enlarging a chamber

[cpa5oh]

I shoot lead bullets (either coated or nasty filthy uncoated)

I'm having some chambering issues with a Tanfoglio Stock 2 .40.

Had the same issues with a G24 with a KKM barrel...so I ordered a reamer from Manson Reamers, opened the chamber up, and the gun ran great with my reloads after that. I did not notice any reduction in accuracy.

Had I noticed a loss of accuracy I could have tossed that barrel and ordered another. With this Stock 2, getting any parts for it is a bear so I doubt getting a new barrel is an option.

General question about making a chamber slightly larger - does this generally cause a noticeable decrease in accuracy? I'm thinking (maybe more like hoping) that the answer is "no" given I'm not a bullseye shooter...that the fitting of the barrel to the slide is the key factor (which will not be changed.)

Thank you!

[Jediwarrior]

Based on my experience, no, it doesn't affect measurable accuracy.

I opened up slightly a KKM 40 S&W bull bareel for a customer coz he was having failure to chamber on his reloads. He didn't notice any change in accuracy.

[practical_man]

Manson makes a nice throating reamer is bullet profile is part of your trouble. It's very affordable.

Their chambering finish reamer will cut the chamber longer and correct any undersized dimensions. It can cause headspace issues if you cut too much.

The plunk test can tell you which you need.

I haven't had a problem with throating reamer negatively affecting 50 yard accuracy. Ymmv