What tools do I need to cut a forcing cone?

[m1garand_man]

I recently rebarreled a pre M10 and lucky everything torqued up at TDC with the cylinder gap ending up at .008" which I am happy with. I do need to cut the forcing cone though because there is still evidence of the riflings in the forcing cone.

I am looking for a complete list of items I need to buy from Pacific Tool and Gauge to be able to perform this service. In the past I have just done independent research only to find out that I was missing things and had to place a second order.

If I understand everything correctly I will need the reamer, a T handle and at least one pilot bushing. Is that everything?


Thank you.

 

[Mercury]

I just finished a caliber conversion for a model 49 and needed to reface the rear of the barrel and used the same set up except a different cutter. The only other bushing that you need is the cone shaped aluminum one for the muzzle.

This set up works extremely well and it takes very little effort to cut. The only recommendation I have it to go slowly and check it often because it works so well you don't want to over do it.

While holding the frame in a vice, I put my thumb on the cone bushing and my index finger on the rear of the cutter (in the frame window) and lightly squeezed to keep everything snugged up. At the same time, I gently pulled on the T-handle while turning it.

Good luck

 

[Protocall_Design]

Pacific Tool & Gage has had a lot of internal problems for years now. Sometimes you don't get anything for a long time or maybe not at all.

I get my tools like that from Brownell's. Their kit is very good and the catalog shows what you need to do the job.

 

[dfariswheel]

The usual tools are....

The Tee handle.

A cutting head with the degrees angle you want the cone to be.

A precision drop-in plug gauge to measure the cone for proper dimensions. Note that you cannot eyeball the cone for proper size.

A brass lapping head and fine valve grinding compound.

You probably should also have a 90 degree cutting head to set the barrel-cylinder gap.
This is far superior to trying to file the rear of the barrel and keep it perfectly square.

Brownell's is the go-to source for the supplies.

 

[steelslaver]

4DReamer Rentals will rent you the kit with everything you need to recut yours for $30 + $6 for the gauge you need. Reasonable shipping cost also. I have my own forcing cone and muzzle kit, (Brownells) but I have rented several reamers from them and they give good prompt service.

If your doing a one and done its a good way to go.

Forcing Cone Tools (rentals) Archives - 4D Reamer Rentals

 

[Steve912]

You probably should also have a 90 degree cutting head to set the barrel-cylinder gap.
This is far superior to trying to file the rear of the barrel and keep it perfectly square.

Brownell's is the go-to source for the supplies.

Would he want to be facing-back the barrel, with the b-c gap
already at 0.008?

 

[dfariswheel]

Not to any major extent.
But the rear of the barrel could be squared up with the cylinder as long as no appreciable amount needs to be removed.

Where things get "iffy" is where someone has filed the rear of the barrel and it's not square, but there's already more gap then needed.

 

[BLUEDOT37]

Brownell's Chamfering Tool Kit has everything you'll need (except the lapping compound, which is separate).

I liked the 5 degree cutter when I did my 357s.

Also has the facing cutter to square up the barrel's breach extension if you need.

I bought a second pilot bushing for each caliber too. I found it beneficial to have one pilot near the breach end & the second one near the muzzle so you don't have to constantly monitor that the muzzle's center guide is staying in place while you're cutting.

The kit's not cheap but worth it though if you'll eventually be doing more guns.

You can save some $$ by using the mouth of a sized 38/357 case to use as a plug gage. (The max FC mouth diameter shouldn't be over .377", which the case's OD" will be close to.)

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