A few questions...300 Lapua

[JJMoody]

Just traded into a 300 Lapua. It came with some loaded rounds, 8 total shots fired 10 twist on a 700 action. Looking at the once fired Peterson brass, all the primers are cratered. The loads were around 93-94 grains of retumbo under 208-215 ish class bullets. It seems this would be a lighter load, on par with what I've seen from RUM loads. I also noticed that primers on loaded rounds were seated proud, sticking out past the face of the rim. I have an ample supply of 208 ELDM/AMAX 212 ELDX 200 and 220 SMKs( barrel twist may not be right for these) 225 ELDM some 215 hybrids. Really want to try 181 Hammers though. I have a big jug of H1000 but may give Retumbo and RL26 a look. And just because I like kinda simple, I'd like to keep powder the same in this and my 28 Nosler.
Questions:
1)Could primer seating depth be affecting pressure signs earlier than should be? (Cratering?)
2) where should load work up begin in a 300 Lapua? Not much info out there. I have looked at accurate shooters article
3) today's best powders? Must be temp stable.
4) how much advantage over the RUM?
Not looking for other cartridge options, just some help on this guy. Thanks

 

[RockyMtnMT]

Is it improved?

I have seen more 700 actions that crater at all load levels than not. Is common.

Steve

 

[JJMoody]

It's not improved, Steve. Is there a better indicator(s) of pressure in something like this?

 

[RockyMtnMT]

Lapua brass is tough stuff. Watch the vel and once you can see the faintest of ejector mark then back off a grain or two. I would not mess around finding the top end too much on the factory Remington action. Could wind up too high. Rum vel our a bit better is a good guideline. Hopefully others will chime in here. My experience is with an improved version on custom or Sako action and running over 3600 fps with 180g class bullets. I would say you should get mid 3500's with 181g Hammer Hunters. This I think would be TOP end. We consistently get mid to upper 3400's with factory rums.

Steve

 

[JJMoody]

What powders you running?

 

[RockyMtnMT]

The h1000 burn rate would be good. Rl26 would be a good bet. Retumbo, Norma MRP is a nice powder. Lots to choose from in this burn rate.

Steve

 

[WeiserBucks]

I agree on the cratered primers in 700's, very common.

 

[JJMoody]

Ok. That's good news.

 

[brentc]

RL26 has become my new favorite for the standard Lapua with 300 grainers to increase 50-75 fps over my best loads with H1000 and Retumbo. It works equally well with 250s. It's truly impressive.

 

[JJMoody]

Brentc that's pretty impressive. I've had a couple bugs in my ear about ditching the big jug of h1000 I have and moving to RL 26 in this and my 28 Nosler.

 

[brentc]

Brentc that's pretty impressive. I've had a couple bugs in my ear about ditching the big jug of h1000 I have and moving to RL 26 in this and my 28 Nosler.

Experimenting with RL26 has exceeded my expectations for velocity and temp stability in several cartridges.

Let us know what you find out if you end up trying it.

 

[JJMoody]

As far as cratering primers, can bushing the firing pin solve that?

 

[WeiserBucks]

I would like to say yes , but I don't know for a fact. It would make sense to me that a sloppy firing pin hole would allow premature cratering/primer flow .

 

[JJMoody]

Maybe a silly question, but does anyone recommend a new firing pin that's a bit larger to accommodate the existing hole instead of a nearly $200 job to make a smaller hole?