Accuracy problems - mag vs single feed

[ported45]

Slight update-

Have not had the chance to do any of the tests to shoot for groups but,

when I pull back the charging handle to about a 1/4" behind the rim of the round (not quite to the bolt catch) and let it go, it will chamber up and the bullet will not move. Pulling back a little farther to the bolt catch or all the way back with the charging handle and the bullet slips forward 0.005".

I know that I could work up a load that is accurate by single loading and then seat 5 thousandths deeper to compensate, but any round chambered and not fired would have to go back to the loading bench for re-seating.

Surely there is some solution that would allow full functioning but less chambering force returning to battery. Buy another spring and start cutting off coils?

[Klem]

Sounds like you are on the verge of achieving handloads that will not move. A bit more neck tension.

.0035"-.004" of neck tension works for me with Lapua brass. Or, 0.1mm on the Redding taper crimp die. Cutting recoil springs, or buying an expensive SCS seems a more radical solution for bullets not being held with enough tension.

[ported45]

Sounds like you are on the verge of achieving handloads that will not move. A bit more neck tension.

.0035"-.004" of neck tension works for me with Lapua brass. Or, 0.1mm on the Redding taper crimp die. Cutting recoil springs, or buying an expensive SCS seems a more radical solution for bullets not being held with enough tension.

Already tried crimping to the point of a pretty good ring is crimped into the bullet itself. No dice. Still the bullet slips forward when chambered by the bolt release or charging handle pulled back that far or farther.

[Randy99CL]

Already tried crimping to the point of a pretty good ring is crimped into the bullet itself. No dice. Still the bullet slips forward when chambered by the bolt release or charging handle pulled back that far or farther.

Are you familiar with the Lee factory crimp die? It's not a normal crimp, it uses a collet that squeezes the neck tighter around the bullet.
It is not like any other crimp. https://leeprecision.com/reloading-dies/...crimp-die/

https://leeprecision.com/factory-crimp-d...endel.html

The first part of this video explains it: https://www.youtube.com/watch?v=YWnw0sTBO8w&t=202s

[Klem]

+1

The Lee collet crimper is not the same as the Redding taper crimp (I have both in 223). The Lee collet crimp is more horizontal and severe.

[Vilk]

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Dear All,

Went to range to test one of the two JP 6.5G uppers with my reloads.

Bullet is 130 grain BERGER OTM Hybrid.

Attaching photos of the damaged bullets,it seems damage is regular and severe on one side only,shown on photo. Sure this must be the reason the bullet gets unstable in flight.

Concentricity is off as well,COAL only shorter by 0.002".

Would appreciate your input - understand your idea of polishing the feed ramps - will that alone resolve shown issue?

Thanks and rgds!
Piotr