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Propdoc03
Guest
I understand that the Bergers usually shoot better with a bit of a jam, is this true with the Sierras?
thanks....
thanks....
3
30378
Guest
With SMKs I use 155s and 190s in my 308, 120s in my 260, and 52s in my 223. All seem to like about .007 to .010 jump.
Propdoc03
Dennis there is more to it than just saying to jam them.
If your necks are really thick and you have 0.003 of neck tension your over all length to the jam will be different than if you had a thin neck.
I use 0.003 of neck tension in all of my guns until I dial the load in no matter the necks thickness.I dial it in later.
I also start all of my loads at the full jam length and change it later.
We will be at the Nationals Thursday,Friday,Saturday and Sunday.If you stop by we can dial you right in and you can shoot my junk as well.After the match is over each day we go and shoot at the 200 yard range.
Lynn
Dennis there is more to it than just saying to jam them.
If your necks are really thick and you have 0.003 of neck tension your over all length to the jam will be different than if you had a thin neck.
I use 0.003 of neck tension in all of my guns until I dial the load in no matter the necks thickness.I dial it in later.
I also start all of my loads at the full jam length and change it later.
We will be at the Nationals Thursday,Friday,Saturday and Sunday.If you stop by we can dial you right in and you can shoot my junk as well.After the match is over each day we go and shoot at the 200 yard range.
Lynn
J
jerryhm
Guest
Jam?
Try just the opposite ---- jump them, not a little a whole lot......Jump them 20, 40, 60, 80, 100, 120 thousands you might get a big surprise. I have one barrel that like the Berger 95VLDs to be jumped 75 thousands.
Jerry
Try just the opposite ---- jump them, not a little a whole lot......Jump them 20, 40, 60, 80, 100, 120 thousands you might get a big surprise. I have one barrel that like the Berger 95VLDs to be jumped 75 thousands.
Jerry
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Frank Green
Guest
I will back up Lynn and Jerry but also add. I don't care if you are buying 20 barrels from the same barrel maker out of the same lot of steel and using the same chamber reamer. Each barrel might want a different tune (load which is the powder charge, bullet seating depth etc...) each barrel I treat as an individual.
One might want the bullet touching or into the lands and the next you might find will have the best accuracy .020 off the lands.
Also depends on what type of shooting/matches you are doing etc....
I start all my loads .010 off the lands and adjust from there.
Don't forget the bullets. From one lot to another might want something different even from the same maker.
There are a lot of variables in shooting. Not just the barrel.
Later, Frank @ Bartlein
One might want the bullet touching or into the lands and the next you might find will have the best accuracy .020 off the lands.
Also depends on what type of shooting/matches you are doing etc....
I start all my loads .010 off the lands and adjust from there.
Don't forget the bullets. From one lot to another might want something different even from the same maker.
There are a lot of variables in shooting. Not just the barrel.
Later, Frank @ Bartlein
B
Boss Hoss 540
Guest
YES----Mine like to "JAM" to Van Halen!!!
Question for Frank...
Frank you have forgotten more about barrels, than I will ever know about barrels. Lets take out the difference in ojive, and variance in bearing surface length in bullets and strictly stay with barrels. You say you treat each barrel as an individual. Would that be because you are making and using cut rifling barrels? Common sense would tell me that every cut rifling barrel would have it's individual charcteristics(sp). Though a button may have its individual characterisitcs they would be repeated from barrel to barrel when using the same button. Lapping is used to make the bore consistent from one end to the other.
Would it be correct to say every barrel is unique in its make-up (structure) but like make barrels that are buttoned would be more simular in characteristics IE: rifling depth, width, even twist. Due to hard and soft spots and cutter wear and adjustment cut rifling is going to be unique from barrel to barrel.
In your opinion is a cut rifling barrel more or less consistent than a button rifled barrel? Is there a metal structural/surface difference between a lapped cut rifled barrel and a button rifled barrel?
Most target barrels today are made of 416 or some varient of 400 series stainless steel. The specs for 400 series stainless indicate it work hardens from machining. All high quality barrels are drilled, reamed, stress relieved, and lapped then rifled. The individual makers have their own procedures and order they follow. Is there a significant difference in work hardening between cut and button rifled barrels. At your former employer you made both cut rifling and button barrels. Can you share your wealth of knowledge.
Rustystud
Frank you have forgotten more about barrels, than I will ever know about barrels. Lets take out the difference in ojive, and variance in bearing surface length in bullets and strictly stay with barrels. You say you treat each barrel as an individual. Would that be because you are making and using cut rifling barrels? Common sense would tell me that every cut rifling barrel would have it's individual charcteristics(sp). Though a button may have its individual characterisitcs they would be repeated from barrel to barrel when using the same button. Lapping is used to make the bore consistent from one end to the other.
Would it be correct to say every barrel is unique in its make-up (structure) but like make barrels that are buttoned would be more simular in characteristics IE: rifling depth, width, even twist. Due to hard and soft spots and cutter wear and adjustment cut rifling is going to be unique from barrel to barrel.
In your opinion is a cut rifling barrel more or less consistent than a button rifled barrel? Is there a metal structural/surface difference between a lapped cut rifled barrel and a button rifled barrel?
Most target barrels today are made of 416 or some varient of 400 series stainless steel. The specs for 400 series stainless indicate it work hardens from machining. All high quality barrels are drilled, reamed, stress relieved, and lapped then rifled. The individual makers have their own procedures and order they follow. Is there a significant difference in work hardening between cut and button rifled barrels. At your former employer you made both cut rifling and button barrels. Can you share your wealth of knowledge.
Rustystud
F
Frank Green
Guest
Rustystud, I found/feel the cut barrels are more consistent from one to the next than a button barrel. I'm not being partial because we make cut barrels but because of what we see in the way that barrels are made.
Several things with the button barrels and you hit on one of them. Hard/soft spots in the steel. When you are button rifling and you hit one of these spots it usually slows the button down. Now your twist isn't uniform end to end. If they are button rifling a 14 twist barrel it might start out as a 14 twist but by the time it gets to the other end it could be 14.5 or even slower. I'm not saying you can't get a button barrel that has a very uniform twist but they vary more.
Big advantage in cut rifling. The twist is more consistent from one blank to the next. This and uniformity of bore and groove sizes to me is the biggest thing. The more uniform the bore and groove sizes and the more uniform the twist and straighter the blank the more forgiving (load sensitive) the barrel blank will be.
Button barrel makers have to button rifle the barrel in the blank form. It cannot be contoured. This will have even more of an effect on bore/groove size uniformity. Then they stress relieve the blank. Then they finish turn the blank. Next problem is if the blank has any residual stress in it when the contouring is done usually what happens is the turning/machining operation will relieve the stress and the bore will go sour on you (open up). Any secondary operation like fluting or even cutting the blank to length and crowning it. When you cut and crown a button barrel it is wise to recheck the bore right at the crown edge. Use a pin gage for example. I've seen them open up .0002 right at the crown.
After drilling the blank (weather it is in blank form or rouged contoured) we then contour it. Then we ream it. Then we prelap it and then we rifle it. When we rifle we induce no stress into the blank and after rifling we then finish lap the barrel.
Work hardening the bore? Actually it's the opposite. The button barrels get work hardened. On average I would tell you the button barrel has less barrel life than a cut barrel. This isn't just me talking either. Talk to a ammunition maker that uses ammunition test barrels and have been in the business a long time. Most agree that the cut barrels last longer. I've seen button barrels go a long time and I've seen cut barrels puke early. But on average the cut barrels last longer in my opinion.
Button rifling does not remove the material when it rifles the grooves. It displaces the material. This work hardens the bore. The material comes in double stress relieved to begin with. Because we don't induce any stress into the blank we don't restress relieve the blank anymore.
Going back to the original question about jamming the bullets. When I put a new barrel on one of my guns in the same chamber I had before. I start with what worked in my last one. Seating depth etc....The gun is usually good to go for me with not to much testing. A good customer and shooting buddy of mine we got into the subject about seating depth. He use to jam his bullets about .020 on his .308 palma rifle. We we're at the range and we we're bench testing our prone guns at a 1000 yards. He cut his group sizes in half. Going from .020 jam, when we got down to .010 off the lands the gun was shooting 5" groups and when he seated the bullets to .020 off the lands the groups again shrunk to 3.500 or 3.750" I don't remember which anymore but it was a sub 4's. Jamming the bullets does not guarantee better accuracy. Each rifle is still an individual and any time a big change is made weather it be a new barrel, different lot of bullets etc....from one to the next they could want a different seating depth.
One of the things that was done at Krieger we made two .224 cal. barrels. One was cut rifled and one was button rifled out of the same lot of steel. Both where prelapped and finished lapped. They we're chambered in .22-250 for prairie dog shooting. Long story short the we're excellent shooting barrels. One thing that stood out more than anything else though was how the barrels where wearing. The button barrel with the same loads shot in the same conditions had twice as much wear in the throat and the the fire cracking etc was worse than the cut rifled barrel had and this was with the same amount of rounds thru them.
I hope I answered your question(s) but probably created more.
Later, Frank
Several things with the button barrels and you hit on one of them. Hard/soft spots in the steel. When you are button rifling and you hit one of these spots it usually slows the button down. Now your twist isn't uniform end to end. If they are button rifling a 14 twist barrel it might start out as a 14 twist but by the time it gets to the other end it could be 14.5 or even slower. I'm not saying you can't get a button barrel that has a very uniform twist but they vary more.
Big advantage in cut rifling. The twist is more consistent from one blank to the next. This and uniformity of bore and groove sizes to me is the biggest thing. The more uniform the bore and groove sizes and the more uniform the twist and straighter the blank the more forgiving (load sensitive) the barrel blank will be.
Button barrel makers have to button rifle the barrel in the blank form. It cannot be contoured. This will have even more of an effect on bore/groove size uniformity. Then they stress relieve the blank. Then they finish turn the blank. Next problem is if the blank has any residual stress in it when the contouring is done usually what happens is the turning/machining operation will relieve the stress and the bore will go sour on you (open up). Any secondary operation like fluting or even cutting the blank to length and crowning it. When you cut and crown a button barrel it is wise to recheck the bore right at the crown edge. Use a pin gage for example. I've seen them open up .0002 right at the crown.
After drilling the blank (weather it is in blank form or rouged contoured) we then contour it. Then we ream it. Then we prelap it and then we rifle it. When we rifle we induce no stress into the blank and after rifling we then finish lap the barrel.
Work hardening the bore? Actually it's the opposite. The button barrels get work hardened. On average I would tell you the button barrel has less barrel life than a cut barrel. This isn't just me talking either. Talk to a ammunition maker that uses ammunition test barrels and have been in the business a long time. Most agree that the cut barrels last longer. I've seen button barrels go a long time and I've seen cut barrels puke early. But on average the cut barrels last longer in my opinion.
Button rifling does not remove the material when it rifles the grooves. It displaces the material. This work hardens the bore. The material comes in double stress relieved to begin with. Because we don't induce any stress into the blank we don't restress relieve the blank anymore.
Going back to the original question about jamming the bullets. When I put a new barrel on one of my guns in the same chamber I had before. I start with what worked in my last one. Seating depth etc....The gun is usually good to go for me with not to much testing. A good customer and shooting buddy of mine we got into the subject about seating depth. He use to jam his bullets about .020 on his .308 palma rifle. We we're at the range and we we're bench testing our prone guns at a 1000 yards. He cut his group sizes in half. Going from .020 jam, when we got down to .010 off the lands the gun was shooting 5" groups and when he seated the bullets to .020 off the lands the groups again shrunk to 3.500 or 3.750" I don't remember which anymore but it was a sub 4's. Jamming the bullets does not guarantee better accuracy. Each rifle is still an individual and any time a big change is made weather it be a new barrel, different lot of bullets etc....from one to the next they could want a different seating depth.
One of the things that was done at Krieger we made two .224 cal. barrels. One was cut rifled and one was button rifled out of the same lot of steel. Both where prelapped and finished lapped. They we're chambered in .22-250 for prairie dog shooting. Long story short the we're excellent shooting barrels. One thing that stood out more than anything else though was how the barrels where wearing. The button barrel with the same loads shot in the same conditions had twice as much wear in the throat and the the fire cracking etc was worse than the cut rifled barrel had and this was with the same amount of rounds thru them.
I hope I answered your question(s) but probably created more.
Later, Frank
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to Frank Green --
Great Reply !!! A good read !!! and I Thank You !!!
I will start out by saying I have one of your barrels and can honestly say it is one of the best I have ever had, to both accuracy and fouling.
Question -- could you amplify on the "lapping process".
I've always wondered about this over-all process and wondered like how many passes, with what grits, how it is pushed, etc...
I'm not looking to making barrels, just wanting to understand it all better...... (knowledge) ......
If Bartlein was to sell a video on your barrel making and process, I would be a buyer.......
to Propdoc -- sorry to invade your post... but it has taken on another topic with in your original topic.
Happy Shooting
Donovan Moran
Great Reply !!! A good read !!! and I Thank You !!!
I will start out by saying I have one of your barrels and can honestly say it is one of the best I have ever had, to both accuracy and fouling.
Question -- could you amplify on the "lapping process".
I've always wondered about this over-all process and wondered like how many passes, with what grits, how it is pushed, etc...
I'm not looking to making barrels, just wanting to understand it all better...... (knowledge) ......
If Bartlein was to sell a video on your barrel making and process, I would be a buyer.......
to Propdoc -- sorry to invade your post... but it has taken on another topic with in your original topic.
Happy Shooting
Donovan Moran
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Thank You Frank for a great reply..
I have found that secant ogive and tangent Ogive bullets in the same chamber/barrel prefer different seating depths. I have also found in non match grade bullets the ogive, bearing length varried more than match grade bullets. I also found wth hunting rifles in sub freezing weather the seating depth has more affect than in hot weather. I have hunted in Canada and Alaska in sub 20 below weather and that makes a tremendous change on barrel characteristics.
Thanks Frank for your personal and professional view. In my gunsmithing business I use both cut and button rifling barrels. When using top quality barrels both seam to be equal in accuracy. I can't speak for longevity.
Rustystud
I have found that secant ogive and tangent Ogive bullets in the same chamber/barrel prefer different seating depths. I have also found in non match grade bullets the ogive, bearing length varried more than match grade bullets. I also found wth hunting rifles in sub freezing weather the seating depth has more affect than in hot weather. I have hunted in Canada and Alaska in sub 20 below weather and that makes a tremendous change on barrel characteristics.
Thanks Frank for your personal and professional view. In my gunsmithing business I use both cut and button rifling barrels. When using top quality barrels both seam to be equal in accuracy. I can't speak for longevity.
Rustystud
N
nemohunter
Guest
mine prefer black berry but strawberry will do in a pinch.