Pressures?

[RG300WSM]

I ended up having some 168 gr bergers, and imr 4350 laying around so I figured I wouldn't be to sad wasting them to get the brass formed to my chamber. I know this chamber brass ends up stretching about 8 thousandths. I figured it being a brand new barrel it wouldn't hurt shooting 100 shots down it haha

 

[skipglo]

So I'm shooting the stuff I sized back to factory specs and just shot 60.5 gr of h4831sc with no pressure issues. It sucks because it's only 25 degrees here so it's hard to know what it'll do at 80 degrees but I have the loads sitting on the defrost heater in my truck until I'm ready to shoot them to try and get the casing hot. But so far it looks like sizing them back to factory is helping with the pressure. It does show the sc in the berger book for 210's but I've never used it in the past. I've always shot h4350 in it which is what I'll try next. I want to get a good group with 4831 and 4350 then decide between the 2 on what to use

Use the one you can get!!!!!

 

[scpaul]

Don't forget that you can use the old cut paper clip to give you an idea just how bad the case stretch is on the inside before you get the shiny band or a separation line. It's not precise but you can feel any extreme stretch.

 

[RG300WSM]

Use the one you can get!!!!!

Luckily they are both pretty easy to get right now

 

[RG300WSM]

To bad I don't want to shoot 168's . 4 shot group by my finger

 

[doverpack12]

Sometimes it's not what we want to shoot but what the rifle wants to shoot. Your 210s look like they will work out. I have some 200.20x that I plan to load in my 300 WSM, both H4350 and H4831sc were on my list of powders with IMR7828ssc.

I never want to waste the components getting new brass once fired but often I will get enough new fired, then size and prep those to fine tune or confirm the load, usually I can load up the rest of the new and not have much change. Occasionally the new brass takes up to 0.5 gr more powder due to the extra energy the brass disks up.

On your brass sizing issue. I would pull your firing pin and ejector plunger and check the brass as you size starting at 0.002" shoulder bumb. Offer that number is arbitrary because another point on the case can be tight in the chamber. You can feel that with no firing pin or plunger. As you keep sizing down and take care of the problem spot if there is one the shoulders grow longer, then come back to 0.002" bumb and then start getting shorter. I use the Redding stepped shell holder set and it's pretty interesting to start at +0.01 holder and see a shoulder not move, 0.008 maybe the shoulder bumps but the case is still tight and bolt handle not dropping freely, 0.006 maybe the shoulder gets longer because you hit a wide spot lower on the brass, this will chamber with drag on the bolt still, 0.004 might be 0.002-3" shoulder bump and now chamber with no resistance. Stop there and size them all.
That's not exactly how it works on all die, brass, chamber combos but generally +0.004-0.008 I will find where the brass chambers freely.

 

[baldhunter]

I bought a 300WSM in 2008.I had pressure issues with my 300WSM from the start.I never could reach book max loads.In fact,if I used 180gr load data,I found it to be perfect for 165gr bullets.When I checked my loads velocities,they were right there where the max book loads velocities showed,but I was about 2grs under book max.I was running around .030 off the lands,so seating too close was not the issue.It was just on of those things,it is what it is and I learned to live with it.I was later informed that the WSM's where designed different.The leads of the lands start right near the opening of the barrel.If you check the SAAMI specs. on the 300WSM prints,you will find that they have a rather long taper to the leads before you reach the full lands.So you really don't have much freebore at all.After I got my borescope I was able to verify that to be true.I also noticed I was getting some erosion so I had 20 Tubb's Final Finish bullets of unknown grit and fire lapped the barrel.After fire lapping,I checked the velocity of my loads and they showed a drop of about a 100fps.For the first time,I could use book max loads for the right bullet weight.I had to increase my loads about two grains to get back the velocity I was getting before fire lapping.After fire lapping,my bullets had to be seated out .070 farther to reach where it stopped at the lands.I thought that was quite a bit,but the large change was probably due to the long leads on the WSM.Here is a picture before fire lapping.


Here is after.



Here is my 7mag.This is similar to what I see on my other rifles too.You can see how much different the WSM is.