Ejector marks

[Gorill@]

Those are deep ejector marks…whatever that load is, your way over. I'd back off the load.

Are you in the lands? If so, get off the lands. Try seating your bullet another .010, .020,etc. deeper. On my 300 NM, my ejector marks vanished with just another .010 deeper seat

I'd do a ladder of 3-5 bullets each. If you get heavy bolt lift, knock it off. Good luck.

 

[parshal]

What speed do you run your BR. We are new to these types and all the reading says between 2925 and 2975 is where we want to be with a 105

I ran a BR in NRL/PRS with 105's at 2830 for almost two years with 29.7 Varget. Ran a match in pouring rain and started feeling bolt lift. I swapped over to a Dasher with 112's at 31.5 Varget (105's were hard to find at that time) and run it at 2840 so I'll never have pressure. Some guys are running their Dasher at 2790 with great results.

Peterson brass is not soft. That's pressure. Back off.

 

[cb4128]

Have to agree with others here, primer cratering, ejector mark - too hot. Back off 2-3 grains from the start of these marks and you should be good

 

[rsbhunter]

First, every brass brand has different internal capacity. Second the first test on any new brass should be pressure, not accuracy. Load new brass at the suggested start load ( low pressure), just to form brass, and expand internal capacity. Then load 3 cases at different powder charges and check for pressure. Experience has taught me that loading 50 or 100 cases of new brass to a med/upper limit only results in using the kinetic bullet bullet ALOT. rsbhunter

 

[WKWRIGHT]

First 50 shots with pressure testing had a couple that looked dark pierced? This last 50 had multiple and at lower charges. He's gonna take to a smith tomorrow to have firing pin looked at. I have a 6 dasher I run at 32.7 with virgin alpha brass and now 32.4 after fired at 2960 no issues. I know different guns different loads but seems too light for ejector marks.

I had a 6 dasher that I had similar issues with and it was pressure. I ended up having to seat them a little deeper and turn the necks, it wasn't the powder charge causing it.

 

[rsbhunter]

It's true that multiple conditions can cause pressure signs, powder charge is the first to check IF the loads are at or close to top loads.... Again, why I suggest that new brass be loaded at low charge weight, it should still be enough to get fired neck diameter, base to shoulder datum line, case web diameter, etc...then you can tell where the problems are...rsbhunter

 

[Conrad]

If this is new Peterson brass more than likely it is 10-12 thousandths too short and you're going to see pressure signs from brass slamming forward in chamber. It can present as building pressure as I found brass streaks in a dasher chamber and as the brass built up I saw more pressure. I shot all new brass at a very mild charge to avoid this and then bumped charge after it was formed. This is specific to Peterson dasher brass, but I also think y'all are pushing your charges. If you saw pressure at lower charges then go measure new vs fired at the shoulder.

I will also add I've seen Peterson show pressure if chamber has a tight neck vs how thick Peterson is. This was in a 25 creed.

 

[CubCouper]

Clearly a pressure problem. 33.6 is simply too much powder behind the 105s, especially if they are touching the lands.
Load might work in ultra-cold temps, but will wreck the brass when it warms up. As the bullets get heavier, a slower powder will help with the pressure. I've found that Reloder 17 seems to fit a sweet spot for my Dasher-cats -- best velocity for the pressure.


31.8 off the lands, and touching...

33.6 off the lands, and touching... both are over pressure.

 

[randy86314]

I concur. The pressure is too high for that brass. Is Peterson brass known to be hard or soft?

Your primers are beautiful. Flattened primers would indicate excess headspace. I think it is the brass

For another comment. I believe that the highest pressure occurs close to chamber, not at muzzle. It's a thing with M1As, port pressure, etc
This might be my first post.

 

[rsbhunter]

I have 3 Dashers, 2 Savage Target models with custom barrels, 1 Defiant with Bartlein barrel. With Varget in all three, 32.5 is higher than I want for pressure, even though totally safe. I shoot RL 16 in them also, and 34.8 is totally safe. This is in Norma brass for the Savages, and Lapua and Alpha brass for the Defiance. And yes, the Alpha has a different (lower) load max.I also think that we have to start understanding that primer signs are part of a bigger part of pressure signs.....if possible, use a chronograph... If the fps is too high, it's not magic, it's high pressure.....trust the math......rsbhunter

 

[Remnut3477]

Hey fellas, new guy from Wisconsin. Hopefully I can add some insight to the problem at hand. This is my rifle. It is a Remington 40x with a Bartlein 28" 1/8 twist, .269 neck. The load is New Peterson brass, first firing, I mandrel the necks, debured and chamfered them, uniform primer pocket depth and debured the flash hole. When I acquired this rifle it didn't have a ejector in it, so I installed one from Gre-Tan. We started load development at 31.8grs of Varget with a CCI 450 primer and . 010 off the rifling. I went in .2gr increments up to 33.6gr. Loaded 50rnds. The ejector mark was always there, from the first shot, it's faint, very faint. No hard bolt lift, no flattened primers, no other signs. It was shooting great, like 5 shot groups in the 2s great, with two different shooters. Now it all changed with the second box of 50 brass, (the ones in the pic) same lot as the first, same case prep. I loaded 10rnds each from 32.2-32.7. It started piercing primers and even a few didn't ignite. We know it's a pressure problem, but from where? And why the big change?

 

[wonderman4]

I always weigh my new brass. Then, I measure water volume of the new cases. Each one. This is the only way I can correlate with my load development. Not saying that this has anything to do with your problem, but one never knows. Plus, I am not a fan of the unknown.

 

[Chas1]

Nice Graphs CubCouper

 

[bigngreen]

Looks like your in serious need of getting the firing pin hole bushed!!!