Groupings? HELP!!!

[Baylian]

I took my CZ 550 .270 Win. to the range today. It is grouping weird. With some types of ammo I get 2 shots close (under .75 inch) together and then the 3rd shot is off (usually low and to the right) making a 1.5 inch or worse group. If I put a fourth into this group it usually hits close to one of the 2 close holes. The Nosler Partition and Grand Slam formed a 1.75 inch triangle. Nosler Accubonds string out wide (3+inches) from 8:30 to 2:30. I don't think my CZ likes Accubonds. Last time at the range it was a 5.5 inch group. I really wanted to shoot this cartridge at elk. SST's have a vertical string at about less than 1.5 inches. A couple other ammo types strung out 11 to 5. Can anyone give me some suggestions to improve the accuracy of my rifle? The range master checked and the barrel is free floated. I was using a Caldwell sand bag as a rest and a sand bag under the butt. This is all factory ammo. I don't reload (yet). The target that accompanied the rifle when I bought it had a ragged .6 inch hole for a 5 shot group at 50 m.

Thanks in advance, TJ

[BradC]

Baylian,

It may sound obvious but did you have the front sandbag under the stock or barrel? When I first began shooting with bags instead of a vise I found that a sandbag under the barrel to have a negative affect on accuracy. I assume this to be because it effectivley "unfloats" the barrel by not allowing it be free. Just a thought. Good luck.

Brad

[Ol` Joe]

Check your mounts and ring screws to insure they are tight. Don`t forget to make sure the action screws are tight also. Look for small cracks in the stock inside and out. I doubt you have any but I once had a rifle go south and found a hair line crack about 3/4" long in the grip area where it met the trigger guard. The rifle went from a .5-.75" shooter to shotgun patterns in the same range session.

If your scope has an ajustable objective lens be sure it is set properly for the distance you are shooting.

Make sure there are no dings or chips in the muzzle crown.

The rifle should be placed on the bags in the same maner for each shot. Keep the rear bag in the same position and watch the sling swivels don`t contact the front rest during recoil. If you hold the forearm on one shot do it for all, keep the same stock to shoulder tension.

If you can`t find any other possible causes, and the demons are still there, maybe you are makeing the wrong offerings to rifle gods. Virgins and beer don`t work, I`ve tried. (well beer anyway) You`re on your own figuring what to do with that one.

[Andy L]

With factory ammo, that group you first talked about being .75 with a flier may be as good as your gonna get. Factory ammo will group good out of some guns, not out of others. Its a crapshoot at best. Thats plenty good for killin elk as far as a 270 needs to be shot at elk.

My experience has been that Noslers of any type are not the accurate in the larger calibers. Period. Factory or handload. Im sure some will say they have good luck, I havent in several calibers. Hornady and Sierra seem to beat them everytime for me.

As for groups, .75in with a flier is actually pretty damned good for factory ammo. In all honesty, I dont see guns very often shooting in the .2s and .3s that you see posted on the net. In real life, on the range, I have seen very few and most are expensive custom benchrest jobs. I see alot more in the .7s to 1.0s and on up. Sometimes guys will shoot several groups .7 or larger and one group .35 and out comes the pocket knife to cut out the bughole for a pic and to put in his wallet to sport around. Happens alot.

Like I said, if your gettin .75 with a flier out of that 270 with factory ammo, thats pretty good. thats 1.5 at 200 yards and 3 in at 300 yards. If you should shoot the flier at the elk, thats still 6" at 300 yards. You shouldnt shoot one further than that with that light of a caliber. It will kill it.

Good Luck
Andy

[Baylian]

I have the stock on the bags. I may not have had the sling swivel free so I'll check that next Saturday. I'll check out screw tightness before I go again but this is a brand new rifle so I don't think there will be any cracks. But I'll check. The most accurate ammo in this rifle is the Federal soft point 130 gr. and the Hornady SST 140 gr. This is an expensive way to see which ammo your rifle likes the best. ANY suggestions on the verticle grouping?

Thanks for the input!!!

Good Hunting, TJ

[rem 700]

Barrel heat and vibration...waiting will cure the heat problem and a sims de-resonator will help the vibration. BTW, don't just tighten your scope bases, loctite them.

[Lycanthrope]

Your barrel twist rate may like lighter bullets. If that's the case, it's OK. You can use a bonded or Barnes X to penetrate in lighter loadings.

Unlike Andy L, I have found Nosler Ballistic Tips to be well loved in every rifle. I never buy factory ammo, however, and work up in .5 increments. All my rifles shoot under .75 MOA.......75 MOA is shot by my least accurate AR 15.

I always take my action and barrel out of the stock and relieve (Dremel!) ligtly around the action and free float the barrel. If your barrel isn't floated, you can easily change groups due to different pressure points and how you hold the gun. Free floatinig is the cheapest and easiest way to get some consistency. A deresonator is a last resort because the pressure they exert changes with tmeperature.

Make sure the mounts are tight. Snug the action screws, but don't clamp down on them with all you've got. Some rifles are horrobly finicky about action screw pressure if you aren't pillar bedded.

When shooting I take the sling off and make sure the swivel studs don't touch the bags. I level the targets (grid targets) so I can align my crosshairs with the lines and know I'm level and not canting the scope. Hold the gun with the same pressure every time and wait for the barrel to cool where you can touch the barrel for 20 seconds without discomfort.

[Baylian]

I waited 4 minutes between shots on a cold day with a 5-15 mph quartering wind. I've been told by expeerts that I need a 140 or 150 grain bullet to kill an elk with a .270. My sling is off.

Thank you, TJ

[Lycanthrope]

The experts say use a 140 for penetration......but you can get the same penetration...or more.... with a Barnes X in a lighter offerring (although the lighter X will be about the same size as the larger lead core bullet).

Just an option should your barrel not be able to stablize the heavy pills.

[Baylian]

But Barnes cartridges cost $38/box. You might as well be shooting Weatherby's.

I went to the range yesterday. I found some Hornady !30 grain Interbonds and compared them to the Hornady 140 grain SST. I had cleaned my rifle with Hoppe's Elite and Shooter's Choice copper remover.

After a fouling shot, the Interbonds shot a 3 shot 1 5/16 inch group. The SST's then posted a 3 shot 1 7/16 inch group. I thought I had found my bonded elk bullet. But the next groups went to pieces. The Interbond had to 2 shot groups that were 5/8" and 7/16" but the 2 shot groups were part of a 4 shot group and were 2 1/4" apart making a 2 9/16" group. Next group for the SST's was 2 7/16". So I shot another Interbond group trying to concentrate and reduce errors. I got a 2 11/16" 3 shot group. The next SST 3 shot group was 1 5/16". I decided to shot one last Interbond 3 shot group. It came in at 1 3/8".

WOW! I go from great to crap to great again. I wonder why? I was trying to be consistant and I watched my sling swivels so they didn't contact the sand bag. No real wind.

So that's my lastest report. Which would you use?

Thanks in advance, TJ

[Lycanthrope]

SST's never ran in my rifles. They are a VLD bullet and to seat them near the lands you'll run out of magazine on some guns.

Your gun acts like it has a bedding, action screw torque problem. Start with them TIGHT and then back off a bit if it doesn't run.

To make sure I'm not canting the gun, get targets with grid lines and use a level to make sure the target is level. Then make sure your vertical crosshairs is aligned with the target on every shot.

[Jonesy]

I've run into people having that same problem quite a few times. Having two shots tight and having a few wild ones. Every time I have seen that problem it had to do with the barrel hanging up in the barel channel or a barrel pressure problem. Check your barrel pressure and check to see if you have a tight area on your barrel channel.

If you have a heavier barrel, free float it. If not, you might have to use accu-glass and make yourself a pressure point at the bottom of your barrel channel about an inch to inch and a half back from the end of your fore end. A lighter barrel has a tendency to jump more when shot. It needs to come back down and settle in the same exact spot in your barrel channel each time. If it doesn't, by getting hung up or not having the correct down pressure you'll get the wild ones.

Don't know if that will help you, but it can eliminate another possible cause of the odd shooting. I would think that one or the other is probably your problem.

[Brithunter]

Hmmm reading this several questions come to mind so here goes:-

1) What is your usual group size when shooting ?(I am assuming that you have another rifle at least)

2) The rifle is a new CZ 550 what is the scope and mount set up?

3) Is the scope known to be good?

4) You said that the barrel is free floated "The range master checked". Hmmm just how much experience shooting wise are we talking here?

5) Is the rangemaster the gunsmith type and how much experience and knowledge does he have?

Now you also mentioned that you cleaned the rifle before the last shooting session. Well quite a few rifles will throw the first few bullets from a clean barrel out of the main group. So before hunting you need to find out if this is the case with your rifle if it is it's not a big deal just don't clean it before hunting after the last sight in session.

Otherwise it's back to basics. Start from the basement and work up checking everything. I am not familar with the 550 model having the older Model 601 so that makes it a little more difficult to help. Now the old 600,601 & 602 models did not have a free floated barrel and shoot very well indeed the bedding on them was good from the factory but they were made completely in the Czech Republic, not sure about the 550 so I wonder if there is a quality finish issue ............ possibly bedding as free floated barrels are the cheap way to bed a rifle which accountants love .

However you need someone who is good, knows what they are doing and is well experienced to check it over. Now a quick easy and cheap way to test the bedding is to get some thin card. Business cards work well. Cut and put it pieces as shims under the barrel in the channel about 1 1/2" back from the end of the fore stock and try shooting again. You may have to try a couple of times with more or less card and see if it tightens the groups or throws it wider. However you need the check the Mounts and the scope and the actions screws as mentioned before by others before trying this.

Now if pressure from the card shims tighten up the group then you need to either bed it yourself or get it done. I have a P-H 1200 super which hates any free floating as I found out by mistake added too much bedding material and acidently free floated it. Groups were terrible about 6-8" at 100 yards with it floated . After bedding with a pressure point it now hovers around the 1 MOA to 1 1/2 MOA groups with factory ammo.

Oh sometimes you are luckyand find the brand/load which your rifle likes straight away, others it takes time and unfortunately money to get there. Good Luck with the grouping and the hunting .

[L. Cooper]

Having read all these posts, I think it may be time to find someone who is a very experienced shooter and let that person see what the rifle will do. Some of the groups you are describing sound to me like it could easily be the shooter that is contributing to the difficulty. Several different loads, along with the occasional bad hold will make the gun seem unpredictably erratic.

[Baylian]

Not having shot for a while and never really having shot a centerfire rifle very much, I think L. Copper's assessment is correct. My dad said the same thing on the phone. Oh, the shame!!! I took the rifle out on the last day our range was open and shot 1 3/8" and 1 1/4" groups with the 140 grain Hornady SST's. It's not sub-MOA, which I would like, but it is acceptable to me. Especially since I am hunting elk. They have a large kill zone. I know I can hit it. I am going to have my rifle checked out by a good smith when I find him. Until then it's practice, practice, practice. "Aim small, miss small." Thanks for all the help!!!

Good hunting, TJ