Question for FIFTY (Kirby Allen)????

[wildcat]

Fifty, my first question is, can you build a 7mm AM on a BAT 8.5" action? I am thinking about having you build me one. I would like to shoot the 120grn V-Max and the 140grn Ballistic Tip out of this rifle. As you can see, I want this to be a super explosive longrange varmint rifle. Second question, what kind of velocities can I expect with the 120grn V-Max and 140grn Ballistic Tip out of a 30" stick? Third, can I hang a 30" 1.350 straight tapper off of the BAT 8.5 action? Kirby, I have all the parts, I would just need to order a barrel and send you what I have. Let me know what you think. I am interested in hearing about the volecties the 7mm AM can produce with the above mentioned bullets. Please, let me know what you think.

Thanks Kirby.
Wildcat

 

[lerch]

I am curious to see if the 120 V-Max would hold up to these speeds. It would definantly be explosive!! Seems like it might be a little over board for the 120gr bullets but you would definantly accomplish your quest for speed!!

I have a somewhat similar rifle being built by Kirby right now, it is also a varmint rifle, but of a little different sort!! /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif

good luck with everything
steve

 

[hvyw8t]

I dont think the vmax line of bullets could handle the kind of velocity the big 7AM can dish out here is why. I have driven 40 grain nosler bts out of a 22-6mmAI to speeds in excess of 4500fps. They held together just fine. In my 257 stw i have driven 85 grain noslers to 4150fps no problem, they even grouped in the .2s and .3s. Just for kicks one day i loaded up just 2 cases with 75 grain vmax to see what they would do. They crossed my chronograph at 4370 fps but didnt make it to the target. A very few little bits of jacket made it there but thats it. I dont think the vmax jacket esp. the heavier .257 and .284 class can handle the tourque and speed that some cases can dish out. Where the 7mm am really shines is with big heavy vld style bullets, thats where it will pull away from the 7rum and 7stw, not with 120s and 140s. You want a rocket for a varmint rifle build a 6mm-06 AI. It will crank out 55s at 4400fps and 70s at 4000fps. Talk about splatter factor! Good luck...

 

[lerch]

So I guess the V-Max is built on a similar jacket as he V-Max, seems like the boys shoot good until they get cranked up to above 3200fps or so, then its shotgun pattern time. A fast little 22cal should provide the red mist you seek. I was always impressed with the show the 105 AMAX would produce out of a 243win. Seems like that much bullet with that thin jacket sends a lot of shrapnel flyin when it hits a pdog!!!!!

good luck
steve

 

[col48]

hvyw8t
You want a rocket for a varmint rifle build a 6mm-06 AI. It will crank out 55s at 4400fps and 70s at 4000fps. Talk about splatter factor! Good luck...


what kind of accuracy do you get???
and how many rounds will the barrel take before she surrenders to them speeds.?????
have you got a link on this case and some info,
i would like to take a look at this puppy.
thanks
colin

 

[hvyw8t]

Mine is a remington 700, krieger 9 twist finsihed at 28.5 inches that Kirby put together for me. It will shoot nosler 55s and nosler 70s into .25 moa all day. The 9 twist will also handle the 105 amax as well. Here are a few pics...

 

[Fiftydriver]

Wildcat,

I do not mean to rail on your parade but I have to totally honest with you. The 7mm AM will not perform as well with a 120 gr bullet weight as you would expect. In fact I would be suprised if it would offer much more velocity then a 7mm RUM would with this bullet weight. That said, the RUM is also far to large for good performance with a 120 gr bullet weight.

I have tested the 140 gr Accubond in a 26" barreled 7mm AM and topped 3700 fps which is where I stopped testing. I was only testing to get load data to offer customers as I have no intention of recommending any bullet weight under 160 gr for this very large 7mm wildcat.

The reason for my comments is because with the powders used in this design, you will be topping 110 gr of powder with a 120 gr pill. That much powder with the light bullet weight will simply not produce a quality extreme velocity spread and accuracy at long range will suffer.

The 140 gr pills are marginal in my opinion. They work but still, for long range shooting they are really to light to get the results you want and need.

At 160 gr you will start getting some very good consistant velocities and the case capacity can begin to be used to full advantage.

My second area of concern is that you want this rifle for a Long range "varmint" rifle. That is not the design purpose of this round. Not that it would not perform very well at this function but its really a waste of componants as barrel life will be extremely short in this role.

Designed for big game hunting, this chambering offers a very useful barrel life but for varmint hunting it would be very short lived.

TO be honest, if you wanted an AM for long range varminting and you wanted to use light weight bullets, the 270 AM loaded with a 130 gr Ballistic Tip in a 1-10 twist barrel would be a better choice.

Still hard on barrels and not extremely well suited to this bullet weight but it does perform well enough to be very useful and very accurate.

I have broken 3800 fps with the 130 gr ballistic tips in my 30" barreled rifles.

Just my opinion. No problem building you the rifle you want but want to give you my honest opinion of the question. That being, the 7mm AM is not a good choice for this type of project.

Remember at long range, +600 yards, velocity is not nearly as important as BC.

Good Shooting!!

Kirby Allen(50)

 

[Fiftydriver]

Lerch,

Your really stretching the "SOMEWHAT SIMILIAR" comment with your project rifle /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif!!!

Kirby Allen(50)

 

[lerch]

Well I guess maybe were getting the Fat @$$ version of the 7mm AM!!! /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif

take it easy

steve

 

[ss7mm]

I don't think its actually the Fat @$$ version Lerch. It'd be more like the bulked up, on steroids, version wouldn't it? /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/shocked.gif /ubbthreads/images/graemlins/grin.gif

 

[lerch]

well lets just say it wont be carry weight!!!! /ubbthreads/images/graemlins/blush.gif /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif

 

[wildcat]

Thanks for all the info Fifty. I figured the 7MM AM would be to big for those bullets, however, I thought I would see what you thought. Can you build a 270 AM on my BAT 8.5" action? it's currently on my 6.5x284. I am really not worried about barrel life with this project, I want something that will shoot the bigger 100+grn varmint bullets to around 3700 fps to 3900 fps. I am currently waiting on parts for my 6-284 project, this rifle is going to be built around shooting 75 to 90 grn pills. I will get between 3700 fps and 3800fps with the 87grn V-Max and 3850 to 3950 with the 75grn V-max. I also have a 220 Swift and a 223, so when I go varmint hunting, I have plenty of different rifles to shoot, so I never really put to many rounds through the same rifle. I want a large magnum caliber varmint rig built and that's why I am interested in one of your Allen Mags. If you have other suggestions, please let me know. I am open to other suggestions. Does anyone else, reading this post, shoot the 270 AM. Please, let know what you guys think about my next project. Fifty, I mentioned I was probably going to build this rifle on a McMillan MBR stock, however, this is what I am thinking about in terms of specs;
1. One of your Allen Mags, possibly the 270 Allen Mag
2. BAT 8.5" action
3. Krieger 30" 1.250 straight tapper, 1-10 Twist
4. Muzzle Brake
5. McMillan A-5 stock with lead added to rear for weight and balance.
6. Jewell 2oz Trigger
7. Davidson Base with 20MOA added
8. Topped with Nightforce 5.5x22x56mm NXS
9. Estimated weight of rifle, 20 to 25 pounds (My Guess)
Let me know what you think. Thanks Kirby for your response.

Wildcat

 

[Northman]

How about a 458 HE..

Here are some of the ballistics
350 gr bullet up to 3500 fps
400 gr bullet up to 3300 fps
450 gr bullet up to 3100 fps

A 300 grain Hollow point should get 3700 fps.. now that would leave a mess of things.

Should probably weight it down a bitt.. say 25-30 pounds?

 

[scott]

Sounds good, but if your into Varmit hunting, why even bother with the 270 AM, why not the 257 AM....
The 270 has more capacity than the 257, but the 257 has more powder per bore size.. also there is not a 270 (.277) bore gun on the plannet earth that can achive the long range ballistic of the 257 AM with heavy bullets...
for example... the 157 ULD can be launched at 3350 fps
the 142 ULD at 3500 fps...
the 169 ULD in the 270 AM can get 3400 fps...

Compare
270 AM 169.5 ULD 0.760 BC at 3400 fps
257 AM 142.0 ULD 0.790 BC at 3500 fps

Think about it.... one not only shoots the same bc at higher velocity, but shoot a bullet with BETTER BC at HIGHER velocity.. and WIN - WIN

Also bigger is not always better... the smaller bore gun like the 22's 24's and 25's are made for varmits, bullets are made with thinner skinned bullets in general to expand..

I'm not saying a 7mm Rem mag can't kill a coyote, but a 25-06 with 75 Vmax or 85 BT's will not just punch a strait .284 hole through it.. they will enter with a .257 hole and depending on bullet either expand and turn the insides into hamberger, or exit with a nice 4-5 inch hole....

Don't get me wrong, I'd not turn down a 270 AM rifle, but if you are looking at the most from the best. I'd opt for a smaller bore.
The 257 AM is just Amazing... a 0.790 BC... Thats about 0.800 BC at 3500 fps.... Nothing can touch it, not even the 338-416 imp 338-408 imp.. That is a whole lot of Ballistic Drag Efficiency, at **** near (180 fps dif) 22-250 factory velocities (55 @ 3680 fps)

also I would not hesitate to use Kirby's services, unlike some (I'm not talking down about the other smiths on this board) of other gun smiths who will not talk to you about the technical side of things and more or less have the attitude of take it or leave it, Kirby has nothing to hide and will tell you what works and what doesn't and will aswer all your questions.

Scotty