I have been asked a time or two about accuracy guarantees on the rifles that I build, and I'll be honest I pretty much cringe when this comes up. So rather than a guarantee I'll discuss realistic accuracy and what I think is realistic expectations, and summarize here.
There are several contributing factors to accuracy, and these are somewhat of an order of importance:
-quality of work performed
-action, stock, and bedding issues
When I build a complete heavy barreled target or tactical rifle, I expect to see no paper between bullet holes at 100 yards, and more realistically 1/4" or less groups at 100Y. Larger calibers (over 30 cal) like 338 magnums you may see closer to 3/8", often because of recoil management. I expect to see these same rifles shoot less than 1.5" at 400 yards, and many/most will be much closer to 1" at 400 yards with good load development
Accuracy expectations with lighter barreled rifles is something I don't have too much experience with as I rarely shoot sporter style rifles or explore the higher accuracy potential of these. I expect my own sporter rifles to shoot 1/2" at 100Y
Barreled actions built and tested in a good chassis like an AICS will shoot to the same accuracy expectations as above. Other systems like HS and Bell and Carlson can be hit or miss without bedding
Most rifles are test fired for function only, and are not accuracy tested. The ones that are accuracy tested will include test targets and possibly load data. I do not do testing and load data for free. If you have a concern with the accuracy of the rifle, and it can't be worked out by phone, you can send it back here for evaluation. If there is a problem I will fix it at no charge- if there is no problem and the rifle shoots properly, you'll get the rifle back with test targets, load data, and a bill