6BR is Siff in Rapid Fire; Resolved.

[rangertim]

Re: 6BR is Siff in Rapid Fire

Chamber is too small at back inn, had the same problem, and loosing primary extraction also don't help as Dan the 40x man said

 

[matorre]

Re: 6BR is Siff in Rapid Fire

Did you ever find your primary extraction ?

I never stayed at a cheap hotel or a back inn, I
resent the implication.

M-

 

[CatShooter]

Re: 6BR is Siff in Rapid Fire

Did you ever find your primary extraction ?

I never stayed at a cheap hotel or a back inn, I
resent the implication.

M-

I used to have a lot of primary extraction - but my "Ex" got all of it in the settlement

 

[hdbiker1]

Re: 6BR is Siff in Rapid Fire

Your ex might object to that insertion. ;D ;D ;D

 

[matorre]

Re: 6BR is Siff in Rapid Fire

You know , my current wife asked about the primary
extraction, but I had to admit I had'n t seen any around.

And she is suspicious about that cheap hotel crack.
thanks a lot, rangertim

M

 

[dfry]

Re: 6BR is Siff in Rapid Fire

Did you ever solve the issue? Just curious, Dave

 

[matorre]

Re: 6BR is Siff in Rapid Fire

Not tested yet. Got small base dies,
and loaded brass accordingly.

Moved and haven't shot yet.

Regards
M-

 

[matorre]

Re: 6BR is Siff in Rapid Fire: Resolved.

Well we can file this one as " done."

The Harrells small base dies made my brass a consistent
.0005 than what the fired brass was.

That made all the difference in rapid fire, apperantly.

Many thanks are over due to Harrells in Virginia for their understanding
of my problem, and their rapid service to me in 2012. Best value
I have ever spent on reloading tools.

Good to be finally on the range
again in Missoura.


M-

 

[bigstick6017555]

i run .003-.004 loaded round neck clearance for my 6br chambers. i remember hearing somewhere to turn thin to win, Jack Neary said it in one of his videos

 

[alinwa]

Re: 6BR is Siff in Rapid Fire

Chamber is too small at back inn, had the same problem, and loosing primary extraction also don't help as Dan the 40x man said

May I repeat....


"The chamber is too small at the back"

 

[KentuckyFisherman]

I had what sounds like a similar issue with a 6BR Savage. VERY stiff load and it was expanding the base; first time I'd ever run into that. Gave me fits until I bought a small base body die, which fixed things right up. Your combination of stiff bolt lift and ejector marks sure sounds like a hot load to me.

What worries at least as much as the load is the neck clearance you reported. Less than 1 thou total release just feels to me like you're asking for trouble. Since you report having this problem with rapid fire more than slow fire, could that be pointing to your tight neck as a big part of the issue? Like during rapid fire maybe the brass or the chamber are staying so hot that it's causing some of the binding?

 

[bigstick6017555]

He had stated that he could not push a bullet in the fired case easily, and if turned upside down it would not fall out. that is a way to easily jack pressure. back a few years when shooters were experimenting with fitted necks they often had these problems. his .00075 ( if his math was right) clearance was way to tight.

 

[matorre]

Well that did not resolve the issue.

I went to Harrell's again and reduced the bass much more. I'm still getting getting ejector marks in the base of the brass at 30 grains of Varget and SMK 107gr.

I dropped the load from 30 grains of Varget down to 29 gr, then to28.5 grain to Varget... I still have a stiff boat lift and ejector marks in the brass.

I did a little math and compare to neck size to the chamber dimensions.

After doing the math I have .00075 clearance for the neck to expand.
I think this is not enough.... but more experienced people have to verify that for me before I buy neck turning tools.

brass thickness .013 Lapua
smk 107....... . .2435
JGS neck chambre... .271

neck clearance .... .00075 per side.
base as sized at .200 line, .469-4685
base with 30gr varget.... .471
base with 28.5 grains .470
JGS base at (edit) .200 line .471

neck clearance doesnt seem like enough.

Bullet is NOT a loose slip-sliding fit in the fired cartridge... you have to press hard and if you stop and turn the cartridge upside down the bullet will not fall out....hard to pull out, too.

your thoughts and advice are solicited.

note. I fire rapid fire in my sport . 10 rounds in 1 miniute. I dont care about brass life.

M->

 

[matorre]

May I repeat....


"The chamber is too small at the back"

The chamber at the bolt face is .471 the sizing die is making the base of the brass .4685 to .469. How small do you want it ?

 

[matorre]

He had stated that he could not push a bullet in the fired case easily, and if turned upside down it would not fall out. that is a way to easily jack pressure. back a few years when shooters were experimenting with fitted necks they often had these problems. his .00075 ( if his math was right) clearance was way to tight.

I showed my math so as you can check on me.
:- )
m

 

[KenOath]

If bullet won’t slide into case neck after firing, opening the chamber neck up should help..

 

[matorre]

If bullet won’t slide into case neck after firing, opening the chamber neck up should help..

Well the thing is I can push hard enough to slide it... but what differentiates a slide versus a loose slip fit?... is that what im looking for ?

(I'm strong enough to shove the bullet in a sized case so I fool myself.)
m

 

[alinwa]

The chamber at the bolt face is .471 the sizing die is making the base of the brass .4685 to .469. How small do you want it ?

You can and will do what you want, but the ANSWER is........... your chamber is too small.

It ain't the neck.

I shoot many rounds with a "scuff fit" neck (learned that term from #2 in BR HOF. I think he coined it) which means NO clearance. You cain't hardly force a BT bullet back in with your fingers, FB, no way.

Necks don't hang up, ever. There's simply no mechanism for it.

"Chamber finish" pahhhhh. I've had chambers with rings you could file your corns with..... no hangups. And 320 grit? 240 crosshatch? Polished mirror smooth? None of them show a tendency to hang up. Other characteristics, YES, but none of them hang up.

.471 is too small, there IS a mechanism for that problem.

I have my reamers ground at .477

I don't know your level of gunsmithing skill but I have two friends who've polished or "honed" theirs out using sandpaper/dowel/power etc, I've done the same but now I spin 'em out on the lathe. If you decide to open up the rear end of the chamber it's best to spin the bbl.

BTST, I don't expect you to believe nor lissen to me

 

[alinwa]

Re: 6BR is Siff in Rapid Fire



I used to have a lot of primary extraction - but my "Ex" got all of it in the settlement

is that you Paul?

 

[matorre]

You can and will do what you want, but the ANSWER is........... your chamber is too small.

It ain't the neck.

I shoot many rounds with a "scuff fit" neck (learned that term from #2 in BR HOF. I think he coined it) which means NO clearance. You cain't hardly force a BT bullet back in with your fingers, FB, no way.

Necks don't hang up, ever. There's simply no mechanism for it.

"Chamber finish" pahhhhh. I've had chambers with rings you could file your corns with..... no hangups. And 320 grit? 240 crosshatch? Polished mirror smooth? None of them show a tendency to hang up. Other characteristics, YES, but none of them hang up.

.471 is too small, there IS a mechanism for that problem.

I have my reamers ground at .477

I don't know your level of gunsmithing skill but I have two friends who've polished or "honed" theirs out using sandpaper/dowel/power etc, I've done the same but now I spin 'em out on the lathe. If you decide to open up the rear end of the chamber it's best to spin the bbl.

BTST, I don't expect you to believe nor lissen to me

Nobody is shooting 6br with a .477 chamber base.
M->
except for you...