.308 zero, what on earth is going on????

[rogeydodge]

I'm really hoping some wiser souls can help shed some light on what could be going wrong with my rifle. I will try to explain events as best I can in the hope someone can offer some guidance.

Blaser R8
Zeiss Deavari 6-24 x 56
308 barrel with approx 700 rds through
A-Tec moderator

For the last few years I have been loading a very accurate round for my 308 & been entirely happy with it. Recently those groups started to open up, so I made a new batch but they also had the same issue.

I carried out a very deep clean of the barrel, but this made no difference at all

I had an imminent trip to Scotland coming up so I brought some factory Sako 150g Super Hammerhead and happily they shot a sub moa group. Thinking it must be something I was missing on reloading front I went to Scotland with high confidence of the Sakos.

I stalked a Roe to around 150 yds and took the shot. When I went to the animal I saw that my shot was two inches to the right of my aimpoint. Frustrated I set up a target and found the group was stringing right with 2 inches between each shot!!! What the hell is going on I thought.

Trip to Glenluce Gunroom (thanks Stewart) bore scope the barrel, no issues & crown in good order. Scope secure on the Blaser saddles mount. Stewart suggested I shoot a target with no mod attached as he has had lots of issues with A-Tec mods recently.

It is this 100m target I have attached to this post.

As you can see bottom right target, first shot is four inches from aim point, second shot two & a half inches.

Top right target 2nd two shots approx 2.5 inches.

3rd 5 shot group now tighter

4th cold barrel group center target back down 2 inches

I'm going nuts! Can anyone help and make sense of this? What was a great rifle is now consistently inconsistent. I have run some paper down the outside of the barrel, and it is still free-floating with no obstructions.

I can hear some of you saying it's gotta be the scope, and I'm tending to think that, but can a quality scope start to malfunction after such little use?

I stopped using the rifle & came home. I've not even unloaded the car, just got on my PC to you guy's looking for advice.

Thanks in advance
Roger

 

[Mungo]

Your 3rd and 4th groups look fine, and would form a natural group - especially if you shifted position in between groups and were starting to get frustrated.

I would shoot 2-3 more groups of three before even beginning to think there was a real problem. The rest looks to me like what can happen after a deep clean: very wild groups for 5-10 rounds before it settles down.

 

[1894]

2" to the right at 150yards is probably within field accuracy?

When rifles (or rifle shooters) start to get problems it pays to take real care and time to avoid throwing baby out with bathwater.

Distance from point of aim is neither here nor there if you take off the moderator. Some rifles like fouling.

 

[rogeydodge]

Thanks Mungo

I should of said it had approx 20 rds through after the clean. So after the roe, the shots were stringing right, two inches between each shot. Next day it's shooting the above. I will shoot again tomorrow but I strongly feel I will be somewhere else on the target. The 3rd-4th groups are tighter yes, but not similar in placement

 

[rogeydodge]

Yes your right, but considering what happened before the trip, this was the reason I checked zero. I get the same inconsistancy with or without mod.

 

[Heym SR20]

Just relax and breath.

Firstly check the rifle thoroughly - are the barrel retaining screws tight. Such random movement means something is loose somewhere.

Does it have open sights - if yes then give these a try.

Next check scope mounts - are these nice and tight. Are the rings tight as well. Has the scoped slipped in its rings.

Next check the scope. Easiest with a bore mounted colimeter, but you can do it without. Set the rifle up and clamp it firmly, with it sighted on a target or an object in the garden etc. Bore sight it for reference. Then take it ten clicks up and then ten clicks back down - should be back to zero. Do it up down, side to side. Finaly go around the box - ten up, ten right, ten down, ten left - if it is not tracking this will soon show up problems. If its ok try 20 clicks. If it goes back to zero its probably OK. Try it at different magnifications as well.

Then check the rifleman. Are you doing anything different - say shooting off a bipod. Get out the air rifle or 22 and go back to basics.

When you get frustrated with a rifle its very easy to think something is seriously wrong and you just get more and more frustrated, when in fact its yourself who has devolved a flinch. Been there many times.

On game I would worry to much about a shot being 2" off - especially at 150 yds. Its difficult to be that precise as most deer do not have a clearly defined target, plus deer do move and field positions are never as stable as the bench.

 

[PeterH]

My money is on a problem with the scope.

I loaded some 308 rounds in a chap's Blaser R8 using 150 gr Accubonds - he was going boar shooting in Turkey. First up with this rifle I had to make 22.250 with his change of barrel using a brand new Swarovski Z6i. The 22.250 barrel shot very well. Obviously POI was going to be different on the 308 barrel and 4 shots later after elevation and windage adjustments it put the last two shots within 1/2"


Moved on to a OCW target (see scan below) and the 1st shot at each target seems slightly left of target. On the 2nd lot of shots the impact moved left of the first. The third lot were again moving left - did not bother to shoot at the bottom bulls. Everything tight action and scope wise. Changed the scope to my NXS and it shot very well - he went to Turkey with my NXS and shot one boar at 525 yds

Swarovski having seen my OCW target agree that the scope has a problem. Sorry scan is sideways - cannot adjust it.


Same everything but using my NXS

 

[deeangeo]

You could nip over to see Michael at Calton Moor range, I’d be surprised if he couldn’t help nail down the problem with you

 

[VSS]

When my rifle started stringing shots it turned out to be the scope.

 

[caorach]

There are two screws on the Blaser QD scope mount, certainly on the R93 and I believe the R8 is exactly the same, that sometimes come a little loose. They have a weird, very narrow, slot in the head of them and so a normal screwdriver will probably not fit. If anything goes wrong with a Blaser, or it's mounting system, it is usually them working loose. You can sometimes feel that the little thumb levers that you close to fix the scope feel a little easy to push over, but because the thing loosens up over time you can become used to it.

 

[Cottis]

After ensuring all screws are where they should be, I would try change of mounts and/or a known good scope. For me, rifle weirdisms like this have almost always been down to the sighting system in some way.

Had the odd issue with a crown or rings in barrel but had various issues with scopes and mounts down the years. Not always with poor kit either. The best stuff can go wrong.

Good luck finding it. You will

 

[rogeydodge]

Relax & breath, great advice. I agree I need to slow down. I will definitely be trying your suggestions Heym SR20. I will dismantle scope from mount, and start again. Mike at Calton Moor may comment on this post, he has been with me on this journey & he is as flummoxed as I am at the moment. I don't think I am doing things any differently than I always have but it's another possibility. It is good to vent some frustration with like minded people who understand the frustration I'm going through. You get in a comfortable place with your gear, then this happens

 

[rogeydodge]

After ensuring all screws are where they should be, I would try change of mounts and/or a known good scope. For me, rifle weirdisms like this have almost always been down to the sighting system in some way.

Had the odd issue with a crown or rings in barrel but had various issues with scopes and mounts down the years. Not always with poor kit either. The best stuff can go wrong.

Good luck finding it. You will

Thanks Cottis. I agree it's looking favourite at the moment, but will follow advice above and go back to basics first, SLOWLY!! I think if it does come back to the scope Zeiss will do a service

 

[kes]

Those answering above have far more expertise than I but I would advise that when I had a major problem with stringing and flyers, it was the scope mounts - I initially tightened everything up, light clean and pleasant surprise the rifle returned to putting them through the same hole (almost) at 100 yds. Make sure however, as mentioned, all the 'framing' screws are super tight.

 

[bluesako]

if you think its down to the scope try another scope on your rifle

 

[jthyttin]

From the target in OP there's 3 different POIs.

1. the very first shot
2. the following 3 shots, and the "4th group cold barrel"
3. the "3rd group"

POI #2 has 6 shots within an inch or so. POI #3 has 5 shots within an inch or so, and is a bit higher than POI #2 but is also shot from quite warm barrel.

After checking the rifle, scope and shooter as advised, I would work on that. Fire first shot on separate target, and then test for "coldish barrel group" wait few minutes and test for "warmish barrel group".

 

[Irish Bob]

You could nip over to see Michael at Calton Moor range, I’d be surprised if he couldn’t help nail down the problem with you

That's where I would take it.

 

[Uncle f]

Have you tried removing the barrel and making sure there is no moisture, grease etc. I had this issue and found out that the two bolts that fit the barrel to the stock there was some tiny bits of grease which made about a two inch difference in zero.

Regards steve

 

[ChesterP]

Sounds very much like a sighting system (scope or mounts) issue. I had much the same thing a year or so ago and a change of mounts solved the problem. Had another similar issue around the same time with another rifle which turned out to be a faulty scope which had worked fine up to the point it didn't! Just as a sanity check have you examined the end of your mod carefully to ensure that you're not getting any bullet strikes within the mod and also examined the shoulder where the muzzle thread is undercut to is nice and square without any damage?

 

[puntgunner]

Stringing

Rogeydodge,

I am not sure if you mentioned if the scope is rail or ring mounted. I will read again, but - from my own personal experience - I had a problem with my R8 and a rail mounted z6i.

Over the course of a session on the range, my rifle started to string out to the left for no obvious reason.
All of the usual course of action was followed, but the problem still persisted. I was convinced that the scope had failed and that this was the problem.

It indeed turned out to be the mount. Not the QD latch cam's, as they were adjusted to give a firm lock when latched over. Or the locating pins onto the barrel.

It was - and not at first obvious - the three torx screws that attach the scope to the rail system. These screw, located under the rail and sometimes hidden by a strip of plastic, had come loose a bit. Locked them up tight and hey presto ! a shotgun became an accurate rifle once again.

Hope this helps.