Case trimming/accuracy

[johnf]

I was having some problems stringing my shots pretty bad with reloads. They were almost 1/2 moa horizontally, but strung up to 5" up and down. I've not had time to remount my scope(nikon prostaff), but that's probably first on my list to fix the problem. I've just started and I got a set of the lee case trimmers this weekend and found that my 25-06 cases haven't stretched much at all and if I put them through the chamfer (sp?) first they won't trim at all from what I can see.

The 243 however has some considerable case trimming IMO. Could this have been causeing accuracy issues?

Has anyone used the lee case trimmers?

[OJR]

I have never used a Lee case trimmer. In fact, I have never used anything made by Lee for reloading!

I will be out of town tomorrow and I will send you a PM on Friday about what I have and will make you a deal on case trimmers. I know I have a RCBS and also a Wilson. The Wilson is very precise.

[huntinguide]

I am straight Rock Chucker "RCBS" they ar just so dependable, but i have found case trimming and de burring to give me more accuuracy in my target rifles

[LifeNRA]

I was always told, make sure the length of each cartridge is the same, and the over-all length of each loaded round is the same. Using a outside vernier caliper. I haven't loaded much rifle ammo, mostly pistol, which the tolerances are not as critical. Sorry not much help here.

[uncle john]

Vertical stringing, in my experience, is usually the result of a barrel heating up. The heat causes expansion, and if the barrel is not free-floated, it pushes on the stock differently after each shot. Most commonly, the first two shots group well, then it starts to rise. I have run into rifles that require a pressure point somewhere along the forend in order to get best accuracy. Finding that spot, and determining how much pressure the rifle needs can be frustrating. A barrel vibrates a good bit, especially lighter contours, and sometimes it needs a "shock absorber". The "BOSS" system does this for a barrel. I have found, also, that a lot of these newer synthetic stocks are not nearly rigid enough, and simply the way you might change your grip on the forearm can cause stringing. Also, check for the proper torque on the screws holding the action into the gun. and the scope base screws as you mentioned.

As far as your ammo goes, I would say, if you are getting very little horizontal variation, the ammo is OK.

Look for a pattern in the stringing. If each time you start cold, the bullets "walk" in the same direction, it's heat. If there is no predictable pattern, it's usually loose screws or a lousy stock.

[huntinguide]

i do agree if you have a gun that is capable of MOA a fast string will typically be less accurate do to barrel heat, give it some time to cool. I typically what a minute between shots if im looking for my best target.

[johnf]

I gave it plenty time to cool checking after every shot and then waiting till the gun was cool.

I was putting a sandbag on top of the scope to keep the gun more stable. I think that may be the culpret. The first shot was way high 7" then the second was 4 and the third 3, all withing 1/4" of the center line. I wasn't thinking about the bag being a problem, and I guy here said it could have been the problem. I did have a very nice 5/8 group of four shots where I didn't use the bag on top. Then after that I sarted using it again and getting the stringing again.

I didn't put that together untill I read a little article on stringing.