.308 bullet weight

[TonyAngel]

Hey guys. I'm new here and new to bolt guns as well. I'm shooting an SPS Tactical in .308. This is my rig....

I've been experimenting a lot with 168gr bullets and have settled on a couple of loads that have performed well at 100 yards. I have very limited access to longer ranges. A friend of mine has invited me to join him on a 600 yard shoot and now I'm starting to worry about my load. Since 600 yards is probably going to be the longest I'll ever be able to shoot, we can limit the discussion to talking about shooting out to that range.

When I clocked my accuracy load of 42gr of RE15 under a 168gr SMK, I got 2400+ fps with a spread of 25fps. I'm thinking that it's pretty slow and this was confirmed by the projection on come ups when I ran it through a calculator. In any case, I did some testing and my load will shoot a consistant group of ~.3" at 100 yards with any powder charge between 42 and 43.5gr. At that point the groups open up and then start to shrink again at around 45 gr. I'm going to try 45.5gr this weekend and look for pressure signs.

Anyway, I'm now thinking that I may be better off going with a bullet that doesn't rely so much on velocity for energy. Maybe going with the 175 might be the way to go in light of my shorter barrel.

I'd appreciate any comments from you guys that shoot to 600 with a short barreled .308. 20" barrel that is.

 

[JSTARSZ]

Re: .308 bullet weight

at 600 yards you can go 155, 168, 175, 178 or what ever hits your fancy. You are slow on your velocity so it is time to get it up to 2500-2600 fps. 45 grains is getting pretty hot so I would watch it at that level as I can imagine that you are starting to fill the case. Use this link to search: Search Engine then go through this link for loads for the 308:
Reloading Depot

that should give you a good idea of where to go next in your reloading.

Oh yea, welcome to the Hide and enjoy the information.

 

[TonyAngel]

Re: .308 bullet weight

Thanks for the info. Never having done it before, I didn't want to show up at the match with the completely wrong setup.

I knew that my 100 yard load was going to be too slow, but getting to 2500-2600 fps shouldn't be a big deal. The 43.5gr load is right there at 2500fps. Amazingly enough, with the 168gr SMK, I can pretty much follow the Sierra load data and then just subtract 200fps from the velocity. The 45gr load is showing the slightest touch of primer flow, but nothing excessive and no sticky bolt. I just want to run the 45gr load over a chrony to confirm my numbers so that I can be sure of the velocity and be able to work up some preliminary come up numbers.

If the 168s will do, that makes me happy. I can run the same bullet for everything. 43.5 of RL15 for out to 300 yards and then the 45gr load for a little more juice when I need it.

Thanks.

 

[MitchAlsup]

Re: .308 bullet weight

If you don't have time to do a complete load workup, stick with the one you have, and just figure out the drop and windage for 600 yard operation.

At 600 yards, the last 100 fps does not mean a lot (in a for fun sense, but could mean a lot in the win/loose sense).

At 1000 yards, the above paragraph is incorrect, the last 100 fps can mean the difference between nice groups and nothinig hits any target.

 

[TonyAngel]

Re: .308 bullet weight

Thanks for the advise.

So, what velocity would you guys say is optimal for shooting out to 600 yards? Or is there such a thing? I guess what I'm asking would be is there a minimum velocity that I should try to attain.

 

[groovebus]

Re: .308 bullet weight

I shoot the exact same load of 42gr of RL15 with a 20" savage 10fp. I also use 150gr FMJ/BTs along with the 168HPBTs they reach out to 600 without alot of issues. The 150gr shoot a little flatter, I use them the most because of the price.

 

[TonyAngel]

Re: .308 bullet weight

groovebus, thanks for that info. I'm just going to stick with my 43.5gr load then. For the time being anyway.

 

[ReaperDriver]

Re: .308 bullet weight

What brass are you using? That makes a big difference when you're talking about powder weights and velocities. You will find a big (IMO) difference between WIN/BHA brass and say FC or Lapua. I have some really good 168 SMK and 168 AMAX loads worked up in a 20" SPS with RE-15, but the brass makes a difference. Let me know what you're shooting and I'll give you my pet loads.

And I agree, 2400fps is SLOW! My accurate 168 loads with NO pressure signs are in the 2650-2700 range out of the same gun. And they shoot EXCELLENT at 600 yds. In fact both seem to be really good to about 800 or a smidge beyond, but really fall apart at about 900, in my experience.

 

[squirrelsniper]

Re: .308 bullet weight

On fixed known-distance targets (where you dial up and stay there), the only problem with the low velocity at 600yds is just a bit more wind drift. With unknown distance targets or targets at greater range, then you might have a real issue.

However, assuming you're not using heavy military brass, 45gr of Re15 behind a 168gr bullet is quite reasonable in most rifles. And since you said the groups tighten up again around 45gr (likely the second "node"), I would try that route.

 

[TonyAngel]

Re: .308 bullet weight

ReaperDriver,

I currently have Winchester, Lapua and Hornady Match brass on hand. I weighed up some of it last night. The Hornady and Winchester seem to be about neck and neck. I'm thinking that maybe the Hornady/BHA brass is made by Winchester. The Lapua brass was a good bit heavier. If you have some load info you can share, I'm all ears. I'm gonna shoot you a PM too.

Squirrelsniper, I've been told by several people that a 45gr charge wouldn't be a problem in my SPS because Remingtons usually have really long throats. Whether that is the case or not, I don't know, but I do know that I didn't have any problems. If I get a chance to go out to the range before the shoot, I'm gonna try some at 45.2gr. This SHOULD put me in the 2600fps range.