Question for Mr Holland

[1967spud]

Laurie did you ever go the 6mmbr-dx route?

[Laurie]

Hi Mark.

 

Sadly no. Vince and I gave up on the idea as it was taking an age to get a DX reamer at the time. Instead, Vince came up with a slightly bastardised Dasher using a .243AI reamer plus something else as a separate op to give us the 6mm HoBo (Holland-Bottomley).

 

We both have barrels chambered for the HoBo, but only Vince has used his to date - my rifle has its alternative 6.5X47L tube on at the moment and that was the one I used at Diggle last weekend in the F-Class league round. I'll swap it for the six in October and run it in / get loads for the Diggle winter 600 yard BR series.

 

The DX seems a nice idea, but the Dasher is more practical if you want an improved 6BR - reamers around, easy to get dies, and we know it works.

[1967spud]

Many thanks for that Laurie

 

 

I just love a challenge as it too will be for the winter 600

[Martin M]

SMACK it:)

Have you got any dasher dies in stock -

[1967spud]

yes mate sure have

[1967spud]

i like the idea of the straighter case for easier feeding when racing the gun

[Martin M]

thats the way to go then

[trucraft]

Hi Mark.

 

Sadly no. Vince and I gave up on the idea as it was taking an age to get a DX reamer at the time. Instead, Vince came up with a slightly bastardised Dasher using a .243AI reamer plus something else as a separate op to give us the 6mm HoBo (Holland-Bottomley).

 

We both have barrels chambered for the HoBo, but only Vince has used his to date - my rifle has its alternative 6.5X47L tube on at the moment and that was the one I used at Diggle last weekend in the F-Class league round. I'll swap it for the six in October and run it in / get loads for the Diggle winter 600 yard BR series.

 

The DX seems a nice idea, but the Dasher is more practical if you want an improved 6BR - reamers around, easy to get dies, and we know it works.

Like the sound of the HoBo.

Can you post a photo and tell us more?

[The Gun Pimp]

The HoBo is very close to a Dasher but, for proofing purposes etc. we couldn't call it a Dasher - because it isn't - quite.

 

Also, 243AI dies are available off the shelf so you don't have the problem of obtaining custom dies as with the Dasher.

 

Mine only has a 24 inch barrel but in the last 1000 yd BR comp I had a six-inch group and two sevens. Just makes 3000fps with a 105gn Berger.

[Scotch_egg]

24" barrell and 3000 fps has got my ears pricked. What powder and weight?

[trucraft]

".243AI dies" Even better. I imagen there modified?

 

You forming from BR brass?

 

Think I may have found my next 6mm

[The Gun Pimp]

36gn of Elcho 17 (usual work up slowly warnings...) - yes, using 6BR brass.

[henryo]

So you just cut off the bottom of .243 AI dies and use those?

 

Does this mean you could do something similar with a .22-250 AI reamer run in short for a .22 improved BR?

[Scotch_egg]

36gn of Elcho 17 (usual work up slowly warnings...) - yes, using 6BR brass.

Thanks Vince. I may just try some Elcho 17 in my standard 6mmbr.

[The Gun Pimp]

So you just cut off the bottom of .243 AI dies and use those?

 

Does this mean you could do something similar with a .22-250 AI reamer run in short for a .22 improved BR?

Yes, just chop the AI dies.

 

The 22-250 may be too slim to squeeze down a 6BR case - I've used a cut-down 22-250 die to make 22 PPC 'short'.

[Re-Pete]

I've been trying Elcho 17 in my 6BR (with 30" 8 twist barrel), and 33.6 grains gives 2960fps with SMK 107's.

 

At 600yds and no wind, it made a 1 moa group off a Harris bipod and no buttbag.

 

However, I'm told it's a barrel burner.................we shall see.

 

H/man

[The Gun Pimp]

I've been trying Elcho 17 in my 6BR (with 30" 8 twist barrel), and 33.6 grains gives 2960fps with SMK 107's.

 

At 600yds and no wind, it made a 1 moa group off a Harris bipod and no buttbag.

 

However, I'm told it's a barrel burner.................we shall see.

 

H/man

Barrel-burner? Let's say you get 2000 rounds out of it. If, like me, you shoot an F Class comp. every fortnight, that equates to about 600 rounds per year - that's over three years shooting. I get bored long before that!

[Swamp Donkey]

I've been trying Elcho 17 in my 6BR (with 30" 8 twist barrel), and 33.6 grains gives 2960fps with SMK 107's.

 

 

At 600yds and no wind, it made a 1 moa group off a Harris bipod and no buttbag.

 

However, I'm told it's a barrel burner.................we shall see.

 

H/man

When you say '1moa group at 600yds', I take it you mean a group of 6.28" or less ?

 

1 MOA being 1.047" @100yds x 6 =6.282".

 

Am I correct in thinking of it like this ? Because if so, then my 4.093" group out of a factory Sako m591 in .308, with an unknown (new gun, no time prior) load at the first fly shoot I did, equates to a .8 MOA group, and that with a 6power scope too. Not too shabby

[Laurie]

I've been trying Elcho 17 in my 6BR (with 30" 8 twist barrel), and 33.6 grains gives 2960fps with SMK 107's.

 

However, I'm told it's a barrel burner.................we shall see.

 

H/man

 

The barrel burning 'trap' with the high-energy Nitro-Chemie powders lies in their advanced infused deterrent technology which controls the rate of powder charge burn so well that they allow larger charges and higher velocities while staying within safe pressures. if you use ALL of the extra charge weight that's available to obtain the absolute maximum possible MV, then the barrel throat and bore rear end are subjected to a longer period (time) over a longer (section of the bore) at maximum heat and pressure. So more bore surface is firecracked faster.

 

At 2,961 fps with the 107 in a 30-inch barrel, QuickLOAD estimates around 56,000 psi peak pressure is needed to get there. That's relatively modest compared to what some people load the BR to, so barrel life should work out OK - not spectacular, but not under 1,000 rounds either as it could be if you were chasing another 100 fps with this powder.

 

Incidentally with a specific energy rating of 3,990 J/g from the N-C high-energy powders (alongside Alliant's Bofors manufactured equivalents), the energy levels are actually a little lower than those produced by some IMR and Hodgdon single-base products. H. VarGet runs at 4,050 J/g, identical to Viht N550 high-energy powder, H4895 is rated at 4,060 and the IMR version at 4,080. Slower burning IMR and Hodgdon powders (4350, 4831 etc) are considerably lower at 3,720 to 3,870 as are Viht standard N100 series powders.

[Re-Pete]

Apologies.........I put 7 consecutive shots, 4 5's and 3 v's, into an F-class 5 ring at 600yds, which I thought was 1 moa.

 

Turns out it's 7.8 inches diameter.........but I'm still chuffed............

 

H/man

[Re-Pete]

Thanks for the info Laurie, much appreciated. I did wonder what kind of pressures were involved.

I've also had good results with TR140. 31.7 grains giving 2860 fps with the SMK 107.

 

H/man