7MM RM and Berger VLD's

[gamehauler]

Well I received my 300 Berger 168gr VLD's this week
and want to start working up a load.

I had Walt Berger send me some load data but its pretty generic.

Since there is not a lot of info out there that I have been able to find
I would appreciate any input.

It seems that Reloder 22 is real popular as a powder.
I plan on picking some up today but have many other powders on hand.

Thanks,
Mike

 

[Pdvdh]

74.9 grains of Hodgdon Retumbo powder is what I've settled on with my 7mm Rem Mag.

168 VLDs seated 0.005" into the lands
Federal GM210M primer
Muzzle velocity of 3080 fps

Tikka T3 Lite with 24 3/8" barrel.

Less than 0.5 moa

 

[gamehauler]

Thank you Phorwath for your input.
I do have Retumbo on hand.
Walts data shows a start load of 66gr
and a max of 70.4 with Retumbo at 3022 FPS.
That has case fill ratio of 104.7%.
Are you showing any pressure signs?

Just got done prep and priming 50 cases
so any more input would be great.

Mike

 

[Pdvdh]

I went from 73 to 76 grains during load development with CCI 250M primers. MV went from 3065 fps to 3165 fps. Everything held together OK.

I eventually switched to Federal GM210M primers and lost some velocity with equivalent powder charges, but I reduced my Extreme velocity spreads and SD substantially by going with these Federal primers. I settled on 74.9 gr Retumbo as the best charge in my rifle.

My powder load isn't a powder puff so I would work up from a lower starting charge weight and see where you can go. But my case life seems to be good with 74.9 gr Retumbo. To answer your question, I'm not experiencing signs of overly excessive pressure in my rifle.

My cases are Federal 338 Win Mag brass which I have necked down and outside neck turned for my 7mm Remington Mag. I did this so the loaded case necks will have a little less space in the throat of the factory chamber. I'm pretty meticulous about my reloads. Using Redding neck bushing competition reloading dies and checking all loaded shells for concentricity. They're almost always less than 0.001" runout. Most are less than 0.0005" runout on my RCBS concentricity gauge.

Last weekend I put three shots into 0.36 moa at 988 yds with this load. I was really impressed for a factory rifle. The Bergers reduced my group size in half, compared to the Nosler 160 gr Accubonds. And those ABs shoot pretty darn good all in themselves.

I have two Tikka T3 Lites in 7mm RM. The one gun loves the 168 gr Berger VLDs. The other does better with 160 Nosler Accubonds.

Enjoy yourself and I hope you end up with a tack driving combination.

 

[gamehauler]

Thank you again for your reply.
I am pretty new to loading and take anything I read with a grain of salt and double and triple check it with other sources.
Your last post set my mind a bit more at ease but I will still start out with a much lower start load and work up.

The cases I just prepped are once fired RP out of my gun but I did full length them just in case a migrant happened to find its way into the work force.

After working up loads with this brass I plan to only neck size.

Mike

 

[gamehauler]

Phorwath,
What do you have for a OAL
I was just playing with seating depth on a dummy round
and can't hardly believe what I am coming up with
seated into the lands and still be able to run it through the mag.

Mike

 

[Pdvdh]

Mike,

My COAL = 3.452 - 3.454"

This measurement is from the case head to the tip of the VLD.

 

[shootinfool]

for mine what has worked the best is 64.9 gr. IMR 7828 ssc Seated .005 into the lands and grooves with a federal gm215 primer and federal brass. It gives me an average of 3063fps. I never did try retumbo though but I did try 4831sc and rl 25 and they did not seem to shoot very well.

 

[Limbic]

Mike,

My COAL = 3.452 - 3.454"

This measurement is from the case head to the tip of the VLD.

That is good to hear. I tried to measure mine with the technique of using fired brass that is crimped with a berger loosely placed in the mouth. I was getting 3.465. Wow that is long.

To be safe I ordered a Hornady Lock n Load OAL Gauge to check how deep the chamber was.

I wait to load some up after I check the chamber out. I can tell you that at 3.420 they don't shoot all that well.

 

[tikkaman]

Hey guys, I'm new to this forum and new to reloading. I currently just reload 9mm with a Dillon RL550. I just bought a new tikka t3 lite in 7mm Mag. I've been reading a lot of posts to try to figure out what to start with. I just have a few questions. What does "....seated into the lands" mean? I'm familiar with COAL but I haven't heard this term before. Also, I'm debating between IMR 4831 and 7828, any advise? Also, any more info for a newbie is much appreciated. gun)

 

[shootinfool]

when it is said that the bullet is seated into the lands and grooves it simply means that the bullet is seated farther out than the max masured ammount from bullet ogive to the base of the brass. You find this masurement using the stoney point seating depth guage system. When you close the bolt you are actually seating the bullet. this is what people call jamming the bullet into the lands and grooves or seating the bullet into the lands and grooves. This method works well for berger vld bullets more times than not.

 

[tikkaman]

If I use a longer max COAL and chambering it actually seats it how much should i crimp the round? Just enough to get the bell out of it?

 

[7stw]

Hello there Tikkaman, I hope this message gets to you before you attempt to crimp those bullets. Unless the bullet has a cannelure in it, you should not attempt to crimp them at all. Crimping a non-cannelured bullet will distort the bullet, and possibly skyrocket release pressures. Typically, the neck pressure alone, be sufficient for most shooting purposes. I dont recommend crimping that bullet at all. At best, velocitities are going to be eratic, and the bullet itself is not DESIGNED for a crimp. Pistol bullets are the more frequent for being crimped, and are usually equped with a cannelure for that purpose, and the reason that MOST rifle bullets are not, is because of un-known intended seating depth. Some rifle bullets are avail with cannelure, but usually with special purpose in mind, (ie30-30 bullets). Goodluck and BE CAREFUL. That rifle and the bullet you have chose are good ones and will reward you well. That bullet alone is one of the very best available at this time, and it will fly true, but DO NOT crimp it. lightbulblightbulbgun)7stw