HV in 243...range visit #1

[JonB_in_Glencoe]

well, I finally got to the range with some HV loads for my 243win in my "off the shelf" Mod 70.

arg !!!!
first I forgot my chrony tripod and my camera.
but it didn't matter as I didn't have very good success.
I had lubed these with SL-68, which I learned I burnt the soap with improper temperature control during the end of that blending process. I also had an issue with seating the GC's...see photo.
http://i640.photobucket.com/albums/uu127/JonB_in_Glencoe/243boolits_zps587f6953.jpg (http://s640.photobucket.com/user/JonB_in_Glencoe/media/243boolits_zps587f6953.jpg.html)

So anyway, I have a few things to improve with the next batch of ammo. I plan on making another batch of Lube (and NOT burn the soap), and also to seat the checks in a different manner to eliminate the imperfections in the bases...which means another batch of heat treating and more waiting.
btw, these boolits ended up at 27BHN,,,maybe to hard ? I'm not sure if I'll change that factor next time or not ?

So anyway, here is the synopsis of results:

Batch one,
IMR4064 36.7gr
per book, they should be going 3200fps (50Kpsi)
I got 5"groups (10 shots) at 100 yds

Batch two,
IMR4064 38.2gr
per book they should be going about 3300fps (53Kpsi)
I got about 12" groups (10 shots) at 100 yards
one group was like I was circleing the bull like the numbers on a clock...none near the bull, all were about equa-distant from the bull.

Batch three,
was a low velosity batch for a 'check' and also for cleaning the bore if I got some fouling, which I did, all in the chamber end of the barrel and on the bottom???
WC844 (mil surp H335), 19.8gr 2000fps (20Kpsi)
2" groups (10 shots).
edited: I forgot to mention, Batch three low velosity ammo had boolits that were NOT heat treated, they were air-cooled 94-3-3 with BHN 12.5 and these were lubed with MML+S

I wish I had my chrono tripod,so I could have verified the speed and see the SD as I didn't individually weigh the charges...I used the Lee pro disk and double checking and triple checking the first few loads, I was within ± 1.0 gr. I figured that was good enough for the initial testing of the load.

[Love Life]

Did you anneal your checks? I do and it helps me get nice flat bases. I also stole Detox's method (thanks Detox) and sand the edges of my checks flush on a granite surface plate. It has helped me in the 308 using cast. I know that's a whole different monster, but maybe it could help you?

I hit my checks with MAPP gas until red hot and then kick them off into a coffer can of water with citric acid (removes the scaling and leaves nice shiny checks)

I will say that a 5" 10 shot group at 3,200 FPS is pretty promising.

What is the weight and bearing surface of your boolit? Also, I would give Retumbo a try. A nice and slow gentle push. Retumbo was the bomb with jacketed in my .243 and I see no reason why it wouldn't be safe to try in yours. I can send you the bearing surface numbers of my 107 SMK so you can compare the bearing surface to your boolits.

[JonB_in_Glencoe]

I did not anneal the checks.
The boolits are about 75gr.
The alloy was heat treated 94-3-3 (that's another thread)
I have not measured the bearing surface, I assume to do that correctly, I need to push a boolit through the bore ?

I've bought 3 lbs of IMR4064, so I will stick with that for now,but I will keep an eye out for Retumbo in the stores...as there is none in my stash and have never used it.
thanks.
Jon

[popper]

You need a proper Lee sizer to put those annealed GC on. Crooked base results, I did the same on purpose in 40sw and got the same results. Bearing surface shouldn't be a problem with that alloy & GC, about the same profile as my 308 boolit, but I don't use the tin.

[Love Life]

Measure bearing surface with a comparator or other item with hole in it that will allow you to measure from base to ogive. I'm asking about bearing surface as I'm curious where it stacks against a Jacketed boolit and see if Retumbo will work with your boolit. Also look at 7828SSC and H4831 and H4831SC.

The .243 has plenty of room for slow powders and I have found that they burn well enough to produce quite exceptional accuracy.

How are you seating your gas checks?

What is your barrel twist?

[JonB_in_Glencoe]

The Gator checks I have snap on nicely with finger pressure. Then I crimped them on with a Lyman die,mounted in the nose first sizer adaptor made by theprofesser mounted in a reloading press, the problem wasI don'thave the correct punch, I used the 223 punch, that's why the problem with the bases. Next time, I'll be using a lyman 45 press to crimp the GC on.

I 'assume' the stock barrel is 1:10

[Love Life]

If you ever get one, try a cupped punch for seating gas checks through a push though sizing die.