175smk with RL15 from a 20" autoloader?

[Mr45auto]

Need to load some 175smks for my LR308 running a 20" krieger 1:11 barrel. I will have to make 1000 yards with it. I'd prefer to run Varget but not going to be possible as I cant get any locally. I've got some RL15 on hand and a bunch of CCI LR primers and Win cases.

A few good recipes would be nice to have. Also what 15ft velocity should I be looking for to make 1K? This rifle has always printed very well with 168s but not so good with the 175s but damned if I can get a 168 to work at 1K. I'm willing to live with going from 1/2" at 100yds to 3/4" if the bullets will do much better when extending the range out a ways.

I dont want to destroy my brass with a single loading so I'd rather not have them so hot they dick up the cases. Autoloaders are hell on brass.

 

[M25BeastShooter]

Re: 175smk with RL15 from a 20" autoloader?

I'm shooting 44.5 gr RL15 over a 175 Sierra in my Rock River LAR-8A4. Standard barrel with their free float handguards. 2.799 OAL cause of the FAL mags length.

Groups 5 shot at 100yds .550-750" Don't know what the vel is haven't had a chance to chrono it yet.

Oh yeah loaded in LC 07 LR brass
As soon as I can I'm going to throw a 178gr A-Max over this and see how the rifle holds it

 

[Mr45auto]

Re: 175smk with RL15 from a 20" autoloader?

I'll give the 44.5 load a shot and see what it chronos. Any idea of target velocity to make 1K?

I just got my bullets in today so it's off to the loading bench this Sunday.

 

[M25BeastShooter]

Re: 175smk with RL15 from a 20" autoloader?

You're shooting for about 1100-1200 fps at 1000yds

 

[M25BeastShooter]

Re: 175smk with RL15 from a 20" autoloader?

Oh just a note the rifle was running 1-1.5 moa initially. I ran a Tubbs barrel finishing kit through it and well the results are as I said. With 45gr RL15 over a 168 .400". I thought the bullets might be a gimick but reading many of the testimony results I figured I'd try them. It worked for my rifle cutting the group size where it's now capable of real long range accuracy.

 

[DT1]

Re: 175smk with RL15 from a 20" autoloader?

Yep, 44-45gr of RL-15 will get you there. I've loaded 308 brass 8-10 times with that recipe for my bolt rifles and my AR-10. No problems noted.

That said, work up slowly and see what happens with your stick...

 

[BCP]

Re: 175smk with RL15 from a 20" autoloader?

I've been told around ~2550-2600 is what you need to keep a 175 supersonic to 1k depending on weather conditions, elevation etc.

 

[MinorDamage]

Re: 175smk with RL15 from a 20" autoloader?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BCP</div><div class="ubbcode-body">I've been told around ~2550-2600 is what you need to keep a 175 supersonic to 1k depending on weather conditions, elevation etc. </div></div>

Definitely close. I did a calculation with the Litz BC for the 175 SMK based on your area. I used 85 degrees (That was right around the high in Oregon City today), 1015 mb pressure (also average for Oregon City), 148 meters elevation (Oregon City), and a 2600 fps muzzle velocity. At that velocity it will be on the cusp, running right around 1147 fps at 1000 (speed of sound is 1144.1). You might want to get it to 2625-2650 to be safe. That transonic area is kinder to 175s than 168s, but you want to be solidly supersonic at 1000.

Josh

 

[Mr45auto]

Re: 175smk with RL15 from a 20" autoloader?

Went out today and 44.6 gave me about 2693fps. Not as accurate as 168s but still pulled 3/4" at 100yds. I think I'll give this one a go.

 

[BCP]

Re: 175smk with RL15 from a 20" autoloader?

I assume you worked your way up to that? That's really moving. Let us know how it shoots.

Me I would've been happy with 2600, maybe I'm chicken or something.

 

[Mr45auto]

Re: 175smk with RL15 from a 20" autoloader?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BCP</div><div class="ubbcode-body">I assume you worked your way up to that? That's really moving. Let us know how it shoots.

Me I would've been happy with 2600, maybe I'm chicken or something.

</div></div>

I started at 44.5 and had a look at the brass, it was low mileage winchester and showed no worse for wear and the primer looked good. I bumped up to 44.6 and 44.7 but 44.6 was the more accurate of the bunch. Even with the 44.7 there was no signs of excess pressure. I'm pretty cautious on this due to how rough the LR308 is on brass.

I will try it out to 1K on Thursday to see how it shoots.

 

[pappy42]

Re: 175smk with RL15 from a 20" autoloader?

Don't be too hard on that 3/4" group @ 100. Some loads don't stabilize properly until extended range.

 

[BCP]

Re: 175smk with RL15 from a 20" autoloader?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mr45auto</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BCP</div><div class="ubbcode-body">I assume you worked your way up to that? That's really moving. Let us know how it shoots.

Me I would've been happy with 2600, maybe I'm chicken or something.

</div></div>

I started at 44.5 and had a look at the brass, it was low mileage winchester and showed no worse for wear and the primer looked good. I bumped up to 44.6 and 44.7 but 44.6 was the more accurate of the bunch. Even with the 44.7 there was no signs of excess pressure. I'm pretty cautious on this due to how rough the LR308 is on brass.

I will try it out to 1K on Thursday to see how it shoots. </div></div>

Measure the case heads, my 45 grain varget win brass loads looked great until I went to prime them a 2nd time. Had a couple that must've been made of rubber and not brass...

 

[Lt. Arclight]

Re: 175smk with RL15 from a 20" autoloader?

Forget the 168 for 1K work. Your load looks good. I use 44grains of RL15 w/175SMK @ 2.800"(-I also use Tubb's metplat uniformer,although this hurt's the BC to some degree,my groups seem to be tighter) but I have a 24" barrel and have had good results. Solid .5moa @300 yards. I think you are in the ballpark.