My Lapua 300 prc brass experience......

[parshal]

If that doesn't work you could always run one of Alex's reamers in by hand to open it slightly. There's a whole thread on LRO where folks are doing that for the 65 PRC. PM me if that's something you need.

 

[ontarget7]

If that doesn't work you could always run one of Alex's reamers in by hand to open it slightly. There's a whole thread on LRO where folks are doing that for the 65 PRC. PM me if that's something you need.

Thanks, I maybe contacting you next week.
I'm hand selecting my current Lapua brass for my trip to Alaska but after that's over I may have to go that route. Really won't do much with it until the end of August when I get back.
Much appreciated !

 

[FrogFire7]

This sounds like my problem to be honest.
I may take a touch off the bottom of the die to see if that makes my situation an easy fix per say

I have had to do this once or twice in the past... I'd suggest grinding down the top of your shell holder first. I'd rather grind on an $8 part than my dies

 

[wasskeet]

I have had to do this once or twice in the past... I'd suggest grinding down the top of your shell holder first. I'd rather grind on an $8 part than my dies

Or a set of the Redding comp. shell holders?

 

[P7M13]

@highdrum, thanks for sharing your detail. I'll be reforming some Lap 300PRC into 7LRM some time this summer.
Those are impressive numbers.
Have you experienced any unburnt N570 at 23" barrel length? My experience with it, 338 Lapua @ 26" with N570 leaves unburnt kernels, almost exact same charge in 28" 338 Edge, none.
I'm also a little confused. Are you saying ejector marks in the case head, or extractor wipe marks on the rim?
If you could also share pics of your fired case heads? My experience has been once you start to get extractor wipe marks, you'll also see primer strike splash/ripple -- this before flattened primers.
Lastly, I've worried about loose primer cups with brass based on the force needed to decap the spent ones before cleaning. No rhyme or reason on that (edit - ones that I thought were starting to loosen would not continue - others would just give up the ghost and not retain primers on firing) Since then my attitude has changed - it can be easy in/ easy out every time for all I care, as long as it holds on firing. Ones that don't hold anymore are in the brass bucket.

 

[ontarget7]

Or a set of the Redding comp. shell holders?

What's the difference, say between the rcbs's ?

 

[wasskeet]

What's the difference, say between the rcbs's ?

Not sure whether RCBS has a set of shell holders that has progressively thinner tops (.002, .004, .006, .008 &. .010") made for accurately bumping shoulders back. Maybe RCBS does? - but I know Redding does.

 

[highdrum]

@highdrum, thanks for sharing your detail. I'll be reforming some Lap 300PRC into 7LRM some time this summer.
Those are impressive numbers.
Have you experienced any unburnt N570 at 23" barrel length? My experience with it, 338 Lapua @ 26" with N570 leaves unburnt kernels, almost exact same charge in 28" 338 Edge, none.
I'm also a little confused. Are you saying ejector marks in the case head, or extractor wipe marks on the rim?
If you could also share pics of your fired case heads? My experience has been once you start to get extractor wipe marks, you'll also see primer strike splash/ripple -- this before flattened primers.
Lastly, I've worried about loose primer cups with brass based on the force needed to decap the spent ones before cleaning. No rhyme or reason on that (edit - ones that I thought were starting to loosen would not continue - others would just give up the ghost and not retain primers on firing) Since then my attitude has changed - it can be easy in/ easy out every time for all I care, as long as it holds on firing. Ones that don't hold anymore are in the brass bucket.

No I haven't experienced unburnt powder, 79gr in a case that holds 94gr in a 7mm bore is less overbore than a 28N and everyone gets good burn with N570 running up to 90gr. I run N570 in my 28" rum @ 92.8gr with 300gr bullets with excellent results as well.

 

[ontarget7]

Not sure whether RCBS has a set of shell holders that has progressively thinner tops (.002, .004, .006, .008 &. .010") made for accurately bumping shoulders back. Maybe RCBS does? - but I know Redding does.

Ordered a set
Thanks

 

[PPR]

Ordered a set
Thanks

These shell holders are made for backing away from the die, for less shoulder bump, not more.

Paul

 

[ontarget7]

These shell holders are made for backing away from the die, for less shoulder bump, not more.

Paul

You lost me.
Decreasing headspace is making the distance between the head of the cartridge case and the firearms bolt face less by bumping the shoulder is it not ?

 

[PPR]

You lost me.
Decreasing headspace is making the distance between the head of the cartridge case and the firearms bolt face less by bumping the shoulder is it not ?

Yes, you are correct. But these shell holders are thicker than a standard one so the case will not go as far into the die. Just for fine tuning the fit in chamber. They will bump the shoulder less. Hope that makes sense.

Paul

 

[ontarget7]

Yes, you are correct. But these shell holders are thicker than a standard one so the case will not go as far into the die. Just for fine tuning the fit in chamber. They will bump the shoulder less. Hope that makes sense.

Paul

I believe they are thick at the bottom portion where the case sits so in return it seats the case farther up into the die if I understand their intended purpose correctly ? As a result you are bumping the shoulder by not having to readjust your die every time and even giving you more adjustments if need be to properly fit your case to your chamber.

 

[highdrum]

Yes, you are correct. But these shell holders are thicker than a standard one so the case will not go as far into the die. Just for fine tuning the fit in chamber. They will bump the shoulder less. Hope that makes sense.

Paul

Are you certain? I do believe the Redding competition holder are sized 000, +002, +004 and so on. This measurement doesn't increase the overall height of holder, but just where the case head sits from ram face reference. This is what I was told anyway.