I actually got the idea from Precision Rifle Blog's article on seating depth. If you haven't read it, it's quite interesting and the thought behind going with 0.060" makes a lot of sense. Basically the cliff notes version is this: There's more forgiveness in the seating depth range from 0.060-0.080" than there is in any other range. So during the course of a match, you're less likely to encounter changes in your load in this depth range.
- Thread starter BoilerUP
- Start date
Do you have a link to the article?
I did my load development at 0.020" off the lands. My groups were well under 1 MOA but not near one hole. I have heard others jumping the 105 hybrids 0.040-0.060" off and having good results.
Here you go:
Bullet Jump Research: Executive Summary & Load Development Tips
This is the last post in a series of articles focused on bullet jump research that has been conduct...
precisionrifleblog.com 
My best groups is with 0.080” jump.
I’m experiencing the same issue. I actually did brass and barrel break in at 32.7g of varget, didn’t get heavy bolt lift with virgin brass.
Now I’m down to 31.5g and still getting heavy bolt lift. I’m at my wits end and about to throw this alpha in the trash.
Good to know I’m not the only one having issues with the alpha brass, virgin was great but from that point forward it’s been a little bit of a wild ride. Heavy bolt lift, inconsistent neck tension to the point that I’ve gone down a bushing to keep the bullets from sliding in/out and the no infamous pressure signs.
I’m about to fireform 500pcs of lapua. I had same issues with alpha.
Some guys I know had to drop down to about 2800 fps with alpha to alleviate the heavy bolt and salvage some of their brass investment.
That’s be the next step/off season project form brass from lapua. I’m happy I only bought 200 pieces to try out instead of going ham with 600 pieces like I wanted.
I only have a .268 bushing for my Whidden die, and I’m getting .0005 neck tension with Berger 105’s. With my (in)experience, this tells me the necks are really thinning out, no?
What charge weights are guys finding this mark at? That was my next step. Im eventually going to switch to Lapua but I don’t have time on my side at the moment. Match in 1 week.
I was running .267 bushing like alpha recommended, but I was able push the bullet in to the case once it was seated. So I dropped down to .266 and that seems to have fixed the slipping but I’ve yet to shoot it to see how they preform. I thought it was a bullets issue but I tried a bunch of different once with the same issue.
I also bought 200 alpha brass for my upcoming dasher build. Just waiting for the match season to finish. I’m going to try RL16 and hopefully do not experience the heavy bolt lift issue
.I have 500 pieces that I am about to start shooting. Has there been any response from Alpha on these issues?
Yes. It’s either user error, gunsmith error, or tight bored barrels.......
They told me everything is with in spec as far as dimensions goes, and maybe lighten up on my amount of should bump, now as for the neck tension I had the stumped
I've been using the Alpha dasher brass for a few months now and experiencing some of same issues. In my main match gun I've gotten all the way down to 30.8 grains of varget with a 105 hybrid going right at 2880. As soon as I got to 31 grains or higher in that barrel I was getting some heavy lift.
In my other rifle I'm actually using 34.5gr H4350 with 110 a tips and getting 2810.
In my other rifle I'm actually using 34.5gr H4350 with 110 a tips and getting 2810.
Hmmm... maybe I’ll download from 31.8 to something a little lighter. I know 31.2 was giving me 2885 but I’m not sure what the groups looked like.
You guys might think I’m on crack, and while that may be true, on the advice of a pretty well known shooter out there I tried his recommended 29.4g of Varget in my Alpha brass and it hammers. I don’t own a chrono so I don’t know how slow it was going, but it shot a 2.5” vertical spread at 800 yards. I shot a 3.4 (.4moa) group at 800 with Berger 105’s. Come up was 6.2mil in a 25” Mullerworks barrel. It also shot tiny groups at 100. Low and behold the heavy bolt lift was gone on a 94* day with 45% humidity.
So take that for what it’s worth. I don’t need to run it piss hot, so I’m ok with the speed, but bottom line there is hope out there for all you guys running Alpha, just dial it back and run it slow.
So take that for what it’s worth. I don’t need to run it piss hot, so I’m ok with the speed, but bottom line there is hope out there for all you guys running Alpha, just dial it back and run it slow.
Attachments
I ran at 30gr to break in the barrel and it was a hammer but slow at 2770, although not having a possible case based catastrophe might be worth the speed.
I've been playing with 200 pcs of Alpha brass and have been underwhelmed. Running 105s, I have a node at 2920 (31.6 IMR 4166 / 31.4 Varget). It won't shoot the heavy 6mms though. At 2810 with 112 Matchburners, I'm running slightly sticky bolt with 31.4 Varget (this is my low low node with Lapua) . Seems like it's ok for the 105s, but won't handle the 110+ bullets. Lapua is just the easy button. No issues, and you can find hydroformed brass for ~$150/100 vs Alpha at $115.
On another note - does anyone have experience with the Alpha Dasher reamer? I'm thinking about just buying that or the PTG Dasher reamer instead of waiting for my customer spec from JGS. Aside from freebore, the Alpha reamer is darn near identical to mine.
On another note - does anyone have experience with the Alpha Dasher reamer? I'm thinking about just buying that or the PTG Dasher reamer instead of waiting for my customer spec from JGS. Aside from freebore, the Alpha reamer is darn near identical to mine.
What’s the freebore on the alpha reamer? I want to compare it to what I’ve currently got in my barrel.
Alpha reamer is .105
I'm currently running .145, but I suppose a throater isn't a big deal
I am going out Friday to shoot the Dasher. The first 10 rounds of virgin Alpha Brass I was running 32.5 g of Varget and no issues. Are you telling me this issues come on the second loading?
That’s when it showed up on me, second firing with a load that didn’t have any issues with virgin brass
Anyone have any experience running H4350 with 115’s?
Messaged them last week. They said look for it to be available in the next couple of weeks!
Awesome, might need to retire the alpha once I get some in hand to play with.
If I had a lot of H4350 powder I need to use up, and wanted to use it in a dasher. What would you expect I would need to get 2850fps for a powder charge? Do you see any potential issues if I'm not looking to get into the 2950+ fps?
How the accuracy?
Who has this brass? I need to order some. I was about to fireform 500pcs of lapua
Only place I’ve seen it so far.
Attachments
Thanks for the advice, that's what I was thinking.
I may need to try some to run next year. I have 500 Alpha I‘m running now. I also was going to FF 400 Lapua.
Got my Peterson in. They are about .0135-.014 neck. Loaded round is .270 and I have a .272 chamber. I have IDOD neck turner, so I’m going to turn them to .012 for .005 neck clearance.
Gonna do 20 to make sure I don’t have the issues I had with alpha dasher. Then gonna load up 200 and use the RO mover clinic this weekend to get my new dasher barrel sped up.
Gonna do 20 to make sure I don’t have the issues I had with alpha dasher. Then gonna load up 200 and use the RO mover clinic this weekend to get my new dasher barrel sped up.
So they have the same loaded OD as the Alpha.
I wonder if all the issue you guys have is because you all run 0.272 or 0.2725 NK combine with an tighter FB overbore of 0.242/0.2425 and probably 0.4705/0.471 base
I’m running a 0.275 NK , 0.244 FB OB AND 0.4715 Base and I have none of the issue you all have.
Who knows. I have had issues even with turned necks. So the neck isn’t the issue. I’ve also had issues with alpha across multiple calibers that did not exhibit issues with lapua or Peterson brass.
I even had issues with Peterson in another caliber so in the end I guess Lapua remains the Gold standard
Me. I'm not having issue as we speak
Other then ejector swipes at mild pressures and neck tension weirdness it’s been pretty solid
Link?
......alpha website.
109’s with 30.0 varget. No load development. Just 30.0 varget with 109 0.30 ish off lands for the first few hundred rounds. Barrel sped up from 2780/90
im building a dasher over the winter for next season. are you settled on 2800 for speed? or do you plan to cook it up a little faster?
Im looking at around 3000 for a goal. I was planning on running it slower but I got a Bartlein barrel with their new metal and advertised to last longer than standard 416ss
I have been running the 6 Dasher in PRS for 2 years (used to run 6.5x47). I chamber my own barrels with a .104" freebore and .272" neck reamer. I thought I'd write a post about my experiences with the 6 Dasher and Berger Hybrids.
They 105 Hybrids are amazing in the Dasher. I have been using 31.0 Grains of Varget in Lapua hydroformed cases. I seat the bullets to jump .020" and never change my seating depth. I usually get 2,880 to 2,920 FPS with this load in a 28 inch barrel. I have used this load in 5 barrels now and never did any load development because it always shoots so good. When I screw on a new barrel it is normal to have groups right around .1 mils. This is certainly good enough for any target in PRS. I load using multiple RCBS chargemasters and my ES and SD are usually around 25 and 6 respectively.
I just recently purchased some 109 Hybrids to try thinking I might shoot them in the PRS finale if I like them better than the 105's. I used the same load as above with 31.0 grains of Varget and I am getting 2,860 FPS with them. They are stupid consistent out to 1,000 yards. I have shot multiple groups from 100 yards to 825 yards that were ~.1 mil. I didn't change powder charge or my seating die setting when switching from the 105's. I measured the distance to touching the lands and I get the exact same .020" jump with the same setting on my seating die. My point of impact at 100 yards was even the same with the 105's and 109's. I shot a 15 shot string over the magneto speed that measured 6 SD and 21 ES.
Quickload accurately solves for my velocity with the 2 loads listed above for the 105's and 109's. Quickload shows the 105 load to be at about 53,000 PSI and the 109 load to be at about 55,000 PSI. This is about as high as I like to push the pressure on PRS loads. The Lapua cases can handle upwards of 60,000 PSI easily, and many loads in this thread are certainly in excess of that, but I have found greater consistency and less frustration sticking with the lower pressure loads.
For external ballistics I have tried both the .292 G7 BC and Berger's custom curve. The .292 BC appears a bit low (.300 is closer) and the standard Berger custom curve seems to also over estimate the bullet drag. I did find a different custom curve for the 109 in the Berger library that exactly matched my drop at 1,015 yards today. This is one of the curves they measured for someone shooting in front of their doplar radar system.
They 105 Hybrids are amazing in the Dasher. I have been using 31.0 Grains of Varget in Lapua hydroformed cases. I seat the bullets to jump .020" and never change my seating depth. I usually get 2,880 to 2,920 FPS with this load in a 28 inch barrel. I have used this load in 5 barrels now and never did any load development because it always shoots so good. When I screw on a new barrel it is normal to have groups right around .1 mils. This is certainly good enough for any target in PRS. I load using multiple RCBS chargemasters and my ES and SD are usually around 25 and 6 respectively.
I just recently purchased some 109 Hybrids to try thinking I might shoot them in the PRS finale if I like them better than the 105's. I used the same load as above with 31.0 grains of Varget and I am getting 2,860 FPS with them. They are stupid consistent out to 1,000 yards. I have shot multiple groups from 100 yards to 825 yards that were ~.1 mil. I didn't change powder charge or my seating die setting when switching from the 105's. I measured the distance to touching the lands and I get the exact same .020" jump with the same setting on my seating die. My point of impact at 100 yards was even the same with the 105's and 109's. I shot a 15 shot string over the magneto speed that measured 6 SD and 21 ES.
Quickload accurately solves for my velocity with the 2 loads listed above for the 105's and 109's. Quickload shows the 105 load to be at about 53,000 PSI and the 109 load to be at about 55,000 PSI. This is about as high as I like to push the pressure on PRS loads. The Lapua cases can handle upwards of 60,000 PSI easily, and many loads in this thread are certainly in excess of that, but I have found greater consistency and less frustration sticking with the lower pressure loads.
For external ballistics I have tried both the .292 G7 BC and Berger's custom curve. The .292 BC appears a bit low (.300 is closer) and the standard Berger custom curve seems to also over estimate the bullet drag. I did find a different custom curve for the 109 in the Berger library that exactly matched my drop at 1,015 yards today. This is one of the curves they measured for someone shooting in front of their doplar radar system.
