New rifle issues with finding load

[TimResin]

So just got a .308 built by GA Precision.
Specs to help

Bartlein 1-10 26"
ARC CDG
Area 419 Hellfire
using garmin xero to measure

Brand new lapua lrp brass
210M Primers(they are from 2010)
Varget
Berger 175 OTM

So gun was broken using GA Precision Instructions

Brass prep. Chaffer and debur. then neck size with no mandrel.
Measuring using RCBS charge master. then 10-10 with manual trickler to finish

42.9 es of 35.8 sd 13.4. 9 shots
42.4 es 45.7 sd 15 10 shots
43.5 es 48.5 sd 14 10 shots

All of that was with a 8 pound of varget from 2010
So I opened a brand new 1 pound of varget still sealed bought 2023

43 es 27.8 sd 8.3 10 shots
so I thought bingo I solved it
but for the heck of it my next 11 I used a stand alone .306 mandrel sinclair model on top of the same brass prep
Also I used a K+M Primer Pocket Uniformer on the next set of 100 Brass. Highly doubt that did anything
43 es 41.8 sd 14 11 shots

Im pulling my hair out. So gun has 111 rounds through it, so wondering if the barrel is still breaking in so to speak. Is it because its brand new brass and its fire forming slightly.

I just bought a Erik Cortina FL Micro Die with a .334 bushing. Loaded rounds at .337. I have 200 Pieces, once I have once fired them all I will start using my new die. I plan on selling the neck die.

Thanks for any help

 

[ShtrRdy]

New brass will generally result in a wider spread of velocity readings.

 

[JR1200W3]

Is this all about the SDs and ES? People place too much emphasis on having single digit SDs and mid teens ES. Then they shoot 90% of their targets under 700yds where it doesn't matter.

How are the groups?

 

[TimResin]

Pretty good 4in 10 shoot at 500. Im shooting PRS matches that go out to 1050.

 

[kthomas]

Your ES and SD should tighten up on the 2-3x firing on the brass.

Otherwise, just try to be as consistent as possible - bump the shoulders consistently, seat the bullets consistently, have consistent neck tension, consistent powder throws, etc.

Honestly, there isn't much to it. You are using good quality components, so you are on your way. I wouldn't sweat it too much.

 

[Rocketmandb]

So just got a .308 built by GA Precision.
Specs to help

Bartlein 1-10 26"
ARC CDG
Area 419 Hellfire
using garmin xero to measure

Brand new lapua lrp brass
210M Primers(they are from 2010)
Varget
Berger 175 OTM

So gun was broken using GA Precision Instructions

Brass prep. Chaffer and debur. then neck size with no mandrel.
Measuring using RCBS charge master. then 10-10 with manual trickler to finish

42.9 es of 35.8 sd 13.4. 9 shots
42.4 es 45.7 sd 15 10 shots
43.5 es 48.5 sd 14 10 shots

All of that was with a 8 pound of varget from 2010
So I opened a brand new 1 pound of varget still sealed bought 2023

43 es 27.8 sd 8.3 10 shots
so I thought bingo I solved it
but for the heck of it my next 11 I used a stand alone .306 mandrel sinclair model on top of the same brass prep
Also I used a K+M Primer Pocket Uniformer on the next set of 100 Brass. Highly doubt that did anything
43 es 41.8 sd 14 11 shots

Im pulling my hair out. So gun has 111 rounds through it, so wondering if the barrel is still breaking in so to speak. Is it because its brand new brass and its fire forming slightly.

I just bought a Erik Cortina FL Micro Die with a .334 bushing. Loaded rounds at .337. I have 200 Pieces, once I have once fired them all I will start using my new die. I plan on selling the neck die.

Thanks for any help

General feedback:

- You absolutely should be using a mandrel, especially on virgin brass. Lapua This will be a major contributor to your SDs.

- I see you're uniforming primer pockets, but not deburring the flash holes. K&M makes a good tool for that too. That will impact how quickly the primer charge hits the powder, which impacts initial burn rate, which impacts pressure profile consistency, which impacts SDs/

- SDs on virgin brass will always be on the crappier side of things. I'm still speeding up my barrel using virgin Lapua and 43.5 gr of Varget and Berger 155.5 Full Bore. This was the last 75 yesterday. Slightly better than you're getting, but close. I expect to get mine down to 6-7ish on once-fired.

 

[918v]

So just got a .308 built by GA Precision.
Specs to help

Bartlein 1-10 26"
ARC CDG
Area 419 Hellfire
using garmin xero to measure

Brand new lapua lrp brass
210M Primers(they are from 2010)
Varget
Berger 175 OTM

So gun was broken using GA Precision Instructions

Brass prep. Chaffer and debur. then neck size with no mandrel.
Measuring using RCBS charge master. then 10-10 with manual trickler to finish

42.9 es of 35.8 sd 13.4. 9 shots
42.4 es 45.7 sd 15 10 shots
43.5 es 48.5 sd 14 10 shots

All of that was with a 8 pound of varget from 2010
So I opened a brand new 1 pound of varget still sealed bought 2023

43 es 27.8 sd 8.3 10 shots
so I thought bingo I solved it
but for the heck of it my next 11 I used a stand alone .306 mandrel sinclair model on top of the same brass prep
Also I used a K+M Primer Pocket Uniformer on the next set of 100 Brass. Highly doubt that did anything
43 es 41.8 sd 14 11 shots

Im pulling my hair out. So gun has 111 rounds through it, so wondering if the barrel is still breaking in so to speak. Is it because its brand new brass and its fire forming slightly.

I just bought a Erik Cortina FL Micro Die with a .334 bushing. Loaded rounds at .337. I have 200 Pieces, once I have once fired them all I will start using my new die. I plan on selling the neck die.

Thanks for any help

How did you arrive at those powder charges? What’s your coal? How much did you neck size? Did you use lube to expand the neck?

 

[BenE]

With only 111 rounds down the pipe I’d lean towards the barrel is simply speeding up and should become increasingly more consistent from here on out. Most hand loaders don’t begin load development until 100-200 round have been shot Occam’s razor

 

[Taylorbok]

I'd say the issue lies between barrel settling in and new brass. I'd just load the rest of your brass and go shoot. then come back and try to establish a load.

 

[RegionRat]

Sometimes, we just borescope the barrel and or just clean it really well regardless, and re-baseline some 308 FGMM to see how a new rig does.

Your recipe has been run many times, so that is usually taken off the troubleshooting list. Nothing wrong with double checking everything again or having a fresh set of eyes do it.

If it still doesn't smell right, then I would ring George or one of his folks and get advice. They may ask you to check the firing pin, spring, and function before going farther, but I would also expect them to ask you to baseline test with whatever factory match ammo they use before taking the next steps.

The troubleshooting process is likely to point at something in your prep or loading process just based on how many 308s I have seen from GAP, but it isn't impossible to find something in the barrel or ignition on a rare occasion.

Hang in there. All that stuff is good so stick with it and you will find it. Good luck and in for the range reports.

 

[Dave62677]

Shoot another 100 rd then revisit your reloads. You are not giving up much barrel life of 308.

 

[Rocketmandb]

Shoot another 100 rd then revisit your reloads. You are not giving up much barrel life of 308.

The barrel should be sped up at his current count (110+), and he has once-fired brass. Load dev should be fine now with both of those behind him and a good reloading process.

 

[Taylorbok]

The barrel should be sped up at his current count (110+), and he has once-fired brass. Load dev should be fine now with both of those behind him and a good reloading process.

I’ve found 150 is usually the number where barrel is done doing its thing. Plus he still has brass to fire form.

 

[TimResin]

Still have about 70 pieces of brass to go then they will be all once fired. I just got my Erik Cortina FL Die. Will use that with a .333 bushing then a .306 mandrel. I will use Hornady oneshot lube and see how it goes

 

[TimResin]

Well I everything has been 1x fired.
I used my Erik Cortina FL Micro Die Bumped the shoulder back .0015

9 Shots

ES: 28.3
SD: 7.7
AVG 2626.8

261 rounds through the gun

Im wondering if that ES is ok. My next too PRS matches are at ranges that go to a 1000

 

[kthomas]

Well I everything has been 1x fired.
I used my Erik Cortina FL Micro Die Bumped the shoulder back .0015

9 Shots

ES: 28.3
SD: 7.7
AVG 2626.8

261 rounds through the gun

Im wondering if that ES is ok. My next too PRS matches are at ranges that go to a 1000

That ES is perfectly fine for PRS matches.

ES is not a great predictor of MV anyways. SD is. And an SD of 7.7 is good ammo.

 

[DeathBeforeDismount]

The barrel should be sped up at his current count (110+), and he has once-fired brass. Load dev should be fine now with both of those behind him and a good reloading process.

Every barrel is different. That's bad advice.

 

[diggler1833]

I'll agree that each barrel is different, and will speed up at different points between 50 - 250 rounds.

However I have found that accurate loads discovered at shots 15 - 25 are generally just as accurate as shots 150 - 250. So I'll start my load development while I'm breaking in a barrel. I keep notes...have yet to have to adjust the powder charge more than 1% when shooting virgin brass in a new barrel. That does not mean my velocities stay the same, because they don't. It means that my accuracy is generally unaffected by the barel speeding up.

YMMV.

 

[straightshooter1]

Well I everything has been 1x fired.
I used my Erik Cortina FL Micro Die Bumped the shoulder back .0015

9 Shots

ES: 28.3
SD: 7.7
AVG 2626.8

261 rounds through the gun

Im wondering if that ES is ok. My next too PRS matches are at ranges that go to a 1000

Looks like you're doing a lot of good things with your brass prep. What scale are you using to measure your powder (I didn't see you mention it anywhere here)?

That SD and ES is good to go for PRS, assuming you can repeat that. Though, keep in mind that with 20-30 shots those ES's are very likely going to be higher.

 

[TimResin]

RCBS Charge master then put on a 10-10 scale to verify and trickle if necessary. Im on the waiting list for the Ingenuity Powder System 3.

 

[jsthntn247]

So just got a .308 built by GA Precision.
Specs to help

Bartlein 1-10 26"
ARC CDG
Area 419 Hellfire
using garmin xero to measure

Brand new lapua lrp brass
210M Primers(they are from 2010)
Varget
Berger 175 OTM

So gun was broken using GA Precision Instructions

Brass prep. Chaffer and debur. then neck size with no mandrel.
Measuring using RCBS charge master. then 10-10 with manual trickler to finish

42.9 es of 35.8 sd 13.4. 9 shots
42.4 es 45.7 sd 15 10 shots
43.5 es 48.5 sd 14 10 shots

All of that was with a 8 pound of varget from 2010
So I opened a brand new 1 pound of varget still sealed bought 2023

43 es 27.8 sd 8.3 10 shots
so I thought bingo I solved it
but for the heck of it my next 11 I used a stand alone .306 mandrel sinclair model on top of the same brass prep
Also I used a K+M Primer Pocket Uniformer on the next set of 100 Brass. Highly doubt that did anything
43 es 41.8 sd 14 11 shots

Im pulling my hair out. So gun has 111 rounds through it, so wondering if the barrel is still breaking in so to speak. Is it because its brand new brass and its fire forming slightly.

I just bought a Erik Cortina FL Micro Die with a .334 bushing. Loaded rounds at .337. I have 200 Pieces, once I have once fired them all I will start using my new die. I plan on selling the neck die.

Thanks for any help

Sounds like your brass prep is spot on. However, why did you stop short of 44 grains? Did your reach pressure? There is a well know FTR load for that bullet, brass combo of 46.2gr of Varget with a .090 FB reamer. Ease your load up in .3 gr increments until you see pressure at a .010 jump and I’ll guarantee you start to one hole.

 

[straightshooter1]

RCBS Charge master then put on a 10-10 scale to verify and trickle if necessary. Im on the waiting list for the Ingenuity Powder System 3.

I too am in waiting for that system, though I already have the FX-120i. Based on my experience the the FX-120i, I feel you'll see a dramatic improvement in ES's and SD's once you get it. It's not that what you've got is particularly "bad", it's just that it's a big part of the issue you've been having IMHO (I also have an RCBS ChargeMaster and very well know what the IPS3 will bring to the table for you). For me, this system will not really improve the results I get with my FX-120i, but it well certainly speed things up for me.

 

[TimResin]

thats alot of varget hodgon says max 45 with a 175.

 

[918v]

thats alot of varget hodgon says max 45 with a 175.

and that’s in a Winchester case, not Lapua. I wouldn’t go over 43.5 grains in a lapua case.

 

[Chris1972]

My best load with 178 A-Max and Lapua brass was significantly more Varget than you’re testing. I’ll not make recommendations, but I don’t think you’re there yet.