Pressure ring

[hepburn45110]

I've read that if the pressure ring on the bullet goes below the sized portion of the neck you'll have trouble getting small groups. Do any of you find this to be a fact in your rifle? Seems to be in mine.

 

[K22]

"What's the pressure ring on the bullet??"

 

[hepburn45110]

On some bullets there is a small portion at the base of the bearing surface that is a little bit larger in diameter.

 

[bozo699]

I've read that if the pressure ring on the bullet goes below the sized portion of the neck you'll have trouble getting small groups. Do any of you find this to be a fact in your rifle? Seems to be in mine.

Yes but when ordering a reamer I keep in mind the bullets intended and order the reamer accordingly, I keep the bullet above the donut.
Wayne.

 

[okedoke]

hepburn, are you shooting modern or blackpowder cast bullets, all quality bullets that i will use are the same OD from the ojive down to the base , boatail or radius. If there is a pressure ring, it reminds me of a gas check on the base of a cast bullet.--- sorry i can't help take care Craig

 

[BoydAllen]

Going back to the original question, the answer depends on whether the powder being used needs a lot of neck tension for best results. The only die that I have run across this problem with is a Wilson neck die, and they will modify the die to put the bushing farther down the neck. Ultimately, if you are going to shoot bullets where this is a constant issue, it may be worth it to modify the chamber so that the free bore is a little longer. This can be done to an existing chamber with a throating reamer.

 

[hepburn45110]

Going back to the original question, the answer depends on whether the powder being used needs a lot of neck tension for best results. The only die that I have run across this problem with is a Wilson neck die, and they will modify the die to put the bushing farther down the neck. Ultimately, if you are going to shoot bullets where this is a constant issue, it may be worth it to modify the chamber so that the free bore is a little longer. This can be done to an existing chamber with a throating reamer.

I am using Wilson dies. I've thought about changing the position of bushing in the dies. Just haven't done it yet. My inexpirence leaves me clueless as to which powder needs a particular amount of neck tension. I have considered a throating reamer.

 

[BoydAllen]

I suggest that having the die modified would be a good fix, as long as they can lower the bushing that far. What caliber and powder? You must be shooting light loads if you can get away with neck sizing as a long term plan.

 

[hepburn45110]

It appears that I can lower the bushing about .060. That will help some. Calibers? 6br 8 twist using 28grs Varget under a 105 Berger. 6 Dasher 7.5 twist using 31.5grs RE 15 under a 105 Berger or 108 Berger. I am using a body die every third firing.

 

[BoydAllen]

One other option worth mentioning is that Harrell's makes Dasher FL dies, that are matched to your fired case. With a close fit to your chamber, FL sizing every time might be a good plan. Just a thought....

 

[hepburn45110]

Die modified. Lowered the bushing .070 in the BR die. Trimmed length to gives .005 end clearence to the bushing. The sized portion ends about 1/16 above the shoulder. Will find out later today if it affects group size.

 

[Bradley Walker]

Die modified. Lowered the bushing .070 in the BR die. Trimmed length to gives .005 end clearence to the bushing. The sized portion ends about 1/16 above the shoulder. Will find out later today if it affects group size.

I would be really interested.

 

[jo191145]

Ummn I may be totally wrong but I thought only flat based projectiles had a pressure ring. Boat tails need not apply.

FWIW back in the day when I shot a lot of 204R's with massive jump and 35gn flat based Bergers I set my bushing and seating depth so that the pressure ring was just under the sized area. Created a false/reversed crimp by my terminology. ;D
When seating I could tell by feel which bullet was qualified for competition and the rejects. If I could'nt feel the projy plop down at the end of the stroke it was a fouler or emergency running out of ammo cartridge.
It sure seemed to work for me in that one application. Never bothered trying to duplicate it in other scenarios.

 

[hepburn45110]

The Berger 105's and 108's that I have on my shelf have a pressure ring.

 

[hepburn45110]

Die modified. Lowered the bushing .070 in the BR die. Trimmed length to gives .005 end clearence to the bushing. The sized portion ends about 1/16 above the shoulder. Will find out later today if it affects group size.

I would be really interested.

If I measured correctly the pressure ring now sits just above the end of the sized portion of the neck. The modification made the gun a little more predictable. Today wasn't a good day for small groups but the groups were aligned with the wind. That is something the gun wasn't good at before.