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

[Mozella]

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?

 

[Ned Ludd]

I'm using a 30" 7-twist and it's plenty precise out to 1000 yd. I estimate I might be giving up a couple percent maximum theoretical BC, but it shoots just fine. In the future, I will likely go with just a bit faster twist, maybe 6.5 to 6.7 or thereabouts. I think 6.0 twist would be much more than you need.

Most of the folks that have had issues with the 90s ultimately found the right combination of velocity, and especially seating depth, to be essential to get them to shoot. I'm seating them around .018" off the lands. However, others have found they needed to be .005" off, .005" into the lands, even .010" or more into the lands. In my hands, 90 VLDs seated .010" into the lands shot "ok", maybe 0.5-0.6 MOA, but not "great". I testing, I found that once the seating depth got to about .012"-.015" off the lands, the groups tightened up very nicely. I would recommend a seating depth test; i.e. test between perhaps .025" off and .010" or so into the lands in .003" increments, if you can stand to test that many rounds. Be aware that moving the bullet into the lands may cause your pressure to spike, so a reduction in charge weight for the jammed bullets will likely be in order if you've only been jumping them so far. In any event, every rifle seems to be different in its preferences and I think you'll find that rigorous seating depth optimization will pay dividends in terms of precision with the 90 VLDs.

 

[Sniper338]

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

 

[boltman223]

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

Did you ever figure out what the problem was? I suppose it would be more of a guess since you never got them to shoot.

 

[chkunz]

"Better" is the mortal enemy of "good enough". But then that is no fun either. I am considering trying 90s with a 1 in 7 but I know it may be another research project. Good luck with your project.

 

[spclark]

I shot 'em years ago in a service rifle 20" barreled with a 1:6.5 PacNor. They shot OK @ 600 yards. Have a friend who tried same combo at 1,000 as a 'Palma rifle' & did OK too considering the short sight radiused iron sights.

I'd hesitate jumping to 1:6 though if you can use a 1:6.5 twist 26" - 32" barrel (shorter being preferred to avoid too much friction / barrel dwell time potentially melting inner lead core) with a node that stabilizes nicely.

Over-spinning at speed will cause anything to fail unless maybe you've ordered a custom, shallow-lands barrel (less jacket & core deformation) or you're really lucky....

 

[eric n]

I shoot the 90 smks in a 30" 7 twist. Like gstaylorg said, seating is critical. I found decent results 10 thou in from touch but better 20 thou out.
I know this isn't what you want to hear, I found more consistency running them harder.
I would get erratic vertical in the lower nodes although I never put a lot of effort exploring different powder/ primer combos. I just use 1 barrel for the 90s and another for the 80vld.
I can't get the 90s to shoot as well as the 80vld at 100 but at 600 the 90s are more forgiving in the wind.

 

[r bose]

Never shot spectacular groups at 100 yds with the 90's but when I test them at 300 yds the groups hold up well, under 1/2 MOA. I think the long bullets need some room to settle down. Test at longer ranges before giving up on them. Just My opinion.....been shooting them since 2006.

 

[jsthntn247]

I'm using a 30" 7-twist and it's plenty precise out to 1000 yd. I estimate I might be giving up a couple percent maximum theoretical BC, but it shoots just fine. In the future, I will likely go with just a bit faster twist, maybe 6.5 to 6.7 or thereabouts. I think 6.0 twist would be much more than you need.

Most of the folks that have had issues with the 90s ultimately found the right combination of velocity, and especially seating depth, to be essential to get them to shoot. I'm seating them around .018" off the lands. However, others have found they needed to be .005" off, .005" into the lands, even .010" or more into the lands. In my hands, 90 VLDs seated .010" into the lands shot "ok", maybe 0.5-0.6 MOA, but not "great". I testing, I found that once the seating depth got to about .012"-.015" off the lands, the groups tightened up very nicely. I would recommend a seating depth test; i.e. test between perhaps .025" off and .010" or so into the lands in .003" increments, if you can stand to test that many rounds. Be aware that moving the bullet into the lands may cause your pressure to spike, so a reduction in charge weight for the jammed bullets will likely be in order if you've only been jumping them so far. In any event, every rifle seems to be different in its preferences and I think you'll find that rigorous seating depth optimization will pay dividends in terms of precision with the 90 VLDs.

If only you could learn to shoot them then you would be unbeatable :0

 

[Ned Ludd]

If only you could learn to shoot them then you would be unbeatable :0

I know...I dropped 5 points in that last match alone...more than the whole rest of the matches combined. I really need to get serious about practicing more .

When you going to switch back to the VLDs from the SMKs? Didn't you tell me you were able to pick some up VLDs recently? I have a large batch on order, supposedly they should be ready beginning of August. Not sure why my order wasn't filled from the recent production run, I placed it in back in Jan/Feb. It's ok because I still have a few. Hope your drive home was smooth and relatively painless.

 

[skiutah02]

I know...I dropped 5 points in that last match alone...more than the whole rest of the matches combined. I really need to get serious about practicing more .

When you going to switch back to the VLDs from the SMKs? Didn't you tell me you were able to pick some up VLDs recently? I have a large batch on order, supposedly they should be ready beginning of August. Not sure why my order wasn't filled from the recent production run, I placed it in back in Jan/Feb. It's ok because I still have a few. Hope your drive home was smooth and relatively painless.

My bullets.com order placed in mid-Sept was only partially filled.....

 

[jsthntn247]

I had an email when I got home that they will ship this week. Ride home was good, I thought about driving back up for the Thursday match but can't. I'll try jumping them some in the high node and see if I can make them work. I'm looking forward to you and skiutah battling it out in Nebraska.

 

[Darrel Martin]

I have a 7 twist 223AI with .175 freebore that I set up to shoot 90 vld's. I used Varget , got my velocities up around 2850 pretty easily, but half inch groups.I would vary seating depth in the usual ranges of 10 in to 20 out and groups would go from a half inch vertical ,to a half inch triangle ,to a half inch horizontal .I tried 80 vld's and got good groups. I was on the verge of giving up on the 90's but decided to try Berger's suggestion to go out to jump of.040, .080 and .120.After some tinkering, lo and behold at .064 out it started to shoot.

 

[Ned Ludd]

Darrel,
But at .064" off, aren't you giving up quite a bit of that .175" freebore? I went with the .169" fb ISSF reamer from PTG and find that at approximately .015"-.020" off, the 90s boat tails are just barely above the neck/shoulder junction. At 2850 fps with H4895, pressure and brass life are most definitely a problem; I'm getting only 3, maybe 4 firings from Lapua brass. Varget likely won't run the pressure up quite as high as H4895 so you may be ok. Just curious.

 

[Ned Ludd]

I had an email when I got home that they will ship this week. Ride home was good, I thought about driving back up for the Thursday match but can't. I'll try jumping them some in the high node and see if I can make them work. I'm looking forward to you and skiutah battling it out in Nebraska.

It will be fun shooting with Drew again. Gene and possibly a couple others will probably be there as well. Wish you could come up and join the fun, but that'd be a really, really long drive.

 

[Darrel Martin]

Darrel,
But at .064" off, aren't you giving up quite a bit of that .175" freebore? I went with the .169" fb ISSF reamer from PTG and find that at approximately .015"-.020" off, the 90s boat tails are just barely above the neck/shoulder junction. At 2850 fps with H4895, pressure and brass life are most definitely a problem; I'm getting only 3, maybe 4 firings from Lapua brass. Varget likely won't run the pressure up quite as high as H4895 so you may be ok. Just curious.

I have not shot this enough yet to know how brass is going to hold up, but after load work up primers still feel ok going in.You make a good point about giving up a good bit of freebore.I was just glad to find a load that grouped at 100 yards and held up when I moved on out to 4-500.I did not go back and really look at a loaded round to see where bullet is located in relation to the base of the neck after finding the load at .064'' off the lands.It is probably a little lower than I want ,but if it continues to shoot good I will likely just pinch my nose and keep on shooting it.

 

[XTR]

My 1:7, 28" Lilja shoots 90vlds like a laser out to 600. I think my 300 yard load test groups ran .25 to .3 something vertical. At 300 yards I will typically shoot ~75% X counts in F-TR.

I don't know what reamer you have used to chamber your rifle. Getting something in the range of .169 seems to be the righht answer for almost everyone who tries them.

As Greg states above, he has good results jumping, I jam .010.

Not sure of the powders you have tried. I know for a fact that H4895 and Varget work. The majority of those who have success use Varget, loading 24.5± .2 grains. (with the associated freebore mentioned above) The number running with Varget may in part be that it's what most TR shooters run in the 308s and they hacve it.

I've been on the line and talking to the other guys with 223s found that we were all running the exact same load. (the only difference being I run Lake City brass and most others shoot Lapua) Velocity for most folks is in the vicinity of 2800 again give or take a little.

I have not had the chance to experiment with H4895 with the 90VLD (Greg has), though I have used it with the 80Amax. My Amax load is over a case full of the stuff and it shoots extremely well. I have a bunch of 80Amax's that I want to use up so I shoot them at 300 when I get the chance. (the point being H4895 should work just as well as Varget in this class of bullet)

 

[1911mag]

A Bartlien HV 1:7 twist 30" will shoot both 80 and 90 VLD's just fine. Like other posts above I would advise get PTG .169 freebore reamer. Then comes the testing process. I use N150 with CCI 450 primers in Lapua brass. After 5 or so firing I have it annealed. Seat depth is one of keys to getting them to shoot good.

 

[vmaxpro]

My 28" 7 twist shot the 90s well with varget with either a huge jump of .144 or a heavy jam of .030. Either one would shoot .1's or less. Anything in between would be an inch or more. I gave up on them after I started printing 1.5" groups at 600 with 75gr amaxs sorted.

 

[Mozella]

PROGRESS REPORT: I made another load work-up consisting of 50 rounds of Berger VLD 90s using two additional powders (CFE-223 and Vihtavuori N-540) with charge weights up to 110% of max published data resulting in a MV as high as 2814 fps. Again the results were disappointing with the best 5 shot group of .369 MOA @ 100yds but most groups worse than 1/2 MOA and one group of 1.080, all with a jump of .030". I didn't want to give up quite yet, so I loaded 35 rounds using the best performing powder (CFE-223) at various seating depths from .120" Jump to .010 Jam.

This time the best group was a disappointing .508 MOA at .010" Jam and a worst of .845 MOA at .064" jump, all shot in dead calm conditions. To my disgust the best group of this test sequence was from my fouler rounds which were a mixed batch of 69gr SMKs loaded for plinking in a completely different rifle using a mechanical powder dispenser (not weighed). They shot .241 MOA. This gun wants to shoot, even with the junk ammo, but it does NOT want to cooperate with the Berger 90s.

So, I've given up on trying to shoot the 90s from this barrel. After a chat with the Berger folks I went ahead and ordered a 30" 1:6.5 twist match barrel. Until it arrives, I'll stick with the Berger 80s which I can expect to shoot 1/4 MOA on a regular basis.