7mm RUM/180gr Berger Disappointment

[davewilson]

Another question: When working up a load, how often do you guys clean the copper out of the bbl? Or do you at all?

Hicks.

sounds like you need to give that thing a serious bath. get the copper out, then clean it some more. some will shoot better dirty. i have a regular production gun that will shoot it's best when it's a little dirty. my guess is the barrel is rough and some copper actually smoothes it out a little. i don't like to shoot any more than 20 rounds before cleaning.

 

[Hicks]

Guys,

Thanks for all the advice. I did two loadings at different seating depths but the same powder weight. 99gr US 869, right on the lands and 2 hundredths back at just under 3100 fps. I couldn't keep it under 2" at 100 yards at the lands, but move it back 2 hundredths and the groups shrunk to .75". WOW!

Hicks

 

[RockyMtnMT]

I very much agree w/ the statement about shooting it at further distances. The rifle that I am currently working w/ barely shoots 1" @ 100yds, shoots about 1" or so @ 200yrds. I was ok with that, not excited. Then took it out to long range and it shot 1/2 moa or better from 600yrds out to 1000yrds. I left the house for this session wondering if I could even hit the 2' steel @ these ranges.

I have no idea how many good loads I have never shot past 100yrds, or good rifles for that matter.

Steve

 

[davewilson]

but move it back 2 hundredths and the groups shrunk to .75". WOW!

Hicks

do you mean .020? most call this 20 thousands.

 

[geargrinder]

do you mean .020? most call this 20 thousands.

I'm not a rocket scientist or anything. But, if I remember my math lessons correctly .020", two hundreds, and 20 thousands all mean the same thing.

 

[davewilson]

i agree, i've never heard anyone talk in hundreds of bullet change in seating depth. was trying to clarify if he actually meant 2 or 20 thousands.

 

[Hicks]

i agree, i've never heard anyone talk in hundreds of bullet change in seating depth. was trying to clarify if he actually meant 2 or 20 thousands.

Sorry, just learning to speak gun geek. I said 2 hundredths, and meant .02, and yes 2 hundredths and 20 thousandths is the same thing. From now on I'll get it right.

Hicks

 

[Hicks]

All,

Taking some of your advice I kept trying w/ the Bergers, after having found what I thought was a good load to work with (99grs US 869 @ about 3100fps 20 thousandths off the lands). I was completely crushed after 3 four round groups failed to squeeze inside 2". I really started to think that it was me and not the bullets or gun or scope. Many 4 letter words later I decided to go back to what I know works, 92grs of Retumbo beneath a 160gr Accubond with Remington 9.5 primers @ right around 3200fps. I could not find any locally, and as I've got a looming Wyoming antelope in two weeks I was seriously considering taking my 8mm RM because at least I can shoot that rifle well. A buddy came up with 18 Accubonds, and yesterday I was rewarded with three groups @ 100 yards that looked to be about 16 mm across (most of holes touched). I was also able to kill a fat prairie dog sized laundry detergent bottle filled with water at exactly 270 yards. I came to the conclusion that my gun just does not like the Bergers.

As an interesting aside, I just had Leupold put M1 turrets on the Vari-X III 6.5-20 that sits on top of this rifle. It was very satisifying to move the turrets around and have the groups follow exactly the changes I made.

Confidence restored, I worked up a dial chart and I'll be looking for a nice doe and buck antelope past 600 yards in two weeks.

As always, thanks to all who gave advice. Eventhough things didn't work out with the Bergers, the advice was much appreciated.

Hicks

 

[Willys46]

Hicks,
Were are you located I could send you 50 Nosler Secounds Accubonds. They are over runs for winchester and have red tips. This is all I shoot in a 7 RUM.

I Paid $16.70. If you want or need them I will let hem go for what i have in them plus shipping.

If you only need a couple let me know. IF not no worries.

Bergers can be very picky and some guns just will not shoot them. The accubond is hard to beat.

Willys

PM for contact info.

 

[wangfat]

Did not mention rate of twist on you 7RUM?
You'll need 1:10 minimum. Try RL-25 and don't worry about FPS! The **** deer does not care either. You'll need to be around 2800-3000 and might have to go as much as 20 thou off the lands, with the Burger's. Obviously it won't shoot close or burried in the lands so think about seriously backing off. All this is academic if the twist won't allow the 180's to stablize.
Try the match kings and make life easier on yourself.

Wangfat

 

[Hicks]

Did not mention rate of twist on you 7RUM?
You'll need 1:10 minimum. Try RL-25 and don't worry about FPS! The **** deer does not care either. You'll need to be around 2800-3000 and might have to go as much as 20 thou off the lands, with the Burger's. Obviously it won't shoot close or burried in the lands so think about seriously backing off. All this is academic if the twist won't allow the 180's to stablize.
Try the match kings and make life easier on yourself.

Wangfat

Remington says that the twist in that bbl is 1:9.5, and I got that from the horse's mouth so to speak as I call them directly. I'm pretty furstrated with the Bergers as I've spend about a month trying to get the right combo. This rifle is strictly for antelope so I'm not really concerned with strong bullets for tougher animals. As such the Accubonds will do nicely, and they can drive tacks so to speak. Looking into the future I'd like to shoot this bbl until its done and then put a 30"er on the action and try the Bergers again. Until then though I'll just shoot the accubonds and collect my cloverleaf groups.

In any case thanks for all the help and advice,

Hicks

 

[AZShooter]

After your hunt you can go back and try some more tweaking. I have a 7 STW and 7 RUM that didn't shoot the 168 Berger VLD when close to the rifling. You won't believe where they do shoot. Both are approx .160" away.

I admit to having several rifles that won't shoot the VLDs BUT the two rifles chambered for 257 Weatherby shoot super tight groups with the 115 VLDs and a .070" jump.

If you still have bullets hanging around try continuing the seating the bullets deeper into the case. .020" increments should show you a trend.

FYI I ordered some 180 VLDs to try in the 7 RUM. If I can get 3100 with a 26" barrel I will be happy.

Have a great antelope hunt.

 

[toddconley]

I am working with a 25-06 right now with 115 vlds from berger and every time I take it above the 3050 the groups start to fall off. I am pretty sure that accuracy node for this combo it gonna be right at 3000 even. There may be another node above that in velocity but I will not have the power to get there in this round. Is this the same thought you have?
T

 

[Boss Hoss]

I know that I will get flamed for this but----never had much luck with the Berger Pills. Not in my custom sporters or my match rifles. In only one instance have I gotten the Bergers to outperform the SMK's and that was in a factory rifle.

Just my .02.....