7mm build

[clownbuster]

This was an interesting observation from Broz on the 7mm 195 killing elk from this thread;
https://www.longrangehunting.com/threads/7mm-sherman-short-mag-vs-300-win-mag.170582/page-2
---------------------------------------------------------------------

"But since I spent last fall killing elk like a mad man (70 elk taken total) and the 300 win with a 215 Hybrid @3035 and the 7-300with a 195 @2950 were the two rifles use most for the first of many kills, let me offer some real world long range hunting results. PS, both rifles loaded to max with equal pressure signs.

First, to the OP, you are cheating your 300 win with the 210 VLD. It is no doubt that the 195 is one of, if not the best bullets for external ballistics there is for a 7. So lets offer the same to the 300 win and feed it a 215 Hybrid with a much higher BC than the 210 VLD. It is only fair to compare hybrid ogive to hybrid ogive right? Plus the 215 Hybrid with its shorter bearing surface than the 210 VLD will actually get more velocity than a 210 with less powder. Been there done it over and over.

Now lets go kill elk. I mentioned the 300 win and the 7-300 were the two most used rifles during a good part of last season here. This included a pre-season management hunt, all season long. And a post-season management hunt. Some nights we even had these two rifles side by side with a different hunter on each rifle while we waited in the blind for the elk to enter the hay field. Here are the results. The 215 Hybrid will out kill the 195 in a way so obvious after about a 15 or 20 elk taken with the 7 I put it away. The 300 with a 215 , not once needed a second shot to dispatch the elk. The 7mm, several needed a second shot. Now, add in the real world possibility of a less than perfectly placed shot and the advantage in terminal performance of the 300 with a 215 becomes even more evident.

This I feel is a great comparison. Why?
1: Because all this info is real and happened.
2: Same parent case were used.
3: Same powder were used
4: Same barrel brand and length were used same number of lands and groves
5: Repeated results were studied with several witnesses
6: I personally field dressed about 50 elk and documented the terminal performance, wound channels and shot placements myself
7: Optimum bullet used for each chambering
8: Both with the same muzzle brakes and barrel contour.

Since I just happen to have both of these rifles in my ballistic app, with drops documented to a mile and confirmed. Lets compare the real world external ballistics.

7-300 win with 195 Berger @ 2950
800 yards 10 mph 3:00 wind
dial up 15.9 moa right 2.6 moa
impact velocity 2150 energy 2000

300 win with 215 Hybrid @ 3035
800 yards with 10 mph 3:00 wind
dial up 15.0 moa and right 2.8 moa
impact velocity 2141 energy 2188

7mm takes .2 moa less wind (one click)
300 has 1 moa less drop (4 clicks)
300 arrives with 188 lbs more energy.

I used 800 yards because the OP was about at that distance for his comparison. And 400 to 850 were where we took all of these elk. But if you want to go further the same trend in results will only magnify the advantages of each.

So I offer these documented results for those who are trying to decide between the 7 and the 30. It will always boil down to personal needs. But if elk are ever going to be in your freezer, under equal conditions, the 30 cal will out kill the 7 all day long."

**** you Wedgy and that .30 cal talk!!! This is 7mm stuff!! Beat it!! LOL

I do like Broz objective study, but caliber choice is subjective to the shooter for a number of reasons.

When your build criteria has been met and all the variables have been equaled, it comes down to what you are comfortable shooting in terms of recoil management and confidence. That will be the rifle you will be the most effective (deadly) with.

 

[kraig]

Thinking of building a 7mm to use the Berger 180's or 195 EOL's. Going to primarily use for S Texas long sendero shooting but also will be packing it out west. Thinking of using a Proof 26" 8 twist to stabilize the heavy bullets. Not tied to a specific caliber. Looking at a Bighorn TL3 long action to be able to have the option to switch calibers at a later date if wanted.

Thoughts on cartridges?

I can only tell you what I know of my one custom built 7mm remington mag. Remage 28 inch 1:8 twist chambered by Sin Arms, Remington 700 action blueprinted, and put together by me. Originally wanted to shoot 195 berger but ended up usually with a compressed load. Settled on berger 180s over retumbo shooting 3050fps and giving groups typically in the .3 range or better. Haven't had any issues with the belted mag cases but I'm annealing and bumping the shoulder back instead of full length sizing. Either way the 7rm case just seems a little small and short necked for the 195s.

If I had it all to do over again I'd go with a case that has a little more capacity, but I started with a left over magnum action to build the rifle from. In hind sight I wish I had heard of the 7-300wm because that would have probably been the ticket for me.

Good luck w/your build.

 

[highdrum]

It is a lot more common to find a used RUM action (needed for the Noslers) than to find a used Lapua or Norma action.

Agreed however now that socom has adopted it as the new sniper cartridge, lapau, peterson, adg, Hornady, norma all make brass, it's not going anywhere.

 

[J E Custom]

I have owned just about every 7 mm made and most of the 7 mm wildcats. I have found no faults with any of them if the rifle is properly built and fed proper loads.

Every one of them has performed as expected from the 7 TCU all the way to the 7 mm RUM. I am bound by the SAMMI pressures for all and don't exceed 63,000 psi on any of the newer cartridges designed for more pressure.

The first 7 mm with lots of power that I fell in love with was a 280 Remington and I was very happy with it (The fact that it was based on a 30/06 case might have had something to do with it). Then it happened, Remington had to come out with the 7 mm Remington magnum, and all bets were off. if you were a serious hunter you had a 7 mag. I had heard about it being hard on barrels but I never saw any problems because I cleaned the chrome molly barrel often and shot it only 2 or 3 times in a row allowing it to cool.

Then they came out with the Stainless Hart barrels and people stopped complaining. Naturally I had to have one of those to.
My brother built one for 1,000 yard matches that was impressive
and I talked him out of it and won many long range matches with it.
I had a tough load for it and it seamed to shoot better the hotter I loaded it. My load was 67.5 grains of powder using a 168 grain match king @ 3254 ft/sec. the rifle will still shoot sub 1/4 MOA groups with 2 to 3,000 rounds down the tube.

Once I got the high pressure loading's out of my system I wanted something that would meet or beat the velocity with less pressure I decided that I needed a newly developed STW (More powder capacity) Again I was not disappointed. I had to make my cases out of 8mm Rem cases because no one loaded factory ammo for it My hunting loads using a 140 grain partition was 3500 ft/sec and was laser flat the 168s were over 3300 with no pressure. An experimental load achieved 3800 ft/sec but bullet jackets would not tolerate that speed and twist rate.

Now to the 7 RUM, As in every case I had to have one of these also. so that I could increase the velocity without over pressure. The big 7 RUM did exactly what I wanted to do with the heaver bullets. the 168
consistently shot 1 to 200 ft/sec faster than the 7 STW with the same pressure limit. It is to big for any real benefit with 140 and 150 grain bullets. so that's where I left it shooting 160 to 180 grain bullets.

Any 7 mm caliber cartridge is great if it is built correctly and proper bullet weights are used. There are no bad 7 mm cartridges just different ones.

J E CUSTOM

 

[el matador]

I think most issues people have with belted magnums are because of sloppy factory chambers. With a match grade chamber, quality dies, and good technique you'll have fewer resizing problems across the board.

Personally I'd get a 7 RM or a 7-300 WM. Or, if you want to get crazy, go for some version of the 7-300 Norma.

 

[MudRunner2005]

Agreed however now that socom has adopted it as the new sniper cartridge, lapau, peterson, adg, Hornady, norma all make brass, it's not going anywhere.

True, but that still doesn't change the fact that there are millions more RUM actions that were produced for rifles, than there has been since this new trend of the .338 Lapua or .300 Norma chamberings in the private sector.

Basically, all I was saying was that it will be 1000x easier to find a RUM action laying around cheap at a gun store or on the market, than it will be to find a cheap Lapua or Norma sized action. You can convert a RUM action, but it costs more money in smithing fees, and for the larger Lapua/Norma mag and follower.

 

[MudRunner2005]

I think most issues people have with belted magnums are because of sloppy factory chambers. With a match grade chamber, quality dies, and good technique you'll have fewer resizing problems across the board.

Personally I'd get a 7 RM or a 7-300 WM. Or, if you want to get crazy, go for some version of the 7-300 Norma.

That's what I've been saying... Some folks just believe everything they read on the internet or hear from someone they trust, instead of looking for correct information from quality sources. Those sources should not include "my brother-in-law's second cousin's ex-husband's best friend once told him that ___________________..."

 

[WildRose]

Rum should outrun a stw, it has 10gr larger case capacity. Build a stw or rum that'll push 195s @ 3150fps and still feed well as a repeater in a bdl bottom metal with bullets seated properly........wont happen. 28 nosler does just that. It's the same mouse trap put into a much more marketable and easy to build right setup. 7mm rum with a 195 seated with boat tail at base of neck is over 4" coal. Good luck with that. It's a performer but not practical and the nosler case will run within 50fps of it at 3.7" coal. It doesn't make senae to go rum or stw, especially since components are so limited for basically all 3 cases, but the nosler is gaining a lot of support for peterson & adg bringing brass out. It won't die as the 33 & 26 will, the 30 nosler may stick around however mine became a 300 norma.

Getting cases for the STW is no problem at all these days and most people won't be chasing the newest, longest, heaviest, highest BC bullets.

The STW performs as well as anything else in any action that can also chamber the RUM's.

 

[WildRose]

I can only tell you what I know of my one custom built 7mm remington mag. Remage 28 inch 1:8 twist chambered by Sin Arms, Remington 700 action blueprinted, and put together by me. Originally wanted to shoot 195 berger but ended up usually with a compressed load. Settled on berger 180s over retumbo shooting 3050fps and giving groups typically in the .3 range or better. Haven't had any issues with the belted mag cases but I'm annealing and bumping the shoulder back instead of full length sizing. Either way the 7rm case just seems a little small and short necked for the 195s.

If I had it all to do over again I'd go with a case that has a little more capacity, but I started with a left over magnum action to build the rifle from. In hind sight I wish I had heard of the 7-300wm because that would have probably been the ticket for me.

Good luck w/your build.

You can always rechamber to the 7-300wm. If you ever shoot it out you can definitely replace it with one or with a 7-375Ruger or LRM.

 

[WildRose]

I think most issues people have with belted magnums are because of sloppy factory chambers. With a match grade chamber, quality dies, and good technique you'll have fewer resizing problems across the board.

Personally I'd get a 7 RM or a 7-300 WM. Or, if you want to get crazy, go for some version of the 7-300 Norma.

Mostly I think it's just poor reloading technique. Even with factory chambers and cheap reloading gear I had no problems for over 25 years. As I said, when case failure signs started to appear, about 90% of the time if not more so they first appeared in the necks as thinning necks started to crack or show signs they were about to.

 

[CWM-RHG]

I agree on the 7RM. Mine shoots the 195gr Berger at 2955, and can shoot groups like this pretty much all the time. It does it with a simple load. Gun weighs 9#8oz.

 

[Hookdown]

I agree on the 7RM. Mine shoots the 195gr Berger at 2955, and can shoot groups like this pretty much all the time. It does it with a simple load. Gun weighs 9#8oz.

What powder/ load are you using? I'm jealous. You're getting 150fps more than I'm getting in my 7RM with 195's.

 

[highdrum]

What powder/ load are you using? I'm jealous. You're getting 150fps more than I'm getting in my 7RM with 195's.

He's probably running max coal and a very stiff load of RL26 or RL33

 

[Bob Wright]

11 pages of some really great options on 7mm cartridges. The one that really sticks with me for an upgrade from either of my (2) 7mmR.M.'s is the 7mm Practical. I just took a 300 win mag case, neck sized it to 7mm, pressed a 180 Berger in it and just stared at it next to a 7mmR.M. for a while. Other than length, the cases are about identical on body size. I popped it into the mag box, cycled the bolt slowly and it fed fine up to the longer OAL. Nothing there to worry about feeding it.
The brass is plentiful and cheap for 300 Win. It just seems to be a natural, elegant way to get more performance out of a 7 mag I currently own. The only downside to convert an old rifle is re-chambering (and/or a barrel) cost, and buying dies. (assumptions here, subject to my smith). For a hunter, that's a big jump in performance, IMO. Interesting discussion and thanks!