.308 Subsonic Reloading Myths?

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375NoLess

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New to the Forum, great place to be with some superb forums, pleased to be part of it.

There are so many myths and opinions on .308 Subsonic reloading (or subsonic centrefire generally).

I would greatly appreciate some input from the forum from people who have a lot more experience in these matters than I do.

I plan to use Lapua Brass with Lapua Subsonic 308 200GRN FMJBT.

So a few questions if I may:

1) POWDER

The first issue I have here in Europe is that I cannot buy Trailboss which is clearly the favourite for subsonic reloading due to burn rate and density.

I can however purchase VihtaVouri N32C (Tin Star), N310 or RedDot. I am favouring Tin Star as it appears the most dense by far if not equal to Trailboss a good second.

Thoughts on these powders much appreciated.

Load wise I appreciate to start high and work down with no Moderator on and try and achieve around 950-980 FPS presuming the Moderator may add around 50FPS when fitted.


2) PRIMER & PRIMER HOLE

There is so much differing opinion here. Ranging from drilling out the primer holes and using Magnum primers to not drilling out and using small rifle primers.

The concern here being powder lying in the case and not being detonated quickly/equally and the issues that will bring, is this still the case with a dense powder like Tin Star.

So what is the answer, drill or not drill, magnum primers or small rifle?


3) BULLET LUBRICATION

Some say lube and some say not needed especially with copper jackets. Some say even with copper go with Moly. I am not sure where to start here.

I would say that, at great expense, I purchased some RUAG factory .308 subsonic (apparently used by police and military in Europe) which has a 200 grain FMJ with a ring of lube around the ogive, see picture below. This ammunition is clearly of the highest quality and they are lubricating the bullets, see picture below.

I know there is a wealth of knowledge within the Forum and it would be great to put these myths to bed once and for all.

Thank you All.
 

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Regarding N32c, I suspect it will work well for your purpose, and I've found that QuickLoad models it reasonably accurately. There's scant data, but I've worked it up in a 300BO, and it performed as QL predicted.

As for drilling flash holes, don't until you find a need. I guess that a subsonic N32c load will have pretty high case fill, and you won't need to worry.
 
Wow that's a speedy reply, thank you edwardware.

Understood re N32C and Flash holes do you lubricate the bullets?
 
The QuickLoad software you speak of is it a UK Software provider or is there another?
 
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I would love to use TrailBoss but it is not available in Europe at all, banned for some EU Law nonsense. So no Trail Boss and no Varget!
 
The only time I used lube on bullets was cast.
I use around 9 grains of a fast pistol powder. Never used either of the ones you mentioned.
I prefer cast or plated bullets.
It's fun shooting subs, but I got over it after a few hundred rounds.
 
N32C is a high volume powder. I have used this powder in my 30carbine when using lead bullets for reduced velocity loads. If I recall, around 6gr of powder almost filled the whole case, whereas I need 14gr of N110 to fill the case to the same level for standard jacketed loads.

I suspect this powder, Accurate 5744 or Lovex D060 might be worth looking at.
 
I have not loaded subsonic .308, but I have used both Trail Boss and N32C powders in pistols and they behave very similarly. If Trail Boss is good for this application I have to believe N32C would be as well.

Welcome to THR
 
I too used trailboss with my sub .308’s but I did find data using N310 back then. Some of it called for the bullets to be loaded backwards.

I didn’t mess with it for long, just an “I’ve done that” kind of thing. I was using cast and coated 150gn bullets and I could already chunk a 147 gn 9mm sub sonic with less expense.
 
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