Analyze my target - what is going wrong?

[timotheius]

I need some help with a recent load of mine....maybe some of you can figure out what is going wrong. As you can see from the pic of my target I shot 3 groups of 4. The first group is pretty sweet. I would be thrilled if all my groups were like this. The second groups is decent, but clearly is opening up a little bit. The third group opens up a lot. What is causing this? Have I worked up a load that it too tempermental?

My gun is a Tikka T3 light in .243. I added an aftermarket Bell and Carlson stock with a full length aluminum bedding block. The barrel is free floated. The load is 100 grain Sierra pro hunter bullet, Hornady Brass, fire formed and neck sized with a lee collet die, 35.6 grains of IMR-4064 powder, Winchester primers.

My gut feeling is that this may be caused by barrel heating? The Tikka T3 light is a light hunting barrel. But will a hunting rifle open up groups like this after only 8 shots? I didn't shoot them all back to back to back. I did wait a few minutes between groups. I'd say these 12 shots took about 20-30 minutes to shoot. Am I seeing the groups open up as the barrel warms up?

 

[Comrade Mike]

The barrel is heating up. My Stevens 200 does the same thing. With the right load it's a half inch gun, for about 6 rounds.... Let it cool down for 20 minutes in between groups and it will do it all day. That's the nature of factory noodle barrels.

There's a reason we pay for bull barrels. Apart from being higher quality they act as heat sinks.

 

[280shooter]

I have a Tikka 3 lite in 223.its not a target rifle, its a lite hunting rifle, you'll be ok with your load, just don't be in a hurry, shoot 3 shot groups, take a magazine with you, shoot 3 rounds.read a little, or take a 22.

 

[higgite]

Even better, shoot one shot at each target, rest a few minutes to let the barrel cool, then shoot one more shot at each target, rest a few, rinse and repeat until you have at least 5 shots in each group.

 

[gamestalker]

Try shooting a group, wait 5 minutes or longer, shoot another with another good cool down, and so on. This is a common issue associated with light hunting rifles, not just Tika's like your's.

GS

 

[ArchAngelCD]

Yes, it's not only possible but probable it's a heated barrel that causing the groups to open like that. A buddy has a Ruger you can shoot 3 rounds in and cover them with a dime. Try shooting a 4th without letting the barrel cool and it's a good 3/4" from the other 3 rounds.

Shoot 4 let the barrel cool at least 10 minutes and then shoot 4 more. I'm sure the problem will go away.

The Tikka T3 light is a light hunting barrel. But will a hunting rifle open up groups like this after only 8 shots?

Think about it, like you said it's a hunting rifle. If you miss a shot and get very lucky to get a second shot, that's all you will shoot at that time. While hunting it's extremely rare to shoot more than a fwe rounds a day if that many.

BUT and this is a very big BUT! The first 8 shots are extremely tight shots and 2 very tight groups. I can't see any of the 12 shots you took missing game. These days even entry level rifles are very accurate so many shooters think unless you can shoot a ragged hole each and every time the rifle is no good. Back when our grandparents wer hunting for dinner it was usually with a rifle and ammo that barely did 4 MOA and the still put dinner on the table. There is nothing wrong with that hunting rifle, nothing at all.

Welcome to the forum...

 

[Zeke/PA]

I'll go along with the warm barrel diagnosis also.
Try timing two or three minutes between shots.

 

[WelshShooter]

Try another group after the barrel has cooled. If the grouping is large or worse then check your action screws are tight. Might want to torque these to minimum of 40 in.lb if you have access to a torque driver.

 

[Andrew Leigh]

Try another group after the barrel has cooled. If the grouping is large or worse then check your action screws are tight. Might want to torque these to minimum of 40 in.lb if you have access to a torque driver.

New stock and a couple of rounds down the barrel has loosened her up. Torque the stock, those variations are simply too much to attribute to heat, your did allow for some cooling time.

Group 3 is the classic two shot group attributable to either rifle fore end slipping on the rest and or action not sufficiently tight in the stock.

 

[timotheius]

Thanks everyone for the help. I agree with all of you, I need to load up some more and see how repeatable these results are. I will do as you said and test some 3 shot groups while giving it a LOT of time to cool in between groups. Ill post my results here for review later in the week.

 

[Sunray]

Hunting shots are about shooting out of a cold barrel. However, even the target on the right is just dandy. Even Texas deer are bigger than that.

 

[mdi]

Try the opposite of the suggestions above. Shoot groups of three with less time between shots/groups. If the groups get even worse, the problem is obvious; barrel heating...

 

[spitballer]

Hunting shots are about shooting out of a cold barrel. However, even the target on the right is just dandy. Even Texas deer are bigger than that.

I must agree with this post.

Also, for the rifle range it may be possible to develop a target load that does best at a particular rate of fire. The guys over at competitive shooting say most matches give you one shot per minute.

 

[Zeke/PA]

I've personally been up and down this issue for years.
I do not PERSONALLY like a rifle that does not shoot close to M.O.A.
My "out of the box" Ruger#1 in .270, was shooting M.O.A. for YEARS then suddenly decided to take a dip!
Forearm alteration and we are back where we started from!
Reloads of course!

 

[Zeke/PA]

Thanks everyone for the help. I agree with all of you, I need to load up some more and see how repeatable these results are. I will do as you said and test some 3 shot groups while giving it a LOT of time to cool in between groups. Ill post my results here for review later in the week.

Between GROUPS??
That IS NOT the answer!
Between SHOTS IS the answer though!

 

[JimKirk]

Some of my hunting buddies laugh at me for doing what I do for group checking my deer rifle ... I'm lucky I have a 100 yd range in my backyard and I am retired ...

I shoot 1(one) cold bore shot at the target ... I go get the target and put it in the shop ... the next day I hang the same target and fire 1(one) more cold bore shot ... I do the same until I have fired 5(five) cold bore shots out of my deer rifle ... I may skip a day or so between shootings... it is usually a pretty tight group ... I want to know where that FIRST SHOT is going because I hope that I never need over a couple shots ... I have never had to shoot a deer more than twice ... I'd rather be confident of what would happen if I climbed my stand and took shot at a deer... rather than worry if my rifle would shoot a five/ten round group ... now a target rifle is a whole different story ...

I have several rifles I deer hunt with ... more or less depending on which stand I chose that day ... so it not that I go out and shoot just one shot and walk back in the house ... there is always pistols and revolvers and .22s that need shooting ...

If for some reason I have to shoot a deer rifle more than a few shots ... I get out the air mattress pump(12v) and plug it into the John Deere Gator I use in the yard ... I open the action and place the rubber hose into the chamber and turn it on ... the moving air will cool a barrel and action down in just a little time ... then I can shoot another "cold bore" shot or so....

 

[JimPGov]

Barrel heating up is the culprit. Fire a shot, leave the bolt open for a time to allow the air to pass through the barrel. When testing for group size i allow about a minute between shots with the bolt open. Jp

 

[ArchAngelCD]

I have 4 rifles I usually use for hunting. Each and every one has been shot for clean bore cold bore shots and fouled bore cold bore shots. Like said above, that is most important with a hunting rifle and I keep the target with the rifle so if I don't use that rifle for a while I have the information available when I take the gun out.

 

[Poper]

The guys over at competitive shooting say most matches give you one shot per minute.

Not the Metallic Silhouette boys.
Try shooting a Hunter class rifle weighing less than 9 lbs in 110 deg weather with two 5-round banks at 2.5 minutes each for a total of ten rounds in about 7 minutes.

Hint: Don't touch the barrel!

 

[Wylie1]

Hint: Don't touch the barrel!

Yeah, what he said!

 

[spitballer]

Even a hot barrel can be accommodated with a suitable load, if rate of fire and temperature are maintained.

 

[Zeke/PA]

Even a hot barrel can be accommodated with a suitable load, if rate of fire and temperature are maintained.

Rate of fire MAINTAINED?
That's precisely what the shooters on this board have suggested.
The "buggy whip" barrels on todays rifles need some attention IF you wish to assure that you can depend on your rifle in a hunting scenario.
I tell my friends to shoot MERELY one shot at the range to really develop confidence in your hunting rifle.
Bottom line? Target rifles and "shoot for group " rifles, today's sporters ARE NOT!

 

[spitballer]

I'm merely illustrating the point that a hotter load can be used to compensate for barrel growth at higher rates of fire. The man obviously cherishes his rifle and he's not going to go that route if he can slow his rate of fire instead. I think we're hammering on the same nail.