First 6BR tight neck or no turn?

brenden270

brenden270

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Just wondering what most have gone with for their first BR. The gun will have no specific purpose ie. benchrest,600m or anything like that. It will likely kill more vermin and paper than anything. Is the accuracy advantage that great with a tight neck? Is it worth the hassle or will a standard br neck be sufficient. The reason for choosing the 6br is obviously the inherent accuracy but I have heard of outstanding "no turn" guns. Which way should I go?
 
I built my first few 6mm Br's tight necked... and turned the brass so I had 1 thou clearance in the chamber on a loaded round.

With the quality of Lapua brass neck turning is not required. It will give you no better accuracy and possibly worse accuracy if you don't do a good job of making brass.

I would never consider making a tight neck for myself unless I had to rely on Winchester/Remington/etc. for my brass... and then I would only turn enough to clean up the brass... not really a tight neck.
 
Before Lapua brass neck turning was what the benchresters all did.
I would't bother with tight necks if you can obtain Lapua brass.
Doubtful you will ever see any differance on the target .
 
If you plan on turning them and not using a sizing button with your die you have to be very precise with your turning otherwise you get different neck tension. Using a button will eliminate that problem.
Stephen
 
Go with a 272 neck, This gives you minimal 2 thou clearance without turning. Having said that, you will find that even new Lapua brass benefits from clean-up.

Give more thought to the bullets you plan to use so that you can get the right throat.
 
OK guys. Thanks! I will opt for a no turn neck. Now the throating issue. I want an eight twist to cover a wide spectrum of bullets. I imagine that being my first I will try everything from 55-105. Until I get a handle on the cartridge and settle into the sweet-spot with a few loads I don't think anything longer than an amax 105 will be needed. If I decide to get into 1000yd stuff and want to shoot dtacs and cl. rivers then I will likely have another br made. With that info what throat spec do you suggest. Slap me around on the twist rate as well if I'm out to lunch.

Brenden
 
brenden270 said:
OK guys. Thanks! I will opt for a no turn neck. Now the throating issue. I want an eight twist to cover a wide spectrum of bullets. I imagine that being my first I will try everything from 55-105. Until I get a handle on the cartridge and settle into the sweet-spot with a few loads I don't think anything longer than an amax 105 will be needed. If I decide to get into 1000yd stuff and want to shoot dtacs and cl. rivers then I will likely have another br made. With that info what throat spec do you suggest. Slap me around on the twist rate as well if I'm out to lunch.

Brenden
Click to expand...

A short throat handles the 55 grain ballistic tips well and that is the bullet for highest velocity and great blow ups on gophers.

But with an 8 twist and the longer bullets you will have to throat longer ... not the best for the little pill. It's tough to try and make it do it all...

I am building mine with a 10 twist and a fairly short throat and will use the 87 grain A - Max for my longest bullet... and the 55's will still work well. It's just a target/varmint/plinker.
 
I just finished testing one which was chambered for a no-turn on Lapua brass. The barrel is a Shilen 8 twist. I fired two shots at 50 yds to sight in then one 5 shot group at 300 meters. The five shots went into 1 1/4 inch which I considered good enough for a new barrel test group. This was with 4895 (it was in the measure) and 107 Sierras. I don't know if the rifle would shoot 55's but I'm sure it will shoot 85's. I throated it to accept the 107's seated to just ahead of the neck/ shoulder juncture.
I will probably never make another tight necked 6BR except in a short range BR rifle. I think one can build a 6BR as a varmint rifle to shoot light bullets through a twelve or ten inch twist and throat it accordingly or he can build a long range 6BR and concentrate on that first. If short bullets shoot inspite of a bit of jump, that's a bonus. Regards, Bill.
 
Ok. So an 8 twist might be on the quick side for the intended purpose. Perhaps I would be better off with a 10 with a shorter throat. Most shooting will likely be 400yds and under so super high bc bullets really arent needed. Can a person still get the legendary accuracy at these ranges with the lighter pills? 60-90 grain range? When guys shoot 300m benchrest with br's what bullets and weights are generally used? Some of the info on 6mmbr is a bit contradictory in terms of data.
 
I just had one built with a 1:8 barrel but have not had much time to play with it. I have only shot 105 Burgers in it but have some 87g V-max's I am giong to try, they have a good BC of .400 so you might want to look at them. I have used the 87 V-max's in my .243 and they seem to be quite accurate in it.
 
Brenden, I believe that if you go with the 1:8 twist you will be able to shoot the 90 grainers just as well (not sure if this will be too fast for the lighter) and if you need/want to shoot the heavies you can still do so.

I haven't shot anything lighter than a 105 out of mine so I can not give a first hand experience on the matter.

Maybe head over to the 6BR forums and ask there, if no one here has done this there might be someone on that site that has. It's worth a try anyway.
 
NO turn neck in the chamber. light neck turning on the brass necks just to clean things up.

I used to shoot clay pigeons at 700 to 800yds with 87gr Vmax in my 6BR. There is nothing short range about this bullet.

Of course, the 105/107's buck the wind better but for mucking about, it's all good.

Short throat for a max weight of 87gr and then you can run all the varmint weight bullet with ease. When you get tired and want to try a longer bullet, your throat would have worn enough that you can seat them out just fine :)

I think you can get away with an 8 twist for all varmint weight bullets too. These are usually pretty durable and the 6BR just doesn't push them that fast.

Ideally, you would go 10 twist but then you top out around 95gr for bullet weight.

Enjoy...

Jerry
 
I built an eight twist for a fellow about 4 years ago and he achieved good accuracy (1/2 moa) with 75 Sierras so it's possible. Anyone who has been around rifles much has seen that a twist which is faster than necessary can shoot just fine while one which is too slow won't work at all.
Short range BR rifles have traditionally used 14 twists and still do, usually.
Long range rifles use a twist sufficient to stabilize the bullet the shooter wants to be able to shoot.
Other rifles use a twist the shooter, usually after obsessing over it for a couple of weeks, decides to use.
If a shooter wants to shoot 107's, he MUST use an eight inch twist or faster. If he wants to shoot 85's, that does not preclude the use of an eight inch twist but it is not necessary. If he wants to use 85's predominately, it will work out better if he throats for them. That throat will be a bit shorter than one might like for 107's but they'll likely work OK. Regards, Bill.
 
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