Who shoots heavies in their 308?

GJ

I meant if I was starting over with all of the mid-range matches that didn't exist back then, I'd probably look at the lighter bullets like the new 155 or the 175 SMK and develop a load for 600 yards out to 1000. It should work great at the shorter distances and still be adequate at 1000. For a dedicated 1000 yard I would not go back to the 308.

As to your choice, I haven't run the numbers to see what they say. I'd first want to be darn sure I could get 2600 with the 208 grain. That's a heavy bullet for the 308 unless you're shooting something like 300 meter where you can keep velocities down to 2400 to 2500.

For the 175s I still like the Berger VLD with a BC of .537.

Are you trying the new 155 Sierra? I haven't talked to anyone who said it wouldn't shoot.

Ray
 
I was referring to the Sierra 155 Palma bullet. After my experimentation I figured they just weren't right for a 10 twist. I aso tried 150gr TSX & 150gr Accubonds in the same rifles with much the same result. Both rifles shot better as I went heavier so I thought maybe I was on to something. Now we have RL17 which will work with bullets previously too heavy for a 308, so I'm looking to "give it a shot". :)
 
Mosrt of us who shoot commonwealth match rifle here in Australia & Britain run 200-210 grain projectilles at 2700 (Amax , 210 SMK) -2800 (200 SMK) fps in .308 chambering. However:

  • Barrels are 32"-34"
  • Throats are cut to permit loading to OALs of up to 3.15"
  • Powders are generally VV N550 or AR 2209, occasionally AR2208 (Varget)
See http://www.matchrifle.org/
 
I personally talked to Sierra about recommended powders for the 155 SMK. I did so because RL-17 was completely filling the case when loaded to the weight recommended by Alliant. The gentleman there, recommended 4064, Varget, or RL-15. The bore to case volume of the .308 requires heavily compressed loads to achieve max performance (2800+) with the 155. The problem with heavily compressed loads in this case is getting the darn bullet to stay put. Mine always kept creeping back out! The Sierra man said that was the issue as he saw it, and that is why he was recommending the powders I mentioned previously. I have tried both the 155 SMK and the Palma with 43 grains of 4064 (a starting load) and the bullets soft seated. They shoot the same at 100 yards, but I have to wait until next month, when the snow is gone, to try them out at longer ranges.
Richard
 
I decided to check my throat in the 308, so I picked up some 175 SMKs to test. They hit the lands at 2.810" COAL- ouch. I think I'd have to ream out my throat to successfully run the 208-210 class projectiles like I'd want to.

Then again, it might be worth it to try the 175 SMK with the RL17 to see if it would bump the velocity up to the next accuracy node (above the standard 2600).
 
Given a short throat I don't really see how you expect to get a significant jump in speed by using a powder (RE-17) that is *slower* than the powders usually used in this cartridge (Varget, RE-15, IMR4064, I/H 4895, N140, N150, etc.).

If you are really bent on using the S175MK in that barrel, I'd recommend about 43-44gr RE-15 or Varget (start a little lower of course).

With that short of a throat I'd probably recommend going with a 155gr projectile - S155MK (Palma), B155.5BT (Fullbore), etc. and Varget/4895/N150.

Good luck,

Monte
 
Confused

GJgo said:
I decided to check my throat in the 308, so I picked up some 175 SMKs to test. They hit the lands at 2.810" COAL- ouch. I think I'd have to ream out my throat to successfully run the 208-210 class projectiles like I'd want to.

Then again, it might be worth it to try the 175 SMK with the RL17 to see if it would bump the velocity up to the next accuracy node (above the standard 2600).
Click to expand...

I am confused on this post. I was following it because I shoot 175 Grain SMK in a Savage. I have also experimented with 190 and 200 gr SMK's.

1. According to my Sierra Manual, the C.O.L is 2.80". If you load a 308 to specs, the bullet should be setting .001 off the lands, isn't that where you are supposed to be?

2. According to the Sierra Manual, 2600 fps is a maximum load, and they urge caution. Why load above the safe limit? Above 2600 fps, it must be a thrill every time you pull the trigger, but what is the percieved advantage?

3. What is an accuracy node after 2600 fps? Are you talking about a vibrational node in the barrel.


Please advise

Julian
 
Julian said:
1. According to my Sierra Manual, the C.O.L is 2.80". If you load a 308 to specs, the bullet should be setting .001 off the lands, isn't that where you are supposed to be?
Click to expand...

Default OAL for a cartridge to fit inside the magazine on any gun on the planet, and what is used for long-range loads in a purpose-built target rifle are two entirely different things. OAL for my *155* grain loads is over 2.9... and thats in a factory 12 F/TR.

2. According to the Sierra Manual, 2600 fps is a maximum load, and they urge caution. Why load above the safe limit?
Click to expand...

Sierra's max loads are fairly... pussified, as compared to what is commonly used in competition, and have been for a long time. They are loading for the lowest common denominator - being safe in any gun somebody might possibly use those loads in.

3. What is an accuracy node after 2600 fps? Are you talking about a vibrational node in the barrel.
Click to expand...

Varies somewhat... I've seen outstanding accuracy right around 2700fps in 24-26" barrels, and others cite similar results around 2800 - usually with a longer (30") barrel.
 
168 Bergers or Match kings with Laupa brass and Varget IS THE LOAD in the 308
 
Hi Guys. Sorry if my brain went a couple different directions in this thread.

First direction- see who else shoots heavies in their 308. I have a big jug of RL17, and guys doing experimentation wththis new powder in 308 are getting into new territory. I'd like to try it out.

Off-track thought. I'll buy a box of good factory ammo (Federal GMM 175 SMK) to see if this rifle is even a shooter before I do anything else. Then I can re-evaluate trying the 190 or 200 SMK after seeing how the 175 shoots.

If the RL17 won't shoot for me I'll have to suck it up and go buy a jug of Varget, but powder is darn expensive these days and I'd like to try what I have first. That's the impetus here, well, that & knowledge.

The GMM 175 SMK is in fact .010" off the lands in this Savage. I suspect That's not a mistake. Remingtons OTOH are known for having a longer throat. A longer throat is what I'd need to seat any 210 class projectiles out where I'd want them in order to gain case capacity (for more powder). The 1.5X" long 208 AMAX wold stick deep in the case at 2.80 COAL! My magazine is good for almost 3.0, so if I ream out my throat I gain needed space for handloads.

Some of you guys picked up on this. :) I also feel that the manuals are an (excellent) guide book & not a rule book- they have to publish loads for every 308 (in this case) on the planet. If you want a good laugh go look at the variance in the published 6PPC loads.

Some people say the 175gr SMK goes to pot above 2600 FPS in a sporter length barrel. We'll see, I guess.

Ok, that aside- I shot the new rifle today for the first time! Range report! I'll stick it in the factory rifle section.
 
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FWIW... the new B210BT has a much shorter bearing length than the B210VLD, at least. You might not need to extend the throat quite as much as you think to be able to use that bullet, for instance.

The other day a friend of mine was up here and we tinkered with some B210BTs in his 12 F/TR (which has been throated waaaay out). Winchester brass, 210M, Varget, two batches of 42.5 & 43.0gr. The latter was clocking ~2550fps with not much in the way of pressure signs. I'm guessing with a little slower powder (RE-17 or N550) in that length of barrel 2600-2650 should be easily doable.

Should be interesting
 
True- the Berger BT are tangent where the VLDs are secant ogive. The SMK 210gr is secant, the only one I've seen (?) in Sierra's line- the 190 & 200 SMK are both tangent. The AMAX are also secant.
 
Checking around locally, the heavies that I can get are the SMK 190 & 200 as well as the Berger 185 hunting VLD. There are no 208s or 210s to be had. I'm tempted to try the Bergers, but $46/ 100 is painful. I've always shot the Begrers in my Sako 6PPC, but lately I've discovered that Ballistic Tips shoot just as good...

Any comment on the long boat tail on the 190 & 200 Matchkings? It kind of makes them look like a football (mass in the center) as opposed to most other projectiles that seem to visually have more mass in the back half.
 
So I picked up a box of 200gr SMKs to try out first. They hit the lands in my tube at 2.805" COAL, which is .005" shorter than where the 175 SMKs hit the lands. I'd call that basically even based on production tolerances. So, it would appear that the ogive shape is the same- I wonder if that's also the case with the 190 SMK? Looking at the photo on this page it appears that there isn't a significant length difference between the 190 SMK & the 200 SMK.

So, that COAL means there will be quite a bit of bullet in my case. I hope to have a range report soon. Interestingly enough the 200 SMK (1.394") is basically the same length as the 180gr TSX (1.387") I shoot in my hunting rifle.
 

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OXYMORON\:noun: a combination for epigrammic effect of contradictory or incongruous words, (e.g.: good factory ammo.).
 
For the flattest trajectory and least wind drift, you need to work out which bullet has the shortest time of flight out to your intended range.

That will not necessarily (almost certainly not) be the bullet with the highest initial velocity, nor will it necessarily be the bullet with the highest ballistic coefficeint.

I'm guessing that you'll come up with one of the mid range (180 - 190gr) weights, but that is only a guess. you need to work it out.

This should give you some of the background

http://www.triplej.com.au/pdfpages/LongRangeBallistics
 
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I was googling yesterday and found a stock of ballistics programs for download at "steve's pages". I haven't tried any of them yet.

There is a health warning about going there, there is a copy of a "white resistance manual" :eek:for download on another page of the site, so be ready to end up on a "watch closely" list if you do go there from a computer that can be traced to you.

Why the hell he goes and spoils an otherwise valuable site with that....(long and continuing rant about racist scum)...
 
Any particular reason you don't just use JBM...? Pretty sure the algorithms and G7 BCs used there are probably several notches above the other stuff floating around the web...
 
Back on topic, Thanks Alpacca. Ive seen other writeups to the same effect. It seem there are three camps:

- Shoot 155s really fast because that's the hot ticket these days. BTW you need a long tube.
- Shoot 175 SMKs because it works. Other projectiles have better numbers, but if it's not broke don't fix it.
- Shoot the heaviest bullet with the highest BC you can stabilize. It will perform better at long range despite the lower MV. BTW there's more recoil.

Still waiting for the mud to dry to try out the 200 SMK loads. Considering ordering some 208 Amax and asking Dan Dowling if he has time to ream out my throat. (Not sure if I want to attempt it myself..) Might suck it up and try some Berger 185 VLD as well.
 
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