Range Report Load workup question... Signs of pressure or not? What next?

[ultrarunner7]

Ok fellas. Im new to this and have a few questions.

Brass Prep
After firing my brass, they measure between 1.573-1.575. I then bump the shoulder back .004 to 1.569(+/- .001). I then trim them to 2.005 with a Wilson case trimmer. I'm not turning the neck yet(waiting on it in the mail). Cleaning with stainless media, trim, clean primer pocket, debur and chamfer

Weapon
GAP-10 .308
20 inch Bertlein Barrel

Wx
Temp: 93F
BP: 29.30
H: 48%

Chrono
V3

Load 1
178 AMAX 2.170
Lapua Brass 2.005
Varget Powder
CCI Primers

Wt(gr) V(fps)
43.3 2578
43.6 2571
43.9 2581
44.2 2599
44.5 2617
44.8 2638 (Primer fell out once it cooled)
45.1 Did not fire

Questions
1. Where would you say "the node" is? My guess is around the start at 43.3 and 43.6.
2. Some of the primers look flat, showing signs of pressure and some don't.
3. Where would you go next? My guess is to tighten the screws around 43.0 - 43.6 doing .1 grain increments. What after that?

In picture, loads run low to high, top to bottom in the picture. ex: 43.3 gr is on top...


Load 2
185 Berger Juggernauts 2.126
Lapua Brass 2.005
Varget Powder
CCI Primers

Wt(gr) V(fps)
43.0 2515
43.3 2542
43.6 2540
43.9 2570
44.2 2583
44.5 2606
44.8 2614

Questions
1. Where would you say "the node" is? I see it at 43.3 - 43.6. It was my understanding, I would see a node right before I see pressure. Again, the primers look randomly flat. I had no blown primers. I would expect to see pressure at a lower powder setting than I did with the 178 AMAXs... I dont see it.
2. Again, where would you go next? Tighten the screws around 43.3 - 43.6 doing .1 grain increments. Again, what after that?

Again, loads run low to high, top to bottom. ex: 43.0 gr is on top...


Any other supporting information thats needed, fire away. Thanks mates.

 

[ultrarunner7]

Beuller? Beuller?

 

[MajorHeadTrauma]

Your load is a bit hot.

To identify the appropriate load, we need to see your target results.

Have you followed an OCW method? If not, give it a read. You are best to start your loads near 41 grains.


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[ultrarunner7]

Your load is a bit hot.

Noted. Ill work them on the low end. I did a workup yesterday on the lower end. I will post data.

To identify the appropriate load, we need to see your target results.

All of these were shooting between .25-.75 MOA. Its my understanding that if you are using a chrono, you dont need to get caught up in punching paper. Just find your nodes and then tighten the screws(dial in in that area with smaller grain increments) and then punch paper once youve dialed it in in that area(the node).

Have you followed an OCW method? If not, give it a read. You are best to start your loads near 41 grains.

I have not. I will give it a read. Im looking at it now...

Thanks a lot bro.

 

[agbm]

Only my .02 I would try some winchester brass, may ease on compaction of powder. You are putting a whole lot of varget in a little lapua case and if you compare it to a winchester case you will see a big difference between the two. I would use a 6 inch drop tube to help. If you by chance have any Alliant AR-COMP or Alliant 2000-MR they may work better. Hodgdons website is using Win brass and at your next to lowest starting loads you are seeing pressure signs with lapua brass. I've learned low volume capacity brass will create pressure's than when I'm using high volume capacity brass with the same grains of powder!!!! Also if you plan on using lapua brass only start at the MIN grains on hodgdons website and work the loads up from there.

 

[ultrarunner7]

Right on man. I've some Winchester brass and I may give it a whirl. Just to be clear, I already did a workup from the minimums to 44gr in the past. I just didn't see signs of pressure so wanted to push it a bit.

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[Advokaten]

Not that my imput has the weight of a sledgehammer however, the brass in the Pictures above has been subjectet to massive over preassure and it just ready for the trash bin, I would guess that primers seat real easy and deep? //Chris

 

[rduckwor]

Some very serious ejector marking on some of those cases. How are you measuring charge weight? Do you have a known good scale? Go carefully as you appear to be very close to the edge with those loads/rifle combo. What was your bolt lift like on those higher charge weights?
Advokaten is right. Some of those upper cases are now scrap.

 

[ultrarunner7]

Im using an RCBS Chargemaster Dispenser/Scale Combo. I calibrate it every time and check the loads on a beam scale every five or so rounds as a backup. Its always been spot on. Its a gas gun man... no bolt lift.

I know that gas guns are tough on brass(ejector pin, etc). The military gas guns Ive run for years beat the hell of brass as well and the 118LR is pretty damn tough(showing ejector pin marks, etc). Ive had ejector pin marks like this on just about everything in this gun. In the past, Ive just taken a small file and deburred the face a little and they work fine after that. Ill check them out closer before scrapping them... but youre probably right. Im gonna do another workup starting at 42 of varget and work up to 44 in .3 grain increments.

It was also 93degrees, a black gun sitting in the sun, in a warm chamber. I should slow down my rate of far while testing. I didnt wait a specific set time between firings when I think I should.

I also check the primers on some loads I worked between 42-43.5 and the primers look flat as well(same brass, bullets, etc). They arent pushing into the bevel coming out of the primer pocket though like these are... which is probably a pretty good sign Im at my limits here. Thanks a low for your feedback fellas. Cheers mates

 

[stinkyDrunk]

Suggest you consider a lower weight projectile, maybe in the 150-155 grn range. It appears your rifle is running higher than typical pressure pushing those heavier pills.

 

[Advokaten]

Missed out on the fact it was a gasser, perhaps you should shoot the brass once or tvice and then just leave it, I know of people that handles the "problem" that way. /Chris

 

[ultrarunner7]

Advokaten
Ive got some Lapua brass that is at 5 firings and is still running great and have a few friends that are getting 8 firings from them. The face looks pretty beat up like this once fired but it cleans right up. I just file down the extracter pin dents and its good to go. Accuracy is good still and is within specs. Im getting between .10 - .30 MOA with 43gr of IMR 4064 with 175 SMK. The funny thing is it likes to be jammed in the lands.
I would agree with you though, the last few are more than likely trash now. Im going to really inspect them.

Stinky
I run 175-178s and it does well. George at GAP recommends the 175s. I run 43.3 of Varget behind the 178 AMAX and get between .10 and .40. I fired it to 600 yds and got .3 MOA groups there.

I just didnt see signs of pressure at the lower powder settings but was seeing a velocity node. I wanted to push to pressure and look for the second node you typically see right before pressure and have two ranges to load in. Ill just keep it =/< 43.5gr ... thats for sure. If you look at the first primer in the 178AMAX pic, it appears to be ok. Also, with the 185 Berger Juggernauts, the first two look ok.

 

[rduckwor]

Yeah, I missed the fact that is was a gas gun as well. Actually, the first two cases in both groups look O.K. If you have a node at <44 Gr., learn to love it. It looks like the higher charges are working your bolt pretty hard.

Good Luck and show us some targets.

 

[ultrarunner7]

Thanks rduck. Bumping back to work those nodes(around 43.3 in both). Im also gonna do an OCW as well then just confirm at distance. I need to make a mobile reloading bench to take to the range so I can just crank them out behind my jeep! Thanks mates. Pics to come.

 

[ultrarunner7]

Great load testing today. Update to come

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[NachtKracht]

Are you actually only using one shot per load? How does this work if i may ask?
I am wondering how you can get any accurate information from load development when only firing one round per load...and what do you need the chrono for? Are you looking for a node in accuracy, or in velocity, or both?

Not to be critical, just trying to figure out if i have missed something or might learn something new.

Kind regards,

NK