What would the proper twist be for a 7x57 and 175gr bullets? Thanks in advance for the help.

1-8.5 should be perfect. I use 1-8 in a 280 Ackley with the long bullets and it's fantastic.

Depends on the bullet. Standard 175's like Partitions, Speer Grand Slam, or even Sierra Game King will stabilize in the standard 1:9. Long 175gr class bullets like Cutting Edge, Bergers, or Nosler LRAB's may not, and you would need 1:8.5 or even 1:8.

I think that a one size fits all barrel would be 1:8.5 twist.

Jeremy

The gunsmith shop going to do the job has a Krieger 8.5 twist 7mm in stock so I have reserved it. Ordered the Dumolin action from Sarco Monday. Probably put it in a Boyd Nutmeg stock with customizing. I will replace the bolt handle with a straight one and rear sight will be a Lyman peep, front a Masterpiece banded ramp. Have absolutely no use for it but have this friend graduating from TSJC and wanted to have some work for him right off the bat.

I have six Dumoulins in the works as spec guns. I had my smith heat the bolt handle on one and straighten it. He used a heat sink and heat stop paste and a bending block so no damage was done to the bolt. It turned out pretty nice so you might consider that before welding on a new handle.

Straightening the original is really no problem,the problem is I have always disliked the FN bolt handle style especially the round flat bottom knob. I will probably put a 2 or 4 panel checkered teardrop shaped knob on it such as a Max McFarland from Brownells. It's just an idiosyncrasy of mine. Most of my nicer rifles have the straight teardrop style handles.