Concern about twist rate for Berger 105 Hybrids

[marwitz89]

Over the past year, I purchased several different brands of 1-8 twist 6 mm barrels to be used on my 6 mm BRX rifle. Berger recently came out with their update stability calculator that now states a 1-7.25 twist is optimal for this bullet and cartridge. It seems odd as I could not even find a 6 mm barrel with less than 1-7.5 twist. Just curious what result people were having using a 1-8 twist barrel on their 6 BRX with the 105 hybrids. Also curious if anyone tried a 1-7.5 twist and had better results than the 1-8. Just wanted to ease my mind that I don't have 4 barrels that are not going to give me optimal accuracy for my BRX.

Thanks,
Joe

 

[Phil]

Joe,

How long are the 105 Bergers??

Do you have any other 105`s available to compare lengths with???

Sounds odd to me, I`ll go measure a Hornady 105 Amax for you to compare with, it`s the only 105gr. bullet I have.....

Phil.

 

[Phil]

1.2365----1.2385

Darn plastic tips.... ;D

Sorry I don`t have any other samples to take for you, others have used 8 twist barrels with the Hybrids, so I`m skeptical.....


Phil.

 

[spclark]

How long are the 105 Bergers??

1.292" according to a year-old (that's the date I downloaded it; same document's still available) Quick Reference PDF from Berger's website. They're long for their weight, that's for sure.

Still, I get consistent accuracy with them out of a 1:7.8 30" Bartlein chambered in 6XC @ 3,050 fps.

I've been reading Brian Litz's latest work, trying to adjust my thinking in view of his updated research results on stability while my own personal experience suggests I may be shorting myself by working with lower-than-optimum velocities. Barrel-makers may not yet have caught on to recent projectile design advancements, some of which suggest faster twist barrels are worthwhile.

 

[Phil]

1.292......

Them dudes are looong........

I think I`d use a 1:7.8 - 1:75 with those dudes if I was starting from scratch, but if I had a 1:8 I`d go for broke and use it.....

 

[LCazador]

I think Berger is a bit aggressive with their twist rate requirements. That 8 twist should work, but if I were to rebarrel, I'd do a 7.5 twist. I would rather be on the plus side, mentally! If you know what I mean 8)!

 

[EricStecker]

Joe,

Our twist rate recommendations are on the conservative side. The new 6mm 105 gr Hybrid Target is the langest of our 105 gr offerings. It will work in an 8" twist but you will need to be certain that it is in fact a 8" twist. Some barrels may be listed at 8" but might be slower.

The 6mm 105 gr Hybrid Target will work in an 8" twist but it is on the edge so as long as your barrel is an actual 8" twist you will be fine.

Regards,
Eric

 

[marwitz89]

Thanks Eric, I'm pretty confident the barrels are a true 8 twist. I intend to purchase a 7.5 twist in the future but I have several barrels chambered already.

 

[6xcshooter]

have 4 rifles with 1-8 twist all shoot the 6mm 105 hybrid lights out. never seen a problem.

 

[marwitz89]

6xc, what speed are you shooting them at? The brx shoots them around 3050.

 

[6xcshooter]

in 6xc 43 grains h4831sc gets me 3140 fps lights out

 

[r bose]

I had my first 6mm rifle, 6XC, built recently and was advised to use a 7.5 Kriger, 31". I shoot nothing lighter than a 105g and up to 115g's and it hammers anything I put thru it. Some just a bit better than others but all very well.

 

[6xcshooter]

possibly elevation may effect the twist rate, maybe at sea level you may need a 7.5 twist

 

[r bose]

And I live at sea level......maybe below sea level.....New Orleans area

 

[Judd]

I'm on my 3rd 8.5 twist that eats these things like candy and shoots them well. I'm no Sam Hall, Mike Hanes, johara, etc but they'll shoot. Further proof that no matter what the internet, an app or some calculation says you just have to try them.

 

[johara1]

When i set a IBS record with the Berger 105H 3 years ago( Berger never recognized) it was done with a 7.83 to 1 twist from Brux. Setting 4 more records last year with the same twist and other different bullets but the same twist. I tried 9 other 8 twist barrels and many good bullets and came to the conclusion 4 barrels with 7.83 twist shot better than the 9 barrels with 8 twist. Don't get me wrong the 8 twist barrels shot good but every 7.83 barrels shot better and easier, holes looked smaller at 100 and 1000 if you know what i mean…… jim

 

[marwitz89]

At that altitude, the 8 twist according to Berger is fine, I shoot at 800. I ordered a Broughton 5c in 7.3 twist just to be safe when shooting the hybrids. I have other bullets I can shoot in my 8 twist tubes. Don't want to waste money shooting the hybrids in a barrel that's not optimal for accuracy.

 

[johara1]

I saw Jim Richards shoot the smallest group ever in march with the hybrid. Then he shot the highest score ever later in the year. Light gun records both, his is an 8 twist.

I watched Alex turn out the best group aggs ever, 6 and 10 match, heavy gun class both. His is a 7.5 twist.

Both turned in at deep creek range, about 3400 feet, temperature range from teens to 90's.

Tom

Tom, it must be in the air or lack of air may be a better way of saying it…… I even checked the holes at 50 and they are small but not with the 8 twist all the time…… jim

 

[Alex Wheeler]

The smallest group I have shot at 1k is with an 8 twist Krieger with the 105 Hybrid. It shot them well at sea level and 5500 ft.

 

[johara1]

Alex, I'm talking aggs. consistent small groups. The 8 twist don't show me that, maybe one or two good groups. I'm talking 9 different barrels from 3 different barrel makers, all display the same thing. Maybe i got 9 bad ones in a row? I have 2 new 7.83's on the way …… we will see…. jim