Seating Depth with long throat

[Newportkiller]

Rifle: Carl Gustaf CG80 6.5x55 Swedish 123-140gr match bullets.

I am currently loading a 123gr HPBT to a OAL of 3.025” this puts about 0.100” of the bullet in the case(not including the boat tail) that puts it 0.065” off the lands using the Erik Cortina method
0.002” Bump
0.002” Neck tension.


1) Am I safe in this position with regards to feeding from the magazine and not getting recoil set back?


2) What can I expect if I do decide to seat the bullets deeper?


3) Are VLD’s an option?


4) Is the “one diameter in case” rule a concrete rule?

 

[Bill Norris]

(1) If there is no hinderance or binding of the cartridge it should feed O K providing neck tension is sufficient to keep the bullet in place.
(2) Most likely it will change the accuracy but more important it will change the over all case volume which will require the load to be re-worked for safety purposes.
(3) Depends on the rifle
(4) One diameter in the case is an old rule and may not apply to a specific load. The bullet does need to be seated deep enough to maintain the safety aspect and operations without upsetting the round.

 

[Herzo]

I have had good luck loading 140 grain boattails to where the full diameter reaches the bottom of the neck in my M96 Mauser.

 

[K22]

Remington 700's have long throats. Often you have to seat far off the lands. I've used the Sierra OAL's published in their manual which are quite conservative (short) with their bullets in various 700's and had no problem establishing very accurate loads in the 1/2 to 5/8" range (at least accurate for me).

Also, in some rifles with some bullets, they shoot better groups with the bullet seated well off the lands. Sierra published a paper on this several years ago.

The one bullet diameter guideline is just that, a guideline but I've found it to be useful. Seating bullet deeper often increases pressure.

I had a light weight 308 that would deform the tips of the Sierra Pro Hunter bullets in the magazine due to the recoil bumping the bullet against the magazine. But the neck tension was sufficient to prevent bullet push back into the case. It's always a good idea to check this and modify your neck tension accordingly.

 

[JB10]

I have a factory r700 in 308. I spent a long time trying to find a load it liked. Most bullets had a long jump to fit in the adl style mag. I seated them longer and single shot them and accuracy started to improve but then i ran out of bullet length to stay in the brass trying to get closer to lands. I now use berger 175gr vld hunting bullets. I can seat them close to lands and enough bearing surface in the case, but they are single feed and it shoots good.

 

[Doom]

The 1 caliber rule is an approximate recommendation that has been around forever. It is not an absolute. In fact the minimum neck length on the 223 Rem is 0.1727".

It not unusual for factory rifles to be long throated. It aids in barrel life and consistency. The rifle was built at a time when bullets were tangent ogive and tolerated jump. My Rem 308 has so much freeborn that the 168 SMK shank would not be in the case if jammed.

I would try loading around the COAL recommended by the bullet manufacture. I'm betting you'll find it suitable. It's what the rifle was designed for. I personally would also consider staying away from any VLD design bullets.