257 BLACKBIRD (250-7 Blaser) for 131 ACE (0.340 G7 @ 3400-3500+ fps)

[Dollarhyde]

What's a guy got to do be put on the list Miles? Also curious who a guy needs talk to getting a resize reamer cut bushing style? I think I just might have to do one these in a 28" barrel.

the chambering reamer reservation link is here https://blackjackbullets.com/produc...lot-0-140-freebore-0-289-neck/?v=8f2564d40946

I have 2 resize reamers coming from JGS - the Newlon Precision Dies we are using can be ordred for FL or bushing using one FL resize reamer. I will probably make mine a FL sizer since I like to run mandrel expanders over bushings.

When we get closer to September I can see how guys want their Newlon Precision dies made - bushing or FL.

 

[Dollarhyde]

 

[Buck Fever]

If you need a new chamber idea with a name, I have one for you:

.25 Merv Griffin

A necked up 6 Gay Tiger.

Merv Griffin was a "quarter-sexual", he would do anything for a quarter.

It seems inappropriate in just the right way.

 

[Dollarhyde]

If you need a new chamber idea with a name, I have one for you:

.25 Merv Griffin

A necked up 6 Gay Tiger.

Merv Griffin was a "quarter-sexual", he would do anything for a quarter.

It seems inappropriate in just the right way.

I've heard guys are running 25 Dasher and 25 Gay Tiger but only see a few blips on the radar now and again. We would like to see actual testing on the 25 GT to see if the no-recoil crowd can get what they need out of it to have higher hit %'s than 6 BRA. The 25x47 is quite low on recoil and works very well for those that don't want to venture into the unknown.

 

[Buck Fever]

Yeah, 25x47 sounds nice but it doesn't have the same ring as .25 Merv Griffin.

 

[highdrum]

I've got a 25cm in a 20# prs rig, there's VERY little recoil with the brake. It's a heavy varmint 26" barrel in a mdt comp chassis with as many weights as I can get on it. Super stable.

 

[dworrel]

Any update on this thread? Anybody got experience with one of these yet?

 

[highdrum]

Any update on this thread? Anybody got experience with one of these yet?

Oh yes I've got one! running 135 bergers at 3375 w/568 from a 28" benchmark carbon 7.75tw barrel, kelbly atlas tactical long action. I get pressure signs at 3400 w/ 135 using N568 and Retumbo. I really had high hopes for this case as my 26" 25 saum would run 3320 w/ rl26. Powder capacity is 10gr towards the blaser, but the norma brass is a lil soft.

 

[Swamplord]

so.... y'all couldn't come up with an original name or what ? I fn told ya guys on FB that John Lazzeroni has the 6.71 (264") Blackbird of the same exact case rim diameter & web diameter (just longer) ..... same as the original .404 Jefferey diameters & of the Dakota cartridges that were derived from the big Jeff ..... later followed by Blaser ....

now necking the Blaser case is cool n stuff but jacking an existing name of an established cartridge is lamer than a one legged Biden trying to climb stairs .....
Lamer than Biden pooping his pants in front of the Pope !

the "Blackbird" from Lazzeroni has been around for quite some time and should be recognized as the "Blackbird" cartridge .... It's case capacity truly reflects the awesome power of the Blackbird ...... a watered down version doesn't measure up in my opinion & Y'all need to change it to something else ....
since Raptor is taken & Hawk is taken too, how about 257 Tweety Bird ? or 257 Peckerwood ?

does that give me free reign to do a 300 Blackbird & 338 Blackbird of my own design ...... with the proper size engines of course ....

just pickin on ya guys but ya... stealing is a no no

...

 

[GoosePilot]

So your not hardly getting anything more out of a blaser over a saum or you have a slow barrel?

 

[highdrum]

So your not hardly getting anything more out of a blaser over a saum or you have a slow barrel?

I mean it could be a slow barrel? It's 28" benchmark. My other two benchmarks have been far from slow. But it's a possibility. I really think I've gotten used to running lapua and adg brass. Now once you go back to Norma......the fun stops there lol

 

[GoosePilot]

I mean it could be a slow barrel? It's 28" benchmark. My other two benchmarks have been far from slow. But it's a possibility. I really think I've gotten used to running lapua and adg brass. Now once you go back to Norma......the fun stops there lol

So would it be fair to say you think a regular saum based cartridge is overall better than the sherman max or blaser based ones?

I'm running the rogue version of blaser and I don't think it's quite as fast as the max (or I'm not pushing it as hard) at least in a 24". They are very very close imho. I'm leaning hard on a 18-20" 6.5 rogue blaser.

 

[highdrum]

So would it be fair to say you think a regular saum based cartridge is overall better than the sherman max or blaser based ones?

I'm running the rogue version of blaser and I don't think it's quite as fast as the max (or I'm not pushing it as hard) at least in a 24". They are very very close imho. I'm leaning hard on a 18-20" 6.5 rogue blaser.

Overall better? No if speed is what you want, Blaser is a bigger case and does have larger velocity potential. The saums are very efficient. The Max is slightly faster than a saum, and may allow you to get to the next accuracy node. The adg brass is sure harder and holds psi a lot better. Here's the deal, 7max is 77gr capacity the 7 blaser is 84gr as I measured. In theory that would make the Blaser about 50-70fps faster at equal psi. Nobody runs a Sherman at lower saami pressures tho.

 

[GoosePilot]

Overall better? No if speed is what you want, Blaser is a bigger case and does have larger velocity potential. The saums are very efficient. The Max is slightly faster than a saum, and may allow you to get to the next accuracy node. The adg brass is sure harder and holds psi a lot better. Here's the deal, 7max is 77gr capacity the 7 blaser is 84gr as I measured. In theory that would make the Blaser about 50-70fps faster at equal psi. Nobody runs a Sherman at lower saami pressures tho.

I have not measured my fired cases, but I believe it is 3-4grains more than unfired. 500 pieces will last me a long time for what I do. Will be talking with T/S after Christmas about a 6.5 version. Extremely happy with my 7mm.