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A Wildcat is born


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I notice there isn't too much in regards to wildcatting on this forum so i thought i would share my journey with the guys here for anyone who is interested.

 

So this started about a year ago when I got the urge to have my own custom rifle built. After I deliberated for some time I decided to base the build on a 6.5mm projectile. The 140gr ELD-M to be exact.

 

The next part of the puzzle was the hardest. The most asked question behind What is the meaning of life?

 

Whats the best 6.5mm cartridge?"

 

Doing like every obsessive firearms enthusiast I read the hell out of everything I could. All the tests, all the reports, all the ballistic info. I wanted short action repeater so that ruled out the 6.5x55 and the 6.5x284. I did consider a the 6.5 SAUM but with the way things are with powder and rounds I didnt want build such a beast and struggle to feed her.

 

So it boiled down to the hot 3 favorites and the most contested. The .260, 6.5x47 and the 6.5 Creedmoor. All of these cartridges are great in their own right but there're are the pros and cons of what I found to be of each

 

.260

Pros:

· Good case capacity

· Easy to get great brass and can be cheap - if you go the .308 or .243 route

 

Cons:

· 20 degree shoulder promotes more growth than a steeper angle.

· Case cant deal with the same pressures as the other two.

· Cant REALLY utilize the extra case when fired from magazine.

· Shorter neck than the other two

· Kinda Boring as EVERYONE shoots one.

 

 

6.5 Creedmoor

Pros:

· Now has Lapua brass a with small flash hole

· Better case design than the .260

· More powder than the 6.5x47

· Longer neck than the .260

· Fits a mag better than a .260

 

Cons:

· Lapua brass is EXPENSIVE

· Doesnt have the capacity of the .260

 

6.5x47

Pros

· Great case design

· Inherently accurate

· Good a barrel life

· Long neck

· Small primer generally aids in shot to shot consistency

· Can utilize full case when used in a magazine

 

Cons:

· Smaller Capacity than the others

· Brass is expensive

· EVERYONE SHOOTS one

 

See a pattern here??.

 

It was after looking at the above 3 I decide to go a different route. I wanted something different from the normal mainstream offerings. And this was my final decision.

 

"6.5 Super LR Improved"

 

A true Wildcat based on an SLR that is based on a 260/6.5x47

post-14013-0-52340200-1498082389_thumb.jpg

 

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Next to .243

 

Initial forming of the case can be formed from any of the 308 family cases with a stoke of the press. I decided to go with the 308 Lapua palma brass to utilize the small primer. Plus the stuff is dirt cheap at only £75 for 100. I have modified an AX magazine that allows the bullet to be seated out to 2.980. This particular case I am having throated to about with 150k freebore (I think) this allows the bullet to be seated above the doughnut, with at least 40k to chase the lands depending on the jump.

 

post-14013-0-85407300-1498081987_thumb.jpg

 

The cases in these pictures haven't been fully formed as the taper still needs to be blown out to allow full capacity. At the moment the case capacity is almost identical to the .260. Hopefully after fire forming I will get another couple/few grains of USEABLE powder and up nearer the .260 Ackley capacity.

 

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This bullet is seated at 2.930

 

Here is why i chose to go with this design:

 

· More capacity than a .260

 

· 30° shoulder less growth and seems to be a big part of the most accurate cartridges

 

· Long neck .330 when trimmed to 2.030

 

· Small primer when formed from the .308 palma

 

· Brass is cheap as hell and easy to form

 

· Feeds from a mag (Modified) and allows bullet above neck shoulder junction.

 

 

Reamer has been sent to my smith so Im hoping to have the rifle with me within the next couple of months.

 

Next up-date will be barrel break in and load work-up

 

Any questions welcome.

Also any "Horse and carter's" telling me how this was a waste of money and that the ".260 Is God" are also welcome :P

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Well done and congratulations. The sharper 30° shoulder is a good idea and same angle as what I'm planning. Please keep us informed on progress. What action/ barrel etc are you planning on? Atb

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Well done and congratulations. The sharper 30° shoulder is a good idea and same angle as what I'm planning. Please keep us informed on progress. What action/ barrel etc are you planning on? Atb

Thanks gunner! I sure will. I can't wait to get the first rounds down the tube to see how long the legs are on her. Spec as follows:

 

AI AX Chassis

Apex Precision (John Carr) Zenith Action Right port right eject

Bartlein 1-8 26' barrel

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What are you hoping for from this cartridge in terms of speed v bullet weight?

Hard to say but i think capacity paired with the small primers should easily reach 3,000 FPS with a 140gr bullet without too much of a problem.

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Hard to say but i think capacity paired with the small primers should easily reach 3,000 FPS with a 140gr bullet without too much of a problem.

Hope it does what you want it to do for you,and it's good at times to be different than run of the mill stuff ,good on ya

Regards Lee

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Hope it does what you want it to do for you,and it's good at times to be different than run of the mill stuff ,good on ya

Regards Lee

Fingers crossed! I Could be on to something... or not! The nature of wildcatting i guess.

 

 

 

What are you doing for dies?

 

I got some custom dies made up by Whidden Gunworks in Nashville.

 

 

If the neck was .050" shorter it would be a 6.5 XC...or near enough

Very similar in terms of design but with around 6-7 grains more H2O capacity.

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Rob, I still have a 408 hunter / improved cartridge of yours kicking around somewhere. The 6.5 looks like a a downsized version of that with a longer neck. My top two criteria would be avoiding the donut and keeping it mag length with room to chase the lands.....seems to tick the boxes.

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If the neck was .050" shorter it would be a 6.5 XC...or near enough

 

6XC capacity is 49.3 gr (Norma).

 

x47 Lapua 48 gr

CM 52.5 gr

260 53.5 gr

SLR 55.5 gr

260 Ackley Improved 57.4 gr

 

Tubb's test velocities for his 6.5XC from a 28" barrel maxed at 2829" for SMK142 and 42gr H4350.

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6XC capacity is 49.3 gr (Norma).

 

x47 Lapua 48 gr

CM 52.5 gr

260 53.5 gr

SLR 55.5 gr

260 Ackley Improved 57.4 gr

 

Tubb's test velocities for his 6.5XC from a 28" barrel maxed at 2829" for SMK142 and 42gr H4350.

Great info (Y)

 

Data matches up with what i have been working with. Taking into account minor discrepancies between different case manufactures.

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  • 2 months later...

Part two of "A Wildcat Is born" saga.

I finally got the new rifle through on Thursday and loaded up 90 rounds to and had a day just putting some C&C down the pipe to get all my brass formed and for me to get used to the Ax Chassis.

 

The weather was absolutely sh!te today! Howling rain. But i deiced to go out out anyway. I had my FPS up as far a 2975 but started to see pressure signs on the case.

 

I shot the the same load of 46.6grs of 4350 on Thursday with no pressure signs. I have a funny feeling this could be down to my chamber and rounds being absolutely soaking due to the rain. I am going to to explore the mid to high 2900 hundred at later date and see as i believe there is a node to be had in there. But in the mean time here is what i have settled on:

 

45.5gr H4350 20 tho of the lands. (Haven't done any depth testing yet)

 

This was a 5 shot group. Slight hesitation on the trigger through that shout out of the cluster. Centre to centre (including the pulled shot) that group was .5 of an inch.

 

The round most certainly performs

post-14013-0-22652600-1505071381_thumb.jpg

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post-14013-0-48647000-1505071565_thumb.jpg

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Up Date:

 

So i took out the beast out again today to retry the loads that gave me pressure last time.

I tried from 46.8 to 47.6. Looks like the barrel has picked up some speed since then. Had a slight pressure from the ejector on the last load. Hello 3k! It's nice to finally meet you. Im going to back off to 2950's if i can get a node around there.

 

All in i think this test was a success. 6.5x284 speeds with about 5 grains less powder. Next I'll sacrifice one bit of brass to find out how many loads i can get from one case.

 

 

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  • 4 weeks later...

Last trip out with rifle i decide to try my groups at range.

 

This was the first and only paper group i shot that day. The rest was all out at 600 to 1000 yards on steel. This was shot off a bi-pod in field conditions. Didn't even bother messing with seating depth.

post-14013-0-51063500-1507140820_thumb.jpg

post-14013-0-64305800-1507140840_thumb.jpg

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Superb project; great results, well done! Might be a silly question but what are you hoping that this will do over say a CM at 1000 yds with a 140? Are you aiming for 2950/3000 for slightly less wind drift or are you hoping to extend the range potential over a CM, which for accuracy I'd guess is around 1200 yds or more? Was this from a 26 or 28" barrel?

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  • 2 weeks later...

Superb project; great results, well done! Might be a silly question but what are you hoping that this will do over say a CM at 1000 yds with a 140? Are you aiming for 2950/3000 for slightly less wind drift or are you hoping to extend the range potential over a CM, which for accuracy I'd guess is around 1200 yds or more? Was this from a 26 or 28" barrel?

More boiler room than the CM. I can get out to 1750yrds (weather dependant) before it goes transonic with the 140s. I settled on 2900 but i have another node at 3000 if i want it. Going by quick load i get less pressure at 2900 than factory 6.5x47 I'm not a competitive shooter by any means so 3000fps isn't necessary for me. I get much better ballistics than any safe CM with moderate pressure. Shot it at the 1000 yard BR match at Dumfries today and It did pretty well to say the least. It didn't lose out to any of the big calibers that were there and i could still spot all my shots through the scope. Barrel is a 26' btw

 

I just wanted something out side the norm with better ballistics than what was on offer without pressure, that dos'nt need a magnum bolt face and doesn't need a long action.

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Those are some very impressive stats! A mile to transonic from that chambering is mighty impressive. That's a surprising increase on CM. I'd always assumed that there was little real world difference between a standard 260 and CM because on most 260s the bullet is loaded further into the case, but to produce a wildcat that gets around this and shoots with moderate pressure is good thinking.

Those are some very impressive stats! A mile to transonic from tnat chamberinf is mighty impressive. That's a surprising increase on CM

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Very interesting indeed.

I have old 260 dies and brass from previous barrels and wonder if new life could be brought by a 6.5 SLR FLS or body die.

May I ask who your smith was and do you know if he has a standard SLR reamer as well as the blown taper version?

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