Opinions please. 308 question

[Wingnut00]

So my question is simply about a 308. It is my practice gun for prs style shoots. I shoot the 308 for practice because of the barrel life. So my question is for my purpose would a 155 grain bullet be better because I can get 3000fps or a 185 juggernaut because of the bc. I know this is gonna be asked so I will let everybody know that I shoot a 6comp match for my comp gun which ain't nothin like a 308 but I feel like if I can shoot my 308 excellent on steel to let's say 1200 my 6mm is really easy. Like I said this is just my practice gun so again your opinions between 155 class of bullets or the heavier 185.
Let me hear your thoughts. I'm open to opinions. Thanks.

 

[Laurie]

I don't shoot PRS and only know what I've read about it, so you'll know what are pros and cons that affect performance. (In fact where I live - the UK - we don't have PRS at all, but we do have various Practical, sniper, and Tactical disciplines.)

First equivalent velocities. (ie those that produce same MEs. If you can get 3,000 fps MV from your rifle with a 155gn bullet that is 3,098 ft/lb ME and the equivalent MV for the 185 is therefore 2,746 fps MV as it also produces 3,098 ft/lbs.)

So a 185 Juggernaut at 2,746 varies from an equivalently efficient 155 at 3,000 fps in the following ways:

1) It'll wear the barrel out faster.

2) It'll move less sideways in the wind. The amount of reduction is valuable / important for the 1,000 yard sling or FTR KD competitor, but may be less for the PRS shooter at your typical / maximum distances (??)

3) It'll recoil harder affecting speed of follow-up shots.

4) it will have a higher, less flat trajectory than the faster lighter bullet. Is range estimation a major issue in PRS as in European tactical competition? If so, more curved trajectories are bad.

 

[Bart B.]

Here's a good review of different bullets shot from 308 Winchester cases:

http://www.geoffrey-kolbe.com/articles/art1.htm

 

[Joe Wade]

Your barrel twist will effect what bullet weight to choose from. Generally, 155gr bullets like 1:12 twist and 185grs work better in 1:11 twist. Results will vary with bullet choice.

 

[Depart123]

All else being equal, I would choose the bullet with the BC closest to your competition bullet. That way your wind calls will still be close to the same.

 

[cinch29433]

I would shoot whatever bullet you can get easy and just do the trigger time. YMMV but I find when I play games where rapid fire goes on it takes a little time to get back to holding and squeezing.

Your dope will be the same practice depending on conditions. Good shooting!!

 

[Bart B.]

Your barrel twist will effect what bullet weight to choose from. Generally, 155gr bullets like 1:12 twist and 185grs work better in 1:11 twist. Results will vary with bullet choice.

Barrel length also determines best twist for given load's bullets as muzzle velocity effects bullet spin rate. FPS times 720 divided by twist in inches equals bullet rpm.

Lots of folks have shot Sierra 190's from 308 Win chambered 1:12 twist 24" barrels very accurate. Same for Sierra 155's through 1:13 twist 30" barrels.

Bullets group closest to point of aim when spun just fast enough to stabilize them to the target. Stability factors too high ends up jumping unbalanced bullets too far off the bore axis as they leave. Some 7.62 M80 147 grain bullets have shot most accurate at long range from 30" barrels with 1:14" twists.

 

[Wingnut00]

Thanks for the replys folks. My 308 is a 10 twist 26" and the damn thing always seemed really fast. I used to shoot 175 Berger otm's at 2820 with no problem and get around fifteen rounds of brass life. So I ran out and shot some 185's .016 off the lands and they show some real promise so I think I gonna try tuning that sow in. Next time out I will get some chronograph data cause 42.8gr of h-4895 is looking pretty good with no pressure signs. I think that would be a pretty decent practice round. Keep the replys comin. Thanks again.

 

[dcali]

I would just buy another 6mm barrel. Do the math on the cost of shooting the two.

 

[NickB1075]

I would spend the money you will spend on Bergers to get a second barrel for the 6mm. Practice with the set up your going to compete with. That cartridge should be good for at least 2000 possible even 3000 rounds on steel accuracy, you don't need benchrest accuracy for prs. I have had 2 6mmslr barrels go till 2450rds. They still shot ok out to 1000. Just my opinion.

Nick

 

[B Nettesheim]

Practice with what you will be competing with, you will learn more and not make as many mistakes at the match because you are already used to it. Like the old saying, "Fear the man who only has one rifle"

 

[Rob01]

I use a .308 to practice with for the same reason. Not going to burn out my 6mms and 6.5s through practice. It's a smart move. My practice rifle is set up like my match rifles so they feel the same. My home practice range was only 400 yards so I used 168s mostly and 178s.

If I were you and looking at the two bullets you are then I would go with the heavier better BC bullet. I would shoot the 178 BTHP as it has a god BC but won't be overly expensive for practice bullets.

 

[memilanuk]

Question for ya @Rob01

I was under the impression that a lot of the guys shooting the small to mid-size 6 and 6.5 calibers with brakes and cans were shooting essentially free-recoil off some of the barricade stages, etc. How well does practicing with a .308 and 178s translate over to *that*?

 

[Rob01]

Some do. I don't so not an issue for me but someone using free recoil could still practice like that and just have a little more recoil to deal with for a follow up shot.

 

[memilanuk]

Some do. I don't so not an issue for me but someone using free recoil could still practice like that and just have a little more recoil to deal with for a follow up shot.

Some of the holds I've seen people use... I'd expect a .308 to pretty much fly off the barricade and land in the dirt. Then again, I'm continually surprised at how heavy the rifles are that people use for that sport. Maybe that helps.

 

[Rob01]

Brakes and weight help. A good brake on a .308 can cut recoil quite a bit. This added to the weight won't have it flying off the barricade. Also the shooter is right there so won't be hitting the ground.

 

[JBT47]

When I first got into precision shooting I shot a .308 and .223 exclusively to become proficient in reading the wind. Those two calibers are great teachers in wind reading. When I began shooting 6’s and 6.5’s it took some adjustment. I was accustomed to holding off much more for the .308 and .223 that I had been shooting. The 6’s and 6.5’s are much more forgiving in the wind so it was a learning curve for me to not hold off so much. Take this into account if you practice with a .308.

 

[Wingnut00]

Again, thanks for the replys. I have thought about just gettin another barrel for my 6 and just runnin it but the reason for me wanting to shoot the 308 mainly for practice is to get better at my wind calls like said above. I do also take my 6mm when I practice but I just don't shoot as many rounds through it during practice. I have been shooting the 308 for practice for several years now and it does seem to make me a little better when the wind is howlin. Like I stated above my old load was the 175 Otm and the main reason I'm wanting to switch is because for whatever reason the 175 seemed to go to hell between 850yds and 950yds. As for the two gentlemen talkin about free recoil with the smaller calibers I agree some can get away with it but I personally hold my rifles as close to the same as I can. My 308 does not have a brake on it and I can shoot it really well and my 6mm has a brake and I can shoot it equally well. That's just me though. I'm really gonna work on the 185's and see what they can do cause I really like the wind bucking bc even though it ain't gonna be really fast the bullet oughta fly a little more consistent in the breeze. And the statement of "fear the man with one gun". I agree completely but at the same time I want to be proficient with all my guns. Thanks again folks.

 

[FeMan]

........the main reason I'm wanting to switch is because for whatever reason the 175 seemed to go to hell between 850yds and 950yds......,

Im not a 308 shooter but do see people try and shoot those at our club level Tactical matches. They invariably seem to suffer from transonic instability and fall apart between 800 and 900 yards. Our density altitude varies from minus a few hunted feet to 1000 or so. If you want to shoot the 308 for PRS ranges make sure you get a bullet that is stabile in transonic zone.

 

[memilanuk]

Weird. Sorry to hear your guys have been having problems like that. I've been apparently lucky with my .308 and the B175OTM... it held together to out just past 1k; haven't had occasion to shoot it any further.