How to Use a Corbin S Press - A Thread Geared Toward Beginners

My wife is a quilter so she makes about anything I need like that. She made a cover my air compressor, been bags for the shooting bench etc. And she shoots so Im luckier than a lot of guys. But my Redneck Engineering degree thinks a leg from an old pair of blue jeens tied or sewn on one end would do the trick. not stylish but would keep the dust off!:ROFLMAO:
 
I shot some groups with a few weights (26-34 grains) out from 25-35 yards. None performed poorly. I got two flyers of all slugs shot. I have a preferred slug out of the batches shot today. I will make more of all weights and continue my exploration. Thanks to those who contributed useful information and answers to my questions.
Like NWIND said, I would go for heavier slugs in .25 cal. . About 31 - 50+ gr. would be better for a .25 cal.
The cores should be cut as close to a clean flat cut as possible. Put those side cutters away. Wrong tool for the job.
Those angled cuts can break a HP eject pin tip off if used to make HP slugs. I know your doing HO's in this case.
Someone else might get the wrong idea about core cutting.
You just need to order a few different size cutters for that Corbin plug cutter. I'm not using the .247" wire for .25 cal. anymore. Hmmm.
The .210 wire can be useful with some slug designs. And almost necessary for others. Works for .22 and .25 cal. Experiment.
"None performed poorly"
Not sure what that means. But in my experience -
At 35 yards a .25 cal. should be making a hole that's = or < .350", not a group. C/C .250" approximately.
Just my .02 cents worth.
 
@Long_Shot In this context “none performed poorly” means from what I saw I am satisfied and have some sort of reasonable expectation of the performance projectiles of given weights for my purposes with my guns.

I mentioned that I shot two flyers. This was my best group and one of the two flyers was in it. The flyer should be obvious. I am very confident that I did not pull that shot. I shot my groups seated on a bucket, off of a tripod - the way I would hunt in certain scenarios.
IMG_7307.jpeg
When I can see results like this, I’m not so concerned with numbers, BC, or much else. I’m making these for my own use and I think this is not a bad starting point for me and where I am in my understanding.
 
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I would also like to state the following to all reading this. The thread has been and continues to be about how to use a Corbin S press. I specifically wanted to target an audience of people new to making airgun projectiles that have little to no experience or exposure to the processes involved. That’s been my focus from the beginning. I could not have done this alone and reached out to several people that have participated and contributed to this thread as well as some folks at Corbin Manufacturing. I made mistakes (and plenty of typos) and was open about my mistakes for a reason - people new to this will also make mistakes. This is part of why I appreciate to those who corrected me and offered constructive criticism relevant to how I am using my setup. What I do not want to do is lead anyone to damage their expensive equipment. In my eyes this thread was just about complete until I purchased some wire that is not sold by Corbin and is of a different composition and when I decided to start working with another caliber. Since I began working with another caliber die and different wire, that added factors to the use of the S press that had not been discussed or demonstrated in this thread. There is more to say on certain topics regarding said elements that I intend to address later.

What I did not intend was to create or include a guide to making the best projectiles. I am personally making slugs for myself and my guns. So when I get results that I’m satisfied with, unsolicited suggestions are not helpful at all. I’ve heard and read enough of “You can’t do that” or “that gun won’t shoot those” types of comments on these forums to where I’m honestly tired of it. I’m tired because some of what I’ve done is exactly what other airgunners told me could not be done. It would be different if I were attempting to do things that defy the laws of physics or are illogical, but I do not believe that is the case. This is one reason details are lacking in some of my posts. Which makes me scratch my head reading some responses when certain details are lacking, yet people are drawing conclusions. Also I will probably have a lot less to say about some of my processes because what has become painfully obvious is that my learning processes are not for everyone. I’m ok with that, but I think there is too much assuming going on because I really try to make it a point to explicitly state what I’m attempting to do. An example of this can be found in post #108. There is a lot that I do not know and I’m not an expert in anything airgun related. So I suggest that others take what can be used from what I and others have posted here. I mean no disrespect to anyone reading this, but this is how I see things after reading over some posts in this thread. I could be a lot more specific but I’m not trying to single people out or get into a chest puffing match. I could’ve misunderstood something as well as been misunderstood.

It is my sincere desire that readers gain something useful without picking up much of any information that is harmful, especially in this sort of informational thread. If anyone reading this feels that I did a poor job I can accept that. If that’s your perception, why not create your own thread to help others by sharing your gifts and talents? I envy some of the talented tradesmen on the forums. Anyhow, thank you all for reading. And thank you to those who contributed relevant, creative, expert input, necessary corrections, and their experiences in using this awesome swaging setup.
 
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For the ones making RBT's, I'm sure you noticed the deformation on the bases caused by trapped air on the 1st pass. I have been following up with 3 passes rotating every time for the best results. What have you all been doing to combat this? So far this has been working very well.

1st press
1000007426.jpg

2nd
1000007429.jpg

3rd
1000007430.jpg

4th
1000007431.jpg


One little wipe with the fingers removes the leftover burs.
1000007432.jpg
 
For the ones making RBT's, I'm sure you noticed the deformation on the bases caused by trapped air on the 1st pass. I have been following up with 3 passes rotating every time for the best results. What have you all been doing to combat this? So far this has been working very well.

1st press
View attachment 526013
2nd
View attachment 526014
3rd
View attachment 526015
4th
View attachment 526016

One little wipe with the fingers removes the leftover burs.
View attachment 526017
What diameter wire are you using?
 
I've found that smaller diameter wire usually works best for BTs. It tends to fill the ends of the slugs first, then smashes out and fills in the rest of the slug if that makes sense. You might measure the back of the boat tail to see if it's smaller than .200 and if so, try .185.

Another thing that can cause the BT not to fill correctly is if the core cutter dies aren't the correct size for the wire. It will cut the cores off at an angle so they won't fill the BT as evenly.

I hope this helps.
 
I've found that smaller diameter wire usually works best for BTs. It tends to fill the ends of the slugs first, then smashes out and fills in the rest of the slug if that makes sense. You might measure the back of the boat tail to see if it's smaller than .200 and if so, try .185.

Another thing that can cause the BT not to fill correctly is if the core cutter dies aren't the correct size for the wire. It will cut the cores off at an angle so they won't fill the BT as evenly.

I hope this helps.
I might give .185 a try. If I can get the results I want with one pass, or two, that would be great! My cutter die is a snug fit, but the blade cuts one end at an angle and leaving one end squared. The angled end goes into the swage die 1st leaving the flat end for the punch. I just came to the assumption that RBT's are just more work and probably why most manufacturers don't offer them. So far I'm liking them.
 
For the ones making RBT's, I'm sure you noticed the deformation on the bases caused by trapped air on the 1st pass. I have been following up with 3 passes rotating every time for the best results. What have you all been doing to combat this? So far this has been working very well.

1st press
View attachment 526013
2nd
View attachment 526014
3rd
View attachment 526015
4th
View attachment 526016

One little wipe with the fingers removes the leftover burs.
View attachment 526017

Are you talking about the shoulders of the base? At the very back of the slug?

Dave
 
I’m also wondering if the hardness of NSA lead wire is also a factor.
@Ta-Ta Toothie I get the same non-fill on my 357 RBT slugs. I would rotate them and re-press as well, but because of trapped air I'm thinking about using less swage lube?
@Airgun-hobbyist Which sized wire? And where’d you buy your wire? Are you forming the boattail at the same time as you’re forming your cores (2-step process)?
 
I’m also wondering if the hardness of NSA lead wire is also a factor.

@Airgun-hobbyist Which sized wire? And where’d you buy your wire? Are you forming the boattail at the same time as you’re forming your cores (2-step process)?
It's .340 wire from corbins.com and yes, the whole thing g is formed in one operation to about 150 grains.
 
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