My Pierce 7 WSM build, now with a new barrel!

[mcfred]

I'm kind of new here I've been trying something new and different by trying my hand at some DIY gunsmithing to build a multipurpose 7mm WSM rifle that I can hunt with as well as plink steel at 1000+ yds and maybe attend a few F-class matches. I thought I'd share. I don't really have a weight or min/max length goal as long as it has some practicality to it.

<span style="font-weight: bold">General specs so far: </span>
Pierce short action custom receiver, sako extractor, Cerakote finish
Jewell trigger with safety
Custom 7075 stainless 45 minute scope base, inspired by Mil-std-1913
Warne steel QD 30mm, medium height rings
Precision Shooting Sports billet bottom metal (sent out to black anodize)
Alpha Ind. 10 round magazines
One modified 3-round AICS mag
Custom 6061 Aluminum pillars for bedding
Custom inletted/bedded laminate stock
PTG 7mm reamer with .050" throat
Currently am using a 26" 1-9 twist Brux barrel

Traded to a 5.5-22x56 Nightforce with MOAR reticle
Total weight's ~13-14 pounds

The best cartridge OAL I can fit in my current magazines is 2.975" and that's after I buff out the weld bead in the top inch of the box to keep the meplats from dragging.

Anyway, here's some picts. Making pockets in the ADL stock for the pillars:

Inletting the bottom for the DBM after indicating off the receiver screw holes stuffed with gage pins and truing it up a little (just take light cuts):

Basic exploded assembly:

I'll still have to do some hand work to to finish the inletting and I still have to open up the barrel channel and finish it in ureathane or linseed/tung oil so I think it's a good start but still a ways to go.

Thanks for looking.

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

I got the bottom metal back from black anodize and had a chance to finish the inletting for the DBM. I also got the 7mm WSM reamer and a fluting tool if I feel that I need to flute the barrel in the future.

Second, I picked up a 12-42x56mm Nightforce NXS, so I think I'm good to go on optics for a while.

Lastly, I didn't order a match grade barrel yet since I've not researched it much, but I have a tactical match I'd like to attend this weekend and purchased a new 26" 7mm Mag Remington take-off barrel that I'll set-back and re-chamber to 7mm WSM. It's supposedly in the mail and if I get it before thursday I'll still have time to get the lathe work done, epoxy bed the action and barrel, work up a couple loads Friday, break in the barrel, clean it, reload Friday night and set out for the match on Saturday.

If the barrel doesn't show it's a show stopper and I'd say that there's a good chance it will all fall through. We'll see.

 

[Cinch]

Re: DIY 7mm WSM build on a Rem M700 clone

Looks great! I look forward to seeing the finished rifle and hearing a range report!

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

Looks like I'll miss my match since the barrel's still not been delivered. If it comes tomorrow I'll try to get it threaded/chambered since I won't be at the match.

 

[AXEMAN]

Re: DIY 7mm WSM build on a Rem M700 clone

looks good so far. nice looking build

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

I got a quick coat of oil on the stock and after it dried a little I weighed the unbedded assembly without the magazine/barrel and it came out a little less than 2.4 kg. Add the rings and the scope it jumps to 3.4 kg. Depending on how the barrel comes out it's approaching 5+ kg (>11lbs). Not exactly light but it's not too hard to reduce the weight if it becomes too heavy.

Might get the threading/chambering done today.

another pic.

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

Barrel's threaded, chambered and installed. I just need to bed it in and try my 180gr SMK and 139gr Hornady Interlock loads I've worked-up. Might have a field-report after this weekend.

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone


Here's a pic of my finished gun next to a friend's F-class gun using a the same Pierce action but as a 10kg single shot.

I did have a chance to get the gun together this weekend. Friday evening I had it all taped-off and the action waxed and set in epoxy by 10pm. Saturday it was still a little softer than I'd like so I just popped the barreled action free and cleaned up all the tape and excess glue. Fits real nice now. I put another couple coats of oil on the stock and waited for the wind to die down. I shouldn't have waited:

Sunday the wind was worse than it was on Saturday but I figured that a horrible crosswind at the range wasn't going to be too bad at 100m just to get it on paper and work the bore a little.

139g Hornady Interlocks zip along at 3429fps on 72gr of Win WXR and patterned at about an inch, despite the wind. I don't think that's bad for the first 5 shots. The gun has pretty bad muzzle jump though. The recoil's not bad but it makes it a bit of a pain trying to get back on target for follow-up shots. I think I'll be shopping for a brake sooner than later when I start firing the 180gr SMKs.

I'll be on the hunt for a match-grade barrel and a Bipod. Id anyone's got a suggestion let me know.

 

[Dirty Deeds]

Re: DIY 7mm WSM build on a Rem M700 clone

Why the long throat in a sub 2.9" COAL mag?

139's at 3429?!? I'm not buying that.

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

That's what Oehler said and Quickload said about the same. I'll try the 180's with Retumbo, and IIRC Quickload says to expect about 2950fps for those. The reamer was the same one used on the F-class build and mag length is 2.97-ish. I think they claim 2.985" but that is scraping paint.

So is there really a big difference between a $20 bipod and a $200 one?

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

I got some more velocity data this morning. I can get 180 SMKs to 3000fps with Retumbo (full but uncompressed) with magnum primers and the new match 162 Hornadys up to 3220fps on WXR where extraction started getting sticky. Dialing it down a grain yields 3160fps and easy extraction. In order to get the 162s to fit in the mag they're ~.075" off the lands and group about a moa, the SMks though are just off the lands and didn't do much better. Might just be limited by the quality of the barrel. I'll have to do a little more testing. Hopefully, one load will tighten up and I can get to banging steel out to 750.

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

I think it's time to add a brake; the 180's are just to punishing to shoot more than 20 or so. I think the light weight 7mm build recoils about as hard as the 510WSM heavy build.

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

It took a few rounds but it seems that the groups from the Remington factory barrel are tightening up and the copper fouling takes longer to accumulate. I got some more loads tested and it appears that the 180gr SMKs are going to work out pretty well (they fit in the magazines too). The standard deviation in velocities leaves something to be desired so I'll work some more on getting more consistent velocities and try some groups at 200+yds. Still ~5/8" at 100 from a factory barrel isn't too bad.

I'll shoot it out and then fit the 27" fluted heavy contour Brux barrel I picked up from another SH member last week. I'm also working on a composite adjustable cheekpiece and my bipod and some Grovtec flush cup swivels showed up this weekend. So I'll be working on the stock for a while too.

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

Getting a little further. Adjusted length of pull and chopped on the front stock to install a rail for the bipod.

I scored a deal on some powder for $13 a pound, shipped. Got some more loads to test and a local friendly precision rifle match in a few weeks.

Here's how it looks now. Still needs a little work. All in due time.

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

I went to my first precision rifle match and learned that I have a lot to learn. I didn't place last but I was pretty far down the list. haha

I made a 'flush' bipod/flushcup rail last weekend. Thread:
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Main=238481&Number=2696387

Pics:

Looks cleaner now. I did some ladder testing at 610 yards and have 2 more loads to try.

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

I've been learning about doping for wind and moving targets, how to better use the reticle for drop and windage. I reworked the loads to eliminate any ejection issues and re-made my drop chart.

Then I went to my 2nd match this last weekend and placed 3rd, which surprised me. I missed a couple shots due to exceeding the time limit which would have bumped me to 2nd had I been faster.

Fun stuff.

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

Had a brake installed and reworked the length-of-pull extension with a chunk of Iowan walnut. I might just black Krylon it later, seems out of place with the existing color scheme.

I went to the range to test it out. Didn't make any friends either.

I thought the guy with the 6" 500S&W revolver was being a little loud so I upped the ante. Recoil's much reduced so I shouldn't have a sore shoulder after 50 rounds anymore. Only issue is that think the brake shifted my POI up and left 2 moa x 1 moa on my pet load and the groups opened up too. I want to remove the brake and see if it returns to zero like it was before. It could be that the lightweight chromoly barrel's shot out already after 500 rounds. I'll work up some more loads to see if I can find a new sweet spot.

Latest pic (with a different scope)

Might thread/chamber the fluted SS Brux I have lying around soon:

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

Someone asked me what my stock weighed and I put it all on a scale.

The gun overall weighs 12.2lb without the sling or magazine but with the heavy Nightforce and bipod. Pull off the barrel/receiver/trigger and the remaining stock weighs 4.0lbs.

When I put it back together I discovered that my scope mount was loose and all 4 8-40 srews had backed out. It's all tight again and I hope it solves my POI shift I discovered when I installed the muzzle brake.

 

[Jackson/Charvelfan1]

Re: DIY 7mm WSM build on a Rem M700 clone

Looks like you built a very nice rifle.

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

Thanks for the compliment, it does alright.

 

[mcfred]

Re: DIY 7mm WSM build on a Rem M700 clone

Weekend before last I went to a 1000 yard F-class match. It was cold and overcast. I can deal with the cold and was looking forward to minimal mirage. Then it got windy and started snowing. It just got worse from there. I only got off about 5 rounds in the 12mph shifting crosswind before it was too hard to see the bull's eye. It was nice that my coldbore shot was a 10. So my drop chart's not too far off and I guessed the wind dope pretty good.

Packin' it in...

There was really low turn-out. I guess some people actually looked at the forecast

This last weekend was the precision rifle match and I actually looked at the forecast this time. It was pretty calm and clear and a balmy 25&#730;F. We got a late start but a decent turn-out made for some fun. I tied for third out of 9 shooters so despite dropping lots of points on the 500 yard coldbore and 8" 600 paper I made up for it later with successful 660, 690, 750 and 800 yard shots later in the day.

600 yard firing line

Sand is yummy.

690, 750 and 800 yard gongs off the Conex Box:

 

[mcfred]

Re: DIY 7mm WSM build on a Pierce SA

Here's my fancy new 26" BRUX 7mm barrel to replace the old factory one that was nearly shot-out.

indicating it in

threaded and chambered.

old (left) and new (right)

old (top) and new (btm)

stock Fore-arm CNC tool path for clearing a fatter barrel.

4x4 test piece/fit

Reverse engineered bottm metal for jigging

it fits!

stabilized the front end with a threaded rod that fits the front flush cup set in a standoff. Tightened up with jamb nuts, then started cutting:

New more better, 3 lbs heavier rifle, I hope it shoots bug-holes:

 

[adkmtnman]

Re: DIY 7mm WSM build on a Pierce SA

Very nice setup... God I need a lathe! and a mill while I am at it

 

[mcfred]

Re: DIY 7mm WSM build on a Pierce SA

Thanks for the compliment.

I played hookie from work for a couple hours this morning to put a few rounds down range with the new barrel. Targets were all at 200 yards. Fairly calm with shifting mirage. Top left was just an existing target for getting on paper. It hit low and left from the previous zero. Not bad for totally dismantling a rifle, reassembling with new and modified components and taking 5 shots.

top left were 5x 180 SMKs
btm left were 5x 175 SMKs (ignore the note on target)
btm right were Berger 5x 180 target boat tails
top right were Berger 3x 180 VLD (!!)

Looks like I'm going to try some more Berger VLDs and Hybrids and see what I come up with. Hopefuly the gun's more accurate than I am. If that's the case, with more load development, I'm looking at a .3 MOA - .6 MOA rifle. Makes me happy that I machined most of it myself.

I think it'll still benefit from a brake despite being 20% heavier than it was. Another project to add to the heap.

 

[justinbaker]

Re: My Pierce 7 WSM build, now with a new barrel!

Great looking gun!

i thought it looked familiar

im third from the bottom in the black shirt and damn my 20 inch barrel looks short compared to everyone elses

im gonna have to pick your brain a little, my dad is wanting to put together a 7 wsm for hunting/occasional matches

 

[mcfred]

Re: My Pierce 7 WSM build, now with a new barrel!

I remember you, nothing wron with a 20" barrel either. I bet it's a lot easier to handle offhand than a 26". I suppose my rifle's a little different than most, people seem to remember it.

Did you go to the match this last Sunday, I couldn't make it since I was still working on the rifle. It started out fairly calm and got pretty breezy by 10am; much much better than the day before: 60 mph gusts.

Regarding your dad's rifle, I'd be happy to help where I can. Shoot me a message.

 

[mcfred]

Re: My Pierce 7 WSM build, now with a new barrel!

I had a chance to go to another local match 2 weeks ago and after ~70 rounds in all kinds of less-than-comfortable positions my shoulder was black and blue despite the additional weight so I took some time over the weekend to make a brake with ports on the side to keep from kicking up much dirt. Here's what I came up with:

I used some 440c stainless. I took it for a test drive on Monday and it seems like it works pretty well at taming the 180gr loads. And here's another shot of how it looks now.

 

[Peepaw]

Re: My Pierce 7 WSM build, now with a new barrel!

Thats a nice stick you got there, really impressive. This thread caught my eye as Im doing my first 7MM build. Not doing a WSM like you, Im just doing a "regular" old 7MM Rem Mag, but had a question for you. I caught a line you mentioned above:
"The gun has pretty bad muzzle jump though. The recoil's not bad but it makes it a bit of a pain trying to get back on target for follow-up shots."

Did adding your brake help with the muzzle jump? I've been shooting my 26" HB Varmint .308 for awhile now (rifle weighs @ 8 3/4 Lbs, no scope/base/rings/ammo), and like most .308, packs a decent punch.
So, when I picked up my 7MM Rem Mag I was expecting a lot more kick, especially since this particular rifle is a lightweight...6 1/2 lbs..compared to my .308.

Now, I bought this particular rifle just for teh action (Rem 700 LA) to build around, but was curious about muzzle jump. WThe amount of jump I am getting from this current setup is crazy! Right now, shooting off a bipod, it makes it very difficult for follow up's.


So, my question to you is: Did the brake help tame the jump?

I also saw that you added some weight to your rifle, and did that help as well?

This being my first go round with the 7MM Rem Mag after shooting my .308 for so long, I wasnt expecting this, as much as I was expecting more kick. Because if anything, my .308 punches harder. I know it sounds crazy, because obviously the 7MM packs more energy, so would stand to reason it should hit harder. So maybe Im losing some of the kickback in muzzle jump?

Excuse some of the "newbie" type of questions. Thanks

 

[justinbaker]

Re: My Pierce 7 WSM build, now with a new barrel!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: McFred</div><div class="ubbcode-body">I had a chance to go to another local match 2 weeks ago and after ~70 rounds in all kinds of less-than-comfortable positions my shoulder was black and blue despite the additional weight so I took some time over the weekend to make a brake with ports on the side to keep from kicking up much dirt. Here's what I came up with:

I used some 440c stainless. I took it for a test drive on Monday and it seems like it works pretty well at taming the 180gr loads. And here's another shot of how it looks now.

</div></div>



looking good, did you shoot in the score hi match?

 

[mcfred]

Re: My Pierce 7 WSM build, now with a new barrel!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Peepaw</div><div class="ubbcode-body">Did adding your brake help with the muzzle jump? [My] particular rifle is a lightweight...6 1/2 lbs..compared to my .308.

<snip>

The amount of jump I am getting from this current setup is crazy! Right now, shooting off a bipod, it makes it very difficult for follow up's.
</div></div>

Lighter bullets, lower velocity, a heavier gun and a brake (or suppressor) will all lessen preceived recoil and will keep the gun settled for faster follow up shots. A stock that fits you well will also help a lot. Another rookie mistake I was guilty of was using too high a magnification on the scope. For 8"x11" sized targets, 15 power is plenty out to 800 yards in my opinion if you're reticle is fine enough that it doesn't block your view of the target. My Nightforce is a max of 32 power and I almost never go there unless I'm spotting a fellow shooter or I'm trying to see holes in paper at 350+ yards.

I "added weight" to my gun when I rebarreled it because at competitions I could fry an egg on the sporter contour barrel after 5 consecutive shots in the afternoon heat. Stainless steel and more mass in the barrel helps keep the barrel temps down so it will last longer than 1000 rounds with my overbore magnum chambering. If your 7mm RM is only only 6.5 lbs then I'd watch the barrel temps if you want that barrel to last.

If you handload you can also tune your laod to the types of shooting you do. Most of my competitions are less than 800 yards. A 162gr bullet at a higher initial velocity will buck the wind better than a 180 at a lower velocity while having a flatter trajectory. But after about 750 yards the heavier bullets will end up grouping better in windy conditions.

Just do some reasearch with the JBM ballistics calculator and go shoot and see what works for you.

 

[mcfred]

Re: My Pierce 7 WSM build, now with a new barrel!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: justinbaker</div><div class="ubbcode-body">looking good, did you shoot in the score hi match?</div></div>

Yes, I did. The range re-scheduling to Mother's day caused a bunch of people to drop out and a few people that did show didn't stay to the end. I ended up in the middle of the pack both from mediocre shooting and guessing poor dope in the wind as well as not bringing enough ammo. I was 24 rounds short.

Charlie knows how to put together a good show.

 

[Peepaw]

Re: My Pierce 7 WSM build, now with a new barrel!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: McFred</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Peepaw</div><div class="ubbcode-body">Did adding your brake help with the muzzle jump? [My] particular rifle is a lightweight...6 1/2 lbs..compared to my .308.

<snip>

The amount of jump I am getting from this current setup is crazy! Right now, shooting off a bipod, it makes it very difficult for follow up's.
</div></div>

Lighter bullets, lower velocity, a heavier gun and a brake (or suppressor) will all lessen preceived recoil and will keep the gun settled for faster follow up shots.

A stock that fits you well will also help a lot
<span style="font-style: italic"><span style="color: #FF0000">That is getting changed, as I have found the "stock" stocks pretty much bite, and this one is no diffrent. With my.308, I finally swapped over to a B&C Tactical M40 and love it!</span></span>

Another rookie mistake I was guilty of was using too high a magnification on the scope. For 8"x11" sized targets, 15 power is plenty out to 800 yards in my opinion if you're reticle is fine enough that it doesn't block your view of the target. My Nightforce is a max of 32 power and I almost never go there unless I'm spotting a fellow shooter or I'm trying to see holes in paper at 350+ yards.

<span style="font-style: italic"> </span> <span style="color: #FF0000">I have yet to decide on glass for my 7MM build....looking at Nightforce, Leupold, Vortex, etc..My .308 I've got teh Vortex Viper 6.5-20x44 mounted on a EGW base in a set of Warne Rings (lows). It's a pretty economical setup, that once I got some seat time behind, has really impressed teh hell out of me. It's sub MOA all day long. I do plan on a stepping up in optics (along with everything else..optics, barrel, trigger, etc..) for the 7MM build</span>

I "added weight" to my gun when I rebarreled it because at competitions I could fry an egg on the sporter contour barrel after 5 consecutive shots in the afternoon heat. Stainless steel and more mass in the barrel helps keep the barrel temps down so it will last longer than 1000 rounds with my overbore magnum chambering. If your 7mm RM is only only 6.5 lbs then I'd watch the barrel temps if you want that barrel to last.

<span style="font-style: italic"> </span> <span style="color: #FF0000">Well, THIS rifle is 6 1/2 lbs. It's just a Rem 700 LA 7MM Rem Mag ADL 26" that I picked up from Academy. Again, I bought it simply for the action. I took rifle out to just shoot it, and to see how accurate a $369 rifle can actually be. After getting her sited in, I put a few down, and I got some 1" to 1 1/4" groups @ 100 yards. Nothing impressive, but for $369, hard to argue with that. I'm sure with more range time, those groups would/could improve, but again, bought rifle just for action. So, packed it up, and broke it down to begin my build. But yes, that barrel got HOT, REALLY REALLY hot after 5 rounds. Being used to my HB .308 and I can easily put down 10-15 rounds, and still not be as hot as this barrel was after 5. What I am getting at is, I do plan on a bigger barrel with my 7MM build</span>

If you handload you can also tune your laod to the types of shooting you do. Most of my competitions are less than 800 yards. A 162gr bullet at a higher initial velocity will buck the wind better than a 180 at a lower velocity while having a flatter trajectory. But after about 750 yards the heavier bullets will end up grouping better in windy conditions.

Just do some reasearch with the JBM ballistics calculator and go shoot and see what works for you.

<span style="font-style: italic"> </span> <span style="color: #FF0000">Thanks for all your insight and info. I havent gotten into handloading, YET. I've been shooting factory loads up to this point, but with the 7MM, I plan on getting into it. I did some research on equipment already, and I plan on giving it a go over the summer and try my luck at handloading. I build Hot Rods/Race Cars for a living, so I naturally like building/making/fabbing shit up. I just find it odd it has taken me this long to get into handloading to be honest with you. Anyways, again, thanks for info, been very helpful. (yeah, I know, i get longwinded)</span></div></div>

 

[mcfred]

Re: My Pierce 7 WSM build, now with a new barrel!

I had a guy ask me to make his McCrees Chassis into a prettier tube gun. I used my Pierce short action to mock up fitment. The whole tube fore end's a few ounces lighter and less ugly. It still needs a coat of paint/cerakote. The project kept me out a trouble for a weekend. Thought I'd share.

 

[Rockfish Dave]

Re: My Pierce 7 WSM build, now with a new barrel!

I'm not much of a tube gun fan, but that looks great!

Congratulations on your work!

I am just guessing, but I would be willing to place a wager that there are others out there that would be interested in converting their McRee's into tube guns as well.

If you don't want to sell it, it would be nice if you shared your design with Scott.

 

[Adam B]

Re: My Pierce 7 WSM build, now with a new barrel!

that tube on the McRee looks badass, great work!!!

 

[mcfred]

Re: My Pierce 7 WSM build, now with a new barrel!

I'm not sure I could get the machine time down enough to make it affordable to anyone that wanting to "upgrade" while making it worth my time. Though I'm sure I could save some time with a better fixture and some larger roughing tools. Either that or forego the aluminum fore end save the time/weight with carbon fiber.

Otherwise I've got no market, advertising or capital to drum up an inventory for 'walk-in' business, though it was a fun project to work on. If it were my chassis I'd've taken more time to lighten it up some more and probably would have cut the recesses with triangles instead of squares since my personal projects aren't billed for the machine time and material's cheap.

 

[Bacarrat]

Re: My Pierce 7 WSM build, now with a new barrel!

The tube forend makes the McRees chassis look have decent now. Great job!

 

[justinbaker]

Re: My Pierce 7 WSM build, now with a new barrel!

looks great, im sure the panda will love it

eta: missed ya at the last match, gonna be there in august?

 

[mcfred]

Re: My Pierce 7 WSM build, now with a new barrel!

Yea I was out of state for the last match. I don't anticipate missing the next one.

The Panda says he likes it but he's not yet got it in hand.

 

[mcfred]

Re: My Pierce 7 WSM build, now with a new barrel!

I've got my rifle all apart because I noticed that all four #8-40 scope base screws are loose again. It explains why I've been chasing dope around and around.

Maybe it's time to get a inch-pound torque wrench and some red loctite. Web searches seem to suggest approx 28 inch-lbs on these bastard 8-40 screws. If it comes loose again I might weld the friggin mount to the receiver.

 

[Jon Lester]

Re: My Pierce 7 WSM build, now with a new barrel!

loctite on base/ ring screws= WIN

 

[mcfred]

Re: My Pierce 7 WSM build, now with a new barrel!

I eventually pulled the scope mount and degreased it and reinstalled it with a copius amount of loctite. It's got about 60 more rounds through it now and seems to be keeping the zero. I'll admit I don't trust it yet in the long run. We'll see.

This last weekend was my first local match of the year and got my first 1st place. I was able to get most of my rounds off, but I still have a lot of room for improvement. One stage I wasn't paying attention and I had the elevation knob off a full rev (20 MOA) and botched the stage entirely.

Still, I think I've gotten better over the last 18 months and have identifyed and addressed some of my equipment issues along the way. It's nice that I don't suck at least one 'sport.'

The WSM muzzle blast picks up some sand too:

 

[mcfred]

Re: My Pierce 7 WSM build, now with a new barrel!

People have asked me how I picked the 7WSM. My short answer is that it provides the optimum ballistics in a short action. Of course a lot of variables go into what's "optimum" and thus the various caliber/cartridge debates. Here is my take:

If you are talking about maximizing the ballistic performance of a short action, then it's hard to beat the 7mm short mags. The short mag cases are about as big around as you can fit in most 308-derived actions (more or less the definition of "short action"), and their length maximizes the case capacity. With this approximate limit on the amount of powder you can burn in a short action, what caliber should it be? There is a "knee" in the caliber curve that falls around 7mm. With smaller bullets the BCs are lower and the overbore case can't push the bullets correspondingly faster. With larger bullets the BCs are better but then the case can't push them fast enough to keep up with the smaller calibers. Run the numbers for yourself. If you have quickload start with a 22 short mag and go all the way to 510. I don't think I've ever heard of a 22WSM but you can make one it quickload easily enough. I actually own a 510 WSM and while it's a fun and affordable way to fling heavy bullets it's just too slow to keep up with smaller calibers, even with BCs over 1. Of course this knee is not a sharp cut off, and arguments could be made for nearby calibers like 277 and 308. There's not a good selection of bullets in .27 though, and in .30 the heavy high BC bullets are starting to run into COL and case capacity issues that definitely plague the calibers beyond 30. If you can give the bigger bullets more case (338 Lapua and up...) then they'll easily out perform the little ones, but were talking about the limitations of a short action.

The graph below shows what I'm talking about. It plots 500 yard and 1000 yard drift by caliber using data from quickload and JBM ballistics for a range of calibers using a WSM case, 2.9" COL, 24" barrel, and where possible Berger heavy long range bullets (the 375 cal is a 375gr sierra and the 510 cal is a 750gr Amax). You can see that the 25 and 27 calibers suffer a lot just from bullet selection, but you can guess where they would fall if they had similar bullets available. Of course I'm not presenting this as gospel; it's just an approximation and some exceptions to this plot could probably be made with longer barrels, special powders, special bullets, etc. My point is only to illustrate the general trend with as few extra variables as possible. I would encourage others to try this experiment on their own and post their findings, if only to check my work.

Now if you say that the short mags are too much for a short action, then you're basically talking about reducing case capacity to reduce recoil, barrel erosion, muzzle blast, cost to shoot, etc. So what does this graph look like with say, 2/3 of the WSM case? This is right in the range of the 308 type cases. I have not run the numbers yet, but reducing the case capacity ought to shift the knee in the drift/caliber curve towards smaller calibers. I think this is why the 260 rem and 6.5 creedmore are finding so much favor.

The distance you're shooting is also a factor when you try to pick what's "optimum." By 2000 yards the heavy bullets have the advantage just by virtue of BC. So if all your shooting is less than 500 you can "get by" with a much cheaper combination and not give up too much.

With this in mind, I think my next project will be a 7 WSSM. This re-uses all of my setup (bolt face, magazines, bullets, etc.) so I can simply swap a barrel and be equipped almost as well for the local matches that are less than 500 yards for the most part.

 

[mcfred]

I spent some time last weekend addressing some potential brass-related issues I've started having at my matches.

According to Quickload, my 180SMK load should have a max pressure of 45ksi but I'm getting high pressure indications including flattened primers, heavy bolt lift and ejector wipe on the caseheads. I've got several firings on my set of brass and think I'm getting donuts. The donuts and my ø.317" "no turn neck" might be spiking the pressure.

Also at my last match (I got 3rd ) I had difficulty ejecting a live round after the buzzer on one stage. I had to hammer the bolt open and when the bolt did come back it left the bullet in the throat and ejected a piece of brass full of powder. Pretty annoying. The load should be .010+ off the lands and the throat should be even longer after 600 shots. The bullet should not have gotten stuck and needed investigation.

So addressing donuts first: These pieces of brass have been shot 5 times now and since 180SMKs are seated deep, donuts could be a real culprit. So I set up the lathe, cut an oversized .2855" mandrel to force the donut to the outside of the neck. Set the tool to cut a .015" neck wall thickness (.003 total chamber clearance) and ran the cutter to the shoulder. I ended up with a nice shiney ring at the NSJ. Donut issue solved for now. I'll re-anneal them for good measure.

Lathe/mandrel/cutter setup:

Product:

Next, I looked at the bullet that lodged in my chamber. I compared it to a few new ones. Turns out the diameter's .2844", a few tenths oversized. Thay's not such a bad thing but my PTG reamer's got a .2845" throat. So my pressure issue could also be a little throat carbon/gunk build-up causing a zero clearance situation. It could be causing bullet setback or generally jumping the pressure up as if a bullet were jammed in the lands.

I am going to clean the sh¡t out of the barrel and look into switching to a true .2840 bullet or start miccing all my SMKs to keep oversized bullets out of the match loads. And all of this, no doubt, will tweek my dope I've been working on for a while... Its always something. Haha.

 

[mcfred]

I got a shipment of new components and had to verify the load still matched my drop card.

I shot these prone, off a bipod and rear bag and after 70 previous rounds.

Not too bad

 

[bjay]

I got a shipment of new components and had to verify the load still matched my drop card.

I shot these prone, off a bipod and rear bag and after 70 previous rounds.

Not too bad

Nice rifle and great shooting.. last month i was having hard time to decide bet wsm n saum on 7mm .. since i already shiped action and arrel to smith and asked him to make me saum...i wish i wouldve seen this thread few weeks ago..

 

[Hennig]

Thought the groups were tidy, then saw they were at 200. Nice!

 

[mcfred]

Nice rifle and great shooting.. last month i was having hard time to decide bet wsm n saum on 7mm .. since i already shiped action and arrel to smith and asked him to make me saum...i wish i wouldve seen this thread few weeks ago..

I think it's hard to lose either way. ~2850+fps with the high BC .284 bullets are hard to beat. They certainly buck the wind!

Thought the groups were tidy, then saw they were at 200. Nice!

It's rewarding when it all comes together, especially since I did most of the work myself.

 

[bjay]

I think it's hard to lose either way. ~2850+fps with the high BC .284 bullets are hard to beat. They certainly buck the wind!



It's rewarding when it all comes together, especially since I did most of the work myself.

I think ill be fine with 30" barrel 30moa base im setting this rifle to hit 2k

 

[mcfred]

3000fps should be easy with 180s through a 30" barrel. Should definately reach out there. You're going to have to heap on the powder though to keep the SAUM supersonic at 2000yds. However, if you're high elevation it gets lots easier.

I guess I need to find another image host...