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Brand New Mark Chanylnn, Bighorn 7mm RSAUM Build

Glassaholic

Optical theorist and conjecturer
Supporter
Full Member
Minuteman
  • Nov 30, 2012
    8,111
    9,349
    Panhandle, FL
    Goal: To build a LR tactical/hunting rifle that could be easily carried in the Rocky Mountains

    The fun specs:
    • Bighorn TL2 SA RH action with magnum boltface and picatinny rail
    • Timney 510 trigger set at 2lb
    • Surgeon SA bottom metal (to be used with Alpha Type 3/4 WSM magazines)
    • Manners MCS-EH1 stock with Elite GAP finish
    • Chanlynn 26” custom light palma contour barrel with fluting – 7mm SAUM
    • Thunderbeast 30BA brake
    • Atlas Bipod
    • Premier Reticles 3-15x50 LT Scope
    • Seekins 30mm low 6/4 rings
    • Flatline Ops Sniper 30mm AccuLevel
    • Triad Multi-CAM Stock Pack
    • Armageddon Multi-CAM suppressor cover
    • Thunderbeast 30BA Suppressor (soon... hopefully)

    Complete with magazine and scope - 10.5 pounds! Goal achieved!!!

    More build pics later in posts
    Chanlynn7SAUM_0016.jpg


    Chanlynn7SAUM_0019.jpg



    Some other interesting shots:
    Piecing everything together
    7SAUMbuild_01.jpg

    At AJ's shop in Brighton (top view)
    7SAUMbuild_02.jpg

    The amazing Bighorn action (bottom view)
    7SAUMbuild_03.jpg

    Parts and pieces
    7SAUMbuild_04.jpg

    Wouldn't you know, Norma comes out with brand new brass for the 7mm RSAUM during my build!
    7SAUMbuild_07.jpg

    Lots of lead to play with (what you don't see are 168 Bergers, 171 Barnes MatchBurners and 168 Accubond LR, but I'm really hoping this sings with the heavies)
    7SAUMbuild_08.jpg


    The Story

    This is my first, from the ground up, custom rifle. Since I discovered SH a few years ago it has cost me way too much money! Before then I was content with my Winchester Coyote Light 300WSM and Zeiss Conquest scope as my LR rifle (and to be quite honest it would probably still do me just fine) but then I caught the custom bug from seeing so many nice rifles on here and so forth (you know the drill if you have been around here long enough).

    Long story short, at the end of 2012 I decided I would like a custom rifle and found a great Surgeon/Bartlein barreled action from Trevor300WSM here on the hide (great guy by the way), there was just one problem, it was chambered for 7mm WSM and since I’m a huge .30 cal fan it was difficult, but in the end my desire for this Surgeon combo won out. It had a 25” Sendero profile barrel on it with a nice muzzle brake and I ended up getting an AICS 2.0 stock to bolt it to, I then bought a Bushnell G2DMR 3.5-21x50 scope from LibertyOptics (Scott is another great SH contributor/dealer). I was all set except for a bipod so I bought the new Sierra 7 from Daniel Horner and took it out to shoot. I had dreams and visions of competing in LR competitions and was excited about being able to use this for hunting and all that… until... until I picked the anvil up – all decked out it weighed over 17lbs! And for any of you who’ve ever hunted the Rocky Mountains you’ll know real quick that you do not want to be lugging around 17lbs all day long!

    Reality finally planted my feet back down and I realized that with 4 young kids at home, my competition traveling days were a bit limited (just think “barely any free time”) which means I couldn’t really use this rifle for what it was intended for. Now what, do I strip down the rifle and try and make it as light as possible or do I sell it and have exactly what I want built for me. Obviously you know the answer to this because this thread is about my new custom built rifle.

    I decided I needed to start with the basics, what round to use, what action, what barrel , what stock and all that. Oddly enough, even though I didn’t "want" a 7mm WSM when I bought the barreled action, I ended up realizing I really like the way that round shoots, not only that, I really like the BC’s from the heavy 7mm bullets. After significant research (that’s part of the fun for me) I decided to go with the 7mm RSAUM; why the SAUM instead of the WSM, well because my research led me to realize that the WSM cartridge was a little too overbore for what I needed and the SAUM offered very close ballistics with less powder and a longer case neck to help seat the longer bullets. The fact that Norma came out with a 7mm SAUM case right after I made my decision just helped solidify this was the right way to go.

    Okay, so now I have the cartridge, whose action am I going to use? I liked the Surgeon action but with so many options what do I do, Stiller, Defiance, Bighorn? Well I have to tell you that I am a bit biased because my old gunsmith from many years ago had once told me about a design for an action he had, and a few years ago I stumbled upon Bighorn actions out of Brighton, CO so I gave AJ Goddard (another stellar SH member/dealer) a call and had a great conversation with him (he’s one of those guys who you could talk to for hours) and come to find out, I was right, Bighorn actions were the ones that my old gunsmith had talked to me about. So when AJ introduced the new Bighorn TL2 action in 2013 I knew that was what I had to get because it had all the features (and then some) I wanted.

    One of the biggest contributors to heavy rifles is the stock and late last year master stock builder Tom Manners (yet another fantastic SH member) came out with something I came to love, his new EH1 series of hybrid tactical/hunting stocks with an ultra-light weight carbon fiber shell.

    I’ve got my round, I’ve got my action, I’ve got my stock, now what barrel to use and what gunsmith to use. I checked with local gunsmiths and with all the major barrel manufacturers and nothing was really clicking, so another conversation with AJ from Bighorn led me right back to my gunsmith of years ago, Mark Chanlynn. For those of you who do not know Mark or his work, when I first moved to Colorado in ’93 I was getting into benchrest competition and Mark was “the man” if you wanted a custom barrel for 22PPC and other super accurate rounds at the time. The fact that his shop was in Boulder, CO and only 20 minutes from where I lived, at the time, was icing on the cake. Mark is now working north of Boulder and I now live south of Denver so even though he is two hours away I decided it was worth it, so another call went out to me ol’ ‘smith Mr. Chanlynn and another great conversation ensued. I explained to Mark what I wanted and he was full of helpful advice on how to get there. When it came to which barrel, well that was easy as Mark is still making his own barrels and I have every bit of trust that he can make it sing. What better marriage can there be between the action that Mark originally designed (albeit AJ has provided some tweaks along the way) and one of his very own barrels.

    My criteria was simple (or so you’d think) I wanted a lightweight tactical/hunter that could sling heavy 7mm projectiles out to at least 1000 yards with accuracy, it needed to be a rifle that I could carry all day hunting but also be something I could use to ring steel way, way out there (or at least the rifle had to be capable of doing that… whether or not I could is a different story ;))

    What I ended up with is what you see here and I must admit that I am pretty darn happy about it! Oh, by the way, along the way I caught the suppressor bug and “better” glass bug as well which led to me spending even more money. Ray Sanchez from Thunderbeast (TBAC) was a great source of information in making my suppressor decision, they are a great company and I will be thrilled once my suppressor clears (my neighbors will be too). I ended up putting the Premier Scope on this build that I purchased from Eurooptic.com who are also SH members and great people to work with; however, right before I picked up the Premier I bought a March F 3-24x42 from Kelbly's and actually spoke with Jim Kelbly himself who is another guy you could talk to for hours, what a great industry this is!

    I look forward to seeing what this rig can really do once broken in and loads developed and all that. I have immediate access to a 100 yard range but getting out to long distances means I have to drive long distances so unfortunately I won’t be able to do that a lot, at least for right now.

    All in all, the process took about 6 months from start to finish, and that included lead times of some of the items. Would I do it all over again, you betcha, it was fun picking everything out and then seeing it all come together. It was a blast visiting AJ Goddard's shop and seeing his impressive equipment and then visiting Mark's shop and seeing all the equipment there. The work these guys put out is absolutely top rate and I look forward to posting some targets with impressive groups as my skills continue to increase as well.
     
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    • Like
    Reactions: EagleBeagle
    Looks nice! I think the 7mm WSM's a bit overkill for plinking steel inside 800yards but the BCs are hard to beat. It is nice that you don't have to hotrod the case to get good velocities though.

    I've not seen any of those Accubond LRs locally, but I'd be very interested in how they measure up in the drop/BC department.

    How much does that CF Manners weigh all dressed up with the DBM?
     
    I have a somewhat similar set up. 7saum in a long action, been using Marks barrels only, Non better! A.J.'s actions Only, non better!
    I'm doing 2920fps with the 180 hybrids in a 27' barrel with a tbac 338 can. Stupid under 600 to shoot. Mark, Matt, A.J., and Diane are
    really good people. On on my second Chanlynn barrel on my 260, Bighorn S.A. on that one. Wouldn't change a thing.
     
    Really enjoyed the read and pictures good luck with the build look forward to seeing it all together!!!
     
    Thanks for sharing
    The 7mm SAUM is a great performer, I've witnessed a string of 5 shots group into around 3" during an LR f-class match @ 1500yards - on that particular day his was the only calibre still supersonic as it passed over the target mantlet. All the rest were silent and not kicking much of a splash on the backstop which made it difficult to be sure your target had been fired upon when marking.
    Cant recall the specifics of his load (might have been up around a 210-230gr proje?), but he assured us it would still be very viable @ "the Mile", should we get the approval to extend our range back that far.

    Good luck with it all.
     
    Sneak peak

    I'm about to catch a plane, but wanted to throw up a quick pic. Sorry for the tease everyone, below are the rest of the bunch ;)

    Chanlynn7SAUM_0018.jpg
     
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    Pictures of Chanlynn/Bighorn 7mm RSAUM Build

    Here are some more pics of the build:

    Chanlynn7SAUM_0003.jpg


    Chanlynn7SAUM_0004.jpg


    Chanlynn7SAUM_0005.jpg


    Chanlynn7SAUM_0006.jpg


    Chanlynn7SAUM_0007.jpg


    Chanlynn7SAUM_0008.jpg


    Chanlynn7SAUM_0009.jpg


    Chanlynn7SAUM_0010.jpg


    Chanlynn7SAUM_0011.jpg


    Chanlynn7SAUM_0012.jpg
     
    And here's some more...

    Chanlynn7SAUM_0013.jpg


    Chanlynn7SAUM_0014.jpg


    Chanlynn7SAUM_0015.jpg


    Chanlynn7SAUM_0017.jpg


    Chanlynn7SAUM_0020.jpg


    Chanlynn7SAUM_0021.jpg


    Chanlynn7SAUM_0022.jpg


    And yes, the Flatline Ops level was mounted backwards (at least for me, I prefer the level on the left side ;))
     
    That is a spectacular rifle. But as a certified mountainbike geek, you should turn the qr-lever on the ADM mount for the ATLAS around so it closes backwards.
    It would just look so much better.
    Its done that way on bikes so they wont snag on branches and what not. The same argument could be used on a rifle.

    (The devil is in the details...)
     
    I've not seen any of those Accubond LRs locally, but I'd be very interested in how they measure up in the drop/BC department.

    I only found them at my local Sportsmans Warehouse. I have not used them yet, but I may have a chance to go out this Friday and do a lot of testing
     
    The rifle looks beautiful, but it's too clean. You need to take it afield and get it a little dirty. ;)

    I'll keep an eye out for the AB LRs at the local Sportsmans' Outhouse. Definately update on velocity/drop experiences, please.
     
    That is a spectacular rifle. But as a certified mountainbike geek, you should turn the qr-lever on the ADM mount for the ATLAS around so it closes backwards.
    It would just look so much better.
    Its done that way on bikes so they wont snag on branches and what not. The same argument could be used on a rifle.

    As an ex mountain bike geek myself (still have my Cannondale Super V 2000 from the 90's), I should have thought of that. Easy enough to remedy with the Atlas QR :)
     
    What a fantastic looking gun, I can't wait for the range report.

    PS better camo your scope and barreled action lest you aggravate the trolls ;)
     
    And here is the man himself, Mr. Mark Chanlynn holding up the rifle the day I picked it up. I'll tell you all, I've had no better experience in the industry working with Mark Chanlynn, AJ Goddard and Tom Manners; these guys are all first rate and willing to share information and help you out!

    Chanlynn7SAUM_0001.jpg
     
    Mine was the second one he did in 7 SAUM. I originally had a short action from A.J. He Talked me into
    doing it in a Long action. Bring that Bad mammer jammer down to Raton this weekend and wring
    it out! You won't be lonely, there will be other Bighorn's with Mark's barrel down there.
     
    Bring that Bad mammer jammer down to Raton this weekend and wring
    it out! You won't be lonely, there will be other Bighorn's with Mark's barrel down there.

    Don't tempt me! I wish I could, but my wife and kids will be coming back from visiting some friends on the western slope so won't be able to get away. One of these days I'd like to do Raton, but I have so much to learn before I jump into any competitions (or maybe I know more than I think I do)...

    I wish there were more LR options that were less than 2 hours from the Springs area, you'd think someone out to the east with 100's of acres would set something up. When I lived up North we'd head up to Pawnee and you could shoot for miles (literally) out there, but that's just way too far now.
     
    That is a beautiful build you have there. I have the same stock ordered for my light weight 6.5 SAUM build, I went with a #4 contour, to keep the weight down.
     
    Ummmmm, Gun Porn ! , I think you are on the right track and now the Bug has bitten me , Thanks A lot !!!!
    I hope my wife is as understanding as yours !
     
    Don't tempt me! I wish I could, but my wife and kids will be coming back from visiting some friends on the western slope so won't be able to get away. One of these days I'd like to do Raton, but I have so much to learn before I jump into any competitions (or maybe I know more than I think I do)...

    I wish there were more LR options that were less than 2 hours from the Springs area, you'd think someone out to the east with 100's of acres would set something up. When I lived up North we'd head up to Pawnee and you could shoot for miles (literally) out there, but that's just way too far now.
    loo


    Raton is only 2 hours from you! If I was in the springs it would be an easy peasy drive.
    Alot of great guys down there, and it's a really well run match. They do sight in at 7:00
    Match starts at 8:00. You would have a blast.
     
    +1 on the photography dang, they look like they are going into a magazine! Nice looking rifle!
     
    Don't tempt me! I wish I could, but my wife and kids will be coming back from visiting some friends on the western slope so won't be able to get away. One of these days I'd like to do Raton, but I have so much to learn before I jump into any competitions (or maybe I know more than I think I do)...

    I wish there were more LR options that were less than 2 hours from the Springs area, you'd think someone out to the east with 100's of acres would set something up. When I lived up North we'd head up to Pawnee and you could shoot for miles (literally) out there, but that's just way too far now.


    You know that guy with the Constipated dog "high right" is absolutely correct!! With Raton only 2 hours from you its a great place to shoot. You will have a great time with an awesome group of people and learn a bunch. :)
     
    loo


    Raton is only 2 hours from you! If I was in the springs it would be an easy peasy drive.
    Alot of great guys down there, and it's a really well run match. They do sight in at 7:00
    Match starts at 8:00. You would have a blast.

    Its 176 miles and 2:50 driving time from where I'm at, not an easy round trip in a day. But like I said, I would like to get down there sometime...
     
    As an ex mountain bike geek myself (still have my Cannondale Super V 2000 from the 90's), I should have thought of that. Easy enough to remedy with the Atlas QR :)

    Nice! I worked two years for the biggest Cannondale dealership in Stockholm, Sweden. Cannondale had their fair share of ups and downs but in general I really like their bikes. I think ive had about 7 of them myself.
    Last year I managed to purchase a Brooklyn Machine Works Racelink from a collector in Copenhagen. Its an old dreambike of mine and I will probably never get rid of it.
    Oh, and ATLAS bipods are awesome, turning the lever around is easy. Just like you write.
     
    Its 176 miles and 2:50 driving time from where I'm at, not an easy round trip in a day. But like I said, I would like to get down there sometime...

    I've been half a dozen times to Raton SRM. Real laid back, inexpensive match yet challenging too. It really doesn't feel like a match. Just go out and hang out with a few other guys and plug steel for a day. If you score well then great, if not then you've spent some time outdoors and learned something. Also, it's crazy the wildlife just waltzing around,deer, antelope, turkey, etc., bullets whizzing over their heads, oblivious. Last month A tom turkey took offense to the Stage 1 540yd gong ringing in its territory and it had to go have words with it, all puffed up. We had to call a cease fire until it backed off. Great fun.
     
    I've been half a dozen times to Raton SRM. Real laid back, inexpensive match yet challenging too. It really doesn't feel like a match. Just go out and hang out with a few other guys and plug steel for a day. If you score well then great, if not then you've spent some time outdoors and learned something. Also, it's crazy the wildlife just waltzing around,deer, antelope, turkey, etc., bullets whizzing over their heads, oblivious. Last month A tom turkey took offense to the Stage 1 540yd gong ringing in its territory and it had to go have words with it, all puffed up. We had to call a cease fire until it backed off. Great fun.

    Too funny about the Turkey! That reminds me of the dear that used to play around at the range in Ft. Benning, you've got all these young recruits firing their M16A2's in 3 shot burst with tracers buzzing around and up come these dear just waltzing through the area with a death wish. Of course, cease fire would be called and all the venison loving soldiers would well up with tears in their eyes ;) In my years of hunting (and believe me, I am not the greatest hunter as I seem to have the worst luck) I have come to question the whole down wind, walk quietly and all that as it seems the most animals I've come upon were when I wasn't stalking but just walking around making noise or chatting it up with friends, etc.

    Raton sounds like a lot of fun, once I work through load development I will have to try and plan a trip down there. Is it "kid" friendly? I might want to take my 13 year old down as I think he'd love to see that as well.
     
    I think it would be. He can shoot, spectate, spot, sit in the car read a book, play angry birds, whatever. If someone's having a less-than-stellar day there might be some coarse language. It can run a while, if he doesn't have the attention span for it he might get bored. It usually starts at 0800, finish around 1400 depending on attendance and conditions.
     
    Goal: To build a LR tactical/hunting rifle that could be easily carried in the Rocky Mountains

    The fun specs:
    • Bighorn TL2 SA RH action with magnum boltface and picatinny rail
    • Timney 510 trigger set at 2lb
    • Surgeon SA bottom metal (to be used with Alpha Type 3/4 WSM magazines)
    • Manners MCS-EH1 stock with Elite GAP finish
    • Chanlynn 26” custom light palma contour barrel with fluting – 7mm SAUM
    • Thunderbeast 30BA brake
    • Atlas Bipod
    • Premier Reticles 3-15x50 LT Scope
    • Seekins 30mm low 6/4 rings
    • Flatline Ops Sniper 30mm AccuLevel
    • Triad Multi-CAM Stock Pack
    • Armageddon Multi-CAM suppressor cover
    • Thunderbeast 30BA Suppressor (soon... hopefully)

    Complete with magazine and scope - 10.5 pounds! Goal achieved!!!

    What reamer (freebore) did you go with? What's your OAL to touch the lands with the 180 hybrids?
     
    Don't tempt me! I wish I could, but my wife and kids will be coming back from visiting some friends on the western slope so won't be able to get away. One of these days I'd like to do Raton, but I have so much to learn before I jump into any competitions (or maybe I know more than I think I do)...

    I wish there were more LR options that were less than 2 hours from the Springs area, you'd think someone out to the east with 100's of acres would set something up. When I lived up North we'd head up to Pawnee and you could shoot for miles (literally) out there, but that's just way too far now.

    There is a monthly match in pueblo where you could get your feet wet. Third weekend of month I believe and it prob a whopping 10 min drive. very friendly prone match shooting itty bitty prarie dogs and you could be home by noon.


    Its 176 miles and 2:50 driving time from where I'm at, not an easy round trip in a day. But like I said, I would like to get down there sometime...

    I do it in one day all the time from north of Denver (4 hours each way lol). There is always people to car pool with tho.

    Why have a rifle if you arnt going to shoot it :)


    Nice rifle btw. I shoot bighorns and love em.
    Good luck,
    DT