Help Needed with Precision .22LR

[Medic505]

quarter sized groups at 100 yards on a consistent basis.

Is this one of those "all day long if I do my part" things?

 

[Appalachian]

My CZ 452’s best 100 yard 6x5 is on the bottom right. This rifle with Center X has shot 3/4 MOA all summer long. At 50 yards it shoots consistently .4-.6 MOA with good lots of Center X.

 

[skeeljc]

Here is the fruit of today's labor. It is a push-feed where the AICS mag is a controlled feed. I may make another with an angled cradle to allow the rim to come up behind the extractors (controlled feed). Right now the extractors snap over the rim with little effort.

 

[Carbide]

I shot these three groups back-to-back today. Note the flyer in each group at 12:00. The flyer was always the first shot. I cannot figure what the cause is.

The rifle is a Bergara B14R with a Harrell tuner. The ammo was Lapua Center-X. Distance was 100 yards. The groups were shot from a front rest and a rear bag.

View attachment 1273817

First things first. Have you run it over a chronograph? What barrel length? For 100 yards you need to be at 1100+ fps at muzzle measured not what is on box or spec.

 

[Chasin Beaver]

I have a Anschutz 1813 that does the same thing. Not only that, but the first round seems to be going higher over time also. Wish I could tell you a cause, but only thing I can think of is that it may be do for a good cleaning. I see lots of posts claiming using error, magazine, tuner, feeding issues, etc. If your case is like mine, I can guarantee that it is none of those issues (and first shot fliers is something you can believe in).
Personally, I have never timed how long it takes for first shot flier to appear, but I shot some smallbore prone at both Perry and Atterbury this year. My first shot would be high, then the rest of the sighters and 20 for record would be all on call. In the time it took to hang next target, the first shot flier would return. In my case, the first shot at 100 would be almost out of scoring rings at 12:00, and second shot would be a “x”. I would then go on to clean target, or come close to, with no elevation adjustment. I will be watching this thread to see if you get anywhere with it, and let you know if I ever figure it out Good luck.
P.S. Not sure if just coincidence, but I am shooting CenterX also.

 

[skeeljc]

I shot the Bergara yesterday. These were shot at 50 yards where I was trying to get the tuner sorted out. SK Rifle Match. The "flyer" is always the first shot of the group.

 

[Papa Charlie]

Very strange, seems as though you have isolated most parts of the rifle. If this was a high powered rifle, I would think that the action is moving in the stock on the first round and then is set for the following rounds. But that doesn't seem possible in this case.

 

[skeeljc]

Very strange, seems as though you have isolated most parts of the rifle. If this was a high powered rifle, I would think that the action is moving in the stock on the first round and then is set for the following rounds. But that doesn't seem possible in this case.

Well I did see somewhere where someone bedded the recoil lug in their Bergara. I am considering that.

Could inserting the mag affect the seating of the action in the stock?

 

[skeeljc]

I modified my single shot adapter so that the rim sits lower and comes up behind the extractors. It is now a controlled feed loader.

I will run a test to see how groups from the single shot adapter compare to the mag if the hot weather ever goes away.

 

[Hunting 2019]

Nice job on your single shot adapter.
Don't know why but Bergara used the same paint under the action,those raised black drops of paint are under your action! I took sandpaper and sanded where the action touches the bedding.It comes off easily,just something for you to consider. Hope you get it figured out!
Rick

 

[Papa Charlie]

Well I did see somewhere where someone bedded the recoil lug in their Bergara. I am considering that.

Could inserting the mag affect the seating of the action in the stock?

That would depend on how solid the action is in the stock. I can really only think of two reasons for this issue being that it is only the first round that is affected from each mag.

1) The action is not firmly stabilized in the stock
2) The mag doesn't properly seat into the mag well until after the first round is driven home and fired.

I think it is a product of the first item. Worth checking into.

 

[skeeljc]

I re-read all the posts this morning. I decided to get the bedding issue taken care of first. When I removed the action from the stock I discovered that it was sitting on just the raised areas around the action screws (I verified this with a piece of .001" shim stock). Pillar bedding only on injection molded plastic. Not good.

I am going to skim bed the action with Devcon.

 

[skeeljc]

The pillars in the Bergara stock are aluminum along with the pocket around the recoil lug. I discovered this when I was roughing up the area for the bedding. The receiver was sitting on paint, contacting only the two pillars.

 

[skeeljc]

I coated the pillars with a felt tip pen and moved the action back and forth to verify the contact points.

 

[Thud]

Bed it so contact points are uniform

 

[skeeljc]

I milled .060" off of the back side of the recoil lug pocket to allow room for the epoxy bedding.

 

[skeeljc]

Bed it so contact points are uniform

The contact points will be the whole underside of the action and a small portion of the barrel when I get done bedding it. I removed all of the paint and roughed up the base material of the stock so there would be room for the epoxy.

 

[skeeljc]

I made two alignment pins to orient the receiver in the stock when I bed it. The pillars in the stock matched the tapped holes in the receiver almost perfectly. My pins are only .005" undersized vs the holes on the pillars.

 

[skeeljc]

Ready to bed.

 

[Papa Charlie]

Did you use clay to fill the recesses in the action?