.308 175gr SMK loads at 2650fps Schneider 27"

[SigsauerP229]

I'm looking for a load that will run well in in my .308 that pushes out at least 2650fps.

I get great results from Fed GMM which gives me an average 2652fps and 1/4" to 3/4" groups.

I'm running a 1-11” Twist Schneider 5P 27" barrel.

My loads so far have been

RL-15 with loads ranging from 40.5gr to 42.5gr. The closer to 42.5gr. I got the more the groups expanded. 40.5 and 41.0gr at 2525 and 2552fps were 1/2" or better but I'd like to get a bit more velocity.

I also tried some IMR 4064 at 42.0gr which pushed them too 2751fps which suprised me a bit for speed but groups were 1" to 1 1/2". I'm planning on knocking it down to 40.5 and 41.0gr as I figure this will give at least 2650fps but I don't know how the groups will be.

The gun loves 155gr. SMK 2155's with 44.0gr. of IMR 4064 give me 1/2" groups at 2943fps but I want a good 175gr SMK load that isn't too hot.

If someone has a similar setup resulting in at least 1/2" groups and yielding at least 2650FPS, I'd appreciate hearing what it is.

I have the following powders to work with on hand.

RL-15
IMR 3031, 4898 (allot of it), 4064, 4350, and 4831.
Varget

I'm not being lazy, I don't mind working up loads but I have a lot on hand to work with and if someone already has a good load it might save me from burning through power that I can use towards another load.

Thanks

 

[B2Riesel]

Re: .308 175gr SMK loads at 2650fps Schneider 27"

I've always heard that 42.5 grains of RL-15 was the go to load...however in my Rem700 I had harmonic scattering at 42.5 and when I went beyond 42.7 to 43.1 my groups tightened up nicely and I have great velocity with very little deviation. I'm running a 26" barrel in a bolt gun so your harmonics will most likely be different than mine.

 

[poke5353]

Re: .308 175gr SMK loads at 2650fps Schneider 27"

I have been running 42gr of alliant ar comp with lapua and Winchester brass and I averaged 2720 out of a 22" kreiger barrel 1/10 twist. And get these 10 shot groups all day long. Caution, this is a load I worked up for my rifle. May not work good for anyone else.

 

[Tx_Flyboy]

Re: .308 175gr SMK loads at 2650fps Schneider 27"

Sigsauer,

Your problem is that you are not loading enough powder in your recipies to properly evaluate speed and accuracy. With a high quality barrel like yours, and the its long length, you should be able to push 175s at around 2750-2850ft/s+ at your accuracy node.

RL-15 is a great powder that gives relatively fast velocities, though its too temp sensitive for my taste. My advise is to start at 90% of published max load(use loads recommended by powder makers, not bullet makers) and work up in 0.2gr grain increments up to .2grains past the book max load. You will be able to find a load that gives you the highest velocity and accuracy close to your rifle's max load.

If you are not wedded to RL-15, i highly recommend Alliant's 2000-MR powder. You will be able to achive about 50-100fps faster velocity than RL-15, at your accuracy node. It is temperature insensitive, meters like water, burns cleanly, and is flash suppressed. What's not to like?

 

[Kevlars]

Re: .308 175gr SMK loads at 2650fps Schneider 27"

I agree with Tx_Flyboy -- you should use the incremental load process as he describes above. You may also want to try Varget as a lot of us use that powder. Most common is 43.5 all the way up to 45.0, I personally use 44.5 with FMG 210M primers SMK 175and lapua brass. Every rifle is different and using the method above will help determine what your rifle likes.

-K

 

[Huckleberry75]

Re: .308 175gr SMK loads at 2650fps Schneider 27"

44.5gns of Varget was showing 2670 with 178 amax's over the weekend with a 23" Hart bbl-suppressed.

 

[Kevlars]

Re: .308 175gr SMK loads at 2650fps Schneider 27"

ya .. I get 2683 out of mine with my 20 inch barrel and a AWC ThunderTrap TI

 

[SigsauerP229]

Re: .308 175gr SMK loads at 2650fps Schneider 27"

Thanks for the advice.

I was thinking about working the load higher based on Alliants suggested measurements. I had all the other powders on hand but only tried the IMR 4064 and I bought the RL-15 based on results people mentioned with 42.5, I decided to test loads from 40.5gr to 42.5gr in .5gr increments. The higher I got the worse the groups got. I'll try some hotter loads and some Varget though to see what I get.

 

[Oneteam]

Re: .308 175gr SMK loads at 2650fps Schneider 27"

Varget and 4064 are great powders with the 175 SMK. Some of the "hotter" Varget loads are some of my most accurate.

 

[EROCO]

Re: .308 175gr SMK loads at 2650fps Schneider 27"

I am getting 2800 out of my 27" barrel that had been melonite treated.

175 smk with 44.7 RL15 on Lapua brass.

 

[KYpatriot]

Re: .308 175gr SMK loads at 2650fps Schneider 27"

25inch 5r
45 grain Varget
FGMM brass
CCI BR2
about 2715 at 900' and 70 deg
averages .6 MOA at 100, and does well on steel out to at least 850