Improving the 308 Win performance

[bamban]

I use bags....have been for 45+ years. As far as a sling, I use the Montana. No need to ridicule a person who states an experienced opinion. I've seen the Good, Bad & Ugly of reaching out. There are far more internet experts that can shoot long, than there are actual long shooters. I choose not to do it on game for obvious reasons. I enjoy this site as there are a few that post interesting ballistic workups. ......Darrel

Not ridiculing you. I am quite familiar and comfortable with sling, I've shot with sling in competition since the 90s. My follow question... do you see POI shift from bags to sling on a hunting rifle.

 

[darreljwick]

AS far as POI shift.....pretty hard to tell as a sling is no substitute for bags , but. ...... if a sling is used incorrectly I could see it shifting the POI.

 

[bamban]

AS far as POI shift.....pretty hard to tell as a sling is no substitute for bags , but. ...... if a sling is used incorrectly I could see it shifting the POI.

I know how to deploy slings, my question, is there a shift in your zeroes from bag to sling?

Do you use hasty or NRA/CMP type sling? You mentioned you shoot long, but not on game. I am correct that you shoot NRA long range matches?

What cartridge do you shoot slung up?

 

[darreljwick]

I use a Montana Sling on my rifles and shoot .270 Win or 30-06 rifles. I am not a competition rifle shooter but am a hunter. My zero is determined from bags and left alone. .........Darrel

 

[JAYgs8163]

Alpha 308 SRP brass info for those interested. I pulled 10 random cases from a box of 100 to weigh. Every case weighed exactly the same of the 10 I pulled. Pretty impressive. Starline SRP brass will be here today and I will do the same. I'm a little under the weather with bronchitis or I'd be at the range testing today in a 18" and 20" 308. I've got 20 test loads for each rig. The 20" has OAL length restrictions due to the mag box. The 18" allows for up to about 2.95 OAL with plenty of room for feeding. Settled at 2.910 which is .050 off the lands. Excited to run both rigs, hopefully next weekend I'll have some solid data to share.

Rigs below:

20

18

 

[bamban]

Alpha 308 SRP brass info for those interested. I pulled 10 random cases from a box of 100 to weigh. Every case weighed exactly the same of the 10 I pulled. Pretty impressive. Starline SRP brass will be here today and I will do the same. I'm a little under the weather with bronchitis or I'd be at the range testing today in a 18" and 20" 308. I've got 20 test loads for each rig. The 20" has OAL length restrictions due to the mag box. The 18" allows for up to about 2.95 OAL with plenty of room for feeding. Settled at 2.910 which is .050 off the lands. Excited to run both rigs, hopefully next weekend I'll have some solid data to share.

Could you possibly do water capacity of fired brass?

 

[JAYgs8163]

Could you possibly do water capacity of fired brass?

Sure. Won't be until next week.

 

[nralifer]

Yes I understand that but a 150 ??? Just a follow-up to the Bravo 4 response to a 150 with .6 BC

I apologize for such a late response. BC is highly dependent on caliber in addition to ogival length, curvature of that ogive, weight, skin drag, and boat tail length to mention a few things. The general concept is that as you increase in caliber the cross section of the bullet increases, reducing BC. The advantage of larger calibers is that the maximum BC that can be achieved is higher that a smaller caliber because the max bullet weight achieve is greater. In the .277 caliber we can make a 0.710 G1BC 150 gr bullet with ease but not a 30 cal due to the greater cross section of the bullet. To get to that 0.6G1 the 175 gr BD2 in 308 cal is needed. The best we can do in a 150 gr 30 cal hunting bullet is 0.515G1 which in that weight for a 30 cal bullet is the highest for both copper or lead core bullets. Recall that hunting bullets have to do more things than target bullets.

 

[VLD Pilot]

I apologize for such a late response. BC is highly dependent on caliber in addition to ogival length, curvature of that ogive, weight, skin drag, and boat tail length to mention a few things. The general concept is that as you increase in caliber the cross section of the bullet increases, reducing BC. The advantage of larger calibers is that the maximum BC that can be achieved is higher that a smaller caliber because the max bullet weight achieve is greater. In the .277 caliber we can make a 0.710 G1BC 150 gr bullet with ease but not a 30 cal due to the greater cross section of the bullet. To get to that 0.6G1 the 175 gr BD2 in 308 cal is needed. The best we can do in a 150 gr 30 cal hunting bullet is 0.515G1 which in that weight for a 30 cal bullet is the highest for both copper or lead core bullets. Recall that hunting bullets have to do more things than target bullets.

Yes I understand why the .308 cannot make that high of a BC in a 150 but either read the post wrong or it was written incorrectly. Not a big deal but I was getting excited to think it could be possible

 

[Spoonbill]

This thread would be dedicated to ways to improve the performance of the 308 Win or the 7.62x51 mm cartridge without wildcatting the case. Experienced and innovative reloaders should find this interesting and are encouraged to participate. The 308Win is so versatile, inherently accurate and commonly used, and yet its performance in terms of MV, trajectory and speed is a bit mediocre. I am sure it can out perform the 3006. To start with I offer up my favorite hunting load I have used for the past 6/7 years in the 308Win. The 150 gr BD or BD2 with 49 gr of Leverevolution going 2920 fps from a 1:10, 20"Douglas barrel in a short action rifle. The same load from a 24" Bartlein 1:9 twist barrel goes 3050 fps. This load would be a pretty decent long range Elk load to 900 yds or so.

I am only a novice reloader . Can you advise who manufactures BD's and BD2's?

 

[JAYgs8163]

Badlands precision

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badlandsprecision.com

 

[nralifer]

I am only a novice reloader . Can you advise who manufactures BD's and BD2's?
[/If you have any questions, many people on this thread or myself can answer them for you.

 

[mrjashu]

Right now my favorite 308 load I've been shooting is a Barnes TTSX 130, running at 3085 FPS out my 18" bolt gun. It's 5 shot one hole accurate and good out to 500-600 yards for my Coues deer hunting. Running with cheap Sig large primer brass and AA2460. Got some other loads I'm cooking up for it and my son in laws 308.

With that bullet and MV it looks like you only have around 1800fps impact velocity for 600yds (used JBM with 5000' elevation). Are you getting pretty good expansion at that velocity with those Barnes bullets?

 

[JAYgs8163]

With that bullet and MV it looks like you only have around 1800fps impact velocity for 600yds (used JBM with 5000' elevation). Are you getting pretty good expansion at that velocity with those Barnes bullets?

So far so good. I have not with my 308 18" bolt gun. My son in law killed a nice Coues buck (below) with that same load from his 308 with a 24" barrel, 540 yards, DRT. Higher velocities with the 24" barrel up near 3200-3225.That being said we're moving to the 150 bullets in the BD2. Testing this weekend, hopefully tomorrow at the Pima County range out by the fairgrounds.