New Backpack Rifle Build - Help

[JM151]

I’m looking to build a new rifle on the Manners folding stock. My goal is to build a lightweight heavy hitter, short barrel, and running suppressed. Spotting impact will be a factor as well. The two cartridges I have it narrowed down to are 300 Rum in a 18” barrel shooting (Berger 215) or a 338 Edge in a 20” barrel shooting (Berger 250). The specs will be:

Manners Folding Stock
TIx or AntiX
Bartlein 3B
UM DBM or Wyatt’s 4”
Suppressor Magnus-S-RR (yes this can does reduce recoil like they advertise). I got several more on order Magnus-k-RR and a Magnus-S-RR in 338
Trigger Tech Diamond

So out of the two cartridges and barrel lengths which would you recommend? Does anybody have experience with a 18” 300 Rum?

 

[greyghostnw]

whats your goal for velocity for the 215’s? Available powder to use?

 

[JM151]

@greyghostnw well my 300 win mag 24” barrel is throwing them 2840 so I’m thinking at least 3050 with H1000. End of the day if I’m at least 2975 I’m good.

Powders I pretty much have everything H1000, Retumbo, N570, RL26

Plan is to sell my 300wm if I go 300 RUM….it’s a Fierce factory rifle and I don’t really like it.

 

[JAC8504]

Spotting impact with a lightweight 300RUM or 338edge

I have a similar build in mind with the manners stock. However, I don’t ask to be able to see impact. I know the recoil is going to happen. I’m probably going the 300PRC route. Probably doing a 20” or 22” proof

Still haven’t decided on action yet. I want a CRF ruckus, ARC action, or zermatt

 

[JM151]

Spotting impact with a lightweight 300RUM or 338edge

I have a similar build in mind with the manners stock. However, I don’t ask to be able to see impact. I know the recoil is going to happen. I’m probably going the 300PRC route. Probably doing a 20” or 22” proof

Still haven’t decided on action yet. I want a CRF ruckus, ARC action, or zermatt

Having the Magnus-S-RR is a game changer with suppressors, it’s like a having a muzzle brake but actually hearing safe. My goal weight is 9 pounds. My 300wm with same bullet weighs 8 pounds and I don’t have any issue spotting impact with the new can. Now when I was running an Ultra 7, it jumped so much I couldn’t see anything.

 

[JAC8504]

Interesting. I have a magnus k on order

 

[JM151]

Interesting. I have a magnus k on order

did you get the RR?

 

[JAC8504]

did you get the RR?

Nope. I got the non RR. I was going for the smallest form factor

 

[JAC8504]

Oh… I am a huge fan of .338 for hunting purposes. I have .338 federal, 338WM, 338 lapua. I’d like a 338 ARC.

I wish there was a 338PRC and have thought about the 338RPM. Not quite sure though. But I have basically the same aspirations of a backpack build to do it all

 

[greyghostnw]

Having the Magnus-S-RR is a game changer with suppressors, it’s like a having a muzzle brake but actually hearing safe. My goal weight is 9 pounds. My 300wm with same bullet weighs 8 pounds and I don’t have any issue spotting impact with the new can. Now when I was running an Ultra 7, it jumped so much I couldn’t see anything.

What bullet and velocity with that can?

 

[JM151]

What bullet and velocity with that can?

Berger 215 2840

 

[Lawnboi]

I don’t think spotting shots in a rifle that weight in 300 run will be doable until time of flight gets up there.

I have a Magnus k rr, and while it does reduce recoil well, my 3006 at 12 pounds is still a bear to manage in anything but prone. Better than a standard can still though.

 

[JM151]

I don’t think spotting shots in a rifle that weight in 300 run will be doable until time of flight gets up there.

I have a Magnus k rr, and while it does reduce recoil well, my 3006 at 12 pounds is still a bear to manage in anything but prone. Better than a standard can still though.

If you’re talking about a 215, my 300wm has more recoil because of weight difference 8 pounds vs 12 pounds. Since I can spot impacts with that rifle Im making the assumption based on adding 1 pound to 1.5 pounds of weight and only increasing velocity by 175-200 fps should be very similar to my win mag.

Edit: Actually just ran it through the calcs and it does jump up in recoil by a decent amount

 

[Lawnboi]

If you’re talking about a 215, my 300wm has more recoil because of weight difference 8 pounds vs 12 pounds. Since I can spot impacts with that rifle Im making the assumption based on adding 1 pound to 1.5 pounds of weight and only increasing velocity by 175-200 fps should be very similar to my win mag.

Amount of powder matters too. More powder seems to make more recoil. But that may play into the RR brake too and make it better.

I’m at around the 400 yard mark for actual shot spotting with my 3006, 185s at 2850 and the Magnus K RR. That’s from prone. It’s not a rifle that’s easy to spot with not prone. I can normally tell where I hit though from the massive crater.

I may also be spoiled being that I normally shoot 22 and 6mm stuff.

I have a dream of a 14lb 300 Norma with a full size Magnus RR. For that reason I’m curious how you think it works on a short barrel magnum like that.

 

[khuber84]

Amount of powder matters too. More powder seems to make more recoil. But that may play into the RR brake too and make it better.

I’m at around the 400 yard mark for actual shot spotting with my 3006, 185s at 2850 and the Magnus K RR. That’s from prone. It’s not a rifle that’s easy to spot with not prone. I can normally tell where I hit though from the massive crater.

I may also be spoiled being that I normally shoot 22 and 6mm stuff.

I have a dream of a 14lb 300 Norma with a full size Magnus RR. For that reason I’m curious how you think it works on a short barrel magnum like that.

I shoot an 12# 300nmi, large braked suppressor. It's a lot to handle. 2# would likely make a notable difference, but these are big ass cartridges. For a LW back pack rig, 300wsm with 200.20X Bergers is what id be running between 2750-2850.

 

[Theringworm]

Curious as to why the Manners folding stock if you are trying to go lightweight. Manners are 2.7lbs or more depending on which you go with. I am getting ready to do the same build, but on a non-folder. If I did a folder it would probably be the MDT-HNT26.

 

[Lawnboi]

I shoot an 12# 300nmi, large braked suppressor. It's a lot to handle. 2# would likely make a notable difference, but these are big ass cartridges. For a LW back pack rig, 300wsm with 200.20X Bergers is what id be running between 2750-2850.

This is about what I think I got with my 3006. I think I could get 2700 out of the 200.20x. 185s are going 2850 without much pushing. LRI Serengeti chamber is right up there in my most accurate barrels I have ever had.

I’m thinking of throwing it in a foundation Gideon.

Have you shot anything with the 200.20?

 

[khuber84]

This is about what I think I got with my 3006. I think I could get 2700 out of the 200.20x. 185s are going 2850 without much pushing. LRI Serengeti chamber is right up there in my most accurate barrels I have ever had.

I’m thinking of throwing it in a foundation Gideon.

Have you shot anything with the 200.20?

Yes I killed a lot of deer, Antelope and a few elk with 300wsm running 200.20x, it was a 21" with a stiff load of rl23 going 2820. The bullet is a shorter bearing 215hyb, the nose and boat tail are the exact same as a 215. They kill like 215s. Liquify vitals and leave frqgmental exits, sometimes the core will stay under offside hide, sometimes it leaves the scene. It's a great bullet.