????? Maybe.

Today with one of My7x57 scout rifles 19" barrel that some love so well, I tried a a mini experiment.Many hours were spent cleaning this rifle .later it was lightly oiled and than a clean patch run thru.

I was shooting 120gr. FPs at 2100fps, not very hot, at 50 yds.

The first shot out of a cold clean barrel was 1 1/2" to the right of aim. The next shoot was 3/4" to the right of aim.The fallowing shot was 1/4" to the right and the next an 1/8" right and the last two touched.The shots were about 30 to 40 seconds apart.I contiued to shoot and the scout was grouping nicely.I saved four of those loads.

Later when the rifle had cooled down I repeated the four shot test and it repeated exactly what it had done before but with a fouled barrel.

What have we learned ?????? I'm not sure. Perhaps the weight of the scope mounted in the middle of that slender barrel makes the rifle more first shot temperature sensitive than it is sensitive to barrel cleanliness.

OK take your best shot Or go out and run the test with one of your hunting rifles. roger

Crickey. So from what I've read, if a barrel has some stresses from manufacture, it may warp a bit as it heats up. Same with barrels touching anything like the stock for instance.

The rifles I have at the moment DON'T wander around, with fouling or heat.

Fired over 860 shots through a 223Rem with a very light 20"barrel no bedding and touching where ever it wants to against a plastic stock. Vertually all were 3 to 6 shot groups, up to 10 shots with barrel getting too hot to hold. This little cheap Zustava won a 200yds shoot against range rifles for me. Go figure that.

Now i often do a one shot tryout just to make sure it's on zero.
John L.

quote:

Originally posted by JAL:
Crickey. This little cheap Zustava won a 200yds shoot against range rifles for me. Go figure that.:

I say mate; don't you think that we know that bullets fly more accurately in the southern hemisphere? we're not all blond you know. roger

Every gun is unique. I have a friend who can shoot easily 400 yds from his deck. He really makes me jealous. When the sunday football games are on I'd be watching the game but taking one shot every commercial till I knew my gun and it's personality inside and out. Darn, and he never does this!!

[QUOTE
I say mate; don't you think that we know that bullets fly more accurately in the southern hemisphere? we're not all blond you know. roger[/QUOTE]

Well I wish my M94 3030 knew it's supposed to be more accurate. But its groups are consistently bad around that first shot.
John L.

JAL--My friend had a 30-30 marlin that was an average shooter. Then we tried the barnes 150 x-fn bullet designed for the 30-30--WOW did that bullet ever shoot great. It's expensive but he's shot a pile of deer from the last batch of 30 I loaded for him. He's never recovered one and has complete confidence from any angle.

The moving point of impact is usually the bedding or the barrel. Most barrels are straightend and that may induce a stress in them that shows up when it gets warmer.

You seem to have proved that cleaning or not does not matter.

I had that same variable show up in a 7X57 in fact but this rifle used to shoot about MOA or better and then it started shooting horizontal groups. Its a carbine also but I don't think that matters.

I am quite sure but not certain that the variable on that Brno 21f was caused by FL sizing so that there was quite a bit of tension to close the bolt. When Mike375 suggested FL sizing for accuracy .003" to .004" off of shoulder contact I tried it on that rifle and that cured it.

If you wonder why I would FL size to make the bolt close hard it was because those darn "perfect" designs will not let the bolt stay closed when the safety is on.

I have two of those "finest" sporters now and they may be the last two.

quote:

I say mate; don't you think that we know that bullets fly more accurately in the southern hemisphere? we're not all blond you know. roger

That explains the patterns I get wth my Mini 14!
I bought a northern hemisphere model!

quote:

Originally posted by bartsche:
...Today with one of My7x57 scout rifles 19" barrel that some love so well, I tried a a mini experiment.Many hours were spent cleaning this rifle .later it was lightly oiled and than a clean patch run thru.

Scout rifle problem???

quote:

I was shooting 120gr. FPs at 2100fps, not very hot, at 50 yds.

The first shot out of a cold clean barrel was 1 1/2" to the right of aim. The next shoot was 3/4" to the right of aim.The fallowing shot was 1/4" to the right and the next an 1/8" right and the last two touched.The shots were about 30 to 40 seconds apart.I contiued to shoot and the scout was grouping nicely.I saved four of those loads.

Later when the rifle had cooled down I repeated the four shot test and it repeated exactly what it had done before but with a fouled barrel.

What have we learned ?????? I'm not sure. ...

Scout rifles are good for shooting "at" game moving from the right to the left, because they automatically start building a "lead" for the shooter.
---

Hey Roger, Good test. I'd suspect that Don got it correct when he posted:

quote:

The moving point of impact is usually the bedding or the barrel. Most barrels are straightend and that may induce a stress in them that shows up when it gets warmer.

I really doubt that having the scope mounted forward of the receiver(improperly mounted as I would say ) has anything to do with the "Left Shift". But, that could be checked by re-mounting(properly) the scope on the Receiver.

If your barrel is not Free-Floated, you could try raising the action in the stock slightly so it is Free-Floated and re-testing. Just cut up some Credit Cards(preferably some belonging to a wife) and insert the same number of pieces at the front and back of the action, then snug up the Stock Screws. Do the old "paper slipping under the barrel test" to make sure it is floated and see how it shoots.

If the leftward movement "Stops", then it is a bedding issue and can be corrected rather easily.

If it keeps moving to the Point-of-Impact to the Left, then I would "suspect" a Cryrogenic Treatment "might" relieve the stress in the barrel that Don mentioned. Then again, it might not. Depends on how well you like the firearm and how much you want to put in it.

Or, just leave it as is and shoot "at" game moving from your right to your left.

quote:

Originally posted by Hot Core:
If it keeps moving to the Point-of-Impact to the Left, then I would "suspect" a Cryrogenic Treatment "might" relieve the stress in the barrel that Don mentioned. Then again, it might not. Depends on how well you like the firearm and how much you want to put in it.

Or, just leave it as is and shoot "at" game moving from your right to your left.

This is a $35.00 Sarco replacement barrel, and the closest it comes to the stock along it's 19" is about 3/32 of an inch.

This experiment wasn't to determine how to make a rifle shoot more repeatable It was to compare effects of clean bore vs. fouled bore. If you send me your E-Mail address I'll send you some fotos of the rifles I put together. At the range Wed. I took some pictures with you in mind of an origial German Military original equipment scout (sniper) rifle. We took the pictures on a phone camera and haven't figured out yet how to get them saved into my computer.
Really a neat piece of firearms history.

We may not always be tuned to the same frequency but I sure do enjoy your way with words.I also realize that your postings are derived from a long and broad background in burning a lot of gun powder.roger

[QUOTE]Originally posted by kraky:
Then we tried the barnes 150 x-fn bullet designed for the 30-30--WOW did that bullet ever shoot great. QUOTE]

Thanks, I'll keep my eye out for some, down here. Tho. I suspect at least half the problem is me with iron sights, but then people often halve my group sizes with scopes and benchrests.
John.

Interesting experiment.

I'vegot weird (related)problem with a sporterized 8mm Mauser...When I first put it together,I got decent accuracyfrom 10 shots, fired fairly quickly (meaning barrel heated up fairly quickly)...1st 6 shots into one hole at 50 yards, next 4 opened out randomly.) Barrel is completely free from 3"forward of action)...Now,no changes made its decided tostring the first 3 shots over 6" vertically???????????? Still working on that one.

But I have a .22 that definitely likes to be dirty...If I clean it, groups will be about twice the size as they are after I've put 30-40 rounds through it.

Like someone said, they all behave differently, only way to findout is to shoot 'em under different conditions.

quote:

Originally posted by bartsche:
...This is a $35.00 Sarco replacement barrel, and the closest it comes to the stock along it's 19" is about 3/32 of an inch.

Hey Roger, Thanks for the kind words. Always nice to be able to discuss things rather than "argue". I remember the original discussion we had on the Scout Rifle concept and though I tried to work you over, you remained calm and steady. Always nice to know "why" a person sees something in a design that I don't see a good use for, and you explained it so I understood why it was an advantage for you.

I've learned something else from you too. Had no idea at all a barrel could be purchased for $35. Didn't even know you could get a "take-off" for less than about $50.

quote:

This experiment wasn't to determine how to make a rifle shoot more repeatable It was to compare effects of clean bore vs. fouled bore.

I can accept that, but now that you know it does it shifts the Point-of-Impact on the second and third shots(as well as additional ones), I would think you probably want to try and correct that issue. If it was mine and I could get it to stay reasonably close together for the first 2-3 shots, I'd be happier than what you have now.

Since the barrel is relatively inexpensive(I do like a deal), I'd think putting $90 in a Cryo treatment probably isn't the thing to recommend. However, perhaps you might want to consider going with a "completely full-length" bedding job. Simple enough to do and it "might" stabalize the barrel enough that it holds the Point-of-Impact a lot closer together for the first few shots.

Before that though, since you mentioned it is Free Floated real well along it's entire length, perhaps adding a pressure point near the tip might be enough to slow the shift for a couple of shots too. I feel sure you know about using a couple of thicknesses of Business Card to create a temporary Pressure Point. Have you tried that?

quote:

If you send me your E-Mail address I'll send you some fotos of the rifles I put together.

Thanks, but I'll pass on the flicks.

Best of luck with that rifle.