308 Pistol 12.5" load development

[freedom88z]

Hey guys. I've got a 12.5" 1:10 308 pistol. Love it. Got a SilencerCo Velos can, externaly adjustable riflespeed gas block ect. Aero upper lower and barrel. 600 rounds down the pipe soooo she's broke in lol. Taken her out to 700 but she falls apart at that range (obviously with a 12.5"). Rock solid at 600 and in though with 168g AAC OTM Factory loads. Love them tbh. Shoots sub moa with those believe it or not.

Anyways, I'm gonna start loading this week. Got a few hundred 168g A-Max (intermediate range) and 110g V-max (close range self defense), and 220g berry's subs I'm gonna load for. All once fired brass, CCI primers, and good ole varget. Anyone got any load data for these on their 308 sbr in 12.5"??
Charge weight ect? I got a few lbs of varget.

 

[pangris]

I do not, but that is one of the guns I never bought/built that I've always wondered quietly to myself about. Good on you for building it, hope you get it where you want it.

Which barrel?

 

[freedom88z]

Just an Aero barrel . Nothing crazy man.

 

[Ape_Factory]

I wouldn't go with polymer tips in a gas gun. Try Speer 125 FB's or some of the lighter solids, and then Berger 175 OTM's, 185 Juggernauts for the heavier stuff, Sierra 169SMK's are really bad ass too. Sierra Palma 155 (original tangent ogive version) for middleweight. I get better results with 4046 but have some 4895 to try as well.

There's also the new Sierra Matching X bullets which come in 175 and 200 grain for 30 cal.

Subsonic 308 I've done once and will never do again. It's easy to get it really, really wrong.

 

[MarshallDodge]

The 155 SMK with 8208XBR shot really well in a 1:12 18" rifle that I had.

 

[freedom88z]

I wouldn't go with polymer tips in a gas gun. Try Speer 125 FB's or some of the lighter solids, and then Berger 175 OTM's, 185 Juggernauts for the heavier stuff, Sierra 169SMK's are really bad ass too. Sierra Palma 155 (original tangent ogive version) for middleweight. I get better results with 4046 but have some 4895 to try as well.

There's also the new Sierra Matching X bullets which come in 175 and 200 grain for 30 cal.

Subsonic 308 I've done once and will never do again. It's easy to get it really, really wrong.

Gotchya man. Why not polymer tips?

 

[wvfarrier]

I have been using the Speer 130 grain Varmint and the 125 grain Winchester USA Ready JHPs. All are mid range power, reduced loads. With my nemo adj gas block they cycle reliably and are accurste enough for my needs.

 

[freedom88z]

What type of powder. And what are your charges weights. 12.5" barrel with 1:10 twist?

 

[pangris]

I'd prefer poly tips for feeding, what am I missing?

 

[freedom88z]

I wouldn't go with polymer tips in a gas gun. Try Speer 125 FB's or some of the lighter solids, and then Berger 175 OTM's, 185 Juggernauts for the heavier stuff, Sierra 169SMK's are really bad ass too. Sierra Palma 155 (original tangent ogive version) for middleweight. I get better results with 4046 but have some 4895 to try as well.

There's also the new Sierra Matching X bullets which come in 175 and 200 grain for 30 cal.

Subsonic 308 I've done once and will never do again. It's easy to get it really, really wrong.

Why would you never do subs again. And what do you mean by easy.to screw up lol Whaaaaat happened

 

[MarshallDodge]

Why would you never do subs again. And what do you mean by easy.to screw up lol Whaaaaat happened

A word of caution when making subsonic 308s. If you are using light charges of a fast burning powder and you accidentally double charge because of the case volume, the results could be catastrophic.

 

[wvfarrier]

Let me just throw this out. If you want a shorty ar10 that packs a punch. Swap your barrel out for a 358 Winchester barrel. Brass, bolt, everything is the same. It is just a 308 necked up to .358 but it packs one helluva punch at short to medium range. It can be loaded to be considerably more powerful than 308 and .358 projectiles can be had pretty cheap.

 

[mettee]

If you do subs in a Shorty 308 gas gun, dont go super slow stay above 1250 to 1350. You want to stay within the ability of the dwell time.

8208xbr, aa2520, powders like those will give you the best speeds for mid range bullets, varget for above 168 prob.

 

[freedom88z]

A word of caution when making subsonic 308s. If you are using light charges of a fast burning powder and you accidentally double charge because of the case volume, the results could be catastrophic.

I will definitely keep that in mind dude. Yikes....

 

[thedude824]

I load 125 grain controlled chaos with 46 grains of TAC in Norma brass - these are just over MOA.
147 grain bulk with 43 grains of TAC These are a little over 1.5 MOA depending on how much brass prep and 168 SMK with 42 grains of TAC which are consistently subMOA. This is from a factory 13” SCAR 17 with DiSCARder and HUXWRX Flow 762

 

[Ape_Factory]

Why would you never do subs again. And what do you mean by easy.to screw up lol Whaaaaat happened

There's so little powder in the case and it can settle in ways that don't lead to stable combustion. I did a number of test loads and I never had consistent velocity and didn't realize just how bad that situation can get. So I just decided I liked my face and digits and to leave the subsonic stuff to 300 Blackout. Just wasn't worth it. Yes, you can use filler and do all that stuff but I don't see the need. I'd rather run subs in a shorter, lighter SBR.

Admittedly my 16" DI gas gun is about the same weight as my 9" piston 300 Blackout. There's just no advantage to running 308 subsonic IMO unless you need an all in one package and you're decided on sticking with 308. 300 Blackout is just easier to load for. I guess it's possible to run longer, heavier subs in 308 due to the mags. There's always that.

 

[Ape_Factory]

Gotchya man. Why not polymer tips?

The feeding of the bullets can cause the tips to deform before being fired. The only poly-tipped bullet I use is the Barnes 110 Gr. Tac-tx and the Hornady 110 grain CX. I've got a few loads for a few other Hornady poly-tipped bullets but I've moved on to HP designs.