Types of rifling and the effects on the projectile

[John23]

Hi Everyone


Over time I have heard many people make reference to particular pills working better in different types of rifling .

Recently I purchased a Bartlien 5r chambered in 6br .
I went to purchase some VLDs only to find out they were unavailable and leaving me with Hybrids as my only option .
I had never felt the urge to try a hybrid as I have seen them fail in a number of barrels .
I was presently surprised when they shot extremely well in mine.

Talking to a fellow forum member and trusted shooter he made the reference that hybrids love cut rifled barrels .

Again tonight when reading a thread about 7mm pills a similar reference was made about a certain pill and rifling styling.


Is this witchcraft or is there a science behind it ?
Dose it simply come down to cut rifle barrels having the advantage of exact twist rates which can be favourable when shooting pills on the edge stability in terms of twist rate ?

We all know there brilliant button rifled barrels available,
Is it possible that owners of cut rifle barrels have a little extra faith in their barrels as they tend to cost more money and are perhaps expected to perform a little better ?


look forward to hearing from your experiences

Thanks

[Frank Green]

John23, I think you are talking about a couple if not a few different things. So I will give you some thought on each.

"Dose it simply come down to cut rifle barrels having the advantage of exact twist rates which can be favourable when shooting pills on the edge stability in terms of twist rate ?" Your comment here is an important one and the answer is yes! I always tell guys the more uniform the twist, the more uniform the size of the bore and groove over the length of the of the barrel and the straighter the barrel and more stress free it is the more forgiving the barrel is going to be. No way around it. All of these is why I've always told shooters the cut barrels don't seem to be as load temperamental or should I say they are more forgiving in my opinion.

Some button makers are trying to guide the the twist of the button. The twist is built into the button. If the button should hit a hard spot or soft spot in the steel it will usually slow the button/twist down. It could speed back up to what it was suppose to be doing or it could keep getting slower. Either way you end up with a barrel with a non uniform twist. When this happens it's a accuracy killer and or makes the barrel very temperamental as to what it will like. A good example of this is when the early 183smk's got into some shooters hands about a year or so ago....the guys who shot cut rifled barrels even with 1-9 twist didn't seem to have a problem but the shooters that had button rifled 1-9 twist barrels couldn't get them to shoot consistently. That came directly to me from the team captain for the U.S. Open team.

Now if you are talking about the type or style of rifling for the most part I don't see a difference in regards to accuracy and or barrel life. Again I say for the most part and will give you a couple of examples. I don't recommend the 5R style rifling with the short jacket 6mm bullets (65-68gr. type bullets) for a 6ppc bench gun. They will shoot upper .2xx's to flat .3xx's but you won't get anything more out of them and for a 6ppc shooter trying for that perfect one hole group it won't do it. Now if it was a conventional style rifling and 5 groove it will hammer for you. Staying with 6mm in your case shooting a long heavy 105gr. bullet in 6mm the 5R is fine. Those long bullet have more bearing surface. The lands do the driving.

We've made ammunition test barrels in 4 groove, 5R and 6 groove for ammo makers and bullet makers in the same caliber and tested the same bullets/lots of ammo and the report back is no difference in barrel life and or accuracy. I've shot 2 groove, 4 groove, 5 groove, 5R, 6 groove and 8 groove barrel in calibers from .22rf up to .338 and again I don't see a difference. We've made 3 groove and 8 groove barrels as well for 6ppc bench shooters and again no difference.

I will also add in regards to the style of rifling the ratchet type rifling for a high power rifle type gun that the barrel life will be really short. Those really knife edge/thin lands don't hold up. In a .22rf probably won't hurt but not in a high power rifle. Mark here several years back (he is primarily a bench shooter said as well they didn't last for nothing. By the way we had him shoot his first f class match last October and he is hooked on that as well!

I do feel the 5R style rifling doesn't effect/upset the bullet jacket as much and this helps fight bullet failure. Bullets can fail because the bullets themselves have a problem with them. They can fail because the throat/chamber is rough ( a lot of rounds on the barrel) or the rifling is damaged etc...but the reason I feel it does help is that the lands don't directly oppose one another vs a even groove numbered barrel. Some ask well then what about a 3 groove barrel. I say no. Why? The 3 grooves the lands tend to be much wider. So one portion of a land is still opposing a portion of another land.

Barrel life? Cut rifling vs. button and hammer forge type rifling. Cut rifling lasts longer on average. This isn't to say you cannot get a button barrel etc...that won't last a long time but on average they do not. I would say cut rifling is about 25% longer on life. Data I've received back from bullet makers and ammunition manufacturers etc....where they do test both with cut rifled and button barrels etc...I've been told 15% min. longer on life with the cut barrel. Why? Cut rifling doesn't work harden the bore where as button rifling and hammer does. Keep in mind there are also a ton of variables to contend with that do effect barrel life. What is it chambered in? Type of powder being used? Type of bullet being used? Rate of fire? How it's being cleaned and how often in between cleanings etc...

Check out the link to the video below...I had nothing to do with making of the video.

This button barrel making at Bergara. Shilen help set up they're plant/shop. Watch real closely right about the 8 second mark when the button goes into the barrel. Watch the face of the barrel blank deform. You can see it better starting at the 6:20 mark and also look at the face of the barrel at the 6:40 mark to about 6:55. You can see the steel is deformed. Also notice how the face of the barrel blank looks twisted. Talk about stress induced into the blank!

Also at the 5:10 mark they talk about straightening the steel bars. Bad! You never want to straighten a barrel blank. Especially after it's been finished. Trying to straighten the barrel blank induces more stress into the steel. And some guys wonder why the POI shift on some barrels!

https://www.youtube.com/watch?v=0XSkhtcAL1w

I have to go for now!

Later, Frank
Bartlein Barrels

[williada]

Just like to endorse everything you have said Frank. David.

[Frank Green]

Just like to endorse everything you have said Frank. David.

Thanks David!

To add a couple more comments/thoughts.

When a button barrel is rifled it has to be done as a blank (no contour on the outside). Why? If the wall thickness varies at all the button will expand and relax the steel differently. You will end up with a non uniform bore size. Then the barrel has to get restress relieved and then go into turning for the contour work. What no barrel maker can measure for is any residual stress in the steel. Yes this includes a cut rifled barrel maker. After stress relieving and during contouring if there is any residual stress in the blank the machining work will relieve the stress and this will cause the bore to open up and go sour. When it does you cannot make the bore go back! It is what it is at that point. Same goes for cutting and crowning the muzzle or even threading the muzzle and or fluting the barrel. These machining operations can relieve any stress at that point in machining and cause problems. Cutting the crown. A good gunsmith with a good set of bushings for his reamer can check to see if the bore changed at all. Just one way. Some button barrel makers will not warranty they're barrel blanks if you flute it. It's right on they're websites and this is the reason why. Same goes for why do some button makers offer different grades of barrels? Your paying for uniformity of the bore and they won't know what they have till after restress relieving the blank and contouring it.

Our steel already starts out as heat treated and double stress relieved. We don't induce any stress into the blank during rifling. So no need for us to restress relieve it after rifling. We've recontoured barrels after rifling and also flute barrels and have never seen a bore go sour/open up as a result. Can it happen? Sure...let's throw Murphy's law into the equation. Also we contour probably 98% of our barrels before reaming and rifling. If there is any stress in the blank it will show up during contouring. If this happens it never makes it to rifling and the customer never sees that barrel blank.

When we we're starting up Bartlein Barrels Tracy (Bartlein) and I we're both offered jobs at a button barrel maker. I politely turned the job offer down during the meeting? We we're asked why? I said we know the short comings of a button barrel. I couldn't work at a company where I don't believe in the product and try and sell and stand behind it as well.

Later, Frank

[John23]

What can I say !

Thanks Frank , I don't think I could have received a better answer !


One more question .

You mentioned that the twist rate of button rifled barrels changing in the rifling process and causing temperamental Barrels


With Bartlein offering gain twist barrels dose this rule only apply to barrels that start fast and end slow or is it more the point with the button rifle barrels the change in twist rate is dramatic causing damage to the pill?

[John23]

One more "last question "

I believe anschutz barrels are hammer forged .
I have seen a fair bit of controversy (with out a better choice of word) about whether anschutz uses tight rifled bores and though the principle cut the contour to relief the stress from the breach end to about 3" short of the muzzle.
Supposedly the barrel tightens up at the muzzle .

The contour of the barrel certainly matches the theory being about 3/4" 90% of the way and finish at the muzzle at 1"



The main argument people put forward in regards to anschutz making barrels this way is the fact they don't contour all the barrels they make this way .

A simple yet very compelling argument.


With out multiple factory Annie barrels to slug I think many of the people on each side of the party (including myself ) are making uneducated decisions on what is and is not true .

Have you ever had any industry experience on the pacific topic with anschutz or other firearm makers ?

Thanks !!

[Frank Green]

Here is something else to look at. Again I had nothing to do with making the video. It was made and sent to me for my thoughts afterwards.

https://www.youtube.com/watch?v=CUm_YXzJJOU

It shows the muzzle going sour during threading. All of the first barrels are button rifled. I know the maker of the barrels and will not give the name out. The last two are ours even though they are cutting the threads larger on at least one of them....the point of the video that Robert Whitley was/is trying to make wasn't to hack on any particular barrel makers etc...but push the point of making the thread diameter as large as possible on the muzzle end to help counter the problem of the bores going sour. This is a problem with button and hammer forged barrels but not cut rifled barrels.

We've made ammunition pressure test barrels and also had to thread the muzzles for suppressors. The material started out at 2.280" diameter. We threaded the muzzles 5/8-24 and there was no change in the bore sizes.

Later, Frank

[Frank Green]

What can I say !

Thanks Frank , I don't think I could have received a better answer !


One more question .

You mentioned that the twist rate of button rifled barrels changing in the rifling process and causing temperamental Barrels


With Bartlein offering gain twist barrels dose this rule only apply to barrels that start fast and end slow or is it more the point with the button rifle barrels the change in twist rate is dramatic causing damage to the pill?

No it doesn't apply to the gain twist as the gain twist is always getting faster towards the muzzle.

What happens with button barrels is either a non uniform twist (getting slower and then can speed back up) or it has a negative twist. Once it starts slowing down it keeps getting slower towards the muzzle. I've seen button barrels where they started out at a 1-8 twist and ended up at 1-8.75 approx. at the muzzle. Same with a bench barrel. Started out at approx. 1-14.25 but ended at 1-15 at the muzzle.

Later, Frank

[Frank Green]

One more "last question "

I believe anschutz barrels are hammer forged .
I have seen a fair bit of controversy (with out a better choice of word) about whether anschutz uses tight rifled bores and though the principle cut the contour to relief the stress from the breach end to about 3" short of the muzzle.
Supposedly the barrel tightens up at the muzzle .

The contour of the barrel certainly matches the theory being about 3/4" 90% of the way and finish at the muzzle at 1"



The main argument people put forward in regards to anschutz making barrels this way is the fact they don't contour all the barrels they make this way .

A simple yet very compelling argument.


With out multiple factory Annie barrels to slug I think many of the people on each side of the party (including myself ) are making uneducated decisions on what is and is not true .

Have you ever had any industry experience on the pacific topic with anschutz or other firearm makers ?

Thanks !!

First off your welcome!

It's been a while since I looked at any annie barrels. If memory serves me correctly they are button rifled and not hammer forged. I forget the reason why supposedly Anschutz made the muzzle end of the barrel diameter bigger but I've always maintained it was so when they did the contouring the bore resisted opening up at the muzzle end. The muzzles crown is the last thing the bullet touches and any variation in the bore here especially getting bigger is going to have a negative effect on a accuracy. So call it fighting the bore opening up or with the bigger muzzle diameter they are trying to put choke in the bore/tighten it up at the muzzle.

Back around 2007 or so a European ammo maker conducted a test for a European Olympic team for .22rf. They ordered barrels from like 20 or so different makers. One was Anschutz, we we're one etc....our barrels came in tied for first place in accuracy. We we're tied with Border. If I remember correctly the annie barrels came in 10th or so. The Olympic team went with Border at the time as shipping costs was less and less paperwork to do to import etc....was the only reason they didn't go with us.

Later, Frank

[John23]

Thank you Frank for your time and experience !
I have the day off today and will spend the time to watch and digest the videos you linked .

I purchased my Bartlein based on its reputation.
Its performance is exceptional and based off this thread I am even more proud to have one in my safe .
Cheers

[Wal86]

All barrels if their (cut or button rifled) and you take excessive amounts of material away from the muzzel to put a thread on will swell over the threaded area.. ive seen in light profile hunting barrels this measurement be as large as .0009"...

Im not convinced that the amount of grooves, or type of rifling has advantages with certain projectiles, i think that barrel manufactures are only as good as the quality of steel they can get at the time... Both button rifling and cut rifle barrel makers accuracy/tolerances/finish are all subject to the quality of the steel they are working on, this i believe translates to the effect/accuracy of the projectile being used...

Cheers

[David B]

No advocating one or the other process but to add some balance most of the medals in Rio were with button barrels...

[Frank Green]

All barrels if their (cut or button rifled) and you take excessive amounts of material away from the muzzel to put a thread on will swell over the threaded area.. ive seen in light profile hunting barrels this measurement be as large as .0009"...

Im not convinced that the amount of grooves, or type of rifling has advantages with certain projectiles, i think that barrel manufactures are only as good as the quality of steel they can get at the time... Both button rifling and cut rifle barrel makers accuracy/tolerances/finish are all subject to the quality of the steel they are working on, this i believe translates to the effect/accuracy of the projectile being used...

Cheers

You bring up a good point on the steel and that's why we buy directly from the mill and not a warehouse. If we have a problem or any concerns I make one phone call to one person. Dealing with a general warehouse/steel distributor.....they can say they have a gun spec. barrel steel etc...but usually you don't get anyone that knows anything about the stuff and if you have a problem they typically won't stand behind it. You get a general salesman who knows very little.

Again you are correct and that's what I say the type of rifling and or number of grooves has nothing to do with barrel life and or accuracy. The only exceptions are the 5R rifling and the short jacket 6mm bullets for 6ppc benchrest shooters and the ratchet type rifling in a cf gun. I've seen the proof to many times on these.

Again with the amount of threading on muzzles that we do and not just on customer guns but doing ammunition test barrels where we have to supply a inspection report with bore and groove sizes etc...I don't see the muzzles going sour at all and even with turning 2.280" diameter material down to a 5/8" muzzle thread. Again it's very common with button barrels.

Later, Frank

[Frank Green]

No advocating one or the other process but to add some balance most of the medals in Rio were with button barrels...

Rio/olympics.....what's sad about the shooting in the olympics there is virtually no centerfire rifle type matches. You never hear of any 300m competitions anymore in the olympics. All small bore and air rifle.

Again our barrels we're tested along with like 20 other makes by Norma for an olympic rf rifle team. Our barrels tied for 1st place along with Border for the accuracy testing. Anschutz barrels came in like 10th place if I recall correctly.

I'd like to see 300m matches come back as well as prone rifle and F-Class type matches out to a 1k yards and have it played out in the olympics but I don't think that will ever happen.

Later, Frank

[David B]

Would agree with that 100%, some of the included sports leave a lot to be desired.