Home Forums Hunting & Shooting Hunting Rifles 2 shots on and then one flyer

Can somebody help me out on this one
I have a 270WSM Win 70 bedded into a Mcmillan stock with floated barrel.
I thought I had a good load using 130g NAB using 61g IMR 4350 getting about 3175-3200FPS.
It was shooting good but on my last few range sessions I have had the below problems -
The first shot on a cold barrel (clean or fouled) tends to be very inconsistent
The rifle will consistently put the first 2 shots touching and the 3rd anywhere from 1-2 inches to the right and slightly high.
I really try to let the barrel get cool and have even built a fan to blow air down the barrel out of a air mattress pump.
Took the rifle out today on a clean barrel and the first group sprayed 2-3 inches.
Second group was back to the same pattern of the first two touching and 3rd out about 1.25"
Any ideas

How concentric is you ammo? TIR for run-out? You said you thought you had a good load, was it shooting better in cooler temps and if so how much better? It may be a combination of a few different things like:

1. Variation in load due to temperature. IMR 4350 isn't as temp stable as H4350 for example.

2. Check your loads run-out.

3. Who bedded it. Do you have pics?

4. Action screw tension can affect groups size.

5. How far off the lands? Sometimes seating further off the lands or closer to the lands will alleviate the extreme "flyer".

6. Check all scope mounting hardware (bases, rings) for any screw backing out or coming loose. If there's a problem with this, loctite them.

7. Use a scope of known quality: One that tracks well, holds poi, doesn't have a problem with parralax.

^^ What he said, especially #3 & #4

Edit: I will also a little experience I've had with high velocity loads. Many years ago I bought a 30-378 Weatherby. I remember reading about it and couldn't wait for it to come out. I bought it first year. Factory installed muzzle break, "high tech" synthetic stock, blah, blah, blah. I thought I was the [bleep] walking out of the store with it.

I can't remember how many loadings I made for it but it was a lot, always max or close to max of course. I kept having the same problem: 2-3 shots were good (maybe 1.5"-2" MOA at best) then the 4-5th shots were fliers, sometimes HUGE fliers of 6" or more. At first I thought it could be the scope but for giggles I loaded up some reduced rounds ~30-06/300WM velocities. The results were dramatic. The '06 velocities held zero far longer and cold barrel shots were perfect. It became clearly evident that the 28" non-fluted "sporter contour" barrel of the Weatherby was the problem. The high velocity of that round simply turned the barrel into spaghetti subsequently throwing rounds all over the place when it got hot. I won't even get into the "grenading" Sierra and Remington pills that couldn't stay together. I promptly sold that rifle. It ushered in a new way of thinking for me regarding the "need" for ultra high velocity rounds. The overall point may be this: if you know that the first two shots are spot on do you care about the third or fourth being off? For me it mattered a lot. However, you may not care. Most game drops on the first shot anyway.

I would ck to see if your magazine box is binding and putting pressure on the action..best to have a little play in the mag box.

I need to look at the above mentioned things this evening.
What do you mean by load run-out - not a term I am completely familiar with
Currently seating 0.030" off the lands - did test loads in .005" increments from 0.010 off to 0.050 and this is what I thought was shooting the best
I checked the ring screws and action screws with a torque screwdriver and they seemed to be good.
Bedding was done by a gunsmith I have had good luck with in the past.
Using a Zeiss Conquest 3-10 scope

Are your cartridges straight, as measured by something like this:

It is probably somewhere in the bedding when you put it together after cleaning, if you did take it apart. It was shooting good till your last few sessions. Magazine bind might be it or action screws not tightened properly. Could also be a loose base or rings in the scope. But if you did take it apart, I'd first check if it's back together right.

Any one read the recent article on wind flags? I'm going to buy a couple spinners.

https://www.24hourcampfire.com/


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Or this:

Could be all the above AND a thousand other things...could be your shooting skills...could just be your brass...here's a prime example of a brass "proble".




The same case # 3 was always out of the group...not by much but ALWAYS in 4 targets.

FORGET about the first shot from a clean cold barrel...THAT shot is the anomoly, not the rest. Always foul the bore with a shot or two before working for groups....I've NEVER had a rifle, benchrester or not, that would put the first "clean bore" round in the same group as the following shots...I foul my hunting rifles prior to hunting season then leave the bore alone until I get my game or the season is over...I shoot at least 2 foulers after cleaning and before hunting in ALL my varminters and during load development.

The next thing to do is to number you brass with a sharpie and shoot them in that order AND record where the rounds hit...I use 3 rounds for group for hunting rifles...do 3-5targets then compare them. If ONE case is the oddball it will ALWAYS be out of the group and usually by the same amount IF the load is consistent. This is not uncommon but most people don't have a clue about the happening or really care for hunting accuracy.

ONCE you have established what is going on with your brass, THEN you can go back and start at the beginning to "retune" your rifle system. I usually start with the bedding, I use pillars or a bedding block in ALL my rifles no matter what caliber...I do another "skin" coat...make sure the barrel is floating, retorque the action screws, make sure the bolt or bolt handle isn't touching the barrel face or ANY part of the stock...sides OR bottom of the handle cutout...make sure the scope mounts and rings screws are tight and sometimes I swap in another scope just to check.

Your ammo needs to be consistent also...weight sorted, primer pockets and flashholes trued and deburred, trimmed and neckturned is it is out by more than about 0.002"(for minute of deer), for a varminter you need it much closer.

If the rifle isn't tuned up you're just wasting money on components...depending on WHAT level of accuracy you require...for a 2 MOA rifle, factory ammo and right out of the box accuracy is usually plenty good...for long range sageratz beyond 300 yds, you need a <.5 MOA or better which means lots of work in the tuneup.

Luck