I started with a Wilton? 4" and broke one side off by turning the crank. Then I went to Sears and bought a 4 1/2" which I proceeded to break last night by cracking the base in half.
Here's how I did it:
I needed to get the barrel pin out so, I took one of those cheap screwdrivers that have the hex bits and cut the phillips head off. This left me with a little cylinder to use as a pushing pin. I then lined it up with the barrel pin in a vise and a piece of steel stock on the other side with a whole so the pin could move. I cranked down as hard as I could by hand then put a steel bar on the crank handle. After I got to the point where I couldn't physically move it anymore, I took a 3lb deadblow and hit the front of the vise like I was trying for a homerun at Wrigley field. That started the pin moving and I could crank a little more.
It only took two or three more cranks and I heard a sound similar to the barrel pin moving more. I uncovered the setup (I always cover with a towel to stop projectiles as much as possible) and the vise had broken at the base.
I know you're probably thinking...get a press. I guess I will. There has to be a vise that can take a little punishment. Maybe I need to move to 6"? What are you guys using?

I think an arbor press is what you need, not a vise.

I've removed 7 Rommy barrel pins using the method you mentioned with a 5" Harbor Freight vise with out any problems.  Maybe I've just been lucky.  I'm sure that Sears will give you a refund for your broken vise.  Maybe try a larger (5 or 6 inch) vise.

I have a little 4 1/2 vice from HF, and I would never even think if using it for pushing pins...

I think you should look into a 6" or come on over to my place and use my 20 ton press.

I have a six inch Wilton, theres two different Wilton vise's. They have the economical brand that is made in China and the pro series that is made in the U.S. I bought the pro series but it was a bit costly at around 250 bucks and i got a deal on it too, they usually run 350-400 but i do a lot of work on the vise. It pays off in the long run to buy a good one right off the bat. Are you soaking the barrel pins in kroil before trying to press them off? Soak em in kroil for a few days, it really helps.

I've got a pretty burly Snap -on vise. I cracked it doing barrel pins.  Broke out the welder, welded the piss out of it, and she is good to go. It is a big ass vise and it only lasted for 6 pins before it cracked.

Kurt 675

Some aren't going to come out without drilling. I have two 81' that using a 12 ton press, that the #8 steel bolts, cut down to 1/4" to reduce pressure along the shank flatten out on the trunnion. On another board others have posted with pictures where some of the Romys had something else stuck in the hole.

As a side note I have removed three other Romy barrel pins with no problem

Quoted: I've removed 7 Rommy barrel pins using the method you mentioned with a 5" Harbor Freight vise with out any problems.  Maybe I've just been lucky. I'm sure that Sears will give you a refund for your broken vise.  Maybe try a larger (5 or 6 inch) vise.

A 4" vise isn't big enough for this operation.   I'm not so sure it's Sears' problem.   However I probably also have gotten refunds on stuff that I broke and it wasn't the fault of the product maker.    

NO offense intended, but if I were real tight on cash I think I would probably return the vise. If I had the money to spare I would eat the cost of the broken vise and consider it the cost of learning.    

if you are only doing 1 build send your barrel to cabhammer.he will push out the pin and barrel for $15 plus shipping and he does a great job.hereis his email [email protected].

But if you are going to do several builds (any buddies building?) you can get a 12 Ton Press from Harbor Freight for around $100 if you catch them on sale.

Lowes sells a "Kobalt" Brand vise that comes with a lifetime, no questions asked, guarantee.
The 6" unit that I bought cost about 40 or 50 bucks and is built like a Tank.
I have beat on mine with all that I have (hammers, mallets...) and have barely scratched the paint.
IMHO I will never have to replace it.
Del