen the bullets be off quite a lot.
Try seating all bullets just a bit further into the case and see if chambering is easier.

[ 03-28-2002: Message edited by: Darryl Cassel ]
Darryl has given some very sound advice and would be where I started looking first also.
In case those suggestions don't work: Something else to consider is that all shellholders aren't made the same. I had an RCBS shellholder for my 223 one time that was to long. They are suppose to be .125" from the surface that the case head sits on by gravity to the top of the shellholder. If the shellholder is to thick or simply runs on the high side of the tolerance zone, and your die runs on the high end of the tolerance zone for the distance from the die base to the shoulder, it's possible to never be able to bump the shoulder back during sizing. This will also effect how your case is sized along the case body for it's diameter dimensions also being the case isn't going deep enough into the sizing die.
If it does come this this, you can simply buy another shellholder and hope it's right, have a local machine shop grind a couple thousands off from the existing shellholder, or grind off a couple thousands off from the bottom of the die also. Both will have the same end result.

Time to get out the calipers and start measuring before and after sized cases to find out if your have a length, diameter, or both problem.

Good luck,
tried the camming over idea and it worked good.i was amazed that you could actually take the die down far enough to crush the shoulder as i did on the first case.thanks for the info!how about another question or 12?i had a muzzle break installed a couple years ago and noticed the crown was off centered by quite a bit.when i questioned this was told that there wasn't enough gas at the end to do anything to the bullet.do you agree with that statement?

No way can the crown be off at all.

Take that rifle to a good gunsmith and have a correct crown put on that barrel. That's one of the most important areas to look for when wanting accuracy from your rifle.

It must be straight and concentric.

Darryl Cassel
I noticed the same problem recently with my .22-250. I have loaded the brass 4 times and trimied it once. I am in all the tolerances but I can't get the brass to chamber. I am running this rifle fairly hot and have noticed quite a bit of case stretch. Any help on getting this brass back to use would be great.

If you know that all of your sizing gear is within spec and you can't size it back, then chances are your load is simply to hot and the brass is going past it's elastic limit to where it will not return to a size that will fit back in your chamber. That would be my guess. Are your primer pockets opening up at all or any other signs of pressure? Also keep in mind what Darryl said above about factory chambers not being concentric.

is the crown off center from the barrel OD. or ID? If it is off center in relation to the ID. it can be corrected easily but how it could be off is the question there. The bore could be off center too. My gunsmith said almost every factory chamber is cut way off some so far off you'd swear the reamer was going to break when they're being opened up larger. A definite plus in getting rechambered to something else.
im not sure how to tell what it is centered to but looking straight at it looks like the reamer was atleast 5 degrees crooked.i first had it installed on a factory 338wm.then had it rebarelled with a douglas and wanted the break back on it.he assured me it was fine so thats why i had it put on again.i did notice when he first put it on the stock barrel my impact point moved almost a foot.thats when i stated looking closly and asked him about it.there is a tube inside the break that is @.04" larger than the bore and the gases are vented out the break as the bullet passes into the tube.but i don't know why he would put a crown in at all if he says there is not enough gases at the end anyway.the gun shoots -1" at a 100 with carefull reloading(250mk), but was hoping for better.
From what I understand, the pilot for the cutter must have been bent. Impact would most definetly be off too. It must be cut square and crowned square, for any accuracy to result. I would find a new smith if he tells you anything differant. I had a smith thread a barrel for a muzzle brake on a 378wby Ruger #1, it was paralell but off center and bullets struck the brake. His fix was to open the ID. of the brake. This opened my eyes to his aptitude and cost him my buisiness.

Have it redone is what I would do, or do it yourself.
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