SMK 175 (308)...can I get it to go faster and longer before going subsonic

[boisepaw]

Remington 700 Varminter stock rifle in 308...1:10 twist...26" fluted barrel. Loading the 175 gr. SMK with 42.1 grains of H4895 I get an average muzzle velocity of 2576 with an SD of 8 and an ES of 24.

That doesn't seem very fast but it is pushing the published limits for that powder.

But if I want to get out much beyond 1000 yards, that combo won't really do the trick will it?

Thoughts, ideas or suggestions?

 

[Powder_Burns]

My book suggests max 48.5gr N550 at 2.8” oal for 2753fps.

That would keep you above transonic out to around 1150yd.

 

[918v]

Remington 700 Varminter stock rifle in 308...1:10 twist...26" fluted barrel. Loading the 175 gr. SMK with 42.1 grains of H4895 I get an average muzzle velocity of 2576 with an SD of 8 and an ES of 24.

That doesn't seem very fast but it is pushing the published limits for that powder.

But if I want to get out much beyond 1000 yards, that combo won't really do the trick will it?

Thoughts, ideas or suggestions?

Your velocity is kinda low. What chrony are you using? Also, what brass? And what data? Out of a 26” barrel you can easily get 2700 or more.

 

[stello1001]

You need to find RL17...

 

[straightshooter1]

Remington 700 Varminter stock rifle in 308...1:10 twist...26" fluted barrel. Loading the 175 gr. SMK with 42.1 grains of H4895 I get an average muzzle velocity of 2576 with an SD of 8 and an ES of 24.

That doesn't seem very fast but it is pushing the published limits for that powder.

But if I want to get out much beyond 1000 yards, that combo won't really do the trick will it?

Thoughts, ideas or suggestions?

Today I tried some Lapua Palma brass for the first time and used 43.8 gr of IMR 4064 (.020 off lands, COAL: 2.856, 24" Krieger barrel) and got 2735 fps . . . more than enough to get to 1000 yds.

PS: Ran some numbers through my QuickLoad app and it suggests that somethings wrong with the numbers you've posed. 42.1 gr of H4895 should be pushing that 175 SMK to amost 2700 fps (maybe even more), so . . . ???

 

[FCS]

185 Juggernaut would be even better.

 

[FLIGHT762]

In my 24" Hart using a Nosler 175 CC / 46.5 Grs. 2000 MR / Federal GMM case / Tula LRP / 2.800" COL, I get 2769 AVG FPS / S-D 8 and E-S 13. No pressure signs and it shoots well @1000 yds.

 

[Jmkjr87]

Remington 700 Varminter stock rifle in 308...1:10 twist...26" fluted barrel. Loading the 175 gr. SMK with 42.1 grains of H4895 I get an average muzzle velocity of 2576 with an SD of 8 and an ES of 24.

That doesn't seem very fast but it is pushing the published limits for that powder.

But if I want to get out much beyond 1000 yards, that combo won't really do the trick will it?

Thoughts, ideas or suggestions?

I got a 30 inch krieger 10 twist and i use 175 smk, 43.5 h 4895, laupa large primed brass, 210m primers and im getting 2834 average velocity. With 26 inch barrel i would think it would be moving faster than that

 

[Doom]

In my 24" Hart using a Nosler 175 CC / 46.5 Grs. 2000 MR / Federal GMM case / Tula LRP / 2.800" COL, I get 2769 AVG FPS / S-D 8 and E-S 13. No pressure signs and it shoots well @1000 yds.

Based on my Rem 700 Tactical with a 20” barrel and 2000MR, I would go that route and switch to Winchester brass for more case capacity. I never chronographed the 178 AMax but with other bullets I could easily get another 100 fps over 4064.

Didn’t pursue the load as 2000MR is slow and turned my rifle into a loud mouth fire breather!

 

[Changed]

27.5” Lapua, Varget, 43.5, 175 SMK = 2760

 

[boisepaw]

185 Juggernaut would be even better.

Just bought some Juggernauts that I will try out as soon as they arrive...

 

[boisepaw]

I can see some folks loading the 175 above Sierra's recommended powder weight...even well above it. This weekend I will try (carefully) loading 20 rounds in .1 grain increments starting from about a half grain below their published max.

Wish me luck.

Call 911 if you don't hear from me on Monday...

 

[Jmkjr87]

I can see some folks loading the 175 above Sierra's recommended powder weight...even well above it. This weekend I will try (carefully) loading 20 rounds in .1 grain increments starting from about a half grain below their published max.

Wish me luck.

Call 911 if you don't hear from me on Monday...

Bro lawyers write the load data. Also loads vary rifle to rifle so what will work in mine might not work in urs. Start low and slowly work up. Look for pressure signs and take it slow and u will be aight

 

[918v]

No they don’t.

The reason Sierra’s data is lower than say, Hodgdon’s, is due to the capacity difference between Federal and Winchester brass.

 

[straightshooter1]

I can see some folks loading the 175 above Sierra's recommended powder weight...even well above it. This weekend I will try (carefully) loading 20 rounds in .1 grain increments starting from about a half grain below their published max.

Wish me luck.

Call 911 if you don't hear from me on Monday...

Yes, be VERY careful in doing that! If you only loading cartridges to SAAMI COAL of 2.800 and shooting in hot sunny temperatures . . . LOOK OUT, especially if you're using temp sensitive powder! One can load above recommended max easy enough if one in loading them long (something like a COAL of 2.865 for a 175 SMKs). Best recommendation is to start 10% below max and work up.

 

[boisepaw]

Yes, be VERY careful in doing that! If you only loading cartridges to SAAMI COAL of 2.800 and shooting in hot sunny temperatures . . . LOOK OUT, especially if you're using temp sensitive powder! One can load above recommended max easy enough if one in loading them long (something like a COAL of 2.865 for a 175 SMKs). Best recommendation is to start 10% below max and work up.

I'll be shooting one round at a time...loaded individually...and checking pressure signs each time.

I will also re-count my fingers each time...

 

[Matches Malone]

Remington 700 Varminter stock rifle in 308...1:10 twist...26" fluted barrel. Loading the 175 gr. SMK with 42.1 grains of H4895 I get an average muzzle velocity of 2576 with an SD of 8 and an ES of 24.

That doesn't seem very fast but it is pushing the published limits for that powder.

But if I want to get out much beyond 1000 yards, that combo won't really do the trick will it?

Thoughts, ideas or suggestions?

Use a better bullet. Helped me with similar velocities.

 

[boisepaw]

Use a better bullet. Helped me with similar velocities.

Which better bullet would you suggest?

 

[Petrov]

Want to stay supersonic at 1000 yards use 30" tube and 155 palma type bullet, berger or lapua 155

 

[Petrov]

I was able to get 155 OLD sierra 155 palma bullet out to 1200 yards, unfortunatley i ran out of windage and reticle to compensate for 18mph wind

 

[Matches Malone]

Which better bullet would you suggest?

A higher BC one.
ELD
Alco
Flatline
Etc
Believe it or not, there are much higher BC bullets than the old smk, a bullet that’s been around since before 1993.

 

[FLIGHT762]

I can see some folks loading the 175 above Sierra's recommended powder weight...even well above it. This weekend I will try (carefully) loading 20 rounds in .1 grain increments starting from about a half grain below their published max.

Wish me luck.

Call 911 if you don't hear from me on Monday...

With my two 308 bolt rifles, I'm getting 2650+ FPS out of 43.0 Varget / 42.0 8208 XBR and 41.0 of AR Comp using the Nosler 175 CC and the Hornady 178 OTM.

H-4895 is very close to IMR 8208 XBR, they are both ADI powders. You should be getting 2600+ with 42 Grs. of H-4895.
I got my speeds using a Magnetospeed.

You should be very careful going @ or above 43 grs. of H-4895. Also, recheck your chrono.

 

[BCP]

H4895 is good but not best if velocity is your thing. Off the top of my head Varget, 4064, 2000MR, CFE223, Reloader 15.

 

[straightshooter1]

With my two 308 bolt rifles, I'm getting 2650+ FPS out of 43.0 Varget / 42.0 8208 XBR and 41.0 of AR Comp using the Nosler 175 CC and the Hornady 178 OTM.

With 43.2 gr of Varget pushing 175 CC's out of a 24" Krieger barrel, I was getting 2630 fps and some pretty nice groups. And 39.6 grs of AR-Comp worked really well, though velocity was on the somewhat slow side, but that's ok as I use it for shooting under 600 yds.

H-4895 is very close to IMR 8208 XBR, they are both ADI powders. You should be getting 2600+ with 42 Grs. of H-4895.
I got my speeds using a Magnetospeed.

You should be very careful going @ or above 43 grs. of H-4895. Also, recheck your chrono.

Yeah, 43.0 gr of H4895 was giving me some pressure signs with velocity at 2793 fps along with poor results on paper. 42.0 gr behind 175's did work well for me with this powder @ 2750 fps and that was in mid 90°F weather. Also, use a MagnetoSpeed v3.

 

[delinquent pleb]

I’m currently running 43gn of varget with 175gn Berger OTMs in a Mag length load (stacking into an ‘Accurate Mag’ AICS magazine). Results are very good out to 500 which is the furthest I have tested them. At that loading level I haven’t encountered any pressure issues. Velocity, however, is Not confirmed.

I’m loading the Berger 175gn OTM for my .308. While not the 175SMKS the similar shape and and weight suggests my observations could be valid.

 

[straightshooter1]

I’m currently running 43gn of varget with 175gn Berger OTMs in a Mag length load (stacking into an ‘Accurate Mag’ AICS magazine). Results are very good out to 500 which is the furthest I have tested them. At that loading level I haven’t encountered any pressure issues. Velocity, however, is Not confirmed.

I’m loading the Berger 175gn OTM for my .308. While not the 175SMKS the similar shape and and weight suggests my observations could be valid.

Yes, velocity is very similar to the SMK's, maybe a tad slower by just a few fps.