SmallCaliberCentral

Hello all. I am new to the posting on the forum here but I have enjoyed reading it very much for some time now. I am very new to reloading and I am having some problems. I have an AR in 204 with a Shilen barrel that is fairly accurate. It will produce the occasional .5" group but then it will act erratic and throw some really wide groups. I have decide to start reloading and wanted to start by measuring the appropriate OAL to seat my bullet just off the lands of the rifling. I purchased a Hornaday OAL measurement device and i am getting the following measurement with a 39 gr Blitzking bullet. 2.437" when the max OAL should be 2.260". What am I doing wrong? Is it possible to have that much gap to the rifling. I hope I'm just making a bonehead mistake.

It is entirely possible to have that much gap to the rifling. Each rifle (chamber) is a rule unto itself that way. Two things to keep in mind when loading for an AR. #1 is magazine length: if you have a long throat it may not be possible to seat the bullets as far out as possible and still be able to use the magazine. #2 is crimping: it may be necessary to crimp your bullets in order for your loads to work in the AR because of the operating cycle and recoil effects in the magazine possibly pushing bullets into the case. As a reloader, there is a lot of case prep you can do to assure uniformity and have a very positive effect on consistent grouping. If your just getting started in reloading it will be helpful if you can pick the mind of an experienced reloader as you get going. Good luck in your efforts...

This is a common issue with all 204s from what i've read. It is almost impossible to seat the bullet out far enought to reach the lands due to the small size of the bullets. I'm seating mine at 2.15 using the same tool to measure as you are.

me to i shoot a ruger #1 and can not set the 30 gr out to the lands well//

Check with whomever cut your chamber and see if they have the ability to cut you a chamber gauge to match.

I had a custom .204 AR upper built several years ago and the gunsmith provided a gauge to match. He also cut the chamber so I only had .030 leade to the rifling. This keeps my magazine length loads with a tight tolerance. It does, however restrict me to 40gr bullets in the rifle.

Just a thought.

I have two different 204rs. Both like right around .22 jump from lands to the ogive. For yours that should be around 2.217 oal at the ogive.