Savage 110 custom build - 7mm Valkyrie

[chuckhammer]

Here's a summary of the improved version of a 7mm-300 Win Mag I drew up for my first custom rifle build. I named it the 7mm Valkyrie after both the buxom blonde "chooser of the slain" from Norse mythology and after the incredible XB-70 Valkyrie bomber from the 1960s.

I chose the Savage 110 due to the barrel nut and floating bolt head. Both of these features make for a very home gunsmith-friendly build. I managed to keep the total cost below $1500 for the whole rig. As a result, some of the parts are not cream-of-the-crop but I believe they will serve me perfectly well for now.

First shots are shown at the bottom! These five were touched off on Sunday 12/8 and were only the 11th through 15th shots ever fired from the rifle. Yes, that is two bullets that formed a single nearly concentric hole.

My goal is to find a FAST 1/2 MOA load at 100 yds and then move out to longer distances. I have several different powders and bullets to try so it may take a couple of hundred shots before I reach that point.

All in all, I am very pleased with how it's turned out thus far. Many thanks to 'Hide member Aeon1 for his assistance helping work out a strategy for the dies.

 

[BoilerUP]

Did you send a reamer to Jim Briggs or Criterion to chamber the barrel, or did you have a gunsmith do that?

 

[hillbillybear]

Very interesting project. I look forward to seeing more.

 

[18Echo]

I read about this chambering on longrangehunting.com when I was researching my fast 7mm build. I decided to go with the straight 7-300WM for ease of case prep and not having to fire form brass. This is a very interesting cartridge and if I ever do decide to delve further into the wildcat realm this would be a good candidate, or a 284 Jarrett. Robert Gradous is building my 7-300 and when it looked like I never would get my reamer he suggested the 284 Jarrett which he said was similar and he already had a reamer for, but my 7-300 reamer finally came.

BTW does that .298 freeborn allow you to load at AICS mag length? Are you also going to try the straight 180 VLD's? My reamer only has .095 FB, but thats what Dave Kiff said I needed for the 180VLDs to feed out of an AICS mag, seemed short but I double checked with them and it was confirmed.

 

[chuckhammer]

Did you send a reamer to Jim Briggs or Criterion to chamber the barrel, or did you have a gunsmith do that?

I first ordered the barrel through Jim (16 week wait) and then finished up the reamer print with Dave Kiff's help at PTG. He tweaked literally a couple numbers on the print from what I had and then we put it into production. He convinced me on the 37 degree shoulder, specifically. It apparently offers an ideal combination of combustion efficiency and eliminated brass flow. When completed, PTG shipped the finish reamer directly to CBI. Once the barrel was done, CBI shipped the reamer and barrel to Jim who then forwarded both to me. Got the best barrel price this way.

I used the reamer to modify the sleeves in both a Redding Micrometer bushing neck die and an RCBS Gold Medal seating die. Seems to be working OK thus far.

 

[chuckhammer]

I read about this chambering on longrangehunting.com when I was researching my fast 7mm build. I decided to go with the straight 7-300WM for ease of case prep and not having to fire form brass. This is a very interesting cartridge and if I ever do decide to delve further into the wildcat realm this would be a good candidate, or a 284 Jarrett. Robert Gradous is building my 7-300 and when it looked like I never would get my reamer he suggested the 284 Jarrett which he said was similar and he already had a reamer for, but my 7-300 reamer finally came.

BTW does that .298 freeborn allow you to load at AICS mag length? Are you also going to try the straight 180 VLD's? My reamer only has .095 FB, but thats what Dave Kiff said I needed for the 180VLDs to feed out of an AICS mag, seemed short but I double checked with them and it was confirmed.

The freebore is .198". Print might be tough to read on here. From what I can see thus far, it still places the bullet a bit too deep in the case versus the ideal with the bearing surface terminating at the base of the neck. My bearing surface with 180 Hybrids touching the lands ends ~0.050" or so below the neck. COAL is about 3.640" with that load. What's the AICS mag length?

The 7-300WM is a great choice. The only tangible advantages of the Valkyrie are eliminated case growth (no brass flow) and ~4 gr additional water capacity. It's not a lot of benefit considering the fire-forming work needed but I think it's still neat.

 

[chuckhammer]

In case anyone is interested, I did my fire-forming in the bullet-less "cream of wheat" manner. I loaded 16gr of Bullseye powder with a compressed column of cornmeal over it, topped off with a 1/4 sheet of single-ply toilet paper. The Valkyrie case you see in the second pic in my original post was formed in this manner and had not yet been fired at full pressure with a bullet. Now that I have fired some full-pressure rounds, the shoulder-to-body junction came out nice and sharp. I'll post a pic showing loaded rounds of 300WM, 7-300WM, fire-formed 7 Valkyrie, and fully-formed 7 Valkyrie.

 

[cav has been]

Interesting build. Looks like it getting it all sorted out has and will keep you entertained. All the gears in my pea brain haven't meshed yet this a.m. but it looks like your 7-Valkyrie should be similar in case capacity to the 7-300 weatherby. The absence of Weatherbys name on the brass and the loss of the "ventrified" shoulder and neck will be a plus.Too bad a man couldn't have ditched the belt at the same time. Regardless the hotrod 7mm's certainly are performers!

 

[chuckhammer]

Yep, very close to 7-300 Weath Mag. QuickLOAD says that one holds about 4 gr more H2O than mine (97 vs. 93). I have some Norma brass to neck down and fire-form. It should end up at around 95 gr H2O but with the supposedly soft Norma case head I'll have to back off the pressure some. Or live with single-use brass. Yuck.

I considered other parent cases, such as a shortened 7 RUM, in order to skip the belt. However, the "archaic" belt does help in fire-forming as it sets the initial headspacing. If you start with something like the 375 Ruger case (see Gunwerks 7 LRM) you have to leave a false shoulder during neck-down at the precisely correct location to establish the real shoulder during fire-forming. Much more tedious, at least until you find that perfect necking dimension.

I may do a shortened 7 RUM after this barrel is shot-out. I was thinking about a case body length that would place it right around 95 gr H2O or so. Body length would be nearly dead-center between 7 WSM and 7 RUM.

 

[scpaul]

Mr.Chuckhammer ,I'm still working w/my build,haven't reached the point/no return reguarding the chamber. Do you have any new developments on the Valkyrie vs. the Practical ? I'm going back/forth regarding the growth/no growth neck thing and the extra case volume ,because it seems with extra volume would allow the use of more/different slow powders, especially since am eventually planning on a bbl. at least 28" and possibly 30". Initally I'm rechambering the orig. 26" 7mm Rem. mag. bbl. The finished product will be used mostly from a bench and a fixed deer stand with a shooting rail. As you can see I'm not too worried about portability. Thanks, Paul

 

[chuckhammer]

scpaul,
I've ben busy with family and work since posting this pre-Christmas update. Just last night was the first time since then I've gotten back into it for further load developement. I have some 7mm neck-sized Norma 300WM brass that needs fire-forming so I packed about 20 pieces last night with Bullseye and cornmeal.

The Practical has some concrete advantages over my cartridge. Primarily that no custom dies, or modifications to production dies, are required. That said, I do like the Valkyrie's 37 deg shoulder. I believe it is a worthwhile improvement over the Pratical's 30 deg shoulder in terms of completely eliminating case growth and also reducing throat erosion.

The difference in case capacity between a standard 7-300WM and the Valkyrie (both using W-W Super brass) is about 4 gr of water. I have not measured the Practical's case capacity but based on the reamer print I would say it is closer to 7-300WM. Maybe 90-91 gr for W-W Super brass. That equates to perhaps 20-25 feet/sec faster than a 7-300WM from a 28" barrel firing Berger 180s with Reloader 33.

Does that help with your decision? It basically comes down to your personal interest level in doing the extra little bit of work for a wildcat like the Valkyrie. Using the chamber reamer to modify production "sleeve-type" dies, primarily.

 

[tui_man]

300 Blaser case is pretty much a short rum

Sent from my GT-I9300T using Tapatalk

 

[scpaul]

Hammer,as far as the case volume I was thinking more of volume, not fps. I'm thinking that with the real slow powders the extra volume might help, but +- 4gr. of water isn't much volume. I'm going to have ck. the conversion on that. On another note I really can't see what the big deal is re: a belted case. Is it possible that the mfgs. are using it to stimulate sales ? I personally like the belt. It gives you additional points of referance for measurements and in the case of fire forming ,less movement of the case prior to the cases full expansion in the chamber giving you a more consistant finished product. Have you noticed any real differance feeding the 37* shoulder vs. the 30* ? At this point I'm using a Savage for the build, if all goes well I have a Rem 700 sendero in 300 Ultra for the next one , unless....well you know. Paul