Help with funny pressure signs

[GhostFace]

Okay here goes, I came across a pretty good deal last month on 1000 30 caliber 210 grain Sierra match kings. Previously I had loaded 190 grain custom competitions and reloader 22. I typically use the OCW method when developing a load. Using reloader 22 with the match kings I started at 56.0 grains and went up to 59 grains and half grain increments. The 56.0 and 56.5 shot a well-rounded group, I started experiencing pressure signs at 57.0 grains and it went away at 58.5. I was getting slight ejector marks on the case head but once I stepped up to 58.5 and 59 the ejector marks went away. Not once did I experience sticky bolt lift or cratering primers or flat primers. The 59.0 loads tightened up really well and was rounded but shifted to the right some.

Yesterday I went to reload these cases( they were virgin) and noticed the primer pockets were seriously loose so I pitched them. The charges that I loaded up yesterday are the 59.0 but I decided to Moly the bullets in order to lower the pressure. I'm hoping with Moly I can save the brass to at least a couple of firings. Has anyone ever seen pressure signs like this before? For what it's worth I'm shooting a custom .30-06 with a tight necked Ombermyer chamber.

 

[spife7980]

If one shot is ruining your primer pockets you need to back off of the gas pedal, plain and simple.

Now, does your tight neck have enough clearance with your brass of choice? Can an unsized fired case neck hold a bullet or does it fall straight through?

Im not sure how temp tolerant rl22 is, could the difference in your shooting a month ago be related to conditions sand temperature? Say 70 degrees then and 105 now could be a potential gremlin.

 

[GhostFace]

Yes, the Winchester brass does have enough clearance. I have not tried to see if a fired unsized case will hold a bullet and I don't have any right now to check. I did the load development with the 210s a couple of days ago and the temp was around 86 degrees. I was just curious as to why the ejector marks showed and then went away. The best groups came from the 59.0 charge but it shifted right some.

 

[Supersubes]

The right shift is probably just due to additional recoil and your position. I have seen what you describe but not quite as stark. The way a charge acts, or series of eacalating charges is not necessarily linear. It only takes one pressure spike to do the damage, whether that be an ejector mark or an enlarged pocket. Were you recording velocities during this test?

Either way, you're well above max for your gun, as spife said.

 

[GhostFace]

No, my chrony took a dump on me, well I guess I'll load some of the 56.3 charges and take it to 1k yards to see how it does.

 

[Deleted member 10043]

It's transcending from one pressure node to another. I've only experienced this once with bullets set into the lands by mistake on my part. Backed off the bullets a little and that range that showed pressure marks disappeared.

 

[GhostFace]

I'm not into the lands but right at 3 thousandths or so. Im just going to back off to the 56.5ish mode even though the higher node shot alot better.

 

[Deleted member 10043]

I was at .003 as well. I changed it like you are doing only to find out it likes factory COAL.

 

[MtnCreek]

Imho, you'd be better off seating them 5 thou long than trying to stay 3 thou off the rifling.

 

[GhostFace]

I only have 4 pounds left so I will be looking for another powder that give similar velocity. I was also looking at trying some RL23 since it is an extreme like powder. Any way I'm going to 1k tomorrow to see how the 56.3 load does. Thanks guys for all of your input...

 

[GhostFace]

I just came back from the 1k yard range and like I said before I used RL22 and 190s but the 210s are a hammer with RL22. My groups were tight at all distances, with the 190s they were tolerable not tight. After trueing strelok called for 33.00 minutes at 1k and I actually used 31.25 my velocity is 2675 from a 22 inch barrel. I ended up using moly so I bumped the charge up a grain from the 56.3...