Primer cratering & flattening

[26Reload]

Guess this place will work...
65284 has developed a problem...
Been same load for couple years..
Lapua brass...fgm210 primers...
Rl23(52.5gr)...142Lrab nosler....been shooting about 2975fps..well...and has gone berserk lately...maybe 600 rounds thru the tube...no brake...off bags....went from holes touching to 1" apart in different directions at 100yds....26" proof sendero cf

Curious what some other gents here are seeing with fired home made ammo...
As to cratering/flattening....
Pics please.....
...to add....have had to clean barrel and chamber about every 30 rounds to get best performance....always....

After 10 rounds...
Brass annealed after 2nd firing....no loose primer pockets....on 5th firing....

 

[HSmithTX]

I see that much cratering with several factory actions, nothing a firing pin bushing won't solve completely if it bothers you. Personally I don't really give it much thought, but I won't push loads hard on one because that primer will pierce well sooner than one without cratering. I don't see any flattening, primer shape looks good to me. Curious why the bolt face is so rough? The primer surface and the brass looks like it has total coverage of impressions from the bolt face roughness. Why is it scattering bullets? No idea honestly. I would start with a brand new workup, if it were mine, ignoring the primer cratering.

 

[orkan]

142Lrab nosler....been shooting about 2975fps.

Definitely not a slow load. I've seen those kinds of loads take out a 6.5x284 within 800rnds before. It's not unimaginable that yours went at 600. 6.5x284's are tough on barrels, especially when run hard like that.

Looks like there's some mild signs of ejector wipe on the case between the L and 6? Is it a factory 700? If so, they crater primers as a matter of course. Never seen one NOT do it. Always looks just like your pic too... the crater isn't generally pressure related, as its a gentle protrusion more so than a sharp jagged edge.

Might have to grab some Hammer bullets or other solids to get the last bit of life out of it.


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[Bob Wright]

What are your chrono speeds when you developed load vs now?
There is carbon build up in the neck area so I would get scrubbing in there.
Primer isn't flattening, maybe a bushing job at some point for the crater.

 

[L.Sherm]

I agree with Bob Wright, I see no primer flattening looks like typical bolt that you might bush.
I would focus on carbon build up first.

 

[Mikecr]

What is your bullet-land relationship?

 

[26Reload]

As to jump....just a touch over what nosler recommends......about 52/53ks...
That barrel throat was shiny before the 10 rounds at the rockpit....shooting 4 rifles..
One rifle..one shot at individual targets..then I walk down and mark the holes(at 100yds).....at 400yds same process but drive..if I was younger I'd run...yeah right........
Rifles have 10 minutes between shots at 100 and 400......

Yes..factory actions....all rem700....semi-custom.....
Same barrel...same throat after 10 shots...

 

[tim_w]

Check for a carbon rings. Check your throat erosion for bullet jump. Either or a combo coukd cause the groups opening up.

Give the throat a good srubbing with JB. Vary your stroke length. It will get the burnt carbon out and help smooth some of the fire cracking. Shoot a couple low pressure foulers and try the main load again. If accuracy is still poor adj seating depth to the longest bto length in the node. That will help keep you inside the node the longest as the throat keeps wearing.

 

[Bob Wright]

Send some target pictures too.

 

[Harry Knutz]

Remington firing pin holes are already close to being too big from the factory. The crater is the primer flowing into the hole, Over time it gets larger, It's nothing to get too worried over until it pierces primers, Then you need to stop shooting it until it's fixed by bushing the firing pin hole, If you don't you will get primer blanks inside of the bolt and at a bare minimum it will stop igniting the primer, Or it will break the spring.

When throats get damaged, Groups start opening up as a result of the jackets being damaged or torn, That's why you will get 2 in the same hole and then it will spit one 3 or 4 inches over.

And you're primers are not flattened, I don't think your load is over pressure at all.

 

[Harry Knutz]

For some reason this cratering problem tends to present itself much more commonly with 6.5 cartridges. You can get away with larger firing pin holes on 30 calibers for some reason.

 

[okie man]

Looks like you have a rough bolt face, sloppy firing pine hole more than a pressure problem. When your primers have lost the rounded edge and more resemble a flattened muffin top is when you're pushing pressures . Pop one out and roll it on a smooth flat surface. If it spins in tight circles your getting into higher than normal pressure.more in a straight line you're fine.

 

[jsthntn247]

Check your velocity. I'd bet you've slowed down enough to be out of your accuracy window.

 

[26Reload]

Actually the rifle is shooting in upwards of 3015ish at 52.3grs rl23...26" barrel...
My other 65284...24" proof ss is spitting the same bullet at 2957fps....this is the other 65 brass....5+ firings on it....



Bob...as to showing you a pic of the 400yd target......be too embarrassed...

Being season opens monday..glad I don't need to rely on the cf65...but it will be at the rockpit Sunday morning...
51.8grs of rl23 is now shooting around 2975... .5gr difference....
Will see what it does.....
Thank ya guys for ideas.....brainstormin' hurts......