How far down the neck do you turn?

[thefitter]

Just got my pumpkin I figured out the cutting depth adjustments but I need to set the length of cut. What's the criteria? Thanks

 

[Terry]

Turn till you bump the sholder.

 

[fdshuster]

As Terry said, just until you touch the shoulder. You should be able to run your fingernail over the break line between the turned and unturned surface on the shoulder and not feel a "bump".

 

[Martin52]

If you stop short of the neck/shoulder junction a doughnut will likely develop inside the neck due to brass flow when the round is fired. Cut about 1/32 into the neck/shoulder junction and this should reduce the risk significanly. Do not cut beyond that as the junction will weaken.
Martin

 

[sailhertoo]

I always turn into the shoulder a "touch" just to prevent do-nuts. Worked so far.

Just enough for your fingernail to catch a little.

 

[260Ravage]

I'm with Sailhertoo on this...Exactly!

 

[artbosco]

I need to set the length of cut. What's the criteria?

Adjust length so that the end of the cut just passes the Neck/Shoulder junction about 1/32" as mentioned above.

Also, this is important, but most overlooked, don't forget to use a cutter with an angle that matches your shoulder angle. Here's what I'm talking about: http://bulletin.accurateshooter.com/2009/01/tool-tip-optimize-your-cutter-angle-for-improved-neck-turning/

 

[82boy]

Well it depends on the cartridge. On the 6PPC, when turning 220 russian brass I go down and leave a bit of the neck unturned. (I use a firefored case as a guide.) The reason why is when you firefore the brass the shoulder junction will move up further. If you cut the 220 Russian brass all the way down, you are now into the shoulder of the PPC, and this can cause neck seperation after multiple firings. On less dificult brass like 30BR and such, I do as others have mentioned, cut to the shoulder junction, and match the cuter to the angle.

 

[mkihne]

Just curious: The OP stated that he has a pumplin turner. The pumpkin turner does not come with a 30 or 40 degree bevel to blend into the shoulder. Not sure if the above advice is based on the pumplin or others experience with the sinclair, KandM or other. This would certainly change the advice. I currently use a pumpkin for a shorter final turn and then run one of my sinclairs into the shoulcer to blend the turn into the shoulder. I am going to put a bevel on one of my pumpkin cutters to allow me to do the final with the pumpkin into the shoulder without a square cut. What are others doing? Surprised that Don does not offer an angled cutter.

 

[thefitter]

Just curious: The OP stated that he has a pumplin turner. The pumpkin turner does not come with a 30 or 40 degree bevel to blend into the shoulder. Not sure if the above advice is based on the pumplin or others experience with the sinclair, KandM or other. This would certainly change the advice. I currently use a pumpkin for a sorter final turn and then run one of my sinclairs into the shoulcer to blend the turn into the shoulder. I am going to put a bevel on one of my pumpkin cutters to allow me to do the final with the pumpkin into the shoulder without a square cut. What are others doing? Surprised that Don does not offer an angled cutter.

The one I just got this week seems to have that bevel on the cutter.

 

[Martin52]

Interesting, the point about the Pumpkin not having a bevelled edge to cut into the shoulder. Haven't seen nor used one so can't comment other than to further query how the Pumpkin cuts to avoid the doughnut.
Martin

 

[artbosco]

John Perkins at 21st Century Shooting, offers a variety of cutter angles, the most I've seen anywhere. Take a look: http://21stcenturyshooting.com/Neck_Turning_Tool.php , 20, 30, 35, 40, and 46 degrees and they're CARBIDE.

 

[mkihne]

Thanks, outdoorsman, I'll check it out. I have purchased three pumpkins thru Bruno's and was told each time that straight cutters were all that was available. I couldn't believe that Don N would not make a bevel cutter. I will check out your source. FWIW, I have tried K and M, Sinclair and Pumpkin turning tools and have found the pumpkin to be the most user friendly turner for exact repeatability. I suspect it's mass keeps things cool, including the turning mandrel and thus the close tolerances. The 4000 Sinclair may be second best for me for the same reason. I did not give the K and M a fair shake, but find it somewhat small.

Just checked the 21st century neck tool. This appears to be a totaly different tool and my comments were directed specifically toward the pumkin tool, unless someone has done leg work to see if they are interchangeable. If so, you would have to be careful to make sure your expander mandrel was matched to the replacement cutter in diameter

 

[thefitter]

Thanks, outdoorsman, I'll check it out. I have purchased three pumpkins thru Bruno's and was told each time that straight cutters were all that was available. I couldn't believe that Don N would not make a bevel cutter. I will check out your source. FWIW, I have tried K and M, Sinclair and Pumpkin turning tools and have found the pumpkin to be the most user friendly turner for exact repeatability. I suspect it's mass keeps things cool, including the turning mandrel and thus the close tolerances. The 4000 Sinclair may be second best for me for the same reason. I did not give the K and M a fair shake, but find it somewhat small.

Just checked the 21st century neck tool. This appears to be a totaly different tool and my comments were directed specifically toward the pumkin tool, unless someone has done leg work to see if they are interchangeable. If so, you would have to be careful to make sure your expander mandrel was matched to the replacement cutter in diameter

I got mine this week from Kelbys and it has the bevel.

I've been told by more than one individual that you don't need to go into the shoulder unless your bullet does. Most of my rounds are only seated in the neck. Thoughts on this? Thanks

 

[mkihne]

Thanks for the pic and info. I guess I'll order my pumpkin stuff from Kelblys from now on.

Many short range benchrest shooters(including Tony B in his book) don't sweat the donut as the bullet base is usually about half way down the neck and fl dies with bushings usually resize only about 2/3 of the neck. Even longer range benchrest with long boat tails usually figure free bore to keep the boat tail in the neck and out of the case. The donut could cause variation in ES and SD in long range benchrest which are a more important factor than in short range. Ie: if your donuts are consistent based on technique, it may follow that your ES and SD may also be consistent and then the donut becomes a "so what". However, some one more versed in long range will likely be able to give you better info on this.

Well, off to Kelblys to get a new cutter for my pumpkin.


Further info, FWIW. For fire forming new cases, you have to turn enough to be sure that there is not an interference fit in your chamber. A friend suggests over sizing (bump back) by about 20 thou more than normal at the shoulder and then turn your neck, checking as you go(with firing pin out of bolt) until you get a slight crush fit(slight resistance for last half of bolt closure). For him, this helps prevent donut formation. This is for 30br from 6br-other cartridges may differ in forming. After fireforming and before sizing, you can use a pin gauge that just fits into the neck of the fired case. It will stop at the shoulder if you have a donut. If you are inclined to remove rather than ignore the donut(as many do in short range), there are at least two methods to do so. You can get a custom neck reamer made to the size of your pin gauge(no larger as you will then be taking neck material off) to fit your case length trimmer(ie: Forrester or Wilson)Warning: do not use a standard caliber reamer in this case. It will be too large. Secondly, you can use your expander for your case neck trimmer to move the donut to the outside of the neck-shoulder junction once again and carefully turn the neck at your desired neck thickness setting and run it(with appropriate bevel) to just see bright brass show on the shoulder at the case neck junction and go no further as fire forming has set your shoulder properly.

 

[thefitter]

Thanks for the pic and info. I guess I'll order my pumpkin stuff from Kelblys from now on.

Many short range benchrest shooters(including Tony B in his book) don't sweat the donut as the bullet base is usually about half way down the neck and fl dies with bushings usually resize only about 2/3 of the neck. Even longer range benchrest with long boat tails usually figure free bore to keep the boat tail in the neck and out of the case. The donut could cause variation in ES and SD in long range benchrest which are a more important factor than in short range. Ie: if your donuts are consistent based on technique, it may follow that your ES and SD may also be consistent and then the donut becomes a "so what". However, some one more versed in long range will likely be able to give you better info on this.

Well, off to Kelblys to get a new cutter for my pumpkin.


Further info, FWIW. For fire forming new cases, you have to turn enough to be sure that there is not an interference fit in your chamber. A friend suggests over sizing (bump back) by about 20 thou more than normal at the shoulder and then turn your neck, checking as you go(with firing pin out of bolt) until you get a slight crush fit(slight resistance for last half of bolt closure). For him, this helps prevent donut formation. This is for 30br from 6br-other cartridges may differ in forming. After fireforming and before sizing, you can use a pin gauge that just fits into the neck of the fired case. It will stop at the shoulder if you have a donut. If you are inclined to remove rather than ignore the donut(as many do in short range), there are at least two methods to do so. You can get a custom neck reamer made to the size of your pin gauge(no larger as you will then be taking neck material off) to fit your case length trimmer(ie: Forrester or Wilson)Warning: do not use a standard caliber reamer in this case. It will be too large. Secondly, you can use your expander for your case neck trimmer to move the donut to the outside of the neck-shoulder junction once again and carefully turn the neck at your desired neck thickness setting and run it(with appropriate bevel) to just see bright brass show on the shoulder at the case neck junction and go no further as fire forming has set your shoulder properly.

Thanks for the info. FYI Kelbys was cheaper than Brunos as well. But they do charge more for a credit card purchase.

 

[mkihne]

Guys.......I lied in the post above. There is info out there on skinning a cat, but it's not pretty. Enjoy. ;D

http://www.youtube.com/watch?v=6OUxUw4GPNg