Cartridge OAL and why

[Wildfire]

I know how match barrels act and react. But not all of us shoot or hunt with match grade barrels. The ultra thin barrels will change POI when they got warmed up. Some claim this is because they were bent at one time. Maybe, and maybe not. Mine was treated {Frozen} and yet still when it got hot would string shots. My extra heavy barrels did not. But there can be many reasons for shot stringing.
Over the past 40 years of loading I have tried many different so called cures. Some helped and some made no difference at all. Some boiled down to the shooter alone. I have seen some post that they never bag or bench a rifle for hunting. OK, how could one know what the rifle actually does then? I would have to chalk that up to lucky shooting or a rifle that was dead on to start with. So, what then happens when their ultra light mountain rifle would begin stringing shots? Without a rest that shooter would never really know.
I do not shot bench rest. I have watched some and picked up some good ideas.
In fact I no longer compete in any form. Just hunt.
Here is a link to a list of reasons for stringing groups.
http://www.6mmbr.com/verticaltips.html

 

[Bart B.]

Wildfire, read post 25 about what causes shot stringing as barrels heat up.

I've had 7 or 8 factory hunting rifles with skinny barrels that shot good hand loads to point of aim after they heated up to a stable. From first to fifth shot, shots walked from point of aim in one direction as the barrel heated up. Then they stabilized and would shoot a few dozed shots to the adjusted point of aim.

None of this most common cause is mentioned in that link listing many others. Yet smart 'smiths building very accurate rifles know about it. And the simple fix is squaring up the bolt face. Brownells and Midway sell trying jigs tub use in lathes squaring up receiver faces.

On all those receivers I had faced before rebarreling had their original barrels reinstalled then tested for accuracy. They all shot to point of aim from ambient to skin burning temperatures. Naturally, they drove pins (pins have smaller heads than tacks) at all temperatures with match barrels. First through 26th shot fired 10 to 20 seconds apart went to point of aim starting with a clean bore.

A bedding pad between fore end and barrel anywhere will cause mostly vertical stringing. It transfers uneven pressure against the barrel from variable external forces against the fore end.

On sighting in .......

Most people could sight in their hunting rifles very well shooting unsupported from standing (offhand) at a bullseye target. If they can keep their aiming eye open while a shot fires then calling that shot reasonably well. Shoot a shot, call it, adjust sight to move bullet hole to where it was called, then shoot 3 more calling them. Refine sight settings based on those last three calls. No shot need strike dead center in the bullseye. A better zero might be had shooting from sitting; with or without a sling. Remember: Adjust sights to call; never to desired point of impact.

The objective is to get bullets striking the point of aim. Once that's done, practice can make you put bullet impact where you want it.

 

[Wildfire]

Oh I agree with you Bart. I know what you are saying. And I know you and "Some others" in here are talking about long range bench guns and shooting. But I also know that others are attempting to learn from this too. Yes, My skinny barrel would stop stringing at some point and then group very well , just not where it would Ice cold. Ice cold is where it would be used in the woods. Most on here are not about to take their rifles in to have that bolt work done. Some may have already and some never will.
There are two worlds here. Average Joe watching is maybe not catching all of it from either world at some point. Then we have some that just know.
The long range and bench crowd are one and normal every day shooters are in the other world. The two rarely meet and become one.

With that in mind, I was attempting to point out some issues that can cause the problems without gun smiths involved. I spent a lot of time at a range and watched so many encounter these issues. The first thing they would do was to mess with their scopes. When that had nothing to do with anything.
I figured you had the bench part pretty covered. I was just attempting to point out other common things that can cause the same results.

My long range P-dog rifles would hold POI no matter how many I tossed. You would never dream of touching that barrel.

Lots of very good info.

 

[Bart B.]

I'm talking about hunting rifles; sporting ones to start with. Please reread my post #27. I am not referring to long range bench guns at all. They're all rifles hand held against ones shoulder.

 

[Wildfire]

I can understand this. But I didn't see what you were getting at first.

I have always used a rest of some sort even while hunting. I even made and extension for my Long Bi-Pod. Until just recently It had been many years since I had even thought of taking an off hand shot at any game. I now hunt with an 1892 lever and can hit running game rather well.
My thing was that I always went for the best group I could get from bags or bench and the rest was up to me knowing the gun was right. Funny that I waited til 60 years old to go back to iron sights on a lever gun. Just more fun now.
I do all of my own machine work right here in my own shop. I have had one too many guns screwed up by others in the past. Ruger rifles are famous for the under the barrel wood. I free float all of them and bed the actions pretty tight. And yes, have had to swap out several stocks. Loose guns just do not shoot right. I do agree with the sight in you explain for certain ways of hunting. We started Hog hunting and I soon found that the scope thing just was not very fast when they get testy. It can work but I choose iron now and it works for me. Shots are rather close. I use a Marbles rear sight and love it.
Amyway, I think we have all learned some here. Thanks.

 

[2 Wild Dueces]

Many folks don't know this....but it is possible to read something you do not agree with on the inter-webs......and simply move-on with your life. However.....I simply don't have the same experience with accuracy as Bart may have. IME buggy whip barrels when heated up WILL (more often than not) string those shots. Also, the post with the ejector and firing pin reliably centering the cartridge in the chamber is just not the real world.....IME.

 

[Wildfire]

I know... It seemed no matter what I did to some barrels they just did not work right. Like I said before, my mountain light weight was an awesome rifle for the first 3 shots. It was and still is just a hunting rifle. It kills critters. I have never had to fire more than one shot anyway.
I did do a lot of accuracy shooting but not what I would call long range as others have. I also stopped any competing for the main reason that as I got older I knew there would always be a faster horse and better gun. And as you say. Inter web talk is inter web talk. I have a big box of salt sitting right here next to me.
A friend of mine is a really cool guy but,,,,,,,, I know for a fact that his .300 Savage cannot bust a milk jug at over 1 mile. He swears it will. He cannot see that far.
I shot IPSC for some years and found the young guys were way faster. So, I went back to hunting. I now take my grand daughters hunting and do not miss any of the action shooting games.