help - poor grouping???

[Baerman]

I have a Winchester Model 70 SS in 300 win mag. I've had a hard time getting it to group tight but this week while testing different loads it seems to be getting worse or the scope is bad and I can't quite figure it out.

I had been shooting factory ammo and getting close to 1" moa. Not satisfied as my last rifle which was stolen was getting under 1/2 moa I tested some custom loads this weekend. I started by shooting factory ammo to get the oils cleared out after the last cleaning and groups were horrible at about 3 moa. scratching my head, I tried the first load and same result. Generally the same result went on for all five loads for a total of 30 shots.

I would get a couple shots at 1 moa then a stray or two would follow. There was no rhyme or reason. I would let the barrel cool between 5 shot groups and sometimes between every other shot just to see if the barrel being hot was the issue and I really don't think so.

My question....has anyone had similar issue with the Win Model 70 SS 300 WM? Thinking that 3 moa is ridiculously poor I'm starting to think it's the scope. Scope is Vortex Viper HSLR. anyone have issue with this scope not holding zero?

Custom loads were H1000 from 76 to 80 grains in 1 grain increments with 185 Berger VLD Hunter bullets and Winchester Mag primers.

I never did adjust the scope and all shots were within about 4" of sight placement, just in varying spots.

your insight is very appreciated!!! At this point, I'm about ready to go get another Weatherby but this group has some great experience to pull from.

 

[Jerky]

I see you cleaned the barrel, but have you used a copper solvent? Did you check all of your screws?

 

[shoots-straight]

1" MOA isn't bad. In fact pretty good overall. That might be as good as it gets. 3" on the other hand is not good.

Try different bullets, and powder combo. dupont4350 with some Barnes TTSX bullets is my recommendation.

 

[HighDesertSage]

Clean the barrel and check all of the screws.

 

[Mthuntinfool]

check the screws holding the action to the stock, if they are loose that can affect your accuracy. also check scope rings and bases.
I have a load worked up for my brother's model 70 300 WM, IMR 3031 and 180 grain hornady bullets, it will shoot 1/2" moa all day long.
Good luck

 

[jryoung]

Screws in the action could be too tight as well creating a pressure point? Is the trigger light an crisp? Have you thought about bedding the action? Have you looked at the muzzle with a magnifying glass to see I'd there are any burrs? Can you test with a separate scope? Are the bergers touching the lands? Or how far are jumping (in general they don't like a jump).

 

[Rancho Loco]

First of all, I never shoot an oiled barrel. Swab it dry before shooting.

Check all your screws, action and mounts.
Shoot some blue box federals. I always start with these. If they shoot good, rifle is sound and time to work up a load. If they spray, rifle needs a looking at.

If the blue boxes don't shoot, try another scope.

I'm betting you'll find your answer with the scope or screws.

 

[6speed]

Lots of good info above. I like to start at the end and work backwards. Check the muzzle for any deformities, then work down the barrel inside should be clean, no copper or lead fouling. Feel the outside of the barrel for any bulges or deformities possibly caused in mfg. or assembly. Make sure the barrel is seated properly in the stock and not having a contact issue on expansion. As mentioned above Berger's can be picky about jumping to the lands also check the headspace and make sure there isn't an issue there. Check all the action screws for proper torque to tight and to loose can cause issues. Check the trigger for proper operation and the bolt for proper lock up. Check the stock for flex and the recoil pad for unwanted movement. Check the mounts and the rings for proper tightness. Make sure the parallax is adjusted properly if equipped and eye relief is set correctly. Shoot a group, as best you can then adjust the scope up 20 moa and shoot again then right 20 moa, down 20 left 20 etc. You should see a 5 inch square made up of similar groups per corner. Odds are if the scope is bad you will see some variation in the group sizes as the internals are adjusted.

 

[Curvebow]

Like others have already stated, check all the screws! Remove the scope with the rings on and check the base screws. I use a torque screwdriver that measures inch-pounds. Also check the ring screws and the screws that bind the rings to the base (depending on which type of ring/base you are using).

Check the action screws to ensure that all is snug there. I hoisted my son's 308 yesterday and I felt & hear a rattle. The action screws were both loose! This explains why the gun wouldn't group consistently for him.

If the gun groups badly, then scrub your barrel. Use a good copper solvent and wet a brush and do like 25 strokes back & forth. Patch it clean and try more copper solvent on a patch. If it comes out colored, do it all again! High pressure cartridges will put more copper fouling in most barrels than lower pressure/velocity cartridges will. Don't overlook thorough cleaning as a potential cure. Many guns, especially older ones with barrels thought to be shot out as really just fouled and dirty.

 

[golfer]

Berger bullets are finicky to get to group. This information is straight from the Berger page that their bulletsmith have published to get your groups acceptable. Hope this helps.

VLD – Making It Shoot
Getting the Best Precision and Accuracy from VLD bullets in Your Rifle.
Background
VLD bullets are designed with a secant ogive. This ogive shape allows bullets to be more efficient in flight (retain more velocity = less drop and wind deflection). While this result is desirable for many rifle shooters the secant ogive on the VLD bullets produces another result in many rifles. It can be difficult to get the VLD to group well (poor accuracy).
For years we encouraged shooters to use a base of cartridge to end of bearing surface OAL (I will use the term COAL to represent this dimension) which allows the VLD to touch the rifling or to be jammed in the rifling. This provided excellent results for many shooters but there were others who did not achieve top performance with the VLD jammed in their rifling. These shooters were left with the belief that the VLD bullets just won’t shoot in their rifle.
Other groups of shooters were discouraged by our recommendation to touch the rifling. Some of these shooters knew that at some point during a target competition they will be asked to remove a live round. With the bullet jammed in the rifling there was a good chance the bullet will stick in the barrel which could result in an action full of powder. This is hard on a shooter during a match.
Yet another group of shooters who were discouraged by our recommendation to touch the rifling are those who feed through magazines or have long throats. Magazine length rounds loaded with VLDs could not touch the lands in most rifles (this is the specific reason that for years we said VLD bullets do not work well in a magazine). When a rifle could be single fed but was chambered with a long throat a loaded round that was as long as possible still would not touch the rifling.
Until recently, shooters who suffered from these realities were believed to be unable to achieve success with VLD bullets. Admittedly, we would receive the occasional report that a rifle shot very well when jumping the VLD bullets but we discounted these reports as anomalies. It was not until the VLD became very popular as a game hunting bullet that we were then able to learn the truth about getting the VLD bullets to shoot well in a large majority of rifles.
After we proved that the Berger VLD bullets are consistently and exceptionally capable of putting game down quickly we started promoting the VLD to hunters. We were nervous at first as we believe the VLD needed to be in the rifling to shoot well and we also knew that most hunters use a magazine and SAMMI chambers. Our ears were wide open as the feedback was received. It was surprising to hear that most shooters described precision results by saying “this is the best my rifle has ever shot.”
We scratched our heads about this for awhile until we started getting feedback from hunters who were competition shooters as well. Many were the same guys who were telling us for years that the VLDs shoot great when jumped. Since a much larger number of shooters were using the VLD bullets with a jump we started comparing all the feedback and have discovered the common characteristics in successful reports which gave us the information needed to get VLD working in your rifle. We were able to relay these characteristics to several shooters who were struggling with VLD bullets. Each shooter reported success after applying our recommendation.
Solution
The following has been verified by numerous shooters in many rifles using bullets of different calibers and weights. It is consistent for all VLD bullets. What has been discovered is that VLD bullets shoot best when loaded to a COAL that puts the bullet in a “sweet spot”. This sweet spot is a band .030 to .040 wide and is located anywhere between jamming the bullets into the lands and .150 jump off the lands.
Note: When discussing jam and jump I am referring to the distance from the area of the bearing surface that engages the rifling and the rifling itself. There are many products that allow you to measure these critical dimensions. Some are better than others. I won’t be going into the methods of measuring jam and jump. If you are not familiar with this aspect of reloading it is critically important that you understand this concept before you attempt this test.
Many reloaders feel (and I tend to agree) that meaningful COAL adjustments are .002 to .005. Every once in a while I might adjust the COAL by .010 but this seems like I am moving the bullet the length of a football field. The only way a shooter will be able to benefit from this situation is to let go of this opinion that more than .010 change is too much (me included).
Trying to find the COAL that puts you in the sweet spot by moving .002 to .010 will take so long the barrel may be worn out by the time you sort it out if you don’t give up first. Since the sweet spot is .030 to .040 wide we recommend that you conduct the following test to find your rifles VLD sweet spot.
Load 24 rounds at the following COAL if you are a target competition shooter who does not worry about jamming a bullet:
.010 into (touching) the lands (jam) 6 rounds
.040 off the lands (jump) 6 rounds
.080 off the lands (jump) 6 rounds
.120 off the lands (jump) 6 rounds
Load 24 rounds at the following COAL if you are a hunter (pulling a bullet out of the case with your rifling while in the field can be a hunt ending event which must be avoided) or a competition shooter who worries about pulling a bullet during a match:
.010 off the lands (jump) 6 rounds
.050 off the lands (jump) 6 rounds
.090 off the lands (jump) 6 rounds
.130 off the lands (jump) 6 rounds
Shoot 2 (separate) 3 shot groups in fair conditions to see how they group. The remarkable reality of this test is that one of these 4 COALs will outperform the other three by a considerable margin. Once you know which one of these 4 COAL shoots best then you can tweak the COAL +/- .002 or .005. Taking the time to set this test up will pay off when you find that your rifle is capable of shooting the VLD bullets very well (even at 100 yards).
Regards,
Eric Stecker
Master Bulletsmith

 

[Southwind]

Eric is right about VLD's being finicky, you might consider a bullet with a more forgiving ogive like Barnes or Accubonds. The Action screws can cause problems as well especially the two piece triggerguard floor piece.Use the correct torque settings. Free floating and bedding can help, Winchester used a hot glue bedding compound that I'm not real fond of.

I don't know why but all my Winchesters seem to like Aliant Reloader powders best.

 

[mtmuley]

Bergers can be "finicky" but not always. If it turns out it is the bullet, give the Classic Hunters a whirl. They were made to address the seating depth issues. mtmuley

 

[Blacktailbc]

- Throw a different scope on there, and give it a try. Check rings and action screws for tightness.

- Clean it with "wipe out" , sometimes when you think its clean, it really isn't. Wipe out really gets it super clean, and it is pretty easy.

- Bergers can be very hit or miss. I wouldn't use them as my means of measuring if the gun is a "shooter" or not. Partitions or Nosler ballistic tips are typically fairly easy to "dial in".

- If all else fails, try a good glass bedding job, or a stock with an aluminum bedding block, like a Bell & Carlson. Also, Hill Country Rifle does an "accurizing" service for about $600, that I have heard good reviews.

Hope you get it figured out.

 

[HalfAce]

I bought a Winchester Model 70 chambered in 300 win mag (not SS) a year and a half ago, and i am having the EXACT same results as you.

I put a NEW Leupold VX-3 scope on it, took it to the range, was shooting 3 moa with one type of ammo. I thought to try some different ammunition, so eventually went back to the range with 3 different types of ammunition and had the same results and even out to 4 moa.

I tried everything, shooting it clean, shooting it dirty, same results.

Eventually i got the time to take it to the gun store and have a professional put my scope on since i figured maybe i fouled that up myself. Once it was ready, i took it back to the range for another go, and it was the same story 3 to 4 moa depending on the ammo (all factory, i dont re-load).

It definitely is not an issue with the scope, rings or screws. Rings and screws were all checked multiple times before and after shooting, no issue there. Lastly, ive shot a 300 RUM since i was 16 with good results, so this 300 win mag doesn't scare me whatsoever. I am almost to the point where i may sell the damn thing. But im going to try shooting it with one of those Limbsaver de-resonators and try a few more different ammo types before i do get rid of it for good.

Let me know if you figure out the problem with your gun, im all ears for suggestions.

 

[WapitiBob]

5 shot string then cool, tells me it might be a heat problem.

If it does it with good cooling between shots, it might be like my old Kimber and is just a junker from the get go.

 

[Baerman]

I bought a Winchester Model 70 chambered in 300 win mag (not SS) a year and a half ago, and i am having the EXACT same results as you.

I put a NEW Leupold VX-3 scope on it, took it to the range, was shooting 3 moa with one type of ammo. I thought to try some different ammunition, so eventually went back to the range with 3 different types of ammunition and had the same results and even out to 4 moa.

I tried everything, shooting it clean, shooting it dirty, same results.

Eventually i got the time to take it to the gun store and have a professional put my scope on since i figured maybe i fouled that up myself. Once it was ready, i took it back to the range for another go, and it was the same story 3 to 4 moa depending on the ammo (all factory, i dont re-load).

It definitely is not an issue with the scope, rings or screws. Rings and screws were all checked multiple times before and after shooting, no issue there. Lastly, ive shot a 300 RUM since i was 16 with good results, so this 300 win mag doesn't scare me whatsoever. I am almost to the point where i may sell the damn thing. But im going to try shooting it with one of those Limbsaver de-resonators and try a few more different ammo types before i do get rid of it for good.

Let me know if you figure out the problem with your gun, im all ears for suggestions.

Interesting. I bought my rifle about 2 yrs ago.

 

[Baerman]

5 shot string then cool, tells me it might be a heat problem.

If it does it with good cooling between shots, it might be like my old Kimber and is just a junker from the get go.

I let it cool all the way down. This has been an ongoing issues. I'm sure its not a heat issue.

 

[Baerman]

- Throw a different scope on there, and give it a try. Check rings and action screws for tightness.

- Clean it with "wipe out" , sometimes when you think its clean, it really isn't. Wipe out really gets it super clean, and it is pretty easy.

- Bergers can be very hit or miss. I wouldn't use them as my means of measuring if the gun is a "shooter" or not. Partitions or Nosler ballistic tips are typically fairly easy to "dial in".

- If all else fails, try a good glass bedding job, or a stock with an aluminum bedding block, like a Bell & Carlson. Also, Hill Country Rifle does an "accurizing" service for about $600, that I have heard good reviews.

Hope you get it figured out.

I'll check those screws. it is the extreme weather version with aluminum bedding on a Bell and Carlson stock already. It should not be the stock or bedding causing the problem but I will have a gunsmith look it over. Thanks!

 

[Baerman]

Thanks again for all input. I'll check the screws, scope mount and bedding on the rifle first. I'll also load some new accubonds to try one more time. After that....who wants a new Winchester Model 70 weather extreme in 300 win mag. It shoots...but that is about it!

If this doesn't get straightened out, I'll never own another Winchester. Thanks for all of your input gents!

 

[jryoung]

If this doesn't get straightened out, I'll never own another Winchester. Thanks for all of your input gents!

I wouldn't judge all winchester by a recent FN manufacturing. Pre 64s and New Havens have earned their stripes.