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Hi learned folk.

I had a question on brass as I have a mixture of PPU and Lapua once fired, from my rifle, cases in .308.

When reloading the two with the same head/seat depth/primer/charge etc should I expect to see a difference in group size (up to 1000yards) say if I shot 5 rounds with Lapua brass then 5 rounds with PPU brass?

sign92

Probably to almost definately.

Ballistix wrote:When reloading the two with the same head/seat depth/primer/charge etc should I expect to see a difference in group size (up to 1000yards) say if I shot 5 rounds with Lapua brass then 5 rounds with PPU brass?

With *5* shot groups at 1000 yards I expect you'd see different group sizes if you used the *same* brass!

rox wrote:

Ballistix wrote:When reloading the two with the same head/seat depth/primer/charge etc should I expect to see a difference in group size (up to 1000yards) say if I shot 5 rounds with Lapua brass then 5 rounds with PPU brass?

With *5* shot groups at 1000 yards I expect you'd see different group sizes if you used the *same* brass!

:lol: Sure. Let me re-phrase my question.

Will 10 rounds using Lapua cases be more accurate than using a 10 shot mixture of 5 x Lapua and 5 x PPU?

What are you really asking Ballistix. Does the difference in quality and price justify the reputation that Lapua has over other makes?

I wouldn't know as at the ranges that I shoot over which is mainly stalking ranges the answer is no. I use both Lapua and PPU and frankly I can't see any significant difference however at longer ranges it might be entirely different or it might not. Give it a try and find out for yourself.

I can't comment on the actual manufacturing tolerances of the cases but as to the brass used a friend of mine who was an absolute perfectionist and who had access to the information via his employment told me that Lapua and PPU brass actually comes from the same source.

As for mixing cases I don't think that is a good idea at all and is normally recommended against in all reloading manuals. Case capacities and thicknesses between brands will vary resulting in different pressures which ca only have a negative effect on accuracy.

Ballistix wrote: :lol: Sure. Let me re-phrase my question.

Will 10 rounds using Lapua cases be more accurate than using a 10 shot mixture of 5 x Lapua and 5 x PPU?

There are so many possible differences it is hard to imagine the effects. Internal volume, flash hole size, primer pocket depth, neck wall thickess and hardness and the effect on neck tension, different springback and response to resizing, etc etc. The many small things might combine to cause a noticeable effect, or they might cancel each other out. I doubt I will ever truly know, since I would never mix 2 batches from the same manufacturer, never mind from different ones, and wouldn't mix 4 times fired with 5 times fired either. Why would you deliberately introduce an extra variable?

..

I would say yes if only down to internal volume.
But pretty much as Rox said.
Tony

OK thanks all that helps. It was a question on consistency and accuracy so for that reason I'll stick to one case manufacturer and ditch the other.

All the best

No do not ditch the other brass keep just in case you ever get another .308/7.62 rifle in the future.


or ditch the Lapua my way :lol: :lol:

bnz41 wrote:No do not ditch the other brass keep just in case you ever get another .308/7.62 rifle in the future.


or ditch the Lapua my way :lol: :lol:

I meant sell on to a fellow shooter