Different 6mm Wildcats

[c_bass16]

Can someone point me at any differences between a 6-06 AI and a .243 Catbird.

With some basic "Gugle Fu", it would seem the 6-06AI has a 40 degree shoulder and the Catbird is designed with a 35 degree shoulder. Both improved, just with a different shoulder angle?

Both made with either 30-06 brass but easier to do with .270 brass...which I have lots of.

The reason for this project is that I've already bought a SS Shilen Select Match 1:8 ratchet barrel but I didn't realize until I started pulling my M70 apart...that I actually have a .243 Win, built on a Long Action.
Since it's just going to be a light use, strictly hunting rifle...I figured...why not utilize the long action and roast that pipe.

Would anyone have a line on a DBM for the long action M70, and to go with it...a Double Stack, Single Feed mag that would handle 30-06 style rounds.

 

[screech]

I also believe going off memory that the jarret is actually based off the 270 and there fore has a longer neck while the 6-06 has a shorter neck. Personally id do the jarret

 

[Fiftydriver]

They are both so close in performance they can be said to be ballistic twins. The 6-06 AI is easier to form as you can use 25-06 brass which is easier to neck down then even 270 brass.

Both of them are boarderline on having more powder capacity then can be used in the 6mm bore. Often times with the slow burning stick powders you can see the occasional powder bridging issue that causes extreme pressure spikes. For this reason, their best performance is left to the ultra slow burning ball powders.

They are also best served with bullets heavier then 100 grains. Lighter bullets can be driven very fast but on average velocity spreads are very wide with lighter bullets.

Personally, I prefer the standard 6-06 over the AI or the catbird, no fireforming needed and it feeds better and also about as much performance as you want in a 6mm. Just a better design all around for this bore size. Coming from me this may be a strange comment but in the case of the 6mm and the bullets we have available, the 6-06 is my recommended top end.

Fireforming a round with such a limited barrel life is hard to swallow at times, this is why the 6-06 is a much better choice. Maybe not as SEXY but a great choice, plus all you need to load ammo is a 25-06 FL die to size the body, a 243 win neck die to size the neck and a 243 Win seater die to seat the bullets, just need to adjust the height position of the 243 dies and they work great.

Catbird dies will be pretty spendy, 6-06 AI dies are not all that bad but can be hard to find in stock from time to time.

 

[B23]

Kirby

What are your thoughts with regard to the 6-284 vs 6-06??? They seem to be nearly identical but I think the 6-284 is about the easiest wildcat out there and that's using the best brass money can buy. My dad recently had a 6-06ai built and it is a beautiful rifle but I always debate the issue with him that it's far to much work for what little he gained over a straight 6-06 or even 6-284.

It seems by the time everyone settles in with their accuracy loads all three are shooting about the same fps.

 

[Edd]

I have a 6mm-280 that doesn't require fire forming.

 

[Fiftydriver]

B23,

Your correct, now that we have very good quality 6.5-284 brass to play with the 6-284 is a very good option, OP just did not include the short action wildcats in his post. The 6-284 and 6-06 are very similiar in performance, the 6-06 will out perform the 6-284 is the 284 is built into a repeating short action rifle and needs the bullets seated deeper but other then that they are very similiar in performance.

The Between the 6-284 and 6-06 in a repeating rifle however, there is no comparision, the 6-06 feeds like its not even there, the 6-284 can be abit choppy to feed, espeically out of a short action, double stack mag box. I generally recommend something like the HS Precision DM system which is a center feed design and then there are no feeding issues at all with the shorter, fatter, rebated rimmed 6-284.

Generally speaking, I recommend the 6-284 for varmint rifles or single shot rifles where feeding and OAL is of no concern. For a light to medium big game rifle, I generally recommend the 6-06 for its better feeding characteristics.

As far as forming brass for either, they are vastly superior to any AI or any other round in this class that needs fireforming as they can be cold formed and loaded for the first time with top pressure accuracy loads.

 

[Fiftydriver]

I have a 6mm-280 that doesn't require fire forming.

Really just another version of the same thing, 6-06, 6-270, 6-280, all are within 50 fps of each other, none require fireforming. Good choices all around for a hyper performance 6mm.

As with all extreme chamberings, no matter what the caliber, they tend to offer the best consistancy when used with heavy for caliber bullets.

 

[Long Time Long Ranger]

Kirby hit on a good point using the 284 case. It is choppy and sticky feeding where the '06 case is slick. The beauty of the 284 case is that it was designed for feeding through a short action. However using it as such defeats the purpose of using it as a long range repeating cartridge with heavy bullets. That is why I didn't build any more after trying it 20+ years ago. The '06 case gave me better performance both velocity wise and feeding wise. The 6.5-284 got a popularity boost in the late 90's when a guy won some matches with it but it is still what it is. Lots of different cartridges have won lots of matches.

 

[Long Time Long Ranger]

Forgot to add there are custom magazines and followers that will feed well with the 284 case. I was just saying rebarreling standard rifles to this cartridge that is one problem you might could expect.

 

[Fiftydriver]

Forgot to add there are custom magazines and followers that will feed well with the 284 case. I was just saying rebarreling standard rifles to this cartridge that is one problem you might could expect.

This is true, the Wyatts 3.000" extended mag box is a good option for longer OAL in your ammo. Still, the 06 is smoother feeding all around.

 

[c_bass16]

Kirby, it's clear that you know your stuff here. Is there any measurable difference in barrel life between the 6-06 and the 06AI?
I'm not overly concerned with it, or I wouldn't choose the caliber...but I would like to get as many as possible.
The speed available in the 6-06 is plenty for me...but I thought I had read the AI shoulder can yield longer barrel life with the same or even increased speed.
Was that a dream I had?

I understand by going AI, it will straiten the case walls, removing the taper, and in essence...make the internal mag stagger goofy. I can see how that would suck, but

I plan on shooting 105-115gr bullets...I've got two other .243 cal rifles for the small varmint bullets.

The internal box of my M70 looks like it can take an OAL of 3.630...so even the 115 bullets should have plenty of room.

 

[Fiftydriver]

While there have been some studies saying the sharper shoulder/longer neck designed cases offer longer barrel life, I would say you would be very hard pressed to prove that point in my opinion anyway. From what I have seen the shooter has more effect on barrel life then any case design, heat the barrels up and keep shooting and barrel life goes down. With these extreme chamberings you want to keep shot strings as short as possible.

By that I mean, if you want a high volume varmint rifle, it would be silly to pick either of these obviously. IF you keep the barrel cool and clean, it is amazing how long todays barrels will last. In the years I have been doing this, 90% of the accuracy problems with barrels was a result of either over heating or poor cleaning practices. It is actually a rare thing to see a barrel that has actually been shot out when cared for properly. I have seen many barrels shot out because the owner got them hot and kept shooting so its more in your hands then the case design!!

I would personally go with the 6-06 for three reasons.

1. it feed like its not even there, smooth as butter.

2. No fireforming means no additional wear on your barrel

3. With many of the long range match bullets, the 6-06 already produces about as much velocity as they can handle, especially with the Berger and A-Max bullets. The 6-06 AI just addes 100 fps to this which actually exaggerates the problem. Simply put, the standard 6-06 is already pushing the envelope with current 6mm bullets, especially the long, heavy VLD type bullets.

 

[Long Time Long Ranger]

While there have been some studies saying the sharper shoulder/longer neck designed cases offer longer barrel life, I would say you would be very hard pressed to prove that point in my opinion anyway. From what I have seen the shooter has more effect on barrel life then any case design, heat the barrels up and keep shooting and barrel life goes down. With these extreme chamberings you want to keep shot strings as short as possible.

By that I mean, if you want a high volume varmint rifle, it would be silly to pick either of these obviously. IF you keep the barrel cool and clean, it is amazing how long todays barrels will last. In the years I have been doing this, 90% of the accuracy problems with barrels was a result of either over heating or poor cleaning practices. It is actually a rare thing to see a barrel that has actually been shot out when cared for properly. I have seen many barrels shot out because the owner got them hot and kept shooting so its more in your hands then the case design!!

Amen! My sentiments exactly. I have some excellent shooters that have been that for many years that are considered barrel burning junk in many discussions here and elsewhere. Take care of your rifle and it will take care of you.

 

[Fiftydriver]

Amen! My sentiments exactly. I have some excellent shooters that have been that for many years that are considered barrel burning junk in many discussions here and elsewhere. Take care of your rifle and it will take care of you.[/QUOTE]



Ya you have some BARREL BURNERS for sure!!! As you are likely well aware of from years back here on LRH, when I came up with some of my Allen Magnum wildcats, I was pretty much told they were a waste of money because you would burn the barrel out before you could ever find a good consistant load. that was mainly concerning my 270 AM and 7mm AM. Turns out, if they are used as they should be their barrels last a very long time. My old 7mm AM, by conventional wisdom should have had its barrel replaced several years ago with the number of rounds down its barrel. It up to 28 big game animals taken between 400 and 930 yards with only one miss in all those hunts(a quick fallowup shot corrected that one pilot error!!!) Not bad for an 8 lb rifle with #3 contour.

As we well know, if you keep the barrels cool and clean, they last much longer then most of us would ever believe!!