Berger VLD 90gr in 1:6 Twist???

[skiutah02]

Sorry to hear of your struggles. Greg is the only person I know personally who did NOT struggle to find the "magic" load for a 1:7, 30 in barrel chambered with the ISSF reamer and the 90vld. I tore my hair out for many rounds (over 1000) to get my first barrel to shoot the 90s CONSISTENTLY well. They are a PITA, BUT when you find the load for your barrel it is a joy to shoot. I bought a local guy's barrel after he gave up trying to find the load for his barrel (he started his project after seeing mine in action). Here is part of the load development I did this week fine tuning that barrel after getting a new lot of varget (4 shot groups at 100). This lot of varget is quite slow compared to previous lots. The 24.8 load is in the zeros.
I can't do better than that. My first two barrels liked about 0.007" jam. This one is over 0.020 jump. The bullet is very sensitive to seating depth. The lower group was my old charge and I used up the last of that powder shooting a Palma match on Sunday. Cleaned the 800 yd target with 8xs fireforming brass...

Drew

 

[jsthntn247]

My bto measurement is 2.105 with the 90's. Looks like I'm 60k longer than yours. What velocity is 24.8 giving you Drew.

 

[Ned Ludd]

My bto measurement is 2.105 with the 90's. Looks like I'm 60k longer than yours. What velocity is 24.8 giving you Drew.

Brad, unless you're using a caliper insert with the exact same diameter hole as Drew, it's pretty hard to directly compare CBTOs. I use the Hornady insert, which is quite a bit smaller that some others, so my numbers would be completely meaningless to anyone using a different insert. My COAL with the 90s is 2.641" with the bullet seated at ~.018" off. How fast were you pushing the 90 SMKs last week? Obviously they were shooting extremely well. Due to the increased temp in the Midwest from San Diego, I backed my load off a tenth to about 2840 fps (at ~75 degrees F), figuring the extra 10-15 degrees would bring it back to about 2850 fps.

Edited to add: any possibility you could make it up to NE for the match in August? I know it's a heck of a long trip, but it sure would be a blast to have you, Gene, Drew, and myself all battling it out with the .223s!

Looks like you have the 90s hammering, Drew. Very nice! I'm pretty much of the same opinion...when I find the right spot, the rifle will shoot much better than I can, pretty much the limiting factor is how small is the group I can shoot that day. I sometimes wonder if everyone really appreciates how much of a confidence builder having a rifle/load shooting that well can be when you step up to the firing line.

 

[stacy]

Im no expert but i couldnt ever get heavier bullets to shoot out of a 7 twist either.

YOU MAY NEED TO TRY A X-CALIBER BARREL AND YOU'LL CHANGE YOUR MIND!!!!

 

[Mozella]

.............. snip........... Here is part of the load development I did this week fine tuning that barrel after getting a new lot of varget (4 shot groups at 100). ....... snip.......Drew

Thanks for the info. What are the particulars of the barrel you're using and what MV are you getting?

 

[stacy]

IM NOT SHOOTING A STANDARD 223 BUT I SHOOT A 223 ACKLEY WITH 1/7 WITH 90GR BERGERS AND IT SPOOKY ACCURATE HAVE NOT SHOT PAST 200YDS YET JUST STARTED THE HEAVY THING VARGET SIMS TO DO WELL FOR ME ALSO IS DOING 2850 2900 FPS BUT ITS MAKING BUGHOLES 28'' X-CALIBER BARREL !!!

 

[skiutah02]

My bto measurement is 2.105 with the 90's. Looks like I'm 60k longer than yours. What velocity is 24.8 giving you Drew.

I'll have to get back to you on the velocity at 24.8. The old lot with 24.7 gave me 2835 at 80oF but the new lot at 24.7 showed 2767, but only used a Magnetospeed shooting into the dirt when I did that check. I moved to testing accuracy at target and did not have MS on for the pictured shots. I do know that I had to go up 0.6 gr in my 308 with 185s to regain the velocity. My COAL at 2.074 BTO is 2.665 in so looks like 2.633 COAL on that round. I'm on the road so this is from memory. Drew

 

[skiutah02]

Thanks for the info. What are the particulars of the barrel you're using and what MV are you getting?

See just above about MV, but barrel is a Bartlein 4-groove, Heavy Palma finished at 30 in, 1:7 tw. Chambered with the notorious ISSF reamer. On Savage action.

 

[jsthntn247]

Brad, unless you're using a caliper insert with the exact same diameter hole as Drew, it's pretty hard to directly compare CBTOs. I use the Hornady insert, which is quite a bit smaller that some others, so my numbers would be completely meaningless to anyone using a different insert. My COAL with the 90s is 2.641" with the bullet seated at ~.018" off. How fast were you pushing the 90 SMKs last week? Obviously they were shooting extremely well. Due to the increased temp in the Midwest from San Diego, I backed my load off a tenth to about 2840 fps (at ~75 degrees F), figuring the extra 10-15 degrees would bring it back to about 2850 fps.

Edited to add: any possibility you could make it up to NE for the match in August? I know it's a heck of a long trip, but it sure would be a blast to have you, Gene, Drew, and myself all battling it out with the .223s!

Looks like you have the 90s hammering, Drew. Very nice! I'm pretty much of the same opinion...when I find the right spot, the rifle will shoot much better than I can, pretty much the limiting factor is how small is the group I can shoot that day. I sometimes wonder if everyone really appreciates how much of a confidence builder having a rifle/load shooting that well can be when you step up to the firing line.

I'd really like to make Ne but it's a little far and I'm shooting a tactical match that weekend that I'm paid up for. My coal is 2.705 with the 90 Bergers. I was shooting the smk's at 2780, one node below what y'all are using.

 

[XTR]

My first attempt at shooting them with N550 and 2000MR in Mcgowan prefit that I throated was an abysmal failure, but that effort was snake bit. At various times over about a yr I found a loose scope, loose action screws among other things. It sits in my safe now, 700+ down the tube and I never found a load for it. (I may try again someday)

My Lilja barrel I found where my load was going to be in two load series, the first one I started too low, and had to run another charge weight series to get to where I needed to be.

 

[raptor1ronin]

I'm jumping my 90VLD .20 off the lands in a Bartlein 32" HV Palma 1-6.7 TWIST with 24.3 Grains of varget. This gun is scary accurate it helped my achieve a record at the SWBN 2016 at 600 yards. My FPS is 2820. The picture below was work up . I stopped at 24.3 because 4 shots went through the same hole. Did'nt even bother to try different jumps because it like .20 off the lands so much.

 

[VaRandy]

My F/TR rifle has a 1:7 twist barrel 26" long. The last ten Berger 80gr VLD five-shot groups average .219 MOA @ 100yds. I think it shoots OK and I usually place in the top 3 and have my fair share of wins in 600yd F/TR matches using the Berger 80s.

However, I'd like to shoot the Berger VLD 90gr bullets I recently began testing. The best 10 five-shot groups with the 90s average .701 MOA, not so good.

I had similarly poor results with some Sierra 90gr bullets I tested last winter using a variety of powders. With the Berger tests I've run so far I'm getting about 2600 fps at 10% over max published charge weights using Vihtavuori N-140 and CFE-223. Those loads show the hints of primer flattening and I hate to jam more powder in the case in search of more MV.

I'm considering a new 30" barrel, but I'm not sure if I want a 1:6 twist or if I should stay with a 1:7 twist. Of course I would hate to order a new 30" 1:7 barrel in hopes that length alone will give me enough MV to find the accuracy I'm after and then find out it doesn't do the job.

I know some people have success shooting 90s with 1:7 twist barrels but I'm curious if anyone has switched to a 1:6 twist barrel in search of better performance.

Berger claims 1:6 is optimum and their on-line twist calculator claims a 1:7 might shoot OK groups but with a reduced B.C. I'd settle for that except that I haven't so far found a recipe which will shoot acceptable groups with the 90s.

Comments?

 

[VaRandy]

My F/TR rifle has a 1:7 twist barrel 26" long. The last ten Berger 80gr VLD five-shot groups average .219 MOA @ 100yds. I think it shoots OK and I usually place in the top 3 and have my fair share of wins in 600yd F/TR matches using the Berger 80s.

However, I'd like to shoot the Berger VLD 90gr bullets I recently began testing. The best 10 five-shot groups with the 90s average .701 MOA, not so good.

I had similarly poor results with some Sierra 90gr bullets I tested last winter using a variety of powders. With the Berger tests I've run so far I'm getting about 2600 fps at 10% over max published charge weights using Vihtavuori N-140 and CFE-223. Those loads show the hints of primer flattening and I hate to jam more powder in the case in search of more MV.

I'm considering a new 30" barrel, but I'm not sure if I want a 1:6 twist or if I should stay with a 1:7 twist. Of course I would hate to order a new 30" 1:7 barrel in hopes that length alone will give me enough MV to find the accuracy I'm after and then find out it doesn't do the job.

I know some people have success shooting 90s with 1:7 twist barrels but I'm curious if anyone has switched to a 1:6 twist barrel in search of better performance.

Berger claims 1:6 is optimum and their on-line twist calculator claims a 1:7 might shoot OK groups but with a reduced B.C. I'd settle for that except that I haven't so far found a recipe which will shoot acceptable groups with the 90s.

Comments?

I would not consider the 6 twist and all the money that gamble brings. I am sure you can find someone that can once an for all tell you of their success. If not, being a pioneer can be expensive. I would remind you that rpms is what you are really tracking (result of a certain speed and a certain twist). I shoot 80 grains at 3560 without problems but my moly bullets and 3 land barrel bay be significant. I will see what I can do with the 90s but not for several months from now I suspect. I suspect a 7.5 with a higher speed (3100 or better) would work fine but the aforementioned placement off the lands is critical and I find most people are too lazy to find it. I know the 3 wide land barrel (Lilja) is a big player in not malforming a jacket.

Good luck to you.

 

[Ned Ludd]

Randy, what parental case (cartridge) are you using to drive an 80 gr .224 bullet at 3560 fps? In F-TR, the cartridge can only be a standard .223 Rem or .308 Win. If you know of a way to obtain 3100 fps with a 90 VLD in .223 Rem (other than using a 39" barrel), I'd love to hear what it is. Most people using the 90s in F-TR have found an upper limit in the 2850-2900 fps range with single base powders, although it's possible to scratch out a little more than that with double base powders. Any faster than that and the primer pockets are gone in a single firing.