6.5-300 wsm pressure signs

[tyfo]

Hey everyone. I have a new 6.5-300 wsm and im getting some unclear pressure signs. i started with 5grs less than hodgdons recommended starting load for h1000 in a 270 wsm. after every shot i looked the case over for signs and saw nothing and there was no heavy bolt lift until i got way up there in powder. after i had deprimed the brass (none of the primers felt loose) and cleaned the cases i was inspecting them again and saw very faint ejector marks on every piece of brass. this is my first wsm and i know they run at high pressure so i was wondering if you guys think this is a high pressure issue even though i started so low with the charge or if it could be an issue with having softer brass in a higher pressure chambering. the brass is norma. thank you for the help.

 

[Canadian Bushman]

Sometimes i dont take ejector marks as a high pressure sign. You know i bought a 50 pack of win brass and when i was prepping them for their first load they had what looked like ejector marks on them. I know win brass is on the cheap side but is there a chance the marks were already there?

 

[tyfo]

I checked the unfired brass from the same lot and there are no marks. i have noticed that the brass im using does seem to get marked or scratched up very easy. thats what makes me think it might be soft brass.

 

[Canadian Bushman]

That was my next comment. When i test chamber my once fired brass it leaves ejector marks. That would be another quick easy test. Just a thought.

 

[Shortmagman]

What bullet weight did you use? Did you chronograph the load? If so what velocities were you getting.

I think you still may be too hot. I did a little comparison between powder data for the 6.5-06 with a 130 grain bullet and the 270 Winchester with the same weight bullet. These case are near the same. The case you are using and the 270WSM case are also near the same. Here is what I found. With the 6.5-06 the Start load of H1000 is 47.7 grains and the Max load is 53.0 grains. With a 270 Win the Start load of H1000 is 61.0 grains and the Max is 64.0 grains.



As you can see even when you drop 5 grains from the starting load of the 270 Winchester you are still above the max load in the 6.5-06. I know that all is not the same with this comparison but it does make you think that you could be too hot.

 

[tyfo]

I did use a chrono and i got between 3100 and 3330 with no signs, no heavy bolt lift, no flatened primers, and i didnt see any ejector marks at that time although weather conditions werent the greatest so maybe i just missed them. At the 68gr load I had heavy bolt lift and a flat primer and a visible ejector mark. My velocity also jumped up to 3420 so I stopped there. I know these are very fast velocities for that round and I was unsure my chrono was reading right because I would expect to have some sort of sign earlier in the proccess. The ejector marks are so faint that I could only see them after I tumbled the brass and instpected each case under a good light. I was using 140 bergers through a 30 inch tube. I thought I started low enough after I compared the difference between the 300 wsm and the 270 wsm with powder charges and applied similar diferences to my 264 and the 270. I also looked at the heavy for caliber 160gr 270 wsm starting loads and made sure that i started below that as well since 140gr in a 264 is similar to a 160gr in a 270. Oh well I guess I will go back out this weekend and start from 50gr instead of 60gr and redo the whole thing. I would like to know if anyone has had this sort of thing happen with wsm norma brass. Thanks for any help.

 

[Canadian Bushman]

IMO i wouldnt back down because light ejector marks. I also get them very commonly. I rely much more heavily on loose/flattened primers and bolt lift. Things like a slightly incomplete radius on the primer and ejector marks are things that are common even on factory ammo and im more than willing to tolerate. If you dont feel comfortable with it or are worried about the rifle, by all means back off the load.

 

[CogburnR]

Hard to tell exactly what you are seeing but I started to have some signs show up with one of my 270WSM's and it was from the brass getting a little too long. Trimmed the brass and the pressure signs went away.

My chamber apparently is a little on the short side as the case lengths did not seem excessively long.

 

[jwing]

You need a new crono. I shoot 6.5 wsm 68.0H 1000 will get you to 3200, shot every powder out. You not going to get more vel less you go to a bigger case. 6.5 wsm and 264 win same case capacity. 6.5 saum couple granes less same vel. Good luck

 

[MontanaRifleman]

I don't put a lot of weight on ejector marks. I get them sometimes on lower than max loads. It varies from rifle to rifle. If my primers start to crater or I get a sticky bolt, then it's time to back off. I also consider primer pocket case life.

 

[tyfo]

I want to apologize to everyone for wasting their time, and also say thank you for the responses. I grossly underestimated what heavy bolt lift on this new rifle was. It felt like ejecting a normal round out of the other rifles I have loaded for. I went to chamber the rounds I shot this weekend and the majority were a snug fit, but I could not lock the bolt on 4 of them. I measured the web and came up with .0015 of expansion over the couple rounds that loaded no problem. I am really embarassed to make such and stupid mistake and also very thankful that nothing really bad happened. I will be doing it over again this weekend, but starting 10gr lower.
As to my chrono being off. I took my friends chrono and put it right behind mine and shot paintballs through it to see if mine was reading higher. There was around a 15 fps difference on average. Both of these chronos have been accurate and verified by drop data many times so Im pretty sure unless something happened to both of them that mine is still reading fairly accurate.

 

[MontanaRifleman]

What did your primers look like? I almost always get craters with a sticky bolt.

 

[tyfo]

all of my primers looked normal until the last couple where they started to flaten out and get cratered. The last load had a loose primer when I deprimed it, the depriming rod barely touched the primer and it fell out.

To the person who said they shoot this round with 68gr; do you shoot that load a lot or is it at the max for you?

 

[jwing]

That is a max load in my rifle. 3180 fps 28 inch rock.