Load development for .308 F/TR

[dcali]

It's important to recognize that the Berger stability calculator, like pretty much every stability calculator on the net, is based on the Miller Rule. That's an approximation of some hard to measure and/or calculate stuff. The resulting Sg is going to be a guideline - not a precise number. Don't let the second decimal place fool you. I've calculated these numbers with more sophisticated methods, and the first decimal place is iffy. I'm not sure I'm confident that you can calculate Sg within +/- 0.1 and bet your life on it. I'm more comfortable with relative comparisons.

Also important is the minimum altitude at which you anticipate shooting. A lot of guys go with too fast a twist because they're calculating twist at sea level, while they're shooting quite a bit higher. In my opinion (experienced shooters may disagree), the only reason to put a 10" twist on a TR rifle is if you're shooting 215s or if you're shooting 200s close to sea level. At even 1000 feet, an 11 will handle the 200s just fine. Another pitfall is going too fast because you *might* shoot heavier bullets. I fall for this myself. If you're not REALLY going to shoot those 215s, don't get the twist for them. My current TR barrel is a 10", and hasn't seen a 215 ever, and never will. :/ A surefire way to buy too fast a barrel is to say to yourself "what if I want to shoot 215s at sea level?". Don't do that. You're not going to.

 

[Medic505]

Save yourself a lot of pain. Change the barrel. Pretty simple and many good pre-fit for Savage out there.

Just my 2 cents......

 

[Bart B.]

ÀThe factory barrel is a 1/12" twist and doesn't do well with anything heavier than 168.

308's with 24" 1:12 twist barrels have shot sub MOA test groups and match winning scores at 1000 yards with Sierra 190 HPMK bullets. 44 grains of IMR4320 in new, unprepped 7.62 M118 primed cases. In match grade Garands.

Ditto with Lapua 185 grain FMJRB match bullets.

At 150 feet above sea level in cool temperatures.

 

[Forrest Mc]

Here's the deal. Realistically, I've got 5 days to get this cartridge developed at a 100 yard range to shoot in a 1000 yard match. Otherwise, I'm at the match with 8 boxes of factory Federal Target 175 gr rounds.
I'll work with the info you all have given me and hope for the best.
Long term I will develop a 600 yard round and a 1000 yard round out at my buddy's ranch where we can go a mile.
Thanks everyone, now to the bench.
Forrest

 

[Martin52]

.....I've got 5 days to get this cartridge developed at a 100 yard range to shoot in a 1000 yard match. Otherwise, I'm at the match with 8 boxes of factory Federal Target 175 gr rounds.

Forrest

Just doing some research for 185 Jug load data ahead of testing - how did you go at 1000 yards ?

 

[Tempest]

Save yourself a lot of pain. Change the barrel. Pretty simple and many good pre-fit for Savage out there.

Just my 2 cents......

Ditto. Did exactly as he said and went long barrel and 200 Berger's. Huge improvement.

 

[calgarycanada]

I am developing a load for 1000 yard FTR. I used 100 new Lapua Palma brass, Berger 185 Juggernaut Target bullets, BR-4 primers, Varget powder. I turned the necks to .14", chamferred necks in and out, ran thru expander mandrel and then loaded 37.5 gr of Varget in 50 cases and seated the Bergers, 5 each, from touching the lands down to .045" jump in .005" increments. Seating test Results:

I opted to do the charge test with the 2.205 seating depth due to the better vertical. Beginning with 39.0 gr. up to 43 gr. in .5 gr increments here are the disheartening results:

Every one of the fired cases of the "charge test" exhibited this ring at the bottom of the neck (the 50 fired in the seating test did not).

I am looking for your observations and advice.

Maybe I’m missing something, isn’t 2.205” has less vertical than 2.195”?
Also 40.0 gr seems to have good vertical? As already mentioned you should find another node between 43.5 & 44.4.

 

[Barossa_222]

You are way too low with your powder charge. You should be up somewhere near 44gr with varget. Take one case and keep loading it until you get pressure signs. You can't select a powder weight range until you know where your top end is. I don't run any of my FTR barrels on high nodes, but I know where they start to peak. Just my 2 cents.

 

[D-4297]

Just spent the last three months going thru this with a friends identical Savage Palma rifle . Replaced the 1/11-1/2 twist with a Criterion 1-10 , bedded the action , and added 1 1/2 lbs. in the fore-stock . First trip to the range , he shoots a 200 - 14x and a 198 - 11x , with Juggs and 4895 at 600 yards . Got him shooting 185 and 200 Hybrids , and 200.20x now , and scores are getting consistent for him .
As Mike and Ned said ; You should find a load somewhere from 43gr. to 44.6 , but caution as you go up . My comp load for 600 is 43gr of Varget with a 185gr Hybrid , and it has given me quite a few high 190's and a couple of 200-20's . Match the speed to the rifle / bullet combo . Forcing stuff may work out for awhile , but cause other issues later on .

 

[Alaska Bush Man]

My favorite load 308 Win
175 Berger OTM
Varget 44.1
CCI Br2 primer
WW brass 2.800 COAL

Really like that Beger 175 OTM

 

[memilanuk]

No reason to restrict yourself to that bullet weight, or that OAL, for FTR...

 

[barefooter56]

Here's the deal. Realistically, I've got 5 days to get this cartridge developed at a 100 yard range to shoot in a 1000 yard match. Otherwise, I'm at the match with 8 boxes of factory Federal Target 175 gr rounds.
I'll work with the info you all have given me and hope for the best.
Long term I will develop a 600 yard round and a 1000 yard round out at my buddy's ranch where we can go a mile.
Thanks everyone, now to the bench.
Forrest

Forrest,
Please let us know if you need any more help on this when you get back 660-460-2802 8am to 4:30pm EASTERN MON thru FRI. One thing you may want to check also is if the tip of the bullet is contacting the base on the bullet seating stem cavity. That can foul up the detail in regards to both CBTO and COAL very quickly.