Subsonic .300blk load for longer ranges

[G3A3A1]

Historically I have always reloaded BPCR calibers, so I am not new to the game of reloading but I am new to the concepts of loading for accuracy. I have just bought a "sniper" .300blk rifle that has a 9 inch barrel and a 1:8 twist and is bolt action. Ideally I would like to only shoot subs through it out to 500 meters. So far I am planning on loading 230gn SMK's over 8.9gn of H110. However before I get too deep into this load I thought I would ask what loads you guys have personally had the best luck with.

 

[NighthawkCG]

Not sure what a "sniper" .300blk rifle is. Bolt or semi? Makes a difference. You can do a lot more with a bolt, especially at subsonic speeds.

 

[G3A3A1]

Not sure what a "sniper" .300blk rifle is. Bolt or semi? Makes a difference. You can do a lot more with a bolt, especially at subsonic speeds.

Pretty sure the sniper part is just a marketing tactic from the manufacture haha. Its a bolt gun.

 

[NighthawkCG]

Never loaded H110, but have used the similar w296. I find it is great for supers, but no so great for subs. Look for a faster powder. Bolt guns are super quiet with things like unique. You can also load lighter bullets subsonic than you could with a semi.

Some folks like the RNFB bullets. Haven't tried them, but had good luck with 220 SMK & 208 amax (with H4198) and 178 BTHP with unique.

You MAY have a bit of a challenge with 230s stabilizing depending on the shape and length.

I find subs are really tough as everything makes a big difference on them. Work them carefully down to your speed and then seating depth. Check for stability. Chrono is a must IMO. I find neck tension can be pretty important for them.

I realize I'm not giving load data for you, but that is only because I haven't worked with your combo of tube length and powder. Hope at least my experience is helpful for you to reload the subs for accuracy.

Hell, to be honest I find 300 yards to be a challenge for good, accurate subs... 100-200 are fun. 300 can get tough. If you get 500 consistently good, I hope you share how. Your drop would be pretty significant... Hope you have A LOT of travel in your turrets, a big angle in your base, and possibly even one of the adjustable bases.

 

[culater]

I did this 2 yrs ago it was a fun experiment.

Range Report - Sub sonic shooting to 800yds with 300 BLK

This is for purely for experimention and fun, to see if i can get to 800 yd subsonic with a 300 blk using a 225 ELD. My setup is a 16in ar 15 upper with a 1-6 twist that i bought from a hide member last month with only 25 rds threw it. I have a 30 moa larue base with a BSA FFP 4-14x44 scope. I...

www.snipershide.com

 

[culater]

A very fast twist like a 1-6 or a 1-5 would do you well if your just subbing.

 

[G3A3A1]

I am asking because I do not know, not to be snarky. Why do you guys think there would be stabilization issues with the bullet in a 1:8 barrel? I picked that specific bullet as it had the best BC so I was hoping that would help me make it out to 500m. Also Sierra has it listed as "must use 1:8 or faster barrel" so I assumed it would be good to go in the gun I am getting. Although is stabilization is a worry perhaps I should shoot it without the can first to make sure everything is stabilizing.

 

[NighthawkCG]

Yes - always test w/o can first for stabilization.

The longer bullets need more barrel or faster twist to stabilize. Been trying to read up a bunch on subs but BC doesn't have as much to do with it at subsonic velocities as supers. There are different schools of thought on what type/shape/weight of bullet works best, but I'm not so sure anyone has a definitive answer on that for subsonic. Your bullet stated it needs at least a 1:8 twist. That is a minimum. It would likely do better with a faster twist.

 

[culater]

I am asking because I do not know, not to be snarky. Why do you guys think there would be stabilization issues with the bullet in a 1:8 barrel? I picked that specific bullet as it had the best BC so I was hoping that would help me make it out to 500m. Also Sierra has it listed as "must use 1:8 or faster barrel" so I assumed it would be good to go in the gun I am getting. Although is stabilization is a worry perhaps I should shoot it without the can first to make sure everything is stabilizing.

First answer to your question is speed because the bullet behaves differently when shot super sonic v sub sonic when shot. Either you shoot faster to stabilize or up your twist rate. Just have to shoot it to find out if barrel likes it. I would highly recommend to find a much faster twist. The big thing is brass and having the same lot and headstamp from the same company and not having a mix match. Hopefully you went though my post and read everything.

 

[phlegm]

I load 208 A-Max with H110, but my charge is less than yours. The are quite accurate under 200 yards or so. This bullet was originally chosen just because they were less expensive than the heavy SMKs, but they shot so well, I kept using them. Not sure yet if I'll move over to the ELD-Ms when I run out.

I've shot them out to 450 for laughs, but they were very sensitive to wind. Making a prediction about their ability to shoot accurately that far out is not something I can do, as I've shot it so little.

 

[NighthawkCG]

The 208 A-Max was a great bullet for me as well. The 208 ELD-M has a slightly different shape according to folks over at 300blktalk. Not saying it is better or worse, but just that is not the same. Haven't tried it yet, but wouldn't cry if it was all I could find. People like it.