long range project 7 mag

[baboltin]

So I had listed a rifle for sale on here in order to fund my project build and was requested to share my build on here so here is what I am wanting to do.

rem 700 action ss, ADL configuration
coated in kg gunkote
pac-nor #4 SS supermatch barrel 11 twist rem 7 mag 25 inch
riflebasix trigger
Holland recoil lug
Davidsons alloy shroud
fluted bolt (flutes coated in kg gunkote)
McMillan classic stock, pro pillar
bedded alum pillars 13.5" LOP
1" pachmayr Decellerator recoil pad
topped with a huskemaw scope

and that's why I need to sell this

http://southerncaliforniahunting.com/huntersforum/index.php/topic,7389.0.html

its a brand new rifle still needs to be broken in not one shot down the tube, so if you know anyone pass on the word great varmint or long range practice rifle. retails for over 1300 dollars without tax and fees .

 

[NBK]

Sounds like a fun build and a great cartridge. Two questions:

Why such a slow twist barrel? You are limiting yourself to very light bullets which will not be conducive to longe range shots.

Do you already have your action?

 

[motorhead]

Sounds like a fun build and a great cartridge. Two questions:

Why such a slow twist barrel? You are limiting yourself to very light bullets which will not be conducive to longe range shots.

Do you already have your action?

my thoughts exactly.... are you just going to bang steel, poke holes in paper, or hunt with it?
What bullets are you looking to shoot?
what brass you using? etc. etc.

 

[baboltin]

im using it to hunt with , im not exactly sure, what would you guys suggest ?

 

[Aeon]

In order to shoot any of the vld bullets you will want 1-10 for 168gr or 1-9 for the 180gr

The vld (very low drag) bullets are long and require more spin than a old school bullet of equal weight. Your builder should be knowledgeable in this and will most likely cut the chamber with a particular bullet in mind.

Looking at the burger table for 7mm hunting bullets the 140 has a 510 bc, if you jump to 168 it's a. 617 bc. That's a switch worth making.
Modify message

 

[NBK]

In order to shoot any of the vld bullets you will want 1-10 for 168gr or 1-9 for the 180gr

The vld (very low drag) bullets are long and require more spin than a old school bullet of equal weight. Your builder should be knowledgeable in this and will most likely cut the chamber with a particular bullet in mind.

Looking at the burger table for 7mm hunting bullets the 140 has a 510 bc, if you jump to 168 it's a. 617 bc. That's a switch worth making.
Modify message

What he said above ^

For a long range gun chambered in 7mm Rem Mag you will want a 9" or a 9.25" twist. It will shoot 140 grain bullets up through 180.

I know a guy who shoots the Berger 180's through his 9.25" twist Rem Sendero with great results.

Also did you already get your action?

 

[baboltin]

Also did you already get your action?
[/quote]


yes I did

 

[baboltin]

I was going to shoot a copper bullet, 140-150 grain bullet would this barrel be good for that?

 

[baboltin]

reason I ask is because I already have the barrel

 

[NBK]

Is the barrel stamped with the twist on it? It will shoot 120 & 140's. Heavier bullets you will have to test and see.

It is perhaps not the first choice if you are setting up for long range.

 

[baboltin]

I will double check once I get home but I am almost positive that it doesn't

 

[Monolithic]

We make a 7mm Rem mag Load that uses a 116 gr. solid copper bullet. We push it at 3500 Fps and it has a G1 BC of .46 ... This makes it a very nice hunting round out to 800-1000 yds. At 800 yards this bullet will only drop 110 inches and still have 1950 fps behind it Also the lighter bullet drastically reduces recoil.

www.monolithicmunitions.com

 

[longbowhunter2]

Monolithic

what is the twist required?
the BC is very good. I'm interested.
what type of equipment is required to shoot that round.

Ghost

 

[Bonejour]

I'm impressed at that BC to for a 116 gr 7mm round.
Still, it doesn't seem to make sense to me that a 7mm barrel should have such a low twist rate. I don't know a lot, but my 7mm rem has a 9.25 twist rate and pretty much all brands I looked at are built with 9-10 twist. Of course, I was only looking at stock hunting rifles. What am I missing?

 

[Monolithic]

That twist rate does seem slow, but the GS Custom 7mm 116 gr HV hollowpoint that we use will be plenty stable in a 1 in 11 twist. It would actually be a good long range bullet for that twist rate because the bullet won't be over-stabilized. We have had extremely good terminal performance on game with these GS Custom Bullets... Also, I've tested some of their BC numbers and they aren't making them up

 

[baboltin]

so I shouldn't worry about getting a new barrel at this time . I will get all my bullet info that I am or was going to run and then see what you think if you don't mind .

 

[longbowhunter2]

OK I was playing with the berger twist rate stability calculator on line based on 7MM round , BC which twist are stable.
cool, I suggest playing with it. yep pretty much agrees what every one is saying faster twist 9.25 -9.00
makes the bergers 140 gr & the 168 gr stable. check it out very cool.

http://www.bergerbullets.com/twist-rate-calculator/

Ghost

 

[Bonejour]

160-170 gr is my expected bullet weight range for my 7mm, but will have to test a few different bullets to know for sure.

 

[baboltin]

this is what I was going to load 150 barness tsx or ttsx with h1000 powder .

 

[Bonejour]

I've been taking with (learning from) John at Fine Firearms about bullet options for my 7mm. The link below is a very thorough discussion of 7mm bullet choices. Barrel length affects muzzle velocity, which is relevant for stock rifles as well as custom. For example, the Sendero (26") vs Sako (24"). At the end of the article, he mentions that optimum twist rate for all 7mm calibers is 1:9. It's a good read.
http://www.ballisticstudies.com/Knowledgebase/7mm+Remington+Magnum.html