.308 1K load with SMK 190 and IMR 4350

[DaveWhite]

I have a 24" barrelled M70 that I would like to shoot at 1000 yards. I also have several hundred SMK 190s and a jug of IMR 4350. The Sierra manual indicates that the maximum load would be about 2500 fps with 48.2 grains, and yet I have been told that I need something on the order of 2600-2700 fps to keep the 190s supersonic at 1k.

Anyone out there have experience with such a load or recomendation?

Thanks,

DW

 

[DukeDuke]

Most likely, IMR 4350 is a difficult path to get 2700fps. RL-15, 17 can get you there very easy, if you feel like going fancy, N550 will do it for twice the price.

 

[kombayotch]

Whoever told you that is wrong. I suggest you familiarize yourself with the JBM ballistics calculator.

http://www.jbmballistics.com/calculations/calculations.html

Use the (Litz) values.

My goto load for 308 Win. is:
190 SMK
42.3 gr. Varget
Lapua brass
210M
COAL = 2.775"
~2550 fps

I shoot at 1k every weekend with this load.

 

[GermanS1]

The JBM program is very good, and now with the Litz values added it is really the Rolls Royce of ballistics programs (and free!).

Dave, I shoot the .308/190 with IMR 4064 (moly bullet, 42.5 gr.) and it works very well at 1000, but I don't have MV data handy (30" barrel). I think it would be pretty tough to get enough 4350 in a case and still seat a 190 unless you had a very long throat. I hate to say it, but there are better powder choices out there for this combination.

 

[Steve Blair]

Velocities over 2450 should give you enough margin at 1000.

German's 4064 load is old school and as proven and reliable as it gets. I also use 190 MK and 4064 at 41.8 for 2610 from a 30" tube. More recently, I have developed RL17 with 190 MK molys at 45.8 for 2718 from the same gun. IMR 4064 still gives me better ES/SD numbers in .308 than RL17.

 

[titus123]

If 2600-2700 fps was the main requirement to make a 1000 yrd. shot then every Army and Marine Scout/Sniper who has ever made a kill at 1000 yrds is the luckest S.O.B ever. Remember the M118 LR sniper round currently used is only moving at about 2550 fps with a 175 gr. Sierra match king bullet. A 190 gr. bullet with superior B.C and sectional density at 2550 fps would be ballistically superior.

 

[alf]

I had a 26" 700 varmint barrel that would do 2625 FPS with the 190's and H-4895

 

[GermanS1]

Just to follow up on my earlier post, I chronographed a 10 shot string of my .308/190 load today, here's the data:

42.5 gr. IMR 4064, Winchester brass, Winchester primer, Sierra 190 Match King, moly-coated, seated to jump 0.020". Barrel is a 1:11" twist Krieger heavy Palma, 30" long.

Avg. MV 2640 fps, SD 7.5 - 10 shot string.

This load works very well at 1000 yards. Very well...