Just got into reloading and have a few questions about bullets and seating depth. I am loading up 129 SSTs for a 6.5 creed. I have been seating to the COAL listed in the Hornady manual which is 2.670. I shot a group of rounds starting at 41.1 and worked up to 42.8 before seeing some flattened primers. The accuracy isn't near what I know the rifle is capable of at any of the charges. I looked at the seating depth first and looks like the longest I can seat a bullet with no contact and smooth bolt close and lift(firing pin removed) is 2.701. If I seat to that COAL the Cannelure is completely exposed, can you shoot these bullets like this or do I need to go with a bullet that doesn't have a cannelure? Anything else I can look at to try and tighten things up a bit?

Hornady brass trimmed to book spec
H4350
Fed 210 primer

If this is the bullet you want to use, don't worry about the cannelure being completely exposed. I have loaded and shot thousands of rounds (including 6.5cm, 264 win mag,270, 223, etc) of Hornady bullets with the cannelure "completely exposed," and still achieved exceptional accuracy. When I was able to obtain the same Hornady bullets with and without cannelure (knowing the cannelures would be seated to a point of being fully exposed), I tested them side by side for accuracy. The exposed cannelure bullets proved to be just as accurate.

Never mind the cannelure unless you are crimping which you don't need to. I always try to seat to the chamber if possible with still being able to run the magazine.

What the books list is irrelevant. Seat the bullet in relation to your rifling where it shoots best. I start even with the lands as long as it will fit in the mag. If that is too long I seat the bullets as long as they will go and still fit in the mag. Then you are bound by that length.

My 6.5 Creed doesn't care for the 129 SST's the best I have been able to get is right at 1" with them.

Try a flat based bullet seated to the lands...then go back and shoot a few seated at--the book OAL...I have always found bullets shoot better if they "jump" a bit...I have had less than stellar results with SSTs...if you don't want to use a flat base to give you a base line--use a Serria game king or match king...they are pretty consistent... Shoot some just ol factory too...tends to give you a baseline...

Ed

The 129 SST is a tangent ogive bullet, so it will not be seating depth sensitive. You can seat it just about anywhere, and it will still shoot good with the correct powder charge tuned to the rifle. The cannelure out of the case is fine. I'd seat the bullet about .040'-.050" off, and tune the load with the powder charge.

Also, what is your testing method exactly (with a bipod or front rest, rear sandbag, how many rounds are you testing and how often are you shooting groups)? Rifle spec will also help. The 65 CM is not a finicky round, so the 129 SST should shoot very well. I've had good results with the 129 and 140 SST.

The rifle is a semi custom built by Derrick . The rifle shot the factory 140 amax into about 3/4" and the 129gr SST consistently under 1/2". That's one of the reasons for initially opting to try the SSTs. I first loaded up 3 rounds at each charge starting at 41.4 and going up in 1% increments until I reached book max, which is where I started getting flattened primers. I don't have my book with me but I believe the best groups were with 42.6 and 42.8. I then loaded up 5 rounds each at 42.6,42.7 and 42.8 and shot them. This go round I got the best group with the 42.7 but still wasn't acceptable measuring right around an inch. I loaded another 5 each at the same charges and this time it shot the 42.6 and 42.8 right at an inch and the 42.7 a little over. I shot these groups over 3 days and let the barrel cool down between groups. All groups were shot bipod and rear bag prone.

I'm also seeing much lower velocity than the factory SSTs. I figured that was the difference between the su performance powder and the 4350. In trying to eliminate as many factors as possible I ordered an additional scale to double check powder charges, a OAL gauge so I can get a very accurate measurement for seating, new redding competition dies and Some 130gr VLDS.

I plan to start over, working my way up seating about 10 thou off the lands(provided they fit and feed well) with both bullets and see what kind of results I get. Am I opening a can of worms by trying two different bullets at once? I also need the load data for the 130gr VLDS from bergers manual if anyone can help me out. The only book I have is hornadys.

Not to hijack this thread, but why are the 6.5 dies double the price of other caliber dies?

Forget what Berger says. They are way too conservative on powder charge. Use Hodgdon.com

No problem using two bullets at once as long as you treat them as seperate tests and document accordingly.

I have never had good groups shooting any Hornady SST bullet in any weight or caliber,and I've been reloading for 35+ years and have many different types of powders to try them with. I've given up on the SST's and stick with the tried and true Sierra Gamekings or Berger Hunting VLD's for my hunting bullets.

Hornady factory ammo is loaded pretty hot,many times you can't get near their velocities without seeing pressure signs.And,if you try to use the factory ammo brass for reloading a lot of the cases will have loose primer pockets after they are fired.
I love the 6.5 Creedmoor,but the brass is the weak link of the cartridge. I've started resizing and fire forming 22-250 brass for my Creedmoor just to have some good brass.

I had the exact same experience with SST's. Mine shoots 140 amax very well but each gun is different. Are you ladder testing with these varying charges to get a node to work within?