Rifling???
- Thread starter Camper
- Start date
To test, go shoot some groups.
A chamber cast will give you a good picture of the throat and it's wear. You can usually see a worn throat by looking at it from the chamber end, but you need to look at a lot of barrels for a comparison.
Rifling in the muzzle can be checked with a cast.
There are gauges for certain rifles that measure the amount of erosion in the throat or muzzle.
A chamber cast will give you a good picture of the throat and it's wear. You can usually see a worn throat by looking at it from the chamber end, but you need to look at a lot of barrels for a comparison.
Rifling in the muzzle can be checked with a cast.
There are gauges for certain rifles that measure the amount of erosion in the throat or muzzle.
I gotta laugh at this one exibitor at gun shows, when a customer wants to sell or trade in a gun at his table, he's a big guy, he'll grab the gun open the action and hold it out in front of himself and close one eye and look down the bore with the other eye from the muzzle end, and has the same reaction every time: "oh, the rifling in this one is really weak, I can't give you very much for this one, what were you looking to get out of it?" I have a hard time to not burst out laughing!
My groups are garbage right now. I tried changing scopes, making sure bases are tight. This rifle shot 1 1/2 - 2inch groups consistently 2 years ago. For the last 2 years i have tried the rifles favorite loads and im getting 6 inch groups maybe???? Its like i put it away for the winter and the next summer it went for a ####??? I am assuming that worn or weak rifling would lose accuracy over time but this seems really fast. I didnt notice any keyholeing int the targets. I wonder if shooting into a few jugs of water, collecting the bullet and checking the bullet rifling marks near the base of the bullet give me a good picture of how strong or weak the rifling is? I would like to rule out this scenario and figure out what the hell is going on with this rifle. Btw the crown is in good shape and the rifle has not been abused and kept cleaned and oiled.
That depends. Do you have any examples of bullets recovered like that from when the rifle was new? What else are you going to compare it to?
If it is shooting accurately, the rifling isn't worn out yet. If it isn't shooting accurately, there are some things besides worn rifling that may be the cause, but once they are eliminated, knowing how worn the rifling is won't really help you. You can't really fix it.
No.
Since you have nothing to compare too, how would you tell whether it was 'strong' or 'weak'?
Shoot for groups, look for round holes instead of keyholes. Provided you are shooting appropriate weight bullets for the twist rate, in any case.
Realistically, the rifling will be sharp or not, pitted or not, worn or not, fouled or not. Not 'weak' or 'strong'.
There is at least one outfit advertising in the magazines that sells a borescope that will allow you to visually inspect the state of the rifling from one end of the barrel or the other. Handy enough for looking at the erosion or cracking of the surface near the chamber, or getting a look at how pitted or copper fouled it may be, but at the end of the day, the rifle shoots well enough. or it does not shoot well enough. End of story that. If it shoots well enough to suit your needs, it's good!
Cheers
Trev
Since you have nothing to compare too, how would you tell whether it was 'strong' or 'weak'?
Shoot for groups, look for round holes instead of keyholes. Provided you are shooting appropriate weight bullets for the twist rate, in any case.
Realistically, the rifling will be sharp or not, pitted or not, worn or not, fouled or not. Not 'weak' or 'strong'.
There is at least one outfit advertising in the magazines that sells a borescope that will allow you to visually inspect the state of the rifling from one end of the barrel or the other. Handy enough for looking at the erosion or cracking of the surface near the chamber, or getting a look at how pitted or copper fouled it may be, but at the end of the day, the rifle shoots well enough. or it does not shoot well enough. End of story that. If it shoots well enough to suit your needs, it's good!
Cheers
Trev
Yes, but it doesn't really matter. What you want to know is if the rifling is uniform in the throat and muzzle. A fired bullet will show the height of the tallest portion of each land, not the area of low rifling.
In the throat and leade, erosion and wear will occur to the individual lands differently. Because of this the bullet will be affected by one land before the others.
Try what H4831 recommends.
Put some up pressure under the barrel at the fore wood.
Sometimes this bit of pressure helps.
Slide a small strip of cardboard in there.
You can pull the barrel off the stock just slightly.
I recall H saying about six pounds of pull or pressure.
Try one strip and if it seems to improve, slide another in there.
Could be the stock has developed a bit of a twist and a heated
barrel may magnify this.
Worthy of a try.
Put some up pressure under the barrel at the fore wood.
Sometimes this bit of pressure helps.
Slide a small strip of cardboard in there.
You can pull the barrel off the stock just slightly.
I recall H saying about six pounds of pull or pressure.
Try one strip and if it seems to improve, slide another in there.
Could be the stock has developed a bit of a twist and a heated
barrel may magnify this.
Worthy of a try.
Good, you are trying things. One thing at a time, eliminating all the things that you can think of that may have gone wrong, and then asking about things you may not have thought of.
Clean for copper fouling? Barnes CR-10 worked for me.
Are you shooting other guns and getting your usual good results? If this is the only one you have shot for a while, and you have developed a flinch or other fault in your shooting that you are unaware of, find out by shooting some other guns to make sure it isn't you, or give this one to a known good shot to try it for you. If it works for them, the problem is you.
RememberTheSomme
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What rifle and caliber are you shooting Camper? What loads were really good and what are giving you 6MOA? How many rounds fired and type of range sessions? This will help greatly for some suggestions based on pass experiences, to help solve your problem.
As already stated by SoBored, if you can get your groups into acceptable range, and you have acceptable velocity, don't sweat the erosion factor unless you are selling an expensive rifle and want to gauge barrel wear as a statement of condition.
Most big game rifles rarely get "shot-out in usual sighting-in range sessions and hunting scenarios. Properly fired and cleaned the barrel should have several thousands of rounds for standard calibers and somewhat less for "throat clearing" Magnums.
You probably have a scope/mount issue, or a bedding issue. Accuracy doesn't drop of from 1.5MOA to 6 overnight, unless you damaged the crown or barrel in someway.
Good luck and get back with rifle particulars.
If this seemed to happen over a winter as you state the problem might be a fairly simple and common one.
If the rifle has a wood stock and has been around moisture the stock could have swelled or warped putting pressure on the barrel.
Best bet would be to free float the stock, then maybe add the fore end pressure if needed.
If the rifle has a wood stock and has been around moisture the stock could have swelled or warped putting pressure on the barrel.
Best bet would be to free float the stock, then maybe add the fore end pressure if needed.
What caliber? Some burn out quickly. 22-250 Ackley lasts about 1000 rounds, max.
How may rounds have you fired total in the barrel?
Barrel life varies, but I get about 2,500 shots out of a blue 308 barrel, and about double that in stainless. When the goup opens, it is time for a new barrel.
Blue or stainless? Stainless lasts twice as long but when it goes it goes all of a sudden.
All the wear is in the first few inches. The rifling marks on the bullet will not change.
If your barrel has a straight shank, the chamber end can be cut off by 2" and a new chamber/throat cut.
How may rounds have you fired total in the barrel?
Barrel life varies, but I get about 2,500 shots out of a blue 308 barrel, and about double that in stainless. When the goup opens, it is time for a new barrel.
Blue or stainless? Stainless lasts twice as long but when it goes it goes all of a sudden.
All the wear is in the first few inches. The rifling marks on the bullet will not change.
If your barrel has a straight shank, the chamber end can be cut off by 2" and a new chamber/throat cut.
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For what it's worth, here is what I look for.
I have to use a light at the muzzle (led is best). Then remove bolt and look through the chamber, focusing on the the first few inches of the rifling. All my brand new rifles, including the ones with about 500 rounds through them, including my mini-14, have nice crisp rifling at the chamber. Try this with some Mosin's and you will see them worn in about an inch or so...maybe even with no rifling for the first half inch.
If your barrel looks like the rifling is smooth at the chamber, then odds are that the barrel may be worn.
If the rifling is crisp and not visibly worn, then you may have a fouling issue which requires a good cleaning.
I have to use a light at the muzzle (led is best). Then remove bolt and look through the chamber, focusing on the the first few inches of the rifling. All my brand new rifles, including the ones with about 500 rounds through them, including my mini-14, have nice crisp rifling at the chamber. Try this with some Mosin's and you will see them worn in about an inch or so...maybe even with no rifling for the first half inch.
If your barrel looks like the rifling is smooth at the chamber, then odds are that the barrel may be worn.
If the rifling is crisp and not visibly worn, then you may have a fouling issue which requires a good cleaning.
Thanks for all the replies and suggestions. The rifle in question is a post mil savage 99e in .300 savage.
The Load that used to shoot the best is 41.1gr of IMR 4895 behind a 150gr nosler ballistic tip or accubond.
Primers are large Winchester.
Groups with other rifles are normal (no decline in accuracy)
I am not sure if the forend on the 99 could cause any grief. I have just yesterday lightly sanded the contour of the forend where the barrel sits in so that it is not putting any pressure on the barrel but I'm not sure this will accomplish anything.
Can you explain a little more on putting up pressure on the forend and will this do anything with a two piece stock?
The Load that used to shoot the best is 41.1gr of IMR 4895 behind a 150gr nosler ballistic tip or accubond.
Primers are large Winchester.
Groups with other rifles are normal (no decline in accuracy)
I am not sure if the forend on the 99 could cause any grief. I have just yesterday lightly sanded the contour of the forend where the barrel sits in so that it is not putting any pressure on the barrel but I'm not sure this will accomplish anything.
Can you explain a little more on putting up pressure on the forend and will this do anything with a two piece stock?
It could be that the barrel is fouled badly. Try some copper solvent, a bore brush and some J&B paste. If a wooden stock, it could be warped. Your guard screws could be loose, or tightened to the improper torque. it could be uneven pressure points between the stock and barrel.
I wouldn't alter the forend. If it is a concern then remove it all together, sandbag on the receiver and shoot some groups. If there is an improvement then focus there.
~ Look for a bulge in the barrel, especially near the muzzle.
~ Shoot some factory ammo for comparison.
~ Install another scope that you know is good.
~ Look for a bulge in the barrel, especially near the muzzle.
~ Shoot some factory ammo for comparison.
~ Install another scope that you know is good.
Another quick test, especially for old guns, is to stand the rifle on its
butt.
1. Slowly lower a cartridge (bullet end first) into the muzzle.
2. If it stops before hitting the case, then you still have rifling at the muzzle.
If not then the rifling is shot out and worn away.
butt.
1. Slowly lower a cartridge (bullet end first) into the muzzle.
2. If it stops before hitting the case, then you still have rifling at the muzzle.
If not then the rifling is shot out and worn away.
