"jj's brit" ™ ... a pretty good load ...

the load.   "jj's brit" ™ cases fabricated from remington peters cases in .243 winchester, as detailed more than once in these pages; 120 grain nosler ballistic tip bullets, seated to 2.440" inches overall cartridge length; 29.5 grains of h-4198 powder; cci 200 primers, and that's about it.

i had shot an exceptional group w/ the 120 grain bullet, but wanted a bit more velocity from the load.  and, previously, i had fired a group with 29.5 grains of h-4198 behind the nosler bullet, and it showed promise, but the group opened on a third shot when i just wasn't paying attention.

the group.  this time i paid attention.  3 shots from the bench at 100 yards, into 0.360".  when you look to the picture, look to the top hole, as it is actually two bullet holes: at the bottom left of the hole you can see an elongation of the hole.

this is a "bragging-size" group, and is exceptional accuracy from any rifle.

the conclusion.  this will be a "standard load."  i have some more work to do w/ the sierra 130, as i think it will eventually group this well, as well.  but, this load will become standard.

a rifle cartridge capable of getting 2650 fps from the muzzle with a 120 grain .284 caliber bullet and shooting a 0.360" group @ 100 yds is nothing to sneeze at.  this attracted a bit of attention from some shooters, who shot the rifle, and all were pretty enthused about it.   they liked it.

that's all good.

john jay @ 05.28.2012

picture.--

caption:  the target is a plaster on a used papa murphy's take & bake pizza tray.  it works pretty well.  "waste naught, want naught."  the trays don't store very well, though, and smell a bit funny.  you cannot, however, beat the price.  they make good targets.

update:  i got curious the other day, and decided to see if a nickel would cover the group.  well it did, so then i tried a dime.  much to my surprise, the dime covered it quite easily.  a dime isn't very big, about 0.704" in diameter.  i figured that there would be enough "space" between bullet holes to account for that, but there was not.  end update, picture to follow.  

caption:  the bullet alongside the dime is a nosler 120 grain ballistic tip, in .284 caliber.  someday i will learn how to focus the camera, a small nikon "coolpix."  it works wonderfully, except it doesn't focus worth beans.  it will have something in focus, and about the time i get ready to shoot, it backs out to "fuzzy."  it makes it kind of a game, i guess.

Comments

[Drew458]

QL loves this cartridge; your results are less than 25fps from those calculated.

Do you have any BLC2, 322 or 335?

[john jay]

drew:

i have used a lot of h-322 (6.8mm rem spc) and h-335 (.223 remington) in the past, and liked them both.

i use h-322 almost exclusively in the 6.8mm, and have given h-335 up for rl-15.

the first powder i tried in "jj's brit" ™ was h-322, but i ran out of case before i could get any velocity. it may very well be that fabricating the case from the .243 remington-peters cases hasn't left me a lot of internal case capacity to play with.

i am finding out from you that quick load has very solid capability in predicting velocity and pressure. very surprising, that, and most pleasing.

john

p.s. i had tried another 1/2 grain of h-4198, and i only got an additional 20 fps of velocity, and groups opened up to 2" with horizontal spreading. i think the 29.5 grains is a most happy "resting place" in loads, and i'll just stay here.

[drew458]

Ah so. We're playing with vibrational nodes then I think.

i have most of a can of BLC2. I never use the stuff. Too bad we've got that nasty Hazmat fee, or I'd send it your way.

PS - "only"? 40fps per extra grain is pretty good in my book.

[john jay]

drew:

laughing.

yes, i think it is the vibrational nodes thingie.

i think the little bugger will shoot.

and, i have discovered a new source of cases to fabricate into "jj's brit" ™ cases. i had a whole sack of winchester 6.5x55mm swede cases, from the days at least 15 years ago when i owned a model 96. (i never should have sold that thing, a nice rifle.)

well, i am making 50 cases of the brit with it, and it is working quite well, ... , no wrinkles or cracking, the necks outside turn easily (or else i am getting way stronger ... those little hand lathes are quite a bit of work), and they run through the dies very easily.

i am going to load up 10 rounds or so, and shoot them multiple times, and see how they hold up.

i may be seeing a neck cracking problem in the remington-peters .243 cases in that regard. i may have to anneal them.

a side benefit of the 6.5x55mm swede, is that the bases are a little bigger. i've made a bunch, run them through the rem-chester, and no problems whatsoever, ... , just a good snug bolt closure.

you know, i think i am on to something with this cartridge. it is just turning out to be a real pleasure working with it. good performance, no nasty surprises just yet. knock on wood.

john jay

[gorras new era baratas]

Jag kan se en hals sprickbildning problem i Remington-Peters .243 fall i detta avseende. jag kan få att para dem.