6mm-06, .243 Catbird?
- Thread starter mattri
- Start date
Thanks for the bump.
Love the velocity with the med-heavy weight varmint bullets. Thinking 70grn Nosler BT and/or Hornady 87grn V-Max.
Would also be very interested in what this round could do with 105grn A-max, 107grn SMK, 108grn Bergers etc.
With an app twist and a 26-28" bbl I think this would be an absolute deadly combo.
Love the velocity with the med-heavy weight varmint bullets. Thinking 70grn Nosler BT and/or Hornady 87grn V-Max.
Would also be very interested in what this round could do with 105grn A-max, 107grn SMK, 108grn Bergers etc.
With an app twist and a 26-28" bbl I think this would be an absolute deadly combo.
mm-06, .243 Catbird?
Mattri -
Howdy !
What type of shooting will you be using these for ?
Paper punch, live varmint, LR deer ?
Technically... these cartridges would be " over-bore " capacity when shooting the lighter 6mm bullets.
To more-fully exploit the capabilites of 6mm cases of this size, one can reach for the heavier/heaviest 6mm bullets.
That is of course, IF bullets of such weight and design match the intended ( live ) target application.
There comes a point where the expansion ratio can no longer be " finnessed " ( for example, via use of longer barrels for a given chamber capacity ).
There are finite velocity gains which can be obtained from increased powder charges/longer barrels.
Once that point is reached, any additional powder becomes little more than "filler".
My point:
Keep a clear eye on what case capacity and bullet weight(s) you realy need.
With regards,
357Mag
Mattri -
Howdy !
What type of shooting will you be using these for ?
Paper punch, live varmint, LR deer ?
Technically... these cartridges would be " over-bore " capacity when shooting the lighter 6mm bullets.
To more-fully exploit the capabilites of 6mm cases of this size, one can reach for the heavier/heaviest 6mm bullets.
That is of course, IF bullets of such weight and design match the intended ( live ) target application.
There comes a point where the expansion ratio can no longer be " finnessed " ( for example, via use of longer barrels for a given chamber capacity ).
There are finite velocity gains which can be obtained from increased powder charges/longer barrels.
Once that point is reached, any additional powder becomes little more than "filler".
My point:
Keep a clear eye on what case capacity and bullet weight(s) you realy need.
With regards,
357Mag
357mag- You make some good points for sure.
Purpose would be a lr varmint/paper gun.
Would like to approach 4kfps with the lighter pills and be stable with the heavier, higher bc bullets as well.
I know the 6.5-284 is popular and uses less powder but it really doesn't achieve the same velocities and with the selection of 6mm bullets and slower powders available now I think this could be a fun projuect.
Purpose would be a lr varmint/paper gun.
Would like to approach 4kfps with the lighter pills and be stable with the heavier, higher bc bullets as well.
I know the 6.5-284 is popular and uses less powder but it really doesn't achieve the same velocities and with the selection of 6mm bullets and slower powders available now I think this could be a fun projuect.
Buddy of mine has a Catbird that he drug along Coyote hunting one time several years ago. Hit a Coyote broadside in a drizzly, sleety rain at about 200 yards. Darndest thing I've ever seen. I was watching through my scope and that Coyote shed every bit of water off it's coat when the bullet hit him. Went straight down without even moving and you could have read a newspaper through that Coyote from the hole it left. Don't remember the load, but he did say he shot is sparingly because of barrel wear. Russ
My grandfather in law has been building his version of the .243-06 for years. Basically and straightend out case with a 30 degree shoulder. Extremely accurate round in a LV barrel. Last year he dropped a buck on a dead sprint crossing him at 200 yards right through the boiler room off hand. Not too shabby for an 83 year old guy! Just about everyone in the family has one. One relative uses his exclusively for long range coyote hunting 500+ yards. His last hit was 670 yards laserd. The old man has been a bench rest shooter and has been building high end custom rifles for the past 50 years.
I can get some info from him this weekend.
I'm scrounging up parts to build one later this winter. I'll be a pro on this caliber by this summer!
I can get some info from him this weekend.
I'm scrounging up parts to build one later this winter. I'll be a pro on this caliber by this summer!
I think the original 6mmCatbird was a 6/270 with 35 Deg Shoulder , and I think Jarrett Rifles made a few . They claimed Barrel Life of about 1500 Rounds , and 4100 FPS with a 70 Gr Bullet , 3800 FPS with an 85 Gr Bullet , and 3500 FPS with a 95 Gr Bullet . You might contact Jarrett ( Not sure of the spelling & I think he's in the Carolinas ) . If you want BIG , look into the 6mm Mach IV and the 240 Incinerator ( both on blown-out 264 Mag. Brass ) by Lee Martin in Virginia which supposedly tops the Catbird by another 300 FPS . Oppps ....forgot ....I think Precision Shooting had an Article on the Catbird maybe 10 years ago . I looked thru some of my old Copies , but could'nt find it . Might have been by Steve Hanson .
Here is an article on the .240 Incinerator, a good read if your interested in a round that pushes the limits of 6mm velocity.
http://www.singleactions.com/240Incinerator.pdf
You may also want to research the .240 Gibbs as well. It does require substantial fireforming as the shoulder is blown forward a good amount as well as increased in angle, it has a bit more capacity than the 6mm-06 and I have read that the shoulder angle helps to burn the large amount of powder more efficiently. Guns and Ammo actually did a loading article on it not long ago, and I believe it can be found if you do a search at Gunsandammo.com I did read the article, and velocities were impressive to say the least. It would make a great long range predator/varmint/deer rifle with the right twist rate for whatever bullet was required for the task at hand.
Not only is the .240 Gibbs a really fast round, it's also not too common for those who enjoy having something different.
Good Luck
Kenny
http://www.singleactions.com/240Incinerator.pdf
You may also want to research the .240 Gibbs as well. It does require substantial fireforming as the shoulder is blown forward a good amount as well as increased in angle, it has a bit more capacity than the 6mm-06 and I have read that the shoulder angle helps to burn the large amount of powder more efficiently. Guns and Ammo actually did a loading article on it not long ago, and I believe it can be found if you do a search at Gunsandammo.com I did read the article, and velocities were impressive to say the least. It would make a great long range predator/varmint/deer rifle with the right twist rate for whatever bullet was required for the task at hand.
Not only is the .240 Gibbs a really fast round, it's also not too common for those who enjoy having something different.
Good Luck
Kenny
Kenny , that's an interesting read . I only had a few Notes on the Incinerator , and no actual Loads . I dimly remember another big 6MM around about the time that the Catbird was being touted . It was called the 6 PBM , and I think it was built on 350 Rem Mag Brass . I had a friend who had access to one of the earliest home Ballistics programs , and the PBM with VLDs available in those days ( maybe JLKs ) was about as FLAT as it gets to 1000 Yards . I was looking for a heavy bullet Big Case 224 , 6mm , or 25 for Long Range Varminting .
Ive got a 243AI shooting 105VLD over rl25 that performs amazing. My bro just built a 6-06 and is shooting the 105vld and 115vld with h1000 with amazing results. This year in WY took 2 antelope and 2 mule deer. One antelope was 600. I love the lil 6mm!
Another wildcat to consider is the 243 SuperRockChucker. I picked one up a couple of years ago. I used 240 Wby load data. I ran 25-06 brass through FL die, no fire forming. The barrel has a 1-12 twist. The loads I've developed so far are 85 gr Seirra HP Gameking/50 grs H4350 and 70gr Nosler BT/53 grs H4350. This twist rate would not stabilize 95 gr Nosler BTs.
Forgot about this thread.
Since I posted last I have built myself a new hunting rifle in 243-06 30 degree improved and blown out. I built it on a FN commercial Mauser with a Rock Creek #5 1-8" twist. Sako trigger, bedding in Devcon and floated. Just found a good load this past weekend.
57.0 gr Ramshot Magnum with 105gr Hornady A-Max, 215M primers, and formed 25-06 win brass. My last 4 shots went in the 0.3" and the 5th shot took it to 1/2". I was testing two bullet weights with the top two holes. Shot at 100 yards.
Since I posted last I have built myself a new hunting rifle in 243-06 30 degree improved and blown out. I built it on a FN commercial Mauser with a Rock Creek #5 1-8" twist. Sako trigger, bedding in Devcon and floated. Just found a good load this past weekend.
57.0 gr Ramshot Magnum with 105gr Hornady A-Max, 215M primers, and formed 25-06 win brass. My last 4 shots went in the 0.3" and the 5th shot took it to 1/2". I was testing two bullet weights with the top two holes. Shot at 100 yards.
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jpretle
Silver $$ Contributor
Been running a 6-06 for the last 25 yrs, out of a VZ-24--not a real tack driver, but more than good enough for deer and antelope. Using the hornady 100g interlock at 3400fps+ and never been let down in terms of performance. It is only a hunting rifle, so bbl wear does not matter.
Would I build another, you bet---in a heart beat.
Would I build another, you bet---in a heart beat.
Mattri, I had a 240Gibbs built a few years back,used a 30" bbl.The gun is very accurate pushing 75gr VMax @4k. Have around 700 rounds thru it and the throat is still in good shape. Devastating on groundhogs and deer.I have a 1-12tw in the tube so it doesn't like anything over an 85gr bullet.Have to use it as a single shot as the sharp shoulder will not feed right out of the mag.
Mine is shooting those 105 A-Max's at 3250 fps with the load I listed before. They will get up around 3,300, but pressure signs start showing and getting a little on the hot end in my rifle.
Just shot a 5 shot group yesterday at 550 yards that went 3 7/8" ctc with the 105 Amax. I also recovered two of those bullets out of deer this year. One i shot from 250 yards broad side. Broke 3 ribs going in, punched a nice hole in the heart, and recovered from under the hide on the opposite side. Second bullet shot from 10 yards, same thing, broken ribs, punched through liver, and recovered on the opposite side under the hide. Everything performed perfectly IMO.
It's a fun versitile round to mess with. The other guys that I shoot with that have gone through several barrels in the caliber say typical useful barrel life ends at 2,500 rounds. One guy had about 2000 rounds down his, then set back and rechambered in 6mm br and it was a shooter for another 1,000 rounds.
I have not got speeds on lighter bullets but they are up there.
Just shot a 5 shot group yesterday at 550 yards that went 3 7/8" ctc with the 105 Amax. I also recovered two of those bullets out of deer this year. One i shot from 250 yards broad side. Broke 3 ribs going in, punched a nice hole in the heart, and recovered from under the hide on the opposite side. Second bullet shot from 10 yards, same thing, broken ribs, punched through liver, and recovered on the opposite side under the hide. Everything performed perfectly IMO.
It's a fun versitile round to mess with. The other guys that I shoot with that have gone through several barrels in the caliber say typical useful barrel life ends at 2,500 rounds. One guy had about 2000 rounds down his, then set back and rechambered in 6mm br and it was a shooter for another 1,000 rounds.
I have not got speeds on lighter bullets but they are up there.
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