Consistency, or lack thereof

[WeR0206]

Sounds like maybe something might be up that's not related to charge weight..?

Something seems wonky. I don't own/run a .308, but just by pumping what you've shared about your load into Hogdon's load data site, with 168s and Varget, it doesn't appear ~42gn should be showing pressure (and while some primers are better than others as far as consistency, IDK if different primers really matter much as far as pressure/MV IME, so I wouldn't even factor that in or worry about that as long as they go bang).

View attachment 8723305

When's the last time you pulled out the borescope and looked at your chamber? Remember, Varget means awesome, but it also means a carbon ring you have to stay on top of...

For cross reference here’s sierra’s load data. Looks like they have max for varget at 45gr @ 2,750 fps. I wouldn’t expect him to be getting sticky bolts at 43 grades either but I guess each chamber and barrow is unique. As you said there could be a carbon ring or something.

 

[flogxal]

Yep. Took a break from the sport for a while, but hit the LR Regional last fall, and it's on the list for September this year as well.

That's my home range, but I avoid it on match weekends as they are always using either the 600yds or 1000yds, and I don't know any of the local BR shooters.

 

[memilanuk]

That's my home range, but I avoid it on match weekends as they are always using either the 600yds or 1000yds, and I don't know any of the local BR shooters.

Not a BR shooter (yet).

There were a couple spots open for the LR Regional in September, as of a few days ago.

 

[Josh Umsted]

Yes you’re correct on that but also, If you have variation in case length or bullet length it causes variation in the seating depth in the neck which causes variation in pressures/velocity. More depth = more pressure.

I never realized this connection before playing around with gordons reloading tool and learning the different relationships between all the different inputs and outputs. IMO the scientific fields that would help one best understand reloading and precision shooting would be systems engineer & statistics.

Yup. I was good at stats in college. Had a good teacher, and was good enough at science to at least understand methodology and figure out a computer program. Spent my career in behavioral science.

 

[Maurygold]

Opinions on click-adjustable sizing dies? Looking at Whidden. Hate to spend the money but it would speed up my process. Whidden offers dies with or without bushing for the same price. If I went with a bushing die rather than expander mandrel, that would really refine my process. Wonder if the bushing in the Whidden die can be removed if I don’t like it, or just go with the FL die. Will ask Whidden before ordering.

bushing dies are FL dies. The click adjustable just moves the die up and down for bump. you should get the bushing die. you do not need a mandrel. but if you later choose to use one you buy a smaller bushing and then expand with the mandrel.

I'm guessing you're new or newer to relaoding in which i highly recommend you just use a bushing die no mandrel as it is entirely possible to shoot 5-8 SD without ever touching a mandrel

 

[Josh Umsted]

Sounds like maybe something might be up that's not related to charge weight..?

Something seems wonky. I don't own/run a .308, but just by pumping what you've shared about your load into Hogdon's load data site, with 168s and Varget, it doesn't appear ~42gn should be showing pressure (and while some primers are better than others as far as consistency, IDK if different primers really matter much as far as pressure/MV IME, so I wouldn't even factor that in or worry about that as long as they go bang).

View attachment 8723305

When's the last time you pulled out the borescope and looked at your chamber? Remember, Varget means awesome, but it also means a carbon ring you have to stay on top of...

I used Hodgdon data until learning GRT. It wasn’t in line with reality. They tested with different brass. In hindsight, it was a headspace issue. That was probably before I learned about shoulder bump, and how changes to brass dimensions effect pressure.

The rifle is due for cleaning. Maybe 200 shots down the tube since last cleaning, and a light one at that, using only hoppes #9. I’ve been cleaning pretty religiously with thoro clean/flush. 200 rounds is the most I’ve shot between cleanings. Don’t have a bore scope yet. Need an adjustable sizing die first. My sizing technique has improved, but my Redding die is hard to adjust. An adjustable bushing die will save a bunch extra steps, and with the right bushing, potentially eliminate need for the mandrel. Deprime, Fl size, prime and expand are each separate steps and I don’t like it. One die can do all that, except prime, which I do on the press anyway.

2700 fps seems to be a happy place for the bergers. Sierras liked that velocity, too. They also seem to like 2630ish. 2700 is achievable at about 43.6 grains of Varget if other pressure factors are better controlled. Not too concerned with brass or barrel life.

 

[JerkyFreak]

.308 with Lapua brass use a .336 bushing and your done.

Never saw the need for an adjustable bump die. The die body has a 14TPI thread. 1/32 turn is approximately 2 thou. Seems easy enough to measure the shoulders and adjust any die to get the required 2 thou jump. Then lock it in place. I have a sizing die for every target rifle and a general die for playing around with my hunting rifle.

Haven't annealed my brass either. Still get the required bump within 1 thou without having to adjust my sizing dies. And I challenge anybody to show me results on how a difference of 1 thou shoulder bump screwed their precision.