270-300 Win Mag now feasible

[Big Jake Duke]

Awesome info guys.

I am going out tomorrow with a .2 gr ladder from 74.6-77.0 gr of Retumbo.

It seems that the accuracy with the Berger 170s will be in this area. The 75 gr load was about 1/3 inch and 3225 fps. I also have apressure/ velocity ladder to 80 grs.


270dt- isnt your barrel 26"? That could be a 50-100 fps difference. 69 gr of imr4350 gave me 3400+ fps with the Cutting Edge 140s. 28" barrel. Cutting Edge Bullets have a seal tite band that can get you about 50-100 fps faster than a normal cup and core bullet.

The h4831-imr7828 region of powders performed dismally for me as it did you. The uber slow had promise, US869 from 140-165 gr and Retumbo all thruought the bullet weights. H1000 was also good, but not as good as Retumbo for the Berger 170s.

That is why im spending all day with Retumbo tomorrow!

 

[270DT]

This is a 270-300 Win Mag wildcat with my rifle, loads and brass, follow at your own risk.

I also hit the range this morning and wanted to try some of the new IMR powders, IMR 4451 and also IMR 4955. I was shooting the 130 Swift Scirocco with Fed 215s.

IMR 4451 has about the same burn rate as IMR 4350.

MAX load with first signs of sticky bolt lift was 69.0 grains at 3,472 fps. Accuracy was great all through the range from 65.5 through 69 grains. Will definitely save this for a hunting load probably sticking with 68 grains right at 3,410 fps. I also like the "marketed" consistency and cleaner burning technology of the new Enduron series of powders that IMR came out with. Haven't shot enough of it yet to see if it does what it says yet.

Moving to IMR 4451 which is slower, around H4831. I got MAX load with sticky bolt lift at 68 grains with a velocity of 3,335 fps. I had higher expectations for this powder but didn't work in my rifle.

I am not getting the velocity that you guys are getting but then again I am also trying some different powders. I am not necessarily wanting to get to ludicrous speed as think bullet failure on game would be an issue and if going to something like a Barnes TTSX think it will just zip through but I still think I have room for more velocity if I can find the right combination for my rifle.

I am going to work with the 140 Nosler Accubond and the 150 Woodleigh PP next and will keep you guys posted. Probably going to try H1000 and Retumbo for those and see what happens.

There is an error in my original post but for some reason I cannot go back and edit it. It should read moving to IMR 4955 which is similar to H4831.

I really liked the 4451 with the 130s. Will probably stick with that one for the 130s and be done experimenting and shoot for accuracy with that load for now.

I loaded up some 140 ABs with H1000 and 150 Woodleigh PPs with Retumbo tonight. Will try to get back to range tomorrow but looks like it is going to be a rain out here in Tennessee for Sunday.

BJD yes I am running these through a 26" tube.

 

[Big Jake Duke]

I am having a custom reamer made for accuracy. It will probably be made especially for either the Berger 170 or a new bullet from Cutting Edge that i hear is in the works- a 155, 168, and 188!!!!

So if you want a great reamer and dont want to buy your own, my gunsmith- Jim Grooning - at Gruningprecision.com will do the chamber jobs.

Look him up, access to a gunsmith like that is pretty hard to get without waiting 7years!

 

[270DT]

That 155 Cutting Edge sounds interesting for me!

I was able to make it back to the range today and here is what I came up with.

This is a 270-300WM, my rifle with a 26" Pac-Nor match grade barrel and my reloading so follow at your own risk. All rounds loaded with Fed 215s.

140 Nosler Accubond

MAX load with H1000 77 grains at 3,329 fps. This is comparable to the MAX load I got with IMR 7977 75 grains at 3,301 fps. Will compare the two for accuracy soon.

150 Woodleigh PP

MAX load with Retumbo 76.5 grains at 3,251 fps. I want to try this with US869 next. Wish I could find some Reloder 33 but cannot ever find it on the shelves around here.

Also each time out I am too industrious in my reloading and have bullets to pull and powder to recover or I can look at it the other way and I am being lucky and hitting the pressure at the bottom of my ladder and saving bullets and powder

My rifle will solely be used for hunting but I am quite impressed with the accuracy of this barrel and round so far! I have been using a Vortex Viper 6.5-20x50mm on it and this is my first experience with this scope and pleased with it as well.

 

[Big Jake Duke]

I was able to hit the range today also, unfortunately my chrono took a dump less than half way thru my ladder' but i shot for accuracy anyway.

All loads were with Retumbo in .2 gr increments.

74.6-75 all shot well with velocity around 3225 top end

76.2 was the best and 77 was the useable max, meaning top accuracy and pressure. I believe i was knocking on 3300 with these loads, but no chrono to confirm.

77.5 -78. Had primer issues so nothing over 78 was fired.

I also have matched this rifle up with a Vortex Viper 6-24. Very nice glass.

 

[270DT]

BJD sounding good man. Sorry about the chrono, stuff like that can't get aggravating!

Looks like I hit pressure a few grains less than you even with lighter bullets. With the 150s I was shooting with 77 grains of Retumbo I had heavy bolt lift. A sticky bolt seems to be the first sign I get of unsafe pressures. I wonder if I have a slightly tight chamber as I also had to turn my case necks to get my first time sized brass to chamber with a bullet seated.

 

[Big Jake Duke]

It sounds that way, I have not turned any necks, but a tight chamber can get you to your velocity numbers with less powder in some cases.

How was the accuracy?

77grs was "Absolute have to shoot a grizzly dead with one shot max." 78 grains I think would cause case failure, 77.5 primers came out. 75 grs was the best area for accuracy.

 

[270DT]

BJD meant to say that chronographs can be aggravating! Just like typing on my Iphone and it changing my words!

Every time I have been out I have just been testing loads but accuracy has been great with everything I have shot so far and especially considering with the magnetospeed attached to the barrel. Maybe I should just leave it on there all the time! I will try to post a pic later of a target from yesterday.

Powders I would like to try but cannot find anywhere on the shelves around here are;

AA Magpro
Ramshot Magnum
VV N170
VV N570
AA 8700
VV 24N41

May have to just order them online somewhere.

 

[270DT]

The four shots to the left of the dot were with 140 grain Accubonds with H1000 (75.5, 76.0, 76.5 and 77 grains)

The one shot in the dot and below the dot were with 150 grain Woodleigh PPs with 76.5 and 77 grains of Retumbo.

These were all taken at 100 yards with the magnetospeed attached to the barrel.

 

[Buckammo]

WooHooo my .270/7mm Rem Mag reamer arrived today. I am going to visit a smith in town tomorrow. Hopefully we can do business.
John

 

[Longtooth32]

The four shots to the left of the dot were with 140 grain Accubonds with H1000 (75.5, 76.0, 76.5 and 77 grains)

The one shot in the dot and below the dot were with 150 grain Woodleigh PPs with 76.5 and 77 grains of Retumbo.

These were all taken at 100 yards with the magnetospeed attached to the barrel.

What speeds were you getting? Did you get close to max with the Accubonds?

 

[Big Jake Duke]

He posted 3329 with the accubonds

He is running a 26" barrel.

I have good groupings at 3465 with a 28" barel.

 

[CogburnR]

Went and banged gongs at 430 yards.

First shot at the top of the 12" plate. Second shot on the 2" bull. Third shot spun the 6" gong around twice, same with the fourth. Fifth knocked the 6" on the ground and then shot it three times trying to flip it over. My buddy shot it trying to remove all the Orange paint from the bullseye. It has become boring to shoot at 430. . Next We go out to 700 then try to find a place to shoot farther. 75g of Retumbo with the 165 Matrix.

 

[270DT]

Longtooth32 my absolute max with H1000 and the 140 Accubond is 77 grains and with that it is taking noticible effort to open the bolt. I would consider it definitely to the point of being unsafe. Anything above that I would have to hammer the bolt open.