1:8” twist 105 hybrids

[Mfitz717]

I am very new to Benchrest so bear with me. I took my 6bra 1:8 twist to a short range br shoot to see how I’d do. There was quite a bit of schooling. One of the shooters there pointed out to me by the holes on my target the bullet is not fully stable. After doing some of my own research and using bergers calculator it says it’s marginally stable.

Going forward is it worth playing with the load, ie more velocity, jammed into the lands, etc.

I believe it’s a 26” krieger, I have the bullets just touching the lands. Loading 30.8 gr varget around 2950 I believe, cci 450 primer.
Thanks.

 

[MDT6BRA]

I’m surprised to hear that it’s not stable in a 1/8. I believe I’m shooting 31.5 varget in my kreiger 1/8 if I remember right

 

[JB10]

I shoot 105 hybrids in a 6br 8 twist at 2700fps perfectly

 

[rwj]

My experience is that the hybrids like a faster barrel twist. One rifle I have has a 8 twist barrel that won’t shoot hybrids very well. Another rifle having a 7.5 twist barrel groups them nicely.

Some report good results using hybrids in an 8 twist. Hopefully, they’ll chime in with some tuning tips!

If they don’t, or their suggestions don’t work for you, try the 105 VLD target bullets in place of the hybrids. A lighter bullet (95 grain) would also help with stability.

Welcome to BR world!

 

[hoz53]

I am very new to Benchrest so bear with me. I took my 6bra 1:8 twist to a short range br shoot to see how I’d do. There was quite a bit of schooling. One of the shooters there pointed out to me by the holes on my target the bullet is not fully stable. After doing some of my own research and using bergers calculator it says it’s marginally stable.

Going forward is it worth playing with the load, ie more velocity, jammed into the lands, etc.

I believe it’s a 26” krieger, I have the bullets just touching the lands. Loading 30.8 gr varget around 2950 I believe, cci 450 primer.
Thanks.

like rwj said i went to 7 1/2 twist in 6br long range gun to stabilize the 105 hybrids. some of the other berger 105s show a better stability factor with 8 tw so you could try that. if you have a new barrel i wouldnt toss it- some 105+ will most likely work…while i have 7 1/2 and 8 twists that shoot good at SR(short range) they are meant for longer ranges. people serious about SR benchrest usually shoot a 6mm in the 68 grain range and 13 or 14 twist (usually a ppc)

 

[1shot]

As I have posted in a couple of previous threads, when you are at the lower end of stability it all boils down to how far you are above sea level. I originally found this when taking a 9 twist 7mm shooting SMK 183 pills to Colorado with a 5,500 ASL and it shot lights out with a high X count. Came back to Ohio where it's 1,050 ASL and the group dispersion was significantly wider with a low x count.
The second time this happened was taking a 6mm 7.5 twist to Missouri (ASL 545) with 110 SMK's. Again, it shot poorly. Back home it did well.
The bottom line is, if you don't travel to shoot most of this is moot. However, if you are on the lower edge of stability at your home range, and go somewhere it's closer to sea level, your results will probably suffer.
I hope this helps,

Lloyd

 

[Mfitz717]

like rwj said i went to 7 1/2 twist in 6br long range gun to stabilize the 105 hybrids. some of the other berger 105s show a better stability factor with 8 tw so you could try that. if you have a new barrel i wouldnt toss it- some 105+ will most likely work…while i have 7 1/2 and 8 twists that shoot good at SR(short range) they are meant for longer ranges. people serious about SR benchrest usually shoot a 6mm in the 68 grain range and 13 or 14 twist (usually a ppc)

I ordered 105 targets and 105 vlds to see if they’d stabilize (per Bergers they would).
I just shot short range cause I wanted to get out and shoot. It was a bad idea cause now I’m thinking about either getting a 13 twist 6br or maybe even a 30 br barrel (I still need to get an action wrench and barrel vise).

 

[hoz53]

I ordered 105 targets and 105 vlds to see if they’d stabilize (per Bergers they would).
I just shot short range cause I wanted to get out and shoot. It was a bad idea cause now I’m thinking about either getting a 13 twist 6br or maybe even a 30 br barrel (I still need to get an action wrench and barrel vise).

is this barrel a new barrel? i think it would be rare not to find a load for an 8 twist new kreiger.
what were you planning on shooting with it? how many times have you shot this gun?

 

[Mfitz717]

is this barrel a new barrel? i think it would be rare not to find a load for an 8 twist new kreiger.
what were you planning on shooting with it? how many times have you shot this gun?

Not a new barrel. Supposedly less than a few hundred shot through it. I have not shot it too much. Previous owner was shooting bart hammers.

 

[Jet]

I shoot Berger 105 hybrids out of a 8 twist Krieger at 500' elevation and they shoot fine

 

[foxguy]

I also shoot 105 gr Berger Hybrids (.030 off the lands) out of my savage 8 twist. They shoot great.
F-Class 600 yards I have shot 198's - 200 scores with high X Counts.

 

[03machstock]

I am very new to Benchrest so bear with me. I took my 6bra 1:8 twist to a short range br shoot to see how I’d do. There was quite a bit of schooling. One of the shooters there pointed out to me by the holes on my target the bullet is not fully stable. After doing some of my own research and using bergers calculator it says it’s marginally stable.

Going forward is it worth playing with the load, ie more velocity, jammed into the lands, etc.

I believe it’s a 26” krieger, I have the bullets just touching the lands. Loading 30.8 gr varget around 2950 I believe, cci 450 primer.
Thanks.

Side note, 30.8 of varget with a 105 hybrid in a 26” barrel for 2950, you have a pretty fast barrel.

 

[SSchnd]

I shot B105 Hybrids in a well worn 1/8 Kreiger at 29" (was set back once from 30") for Mid & Long Range.
31.0 gr Varget was about 2890

Most of the time ran 29.8 gr H4895 at 2850. Nice Sweet Spot there.
Lapua brass jumping 10 to 20 thou CCI450

They shot clean for me one day at 1000 yds. Sling guy but they work in 1/8 twist.

I would not use them for Short Range, pricey bullet for not very far. Has to be a better FB bullet for short range stuff out there. YMMV

 

[a-dog]

I did something similar recently. I shot my 6BRA f class rifle in a 100-200 yard Benchrest match just to get some shooting in. I am shooting 108gn bullets in a 1-8 twist 30" barrel. I did surprisingly well given it was my first br match ever. I think I finished in the top 5 in a field of around 17. 105s will stabilize just fine in a 1-8 twist barrel. I'm also shooting a bit slower than you. I run around 2885 with h4895. When I push above 2900, I see reduced brass life with no increase in accuracy.

 

[Liven The Dream]

Bartlien 1-8 27” 6BR 105 HB 450m 29.8 Varget
Clean a 600 yard F/Class Target
2800 + Vol ?

 

[Fire Dog]

I shot B105 Hybrids in a well worn 1/8 Kreiger at 29" (was set back once from 30") for Mid & Long Range.
31.0 gr Varget was about 2890

Most of the time ran 29.8 gr H4895 at 2850. Nice Sweet Spot there.
Lapua brass jumping 10 to 20 thou CCI450

They shot clean for me one day at 1000 yds. Sling guy but they work in 1/8 twist.

I would not use them for Short Range, pricey bullet for not very far. Has to be a better FB bullet for short range stuff out there. YMMV

Berger makes a 6mm “column” flat base bullet and that would perhaps be more suitable for short range BR.
I’m shooting Sierra 107’s in a 6BR with 30.7gr of Varget giving 2850, jumped 10 thousand in a 1:8, 28” barrel with good results but in F Open and our short range is 300 meters {328yds} on out to 1,000yds. Peterson brass holding well.

 

[dat]

I also shoot 105 gr Berger Hybrids (.030 off the lands) out of my savage 8 twist. They shoot great.
F-Class 600 yards I have shot 198's - 200 scores with high X Counts.

What is the elevation where you are shooting?

 

[6MMsteve]

Try the Berger 90 gr boat tail target they have shot very small in every 6mm I have owned .1's and some .0's give them a try

 

[foxguy]

What is the elevation where you are shooting?

Cadillac Michigan Avg 1315 feet.

 

[JLT]

I've never had a problem with 1:8 twist barrels and the 105 Hybrids. I put a 1:7.5 twist barrel on a Dasher several years ago and my scored went down - not a lot, but noticeably, one or two points over the course of a match. I went back to Brux 4-groove 1:8 on that rifle and it was back to normal. I'm sure it could have been that particular barrel, but the 1:8 has always handled the 105 Hybrids very well.