Short-range cousin of SMK 168 in .308?

[Shmackey]

Anyone have a lightweight accuracy load for .308 out to only 100 yards? SMK 168 over Varget is great for longer, but I suspect similar accuracy at short ranges can be had with a much lighter load.

Heading to the range now to try some 110 HP over 42 gr of 748.

 

[amlevin]

I have had some great accuracy from the 168 SMK using 44 gr of Varget. The rifle is a Remington 700 SS 5-R Milspec and shoots just about everything from 155 to 175 gr really nice. My favorite though is 175 gr Nosler Custom Comps over 43.5 gr of Varget. Personal best is 5 shots in a .202 group. If it wasn't for one little mistake on my part the group would have been close to .125" For some reason it's always that 5th shot.

 

[USSR]

Shmackey,

I think you will find greater accuracy by loading down your 168SMK's, rather than going to a really light bullet like 110 grains. I developed a really accurate 200 yard match load using the 168SMK and 37.2gr of IMR4895.

Don

 

[Jim Watson]

At the sporting rifle level, I had as good shooting at 100 yards with the 130 grain Speer HP as heavier bullets. I think the 125 gr Sierra would be worth a try, too.

The score benchrest shooters typically use something like a 131 gr .30.

 

[Funshooter45]

On a lark, I loaded up some 110 gr HP for my .308 a few months back. I was actually very surprised at the accuracy at 100 yards. As I recall, I used RL-7. I can't recall the charge weight because I don't have my load data with me now but it was pretty low, somewhere in the 38 gr range. I wasn't after screaming velocities, just an accurate lightweight load for plinking. As I recall, I found one load that was grouping around 1" at 100 yds.

 

[rodregier]

The 168g SMK was originally designed for 300 Meter International Match competition (328 yards). It is legendary for dynamic stability issues at much longer ranges.

It's accuracy at 100 yards has been fine in my experience.

I presume you want a lightweight loading for reduced recoil?

Have a look at the 125g Nosler Ballistic Tips for an accurate lighter projectile.

 

[REL1203]

I thought about trying this for my R700 AAC, but when I can get this kind of accuracy out of 168SMKs, why bother.

 

[Shmackey]

I presume you want a lightweight loading for reduced recoil?

Yeah, I want to teach someone to shoot more than a .22, and the .308 is my other rifle. It's in a stock that's not terribly cushiony.

Not sure how low I can load the SMK 168s. I think I was loading them over 43 gr of 748 the other day and getting sooty necks already.

 

[MtnCreek]

I think you will find greater accuracy by loading down your 168SMK's, rather than going to a really light bullet like 110 grains. I developed a really accurate 200 yard match load using the 168SMK and 37.2gr of IMR4895.

Don

^That's what I would do. Varget may not be the best choice for reduced loadings. A faster powder will likely do better. Don mentioned IMR 4895 and that would be a great choice. You may get good results from 8208xbr or Benchmark.
I didn't like Benchmark w/ 168gr projectiles, but that was just because I wasn't getting the velocities I was looking for; so it may work for your needs.

 

[rodregier]

I've loaded bulk 110g .30 SP projectiles designed for M1 Cargine loadings in .308 Win. I use a fairly fast rifle powder and load them to max M1 carbine speeds, so there should be no stabilization issues at any reasonable range (say 100 to 200 yds). The cartridge profile is a little wonky, so fast feeding from the magazine might be an issue, but they work great.

Because the recoil is so light compared to the heavier projectile loadings, your zero will likely be substantially different, so you'll have that to deal with. Muzzle blast is reduced, which also helps with new shooters too.

.308 Win reduced recoil loading I used:
110g Rem .30 SP
24.3g IMR 4227
LOA 2.400"

chrono avg velocity 2152 ft/sec

Derived from Speer #11 (1987) and Speed #12 (1994 )starting load data for .308 Win.
They used 25g for a velocity of 2121 ft/sec

This is just bulky enough (1.9cc of powder) that double charging should be detectable, which is not the case for loadings using pistol powders like Unique or Red Dot would be in such a case. Empty case volume with that projectile will be around 3.1cc

You can use a 110g .30 cal FMJ too. I used the softpoints because I also use them in a .30-30 reduced loading in a tubular magazine.

 

[Shmackey]

Hm--I think this kind of thing is what I'm looking to do, assuming I can still keep groups within an inch at 100.

 

[Funshooter45]

I don't think you'll have any problem keeping groups under an inch with the little 110 HPs if you do it with the heavy bullets. It's just that the little bullets don't do so well when the ranges get longer. There's plenty of options for powder out there. Think something pretty fast burning. In my case, it was kind of intriguing when I shot my test batches using RL-7. But I only made up 20 of them using different weights of powder and never got around to coming back to experiment further. My main observation was to keep the charge weight and velocities on the low side of the published data. Evidently, if you push them too fast, they get kind of wonky.

 

[Cherokee]

I have had good 100 yd groups with my old Ruger Heavy Bl 308 using Hornady 130 JSP and cheap Remington 125 JSP. H335 was my powder.

 

[rodregier]

(From memory) when I tried 110g projectiles w/H335 in .308Win, I got tremendous muzzle flash and blast. Might be more tame with heavier (125/130).

 

[Shmackey]

I ordered up a box of these, which somehow I never noticed before. They look literally like the smaller cousin of the SMK 168.

Now I just need to decide what powder to use to cook up a really soft load.

I've been reading about using Trailboss powder to get down below even 1500 fps. I assume there are reasons why this is a bad idea....

 

[Shmackey]

Looks like even IMR recommends Trail Boss for light rifle loads. I've got to try some of this.

 

[rodregier]

Careful about going to really low speeds with jacketed projectiles in rifles. The warnings I've seen is that you can "stick" a projectile in the bore. Much below 1100 ft/sec seems to be the threshold.

The other limitation is that going below a recommended starting load can produce a squib that won't push the projectile out of the bore either, which then sets up the circumstances of a powder charge driving two projectiles. (Proof load and beyond!)

I had a look at IMR's recommendation for Trail Boss. Since they are talking about 70% load density, that also avoids using such small power charges that undetected double charges would be an issue.

The 135g Sierra Match Kings you reference are likely an excellent choice for a reduced .308 Win loading.

If it was me I would go with the max Trailboss loading which is around 1400 ft/sec. That will be say 43% the recoil of a normal .308 Win loading, but still fast enough to have fairly good ballistics/stability at 100 yds.