.308 Quickload Data

[pigsy]

Please could I ask if someone is kind enough to run the following through Quickload?

I've developed an accurate load but I've been restricted to shooting it on Short Siberia to date and I just wanted to theoretically check pressure and velocity to see if it's got the legs to go out to 1000 yards.

N140 - 41.2 grns
SMK 155 (2155)
CCI 200 primer
Seated 40 thou off the lands

24" Barrel - 1:12 twist

Thanks very much in advance.

Adam

[Steve E]

I do not use quick load, but with that powder load you will struggle at 900 yards and the bullets will probably not reach 1000 unless you use way over the normal rises.
My reduced load for 300yds is significantly higher than that. With N140 and the 155 smk you need a powder load that will fill the case to just below the bottom of the neck to provide enough velocity and consistency for long range.

[pigsy]

Thanks for that Steve - that's interesting. Looks like that may be my short range round and I'll work up loads for the longer distances.

[EagerNoSkill]

My generic QUICKLOAD shows the following

308 Win PMAX is 62,000 PSI
H20 is 55 grains
and I set C.O.L to 2.800 inches

Use care and develop only a prediction and no guarantees!

N140
Charge : Velocity : PSI
41.2 : 2,583 : 43,906 You load data
43.0 : 2,686 : 49,863
44.0 : 2,737 : 53,352
45.0 : 2,791 : 57,460
46.0 : 2,845 : 61,701
The 46.0 charge would be the minimum you would require to ensure velocity above SOS for 900 yards at Sea Level

IMR 4895
Charge : Velocity : PSI
43.0 : 2,697 : 46,784
44.0 : 2,758 : 50,197
45.0 : 2,818 : 53,869
46.0 : 2,878 : 57,822
47.0 : 2,938 : 62,081

The sleeping beauty powder IMR4895 gives you more speed at less pressure
The 46 and 47 grain charges give you 1000 yards capability.

H4895
H4895 is a great powder and for same charge gives about 20-30 fps more but has higher pressures.
At the same pressure IMR 4895 will give more speed than H4895.
I only dabbled with the upper charge to illustrate

47.0 : 2,989 : 68,397 Same Charge = More Speed More Pressure (50 fps)
47.0 : 2,909 : 62,074 Same Pressure as IMR4895 but less speed (20 fps or so)

I also played with Varget - it gives the following

VARGET
Charge : Velocity : PSI
43.0 : 2,655 : 47,939
44.0 : 2,714 : 51,394
45.0 : 2,773 : 55,094
46.0 : 2,831 : 59,079
47.0 : 2,890 : 63,376

[pigsy]

Tim,

That's incredibly kind of you, thanks.

Well it would seem that at the least load was safe!!

Interestingly I'd always assumed that N140 was the "go to" powder but that's thrown up some interesting options which I'll pursue, although it feels like by the time I get a good load I'll have shot the barrel out!

Adam

[20series]

Adam

When I had my old PSS which had the 26 inch 1/12 barrel my prefered bullet for long range was the 175 gn smk using Varget

Alan

[EagerNoSkill]

Tim,
That's incredibly kind of you, thanks.
Well it would seem that at the least load was safe!!
Interestingly I'd always assumed that N140 was the "go to" powder but that's thrown up some interesting options which I'll pursue, although it feels like by the time I get a good load I'll have shot the barrel out!
Adam

Get it around 46.0 of IMR 4895 set it to +- 20 thou jump and you are likely to have a zinger!!! :lol:

20 shots and you WILL have a round developed!

And you will be good for 6,000 to 8,000 rounds ... as long as you use C2R (could NOT avoid the plug - sorry!)

[pigsy]

No plug necessary Tim - C2R next on my shopping list. The testimonials I've read have been glowing! :goodjob:

[mag41uk]

Or try N550.

http://www.lapua.com/en/products/reload ... odata/5/70

Tony

[ovenpaa]

I find N550 too slow for my rifle and much prefer N540 behind 155's when looking for a good case fill.