.308 Subsonic Reloading Myths?

[375NoLess]

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:

• 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.

• 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?

• 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.

 

[375NoLess]

No answer from anyone?

 

[Dill]

this topic caught my attention as I am also curious. I shot with a guy last weekend that shot a lot of .308 subs out of his AR10 (loaded with Trailboss), but I've never loaded subs for .308, only 300 BLK. I think your idea of trying the bulky powder first is a good one, you don't want a ton of empty space in there. Good luck and update this thread as you learn.

 

[ESBVader]

Not saying my way is the correct way, just letting you know what I've done that has produced no issues and performs and sounds great!

I purchased 200 pieces of Lake City brass and drilled out the primer hole with a 9/64" drill bit if I recall correctly. I use Winchester Large Rifle primers with 10.5 grains of Hodgdon Trail Boss and a 175 grain SMK (though I have switched to TMK's because I have a ton of them...) I did not use any bullet lube.

I am shooting them through a 16" surgeon barreled action with an Omega suppressor.

I ran a test against a 300 Blackout with the same suppressor I was running (Omega) and the other individual and myself felt the .308 was just a bit quieter.

Great round to shoot!

 

[Huskydriver]

Not saying my way is the correct way, just letting you know what I've done that has produced no issues and performs and sounds great!

I purchased 200 pieces of Lake City brass and drilled out the primer hole with a 9/64" drill bit if I recall correctly. I use Winchester Large Rifle primers with 10.5 grains of Hodgdon Trail Boss and a 175 grain SMK (though I have switched to TMK's because I have a ton of them...) I did not use any bullet lube.

I am shooting them through a 16" surgeon barreled action with an Omega suppressor.

I ran a test against a 300 Blackout with the same suppressor I was running (Omega) and the other individual and myself felt the .308 was just a bit quieter.

Great round to shoot!

Did you read the ops post.... He doesn't have access to trailboss... SMH

 

[ESBVader]

Did you read the ops post.... He doesn't have access to trailboss... SMH

I did. What I read is that there were several questions. Powder was one of them. He stated he has likely found a substitute for Trail Boss and sounds like he's set there.

The other two questions were about primer flash hole drilling and about bullet lube. I replied with my entire process for loading subsonic .308 (including powder for others who might read the title and be curious) to give a full perspective of what has worked for me.

 

[kindabitey]

I've loaded quite a bit of subsonics in 308 and 300blk. Trail Boss would be preferred in the 308 due to nearly 100% case fill. With N32C, you should have around 65-70% case fill. I don't worry about flash over unless fill is less than 40%. I don't think 310 or Red Dot will fill the case enough to be viable.

All I've ever done to primer holes is to uniform them. Drilling them oversize is not required.

Never used any type of lube, either.

When doing load development with subs, start high and work down. This helps avoid a stuck bullet in the barrel. Also, check for bullet stability without a suppressor attached.

 

[Brandon05_88]

Powder: I've only used Trailboss.
Primer & Primer Hole: I did not modify the case in any way. I even used the same primer from supersonic: CCI BR-2.
Lube: None. I loaded a normal copper jacketed bullet. I did clean my bore before testing subs, and the firstshot was slightly slower.

Overall, I essentially just changed the powder from Varget to Trailboss. Everything else remained the same. It produced 1.5" 5 shot groups out to 200 yards. I used a 175 RDF in a Lapua case with a CCI BR-2 around 2.850". I used enough Trailboss to get me to 1050 fps. This was in a Rem 700 16.5" .308 Win 1:10" twist with a TBAC 30P-1.

 

[375NoLess]

Thank you all for some very valuable inputs, much appreciated.

I have enough here to get going and will report back.

I suppose the only thing bugging me still is why does a top line manufacturer of Military and Police grade ammo put a lube ring on.

Maybe just protection against stuck bullets as their bullets could be used in such a wide range of applications..?

Viht N32C Tinstar will allow for 60-70% case fill which sounds to as though that should avoid all the issues of powder laying in the case when at 90 degrees.

 

[jet_lagged]

Take Aim at Rifle Reloading Data | Hodgdon Reloading

Find what you need in four easy steps. Select your cartridge type from the drop-down list. Then select your bullet weight, powder manufacturer and powder type. If you're unsure, or just want options, check as many boxes as you'd like. Click "Get Data" to view results.

www.hodgdonreloading.com

Hodgdon has load data for .308 (and .223 subsonic) using small charges of Titegroup pistol powder.

I use 180 grain round nosed/flat based hunting type bullets for more stability (shorter bullet =more stability) as recommended by Gemtech. No primer pocket modification and a standard LR primer. I do lightly crimp the round in the thought that some pressure will help combustion. Have also used mil-surp WC-820 powder from pulled .30 carbine ammo. So pistol powders in the H110 or Accurate #9 or those used for .357 magnum could also be experimented with. But all of these have the drawback of a low case fill %.

 

[absolutchris]

Following

 

[375NoLess]

Thank you jet_lagged very useful info.

 

[Carolina Hill Billy]

FWIW, I saw an older fellow shooting really light loads at the range one day. Plenty accurate at 100 yards. He said that you could use 8.0gr of Red Dot in a .308 with most heavier bullets for "rabbit loads." He was still alive when I left the range that day!

Looks like it would only give a 38% fill, but Red Dot is pretty easy to ignite and has always been pretty clean when I've used it.

 

[375NoLess]

That's brilliant thanks jmackey.
Is Quickload still the way to go? Looks rather antiquated but great outputs by the looks of it.

 

[Carolina Hill Billy]

That's brilliant thanks jmackey.
Is Quickload still the way to go? Looks rather antiquated but great outputs by the looks of it.

I'm happy with Quickload. I've used it for years to model loads without having to actually shoot them. I don't know how accurate it would be for pistol powder, but it's close for rifle loads. I wouldn't trust it completely.

One thing that I did notice while putting in the data, the velocity didn't change much with barrel length from 16" to 26" so I just left it at 26"

 

[375NoLess]

Thank you for your reply. Good to know.