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270 Weatherby - grouping problems?

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07 October 2007, 21:22
Manybears
270 Weatherby - grouping problems?
I have the mark 5 synthetic in 270 weatherby, and I am having problems getting tight grouping at 200 yards - 4" to 5" groups. Using remington primers, IMR4350 powder (from 60 to 68 grains) and have tried hornady 140 interlocks, nosler accubond 140, and barnes tripleshock 130 grain bullets. I am utilizing a nice "hyskore" benchrest shooting vise for stability. Tried different amount of powders, different seating depth for bullets, small chunk of paper between barrel and stock (worse) and tried another leupold scope, with not much difference in performance. Any suggestions, other than "sell the rifle" would be welcome.
07 October 2007, 21:31
David
Try a different powder and or bullets and or primers. I have two rifles in 270 Wby, one on a VZ-24 Mauser and one one a Montana 1999. I use Fed 215 or 215M primers, IMR-7828 in both with good results. I think IMR4350 to too fast for this chambering. Both of my rifles like 130gr bullets best for accuracy, but shoot 140gr OK. I have used 140gr Nosler Accubonds and Barnes TSX. I also tried some Northfork 150gr. But the best shooting bullet in my rifles was the TSX 130gr and 130 gr Nosler Ballistic Tips and Partitions.
07 October 2007, 22:40
Robgunbuilder
2 to 2.5 MOA for a stock Weatherby is about what i'd expect at 200 yrds. for a stock gun If you want better you might consider the following:
1.Recrown the muzzel.
2. Check the headspace. Weatherby's shoot best with less than .001 headspace in my experience. Check your brass and select brass for a tight feel on closing the bolt(optimum) If its .003 don't bother looking for better accuracy, it probably won't happen.
3 Neck size only, don't full length size. Do everything you can to minimize headspace. Shoot for groups with ONCE FIRED BRASS thats been necksized only. Try annealing your case necks and trim to a constant length. Load the bullets out to .030 off the lands. with the Weatherby throat thats hard to determine.
4.Glass bed the action( pay attention to the rear tang area) and bed the first 1.5 inches of barrel in front of the action and free float the rest.
5. Tune the trigger to 2lb let-off.
6.Try different rear bag and front rest pressure settings. I had a Weatherby that would only shoot with a death-grip on the stock.

7. Shoot 3 shot groups only Weatherby barrels tend to drift as they heat up.
8. Play and Play some more till you find a load that will shoot as accurately as possible. Chrono your loads and tune for lowest std deviation not velocity. Once you get past 100yrds sd matters more than velocity.
9.Trade the Weatherby for a box stock M700 Sendaro in 300RUM or 7MM STW. By the time you get that Weatherby to shoot you would have both saved money and had much less aggravation. Thats what I'd do.-Rob


Never underestimate the power of stupid people in large numbers to do incredibly stupid things- AH (1941)- Harry Reid (aka Smeagle) 2012
Nothing Up my sleeves but never without a plan and never ever without a surprise!
08 October 2007, 05:37
Magnum Hunter1
Get rid of the vise.
08 October 2007, 06:30
Big Bore Boar Hunter
quote:
Originally posted by Manybears:
I have the mark 5 synthetic in 270 weatherby, and I am having problems getting tight grouping at 200 yards - 4" to 5" groups. Using remington primers, IMR4350 powder (from 60 to 68 grains) and have tried hornady 140 interlocks, nosler accubond 140, and barnes tripleshock 130 grain bullets. I am utilizing a nice "hyskore" benchrest shooting vise for stability. Tried different amount of powders, different seating depth for bullets, small chunk of paper between barrel and stock (worse) and tried another leupold scope, with not much difference in performance. Any suggestions, other than "sell the rifle" would be welcome.


I would first fire their factory ammo to see if you get better groups. If not, then contact the factory, they guarantee 1.5" or better at 100 yds, they can help at no cost to you. On a reloading note, I would use a slower powder than 4350 if you can.

John
08 October 2007, 21:53
Heat
Though the 270 is not one of their big kickers it wouldn't surprise me if the tupperware stock is part of the issue... Bed it and possibly free float it... I have a 338-378 Accumark which is factory free floated and has an aluminum bedding block and has had no custom work done to it... It's pretty much a MOA shooter even with factory ammo... By pretty much MOA I mean that some days I'm on and other days I'm not... When I'm not on it's real close to MOA and when I'm on it's about .75 MOA... One thing that I've heard and read when handloading the Weatherby cartridges is that you want to use Fed 215 or 215M primers... I'm pretty well stocked up on Fed 215s now and look forward to putting together my first loads for it (that will be right after elk season Big Grin)...

Ken....


"The trouble with our liberal friends is not that they are ignorant, but that they know so much that isn't so. " - Ronald Reagan
08 October 2007, 22:13
KSTEPHENS
try a box of factory before you give up.
09 October 2007, 00:03
MTM
While I agree that the new super slow powders may be better, I used to shoot 68 grs. 4350 under 130s and 66 under 150s for 3450 fps and 3200 fps. Both very accurate. Shoot it off a normal rest and switch to Fed. 215s.
09 October 2007, 00:09
Jon2
I have recently had a M700 XCR 7mm Rem Mag re crowned. Out of the box I was getting 1.5 inch groups. I was going to get rid until I took it to a gunsmith friend of mine.

He noticed the crown was slightly oval shaped. I hadn't noticed this but when he pointed out the defect it was hardly noticable. He re crowned it and I shot a .452 group straight away and then onto shoot a .377 group.

This is the first rifle I have ever had re crowned and the transformation was amazing. I was very happy because I like Remingtons and I like 7mm mag and wanted to keep the rifle. It will now be a keeper and I am very happy with the result.

Just thought I would share my experience just incase your rifle has the same problem.
10 October 2007, 06:16
Magnum Hunter1
Get rid of the vise, Oh I already said that!
Try a flat base bullet that is not a Barnes. The Weatherbys that I have had alway preferred flat base bullets. My $0.02
10 October 2007, 19:39
Reloader
Manybears,

Don't give up on her just yet. My best success with 270WEA has come with R22 and IMR7828 both lit by Federal 215s.

Try those powders if you can get your hands on some. Also may want to try the 150 grn Hdy SPs, they have been very accurate in several 270 WEAs I've been around.

Good Luck

Reloader
10 October 2007, 19:52
Heat
quote:
Originally posted by Magnum Hunter1:
Get rid of the vise, Oh I already said that!
Try a flat base bullet that is not a Barnes. The Weatherbys that I have had alway preferred flat base bullets. My $0.02


Well said Magnum... It does seem that the Weatherbys prefer flat base bullets...

Another place you might check to see if someone knows what is happening is to check this Weatherby forum: http://www.weatherby.dk

Ken....


"The trouble with our liberal friends is not that they are ignorant, but that they know so much that isn't so. " - Ronald Reagan
21 October 2007, 10:55
thechamp
Have a 270 Mark 5 that was made in Japan. Beauty of a rifle. First time out I had new Federal ammo. Groups were 5+ inchs at 100 yards. I was ready to dump it but found 5-6 rounds of factory Wby ammo that the original owner had given me. It shot well under 1", probably under 3/4" from what I recall. Since I don't reload I have to rely on factory ammo. NOTHING except Wby's own ammo will shoot in the rifle and all of the load's I've tried are under 1". Still want to try a box of the 100 grain Wbys but never got around to it.

I'd try the Wby factory stuff and see what it does and go from there.

On a side note, had a 300 Wby that shot the factory 150 gr Hornady Spire Point 1/2" or so. It wouldn't shoot the same bullet in a 3" group when Hornady loaded it in their own brass with I'm sure a different powder. Wby knows a thing or two about loading for their rifles that they haven't shared with anyone else....
21 October 2007, 11:03
Macifej
No big mystery to getting a Wby to shoot right. Pick up a Barnes Reloading Manual and follow the bouncing ball and the results will be as good as factory.
26 October 2007, 09:21
40-65
Let me know if you do deside to sell it.