7mm Allen Mag test rifle finished.....

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Fiftydriver, Jul 3, 2005.

  1. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    TO all,

    Well, after a late night last night I got my first 7mm Allen Mag test rifle finished up. I do not have any pics of the rifle yet, nothing special, here are the componants of the rifle:

    -Rem 700 fully accuraized receiver
    -Holland Comp Recoil Lug
    -Lilja #5 contour,27" 1-9 twist(1-7 barrels not ready yet)
    -Holland QD Muzzle Brake
    -Fajen Thumbhole sporter laminate stock, Pillar bedded
    -Burris base, Signature rings
    -Weaver 4.5-14 Tactical mil dot

    Anyway, got the rifle assembled about 10:30 PM last night and simply had to see what one of these fat 7mm's would look like fireformed so I loaded up some fireforming loads using 90.0 gr Retumbo under a 160 gr Accubond, only 7mm bullets on hand at the moment.

    This is a pretty mild load but blows the shoulders out well. I think 93.0 or 94.0 would be a better choice to get sharper shoulders but this works.

    [​IMG]

    Sorry for the huge size, I am using a picture host I generally do not and I can not seem to get the pics smaller. Don;t know why.

    Anyway, these are two fireformed 7mm Allen Mags flanking a 7mm-338 Lapua virgin fireforming load.

    [​IMG]

    This pic compares the 7mm Rem Mag, 7mm Allen Mag and 7mm RUM. The case capacity of the fireformed 7mm Allen Mag is 15 grains larger then the 7mm RUM in spite of only having a case length of 2.700"!! When both seat bullets to 3.650" the Allen Mag has an even larger capacity advantage.

    [​IMG]

    Here we have the 257 Allen Mag(156 gr ULD RBBT), 7mm Allen Mag (160 gr Accubond), 7mm Allen Mag (200 gr ULD RBBT prototype) and finally the 270 Allen Mag with the 169.5 gr ULD RBBT.

    It is kind of hard to believe the shorter 7mm has the largest capacity of the three but sometimes good things come in short packages. Considering the shoulder diameter of the 7mm Allen Mag is 0.021" larger then the base diameter of the other two Allen Mags it is easier to understand way. Again, if the rifle is throated to seat the bullets to 3.650-3.700", the capacity advantage of the 7mm Allen Mag increases even more.

    I throated the reamer as it was as I did not have a 200 gr ULD RBBT to design the reamer off from at the time. I have a 7mm throating reamer ordered that will allow me to throat the rifles for these huge bullets and provide a increase in usible case capacity.

    At this time I am simply in the barrel break in process but wanted to get those interested a sneek peak at the new Allen Magnum case design.

    I hope to get some range reports by the end of the week.

    Kirby Allen(50)
     
  2. ss7mm

    ss7mm Writers Guild

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    Kirby:

    Looks like the newest member of your family is a stocky little devil. Get him some good stuff to eat, a good tube to run in and start the workouts.

    Very interesting visual comparison between the 270 and 7mm rounds.

    It looks like the waiting has been worth it. I can hardly wait to see the range results.
    /ubbthreads/images/graemlins/grin.gif
     

  3. Guest

    Guest Guest

    Kirby,
    Thanks for the sneak peek, looking forward to the range reports.
    Wayne
     
  4. 7Rumloader

    7Rumloader Well-Known Member

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    I will be setting on the edge of my seat waiting to hear the results on this one for sure Kirby!! /ubbthreads/images/graemlins/wink.gif
    This one is next on my list of Allen mags!!
    I'm drooling anticipating the arrival of my first and reading of it's new big brother makes it even sweeter!!
    Keep us posted Kirby!
     
  5. Derek M.

    Derek M. Well-Known Member

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    Hey Kirby. I don't mind the larger pics that much. Photobucket just seems to be that way. Nice close ups though!

    What is the magazine capacity again on the new 7mm? I may have to get one of those to join the 270 you're already making me now. /ubbthreads/images/graemlins/grin.gif
     
  6. Eaglet

    Eaglet Well-Known Member

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    Kirby,
    the pressure is on. Now you got us waiting! /ubbthreads/images/graemlins/wink.gif
     
  7. Buffalobob

    Buffalobob Writers Guild

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    Really nice. What a way to spend the Fourth of July weekend

    It will look even better when the throat reamer comes with the bullet seated out a little further.

    Once everything is tested out would there be any difficulties in building a customer a 7mm AM on a Nieska Bay or Bat single shot action? I am so used to a Ruger #1 that I do not feel any need for a magazine.
     
  8. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    7RUMloader,

    Yes, I am pretty excited as well. I expect alot from all my rounds but I hope this one is really something special with the addition of the ultra strong and very high quality Lapua case used as the parent case.

    Not to detract from the smaller caliber Allen Mags as they are all extremely impressive as well, especially that 270 AM when you figure the ease of loading to the level of performance you get, it is also an extremely impressive round.

    Took my 270 AM out the other day playing at 2000 yards and was impressed with its consistancy once I got the scope on target. Only problem was it was breeze which made it hard to see the bullet impacts all the time. Still I made several hits on a rock we use for a target which is roughly 20" in diameter. In fact once I got on target, it was pretty simple to land a bullet on the rock. It is an impressive long range cartridge. I hope the 7mm follows in its little brothers foot steps!!

    I will keep posting any results I get.

    Kirby Allen(50)
     
  9. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Derek M.

    As you see the rounds in the pics above, the usible powder capacity for each of the big rounds is as follows: This is using WC872. This is not the top load they can be loaded with, just the top volume converted to powder weight in grains.

    7mm RUM...........104.0 gr
    257 Allen Mag.....105.0 gr
    270 Allen Mag.....111.0 gr
    7mm Allen Mag.....118.0 gr

    Now, with the throating reamer I have coming in, I will be able to seat the 7mm Allen Mag out to the max 3.650-3.700" allowed in the Rem 700 and this would bring max usible case capacity to the 121-122 gr area compared to 104 for the 7mm RUM.

    These figures are all figured using the 160 gr Accubond in the 7mm AM and RUM, the 156 gr ULD RBBT in the 257 AM and the 169.5 gr ULD in the 270 AM.

    Not only will the added case capacity help, just as important, the stronger case design will allow the loads to handle higher pressures with the WC872 powder which will result in a more consistant, cleaner burning result which is also a benefit.

    Good Shooting!!

    Kirby Allen(50)
     
  10. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Eaglet,

    No pressure, this is the fun part of all the work /ubbthreads/images/graemlins/grin.gif!!

    Kirby Allen(50)
     
  11. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    Buffalobob,

    This would not be a problem to use a Nesika or BAT single shot. The only issue would be with the short action allowing the case to be ejected and if they would machine the bolt for the .590" bolt face for the Allen Mag.

    I have three Nesikas in shop right now ready to be built on. Two will be 7mm Allen Mags and one is going to be a 338 Lapua. These are the Model M receivers designed for a repeating rifle though.

    I would agree with you on the single shot issue. I hunt alot with the big single shot handcannons and as such have never felt under gunned. In fact I will say, knocking on wood!!! That I have yet to miss with the big handguns. Personally I feel using a single shot will make you a better shot and hunter.

    Kirby Allen(50)
     
  12. 7Rumloader

    7Rumloader Well-Known Member

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    Kirby I'm sure the 7mm Allen will meet your expectations with ease. /ubbthreads/images/graemlins/wink.gif
    I'm glad I ordered in that WC872 powder and the way it looks I'm gonna be using the full capacity of the RUM case with the SMK's I have started load development with.
    I'm up to 102 grains with no excessive pressure signs and the groups are starting to tighten up.
    I plan on working up to max this weekend ( weather permiting ) Hopefully I can get some chrono readings this time as well.
    I will be looking forward to your range results with the 7mm Allen mag.
     
  13. Kenster-Boy

    Kenster-Boy Well-Known Member

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    I guess that I have to say that I am impressed that you have stuck with this venture for so long and there is no signs of quitting yet. /ubbthreads/images/graemlins/grin.gif But after such good results I guess why not.

    I am very curious as to what kind of barrel life are you getting out of the 270 AM and what do you speculate you will get out of the 7mm AM?

    Just curious, and I would be even more impressed if you could get + 1000 or 1500 /ubbthreads/images/graemlins/shocked.gif with the AM's.
     
  14. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    7mmag man,

    The Allen Mag rifles are really a total rifle system designed from the ground up to not only offer the highest level of performance for these caliber families but also do so with the longest possible barrel life.

    Now obviously burning +100 gr of powder per shot will limit barrel life. This is why we specifically had Dan Lilja design stainless 3 groove barrels to limit throat errosion as much as possible.

    That combined with the extremely tight throat dimensions of these rifles also greatly reduces the flame cutting that can occur with a looser throat diameter which results in increased throat errosion.

    Along with these factors, the rifles have been designed to use ultra slow burning ball powders such as WC872. Not only does this powder offer top velocity potential with 95 to 105% load density, it also burns dramatically cooler them modern high energy stock powders. THis keeps bore temps down in comparision.

    Also, this ball powder is extremely non abrasive to the throat as the powder is forced through the throat under high pressure and temps when fired.

    This all combines for a long of an accurate barrel life as possible.

    You will also notice that all of these rounds are designed to shoot extremely heavy for caliber bullets, again, in an attempt to keep performance as high as possible but save on throat and barrel life.

    I have shot my 270 Allen Mag the most by far, coming up on 300 rounds and the throat looks very sharp still. The origins of the lands are still sharp and clean and I have not seen any real errosion as of yet.

    I predict barrel life for my rounds using my Extreme Sporters will be as follows, remember this for effective accuracy potential when used on deer size game out to 600 to 700 yards.

    257 Allen Mag.........1100-1200 rounds
    6.5mm Allen Mag.......1200-1300 rounds
    270 Allen Mag.........1400-1500 rounds
    7mm Allen Mag.........1300-1400 rounds
    338 Allen Mag.........1400-1500 rounds

    These are only predictions and time will tell but I will say I have a couple 257 STW rifles that customers have 1100 rounds through the bore using Retumbo and are still getting 3/4 moa accuracy in sporter weight rifles.

    Now in range testing these rifles I can tall you that 5 shots in an STW with Retumbo will make a #6 contour barrel to hot to hold in 50 degree conditions. The 257 Allen Mag loaded with WC872 can be fired up to 8 times and still be able to comfortably holt the barrel with a bare hand indefinately. This is with 20 grains more powder and 200 fps more velocity as well.

    We will see what they do. As these rounds are designed for big game hunting, they will offer even the most serious hunter a lifetime worth of faithful survice. Now if you go p doggin with them, I will see you every other season for a new pipe which I would greatly appreciate /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif!!!

    Good Shooting!!

    Kirby Allen(50)