The start-6bra Load development

[DHuffman]

Here is a picture of the group and the rifle. The rifle is a early/mid 70's Savage 112V single shot. Was originally a .243win but of course the barrel was toast when I got it. Tuned/adjusted the factory trigger. Breaks clean and right at 3#.

You could pretty much call this our drop in Savage prefit barrels. When the blank got contoured before rifling etc...Justin threaded it at the same time.

Scotty in the shop chambered it for me and cut and crowned the muzzle as well as pillar bedded the stock.

On the action I bought a .250" thick recoil lug and after truing up the receiver face I had Todd double pin the recoil lug to the receiver in the cnc mill. Pinned the lug at the 3 o'clock and 9 o'clock position.

I trued/cleaned up the bolt face and shortened the ejector spring so the rounds don't eject out of the bolt when you open it and lapped the bolt lugs.

Very nice Frank. I have one of those old 112V single shot medium action rifles that came with a 220 swift barrel. It was replaced with a used Criterion 6 BR Norma barrel and I shot my first 200 yard 1 hole group with it.

That rifle and barrel started me down the long dark hole!

The first pic is the 3 shot one hole 6 br group and the other two it's in a Stockade stock with a 6 Creedmoor barrel and a Vortex GE and makes weight for the 11# match coming up at Deep Creek.

I appreciate the tech you contribute here and elsewhere, thanks!

 

[FrankG]

That must be one long bullet. How much is in the neck?

I'll take a picture tonight with a bullet laying next to the loaded round so you have a comparison and give you some numbers also.

 

[MDM]

Well, I didn't expect this year old thread to get traction again. So after all the load development when I was new to BRA last year, I rode that thing all the way to winning the Ohio PRS Club series, winning the PRS Northeast club series finale match and all the way to the 2018 PRS finale. I couple of chamberings later and I feel like I have a pretty good handle to the BRA and what load a chamber cut with my reamer likes. I'm still shooting the 105 hybrid and they only thing I'll say is if you haven't experimented with larger jumps to the lands, i.e. .045 to .75 area, give it a try.

 

[FrankG]

That must be one long bullet. How much is in the neck?

Here are a couple of pic's for reference. I tried to take them as only one picture looked like it gave a false reference to that the bullets where not lined up.

2.465" o.a.l. and 1.837" (if you don't zero out your Stoney Point/Hornady loaded round checker add about 1" to the 1.837") base to ogive.

 

[FrankG]

Well, I didn't expect this year old thread to get traction again. So after all the load development when I was new to BRA last year, I rode that thing all the way to winning the Ohio PRS Club series, winning the PRS Northeast club series finale match and all the way to the 2018 PRS finale. I couple of chamberings later and I feel like I have a pretty good handle to the BRA and what load a chamber cut with my reamer likes. I'm still shooting the 105 hybrid and they only thing I'll say is if you haven't experimented with larger jumps to the lands, i.e. .045 to .75 area, give it a try.

I always say jamming the bullet isn't always better. I've seen guns up to .060" off the lands shoot better than closer/jamming.

Just yesterday a really good customer sent me all his load data for a 6.5CM in a hunting rifle with our #3 contour. With 140 Hybrids he found that at around .030" to .035" off the lands he shot 4 three shot groups from a .120" to a .213".

 

[JohnMill]

Here is a picture of the group and the rifle. The rifle is a early/mid 70's Savage 112V single shot. Was originally a .243win but of course the barrel was toast when I got it. Tuned/adjusted the factory trigger. Breaks clean and right at 3#.

You could pretty much call this our drop in Savage prefit barrels. When the blank got contoured before rifling etc...Justin threaded it at the same time.

Scotty in the shop chambered it for me and cut and crowned the muzzle as well as pillar bedded the stock.

On the action I bought a .250" thick recoil lug and after truing up the receiver face I had Todd double pin the recoil lug to the receiver in the cnc mill. Pinned the lug at the 3 o'clock and 9 o'clock position.

I trued/cleaned up the bolt face and shortened the ejector spring so the rounds don't eject out of the bolt when you open it and lapped the bolt lugs.

Hey Frank, I don't think Savage ever intended that rifle to shoot that well. You'll have to send it back. Seriously, that just shows what a lot of hard work can do for a rifle. You guys should be very proud.
John

 

[FrankG]

Hey Frank, I don't think Savage ever intended that rifle to shoot that well. You'll have to send it back. Seriously, that just shows what a lot of hard work can do for a rifle. You guys should be very proud.
John

The shop test rifle when we started was also a 70’s 112V. Bedded the stock and a os recoil lug. That’s the only work that was done to it. Fit all the barrels up like a Remmy. Originally a .220 Swift. It’s had barrels on it in .308win, 6mm Rem., .338 Lapua (yes used a standard mag bolt head and opened it up for the Lapua rim), .300wm, .223 and currently has a barrel on it in 7.5x58mm (basically a 8x57 necked down to .30cal) and all of them have shot.

Rebuilt an original .223 112v for my 12 year old last year. New barrel again in .223 but 1-7.5 twist, new recoil lug and double pinned and pillar bedded. Also another hammer. First time he shot it I asked him if he liked the rifle. All he said was “Yep” and kept shooting!

I did have the original bolt handles threaded so I could put a oversize bolt knob on them also.

Later, Frank

 

[JohnMill]

So here is what I did today using a version of Eric Cortina's method. I'm just trying to find the powder charge, so nothing spectacular with the crosswind I had. All I'm worried about is the vertical center of the groups. I have my thoughts on where I should go for the charge when I test seating depth next, but let me hear your thoughts please. I tested Varget and H4895

105 Hybrid
.005 in the lands
150yds
3-7 mph crosswind

H4895
View attachment 1057052

Varget
View attachment 1057055

Initially the 30.4 looks good but the 31 has about the same vertical. spread and better SD and ES numbers. The bullet holes look a lot "quieter" too.

 

[Jim Esarey]

Just remember that the BRA has 1.1 grains more capacity than a BR. Slower powders can be used as well. I am shooting Danzac coated 108 Bergers with 33.2 grains of N550 @2890 and getting good accuracy out of an old set back to 26" barrel that coppers up. I have a new barrel on order and can't wait to get it chambered up in 6BRA. I really like that chambering.

 

[JohnMill]

So here is what I did today using a version of Eric Cortina's method. I'm just trying to find the powder charge, so nothing spectacular with the crosswind I had. All I'm worried about is the vertical center of the groups. I have my thoughts on where I should go for the charge when I test seating depth next, but let me hear your thoughts please. I tested Varget and H4895

105 Hybrid
.005 in the lands
150yds
3-7 mph c

H4895-30.4 has less than .243 vertical spread.
Varget-31.0 roughley the same. Only vert spread in powder charge test.

 

[urbanrifleman]

I also used the Cortina method. Found the node at 30.8 of H4895, 2,930 fps using 108g Berger BTs

Looks like you have a similar node with less powder between 30.2-30.4 and similar velocity.

Finding a node around 2,930fps has been repeated so many times by so many people that it can’t just be coincidence.

I’d take 30.3 and do a seating depth test.

Thete are two nodes that keep popping up 2880 and 2930.

29.6 and 30.4.

 

[JFrank]

I really don't rely on a chronoghaph but this bra seems the exception at least to get in the ballpark