Still failing

[303Guy]

case lenth 2.253 inch 57.24 mm

That's too long. Length should be 2.222 inches/56.44mm. Chamber clearance might tolerate a 57mm case but more is getting dodgy. That does not make it the cause but it would be a common denominator if the same load fails in another gun. It could be crimping the boolit on chambering - maybe?

Just a thought based on what I do - it's true that a .314 boolit would not chamber in your gun but the seated portion may be increased in diameter. It will swage down as it enters the throat. My rifle has a taper in front of the rifling leade. I can actually chamber the boolit against this cone and it will seat the boolit deeper into the case. That's not to say yours does.

Is your boolit a gas check design and are you using without a gas check?

[herbert buckland]

The boolit is a gas check desighn i am not yousing GCs,I will trim the cases and see weahter that makes a difrence ,one thing i never thort of,if the seated portion is biger than .314 it expands the neck to much ,the boolits drop at .315 and if i do not put them through the .314 sizer it expands the neck so it will not chamber in 3 of the H barells i have ,no problem in the standard barell and the rifle i am trying to youse is a 1920s Lithgow long tom replacment barell,H barells are just shortend versions with slight modifications and every barell i and others i know have measured very close to spects ,they will acept military amo but not a fired case from a standard barell,they all seem to be chamberd for the MkVI cartrige even the barell made in the late 50s,this should make them beter for PPing i was thinking

[303Guy]

Don't trim too much. Personally, I don't like a huge gap between case mouth and throat - too much space for unwelcome boolit upset as ignition. How did your cases get that long in the first place? Mine never grow and I only trim to square the mouth if the case is long enough.I also keep my pressures moderate and I lube my loaded cases - not dripping, just as I would for case sizing. Some say this a dangerous and unsafe practice but I have found evidence of any adverse effects. My cases last forever - hardly a sign of over pressure or bolt face overload but still, the cautioning is out there.

[herbert buckland]

I never crimp my cases and size as litle as posible so the only time i trim is to squar the mouth ,if they are feeding well i am fine whit that,I have alway tryed to keep the cases as long as posible ,anealing faily often keeps the brass softer so i supose this lets them grow more

[303Guy]

I try to keep my cases as long as possible too. Problem is, some are shorter than others so I have to compromise somewhere.

I am no longer resizing the necks so to I feel I need to keep the necks as hard as possible to retain sufficient springback for reloading. It sort of works with a need to size after a few loadings, depending on the initial state of anneal and the chamber size in the neck area. I've made my own sizer and expander to this end. Now for the test of time.

[docone31]

What size mold are you useing?
I use the Lee 303B mold. They go in the case like jacketeds do.

[herbert buckland]

What size mold are you useing?
I use the Lee 303B mold. They go in the case like jacketeds do.

I am using the CBE 315-218 mould ,boolits drop at .315 and i size to .314,I am wating on a Lee 308 mould to try with PPs

[docone31]

I use the Lee C185/312 gn mold, size it to .308, then wrap it.
If you wrap a .30cal casting, the nose will rattle in the bore. You need .304, rather than the .301 you will get.
Size it to .308, wrap with notebook paper, then size to .314.
That is what works for me.

[herbert buckland]

I found some comersial cast 303 boolits ( sure they are cast from a Lee303B mould) they were ruined when the GC were put on ( expanded the nose with too much presure) I ran these through a .308 sizer ,raped them in notpaper and sized to .314 they work well and no leading ,reasnoble acuracy ,trouble is these are GC coated boolits so i am not sure if it is a good test ,but as the barell seems to be polishing up I think it is,I have 20 left so I will keep polishing,after going through the .308 sizer these boolit are a straight .308 cilinder with a round flat nose

[303Guy]

herbert, might I ask what the nose section diameter is on those CBE boolits? How do they shoot as plain cast?

[herbert buckland]

herbert, might I ask what the nose section diameter is on those CBE boolits? How do they shoot as plain cast?

nose section is .303,they shoot realy well with GC lubed with LLA ,pouder i am using is 22 1/2gr AR2207 or 11 1/2gr Trail Boss for 100 meter load this is very acurate

[303Guy]

My sizer whic suites three of my rifles, sizes the nose section down to .2974. Patching brings that up to .312 which chambers by virtue of the patch compressing. These are awaiting range testing. I have a Chrony now so I'll be able to chrono them at the same time. I'll take more than one rifle in case those loads don't perform.