303 Brit Cast Boolit trials

[303Guy]

Some of you will have read my previous posts on my trial boolits. Well, yesterday I test fired a few more into my 'test tube'. These are 245gr tapered boolits without lube grooves. The problem I am finding is that the bullet is too big to hold lube in the throat. The previous 220gr bullets sit further back, being shorter, and hold enough lube. Another thing I was doing is filling the case with cotton balls. This because of the 60% load density of the Varget/AR2205 powder. Trouble is, the cotton balls wipe out the lube from the barrel! I got leading!!!

I seated the bullets into a paper 'cup'. That means no neck sizing other than expanding sufficiently to accept the boolit inside the cup. The boolit and neck were then dipped into molten 'waxy-lube' and alowed to drip, leaving a coating of the stuff on the bullet shank and nose.

Here's a perfect mushroom. This one was fired from a two-groove barrel. No leading. The two groove has a larger throat and accepts the coated bullet with a thick layer of lube in full contact with the leade.


Here' a plain base. It over- mushroomed somewhat. Note how the groove lands gave way, widening the groove. There doesn't seem to be any base deformation nor flame cutting but there was some leading of the bore.


Here's one that made it into the sand pot below - it lost some of it's 'mushroom'. There was leading on the first shot! Five groove barrel. There is a tiny amount of flame cutting at the start corner of the groove land.


This one is/was a 220gr. It lost all its 'mushroom'. Well, the outer rim anyway!


The primer for pressure indication.

[waksupi]

Alloy and velocity?

[303Guy]

Alloy and velocity?

WW, sinkers, range pick up - who knows? Not hard, that's for sure. I would have no idea of velocity. I would guess at around 16-1700 fps. The 220 grainer should be around 1900fps.

[Bret4207]

Have you considered knurling the surface for the lube to adhere to? I know it's an extra step, but .....

[303Guy]

Have you considered knurling the surface ...

It has been suggested and I did try that. It doesn't make any noticable difference in just test firing but could well make a big difference in the field! The bullets I were testing were too tight a fit in the throat and most of the lube was being pushed off the front area. Thought the knurling might help there but could not tell. I suspect the cotton balls were wiping residual lube out the bore (well, the recovered cotton balls did have lube on them), and this resulted in some leading. How much leading is considered acceptable? With the length of my bullets and the pressure they are being driven with, and the softness of the alloy, there must be a helluva pressure between bullet and bore! These bullets are supposed to lube by the dynamic film principle as opposed to boundry lubrication.

[Bigjohn]

Knurling; lay a boolit on a flat surface, take a rough cut file, lay it across the boolit and with a bit of downward pressure, roll it for a short distance.

This method should apply a small amount of knurling to the boolit and is adjustable for desireed affect.

John

[longbow]

I make a very similar style of smooth boolit though not tapered. They are modeled after the 314299 in proportion but no lube grooves.

I make a simple push out mould with bore riding nose section of 0.307" and body of 0.315" for one and I decided I want to try knurling which increases diameter by about 0.003" so made another mould which turned out 0.305" nose and 0.312" body knurled to 0.315".

Barrel slugs at 0.303" x 0.314".

Both shoot quite well over moderate loads of 4227 or 4198. I haven't pushed the envelope but testing is still on going. One is 200 gr., the other is 215 gr. and I have loaded them over up to 24 grs. of 4198 and generally with COW filler. Little to no leading and accuracy the same as a gas checked 314299 which I have also loaded unchecked over filler with good results as well.

I generally dip lube and leave a thin film on the bore riding nose section and for the knurled boolits I dip the knurling.

I have had best results with oven heat treating though. I found the lands were swaging over width grooves in the softer boolits so hardened them to solve that problem. COW filler seems to eliminate any gas cutting issues with plain base boolits.

Longbow

[The Double D]

How about increasing the amount of lube with a grease cookie.

Or instead of cotton try kapok or dacron.

[303Guy]

longbow, I am going to re-read your post! The lube I use is what I call 'waxy-lube' because it is made up of candle wax, alox (or any bullet lube lying around) and STP type engine oil additive. It requires melting and seems to work fine. The residue does stop corrosion on the inside of the suppressor/muzzle break! I also use it on jacketed bullets and as a bonding agent for my hornet with paper cup seated bullets. (The hornet is another story - 55gr jacketed bullets at around 2700fps with Lil'Gun! Indefinate case life due to case mouth head-spacing and no sizing.)

How about increasing the amount of lube with a grease cookie.

Or instead of cotton try kapok or dacron.

Aah.. Hah! We're on the same page!
I don't actually don't know how to make a 'grease cookie'. (I didn't know what to call it iether so I refered to it as a waxy-lube wad - not the same thing, actually).
I was thinking of grease sandwiched between two cardboard wads or even between bullet and cardboard wad but haven't figured out how to make them a consistant thickness. With the grease cookie idea, gas pressure should force lube onto the bore even with a filler. Why would kapok or dacron work better? (I have access to possum fur which is a hollow fibre - I am told wool wads work good so why not possum fur?)

Someone over on AR suggested knurling between two bastard files - works great! Notice that this particular 303 has a longer neck. Perfect for cast bullets! (Well, better than usual, anyway).

I have had best results with oven heat treating though. I found the lands were swaging over width grooves in the softer boolits so hardened them to solve that problem.

I was wondering about that. I thought the cotton filler had protected the bullet from flame cutting. Notice how the bullet stayed nose forward throughout it's passage in the medium. (Or should that be tail behind?)

You can see the 'over width grooves' quite clearly. Would that actually affect accuracy?
May I ask how to do the oven heat treating? (It has been explained to me before but I have forgotten the details).

P.S. I wouldn't want to be at the receiving end of that bullet!

[swheeler]

303; I see you've got this over on Accurate too. Have you tried going to a slower powder, maybe try being kinder-gentler on the bullet? Add some magnum SG shot to your alloy or heat treat the bullets. Have you ever considered your home brewed lube just isn't up to the task at hand? maybe try a commercial lube, the grease cookie is another good idea. Start with one recommendation and try it, if it doesn't work move on to the next, one thing at a time and you will find the answer to your questions. Now for me, first thing I'd try was keep everthing the same and try a slower powder, use extrapolation to get equal target velocities. You've got bullets, lube, cases ready so a powder switch is nothing more than loading a couyple test rounds.

If you go back and read the posts on AR forum you will see that I suggested knurling several months ago, Feb. Then you wanted to use a boatailed cast bullet to carry lube, I told you I thought that the boatail would obturate deforming the base, so if you carried enough lube the load still would be unusable because of inaccuracy, did you ever try?

You've got to weed out what will not work, one thing at a time, if you don't try you'll never know if it is viable. Scot

[303Guy]

... you wanted to use a boatailed cast bullet to carry lube, I told you I thought that the boatail would obturate deforming the base ...

From that thread I decided not to persue the idea. I did do a test by firing a bullet that didn't hold it's gas check. As you said it would, the base obturated!



At that time I wasn't having leading issues. I did forget the knurling suggestion but when it came up again I decided to try it and it seems like a good idea. For ease, I knurled the bullets after seating!

Because of cartridge length and seating depth issues, I plan on staying with 220gr bullets. That would allow a small space in the neck for a wad or grease cookie and still fit the throat with a lube layer. My first field trial with the 220gr bullets yeided rather encouraging results with zero leading.

I love this picture! It's only at 50yds and is only three shots but still .... ! And I was shaking when shooting, so ...

Have you tried going to a slower powder, maybe try being kinder-gentler on the bullet?

Well, the powder I am using is Varget/AR2208 which is my 'normal' rifle powder. I am thinking what slower powder I could use for both 'normal' and cast bullet loads, mainly to fill the case more and achieve target velocity at lower pressure and with a slower pressure rise time. The powder most readily available to me is H4350/AR2209. This would be usable in my 303-25 too. It's just that from all accounts, Varget?AR2208 seems to be the most widely useable and accurate powder. There are one or two other slower powders I could try but the loading manuals don't list them in all my calibers making me wonder... ? Varget/R2208 is shown as the powder producing the highest velocity and lowest pressure, so ...??? I am due to restock on powder!

Have you ever considered your home brewed lube just isn't up to the task at hand?

Yes I have. I developed it to hold hornet bullets in a paper cup seat. Now I am using it because it is hard enough to stay in place during chambering and It seals the neck if I don't actually size which I am trying out too. Sizing is an issue because my bullets are somewhat larger than my neck sizer was design for. I have an expander to fit them correctly. The last trials i did was with a paper cup seat, the same as I use with my hornet.

The molten waxy-lube soaks up into the paper, 'gluing' the bullet in place.

[swheeler]

Well, the powder I am using is Varget/AR2208 which is my 'normal' rifle powder. I am thinking what slower powder I could use for both 'normal' and cast bullet loads, mainly to fill the case more and achieve target velocity at lower pressure and with a slower pressure rise time. The powder most readily available to me is H4350/AR2209. This would be usable in my 303-25 too. It's just that from all accounts, Varget?AR2208 seems to be the most widely useable and accurate powder. There are one or two other slower powders I could try but the loading manuals don't list them in all my calibers making me wonder... ? Varget/R2208 is shown as the powder producing the highest velocity and lowest pressure, so ...??? I am due to restock on powder!


303; this is from Hodgdons powder manual #25

303 british
215 gr jacketed
h 4831 42.0=1800 to 45.0=2001 fps

I believe you should have this powder as mulwex 2213 and probably in a standard and a short cut version, we do. its manufactured by them and marketed by Hodgdon. Looks like it meets your velocity criteria just like it was made for the old 303 shootin a heavy cast bullet. Now this is just my opinion, but I would think this powder may actually give you higher velocity with lower pressure in your 25-303 and heavy jacketed bullets, even if it didn't it doesn't take long to burn up a pound of powder, or give it to a mate for his 25-06.

[swheeler]

same manual, 303 with 215 gr j
H435040.0=182043.0=2090 fps mulwex 2209

[runfiverun]

i wouldn't lower the 4350 any though ,it gets erratic.

[303Guy]

i wouldn't lower the 4350 any though ,it gets erratic.

This has been my concern. But still, if one of the powders suggested by swheeler works with a full case and heavy bullets then I can live with two powders (well, make that four - I already have three). I know that AR2209 will most likely work in both 303 and 303-25 but was not sure how it would behave at lower pressures.

I believe you should have this powder as mulwex 2213 and probably in a standard and a short cut version ...

Yes we do. Thanks for the info. Much appreciated! I see that both Hodgdon and ADI do not show too many loads for the 303-25 using H4831/AR2213. Some for the Roberts though.

[303Guy]

I made a new mould. This one casts them at 200gr with a hollow point but it is a little fat for my NoI MkI's throat. It does not leave any room for surface lube but seems to work. Just a bit dodgy as far as chambering reliability goes. In the No4 they fit just snugly with a layer of lube.


245gr, 200gr with sprew sharpened, 200gr with hollow point impressed and a 185gr Lee.


200gr with sprew, 200gr with cast hollow point and sprew from the hollow point funnel device.



This last pic shows about 50% narrowing of the rifling land on the bullet. Powder charge was 30gr Varget/AR2208. This time I placed a clean flat rag under the muzzle to check for unburnt powder. None found! That is a cardboard wad that made a lube sandwich. It looks out of shape from being washed in water to get the dirt off. This shows clearly that there was no flame cutting! (Maybe I am getting somewhere).


This one, which is hard to make out, lost 90% of it's land. Powder charge was 35 gr Varget/AR2208. There was no leading with either bullet fired.


This one was fired through the NoI MkI. I used a reduced charge of Lil'Gun for this one.

[Frank46]

303guy, I see that you are shaving off some of the bullet metal when seating the bullet in one of your pictures. try chamfering the inside of the case neck slightly and bell thecase mouth also slightly. Should make seating your bullet easier and will prevent shaving off some of the bullet metal. As far as bullet lubricant is concerned have you ever tried the liquid lee alox lube?. Before seating tumble lube the entire bullet in a margarine container and let dry overnight on a sheet of wax paper. Maybe that will help lessen the leading. Only change one variable at a time, so that if it doesn't work you'll know that and try something else. Frank

[303Guy]

Thanks Frank46. Which picture shows bullet shaving? There shouldn't be, all loads are with unsized necks - the bullet is too big to fit a sized neck.

Aah...! I think I know which pic. It does look like lead shaving! Actually, it's exposed bullet from removing excess lube from the neck while still warm and soft.

This the one? Those are 245gr bullets and are seated in paper cups!



My new 200gr bullets don't even fit a paper cup. They are snug in an unsized neck and seat up firmly against the 'dough-nut'. Actually there is no real 'dough-nut' - just less neck expansion at the neck shoulder junction. These ones measure .319 at the widest point! They only just fit the NoI throat! They taper down to .311. I tested them again with 30grs powder and they worked just fine with no leading or smearing. Time for range testing! (In the meantime, I have run out of lead!)

have you ever tried the liquid lee alox lube?.

No I haven't. Would I be able to dip the exposed bullet after seating?

[legend]

very interesting...GREAT PICTURES!!

[303Guy]

very interesting...GREAT PICTURES!!

Thank you! (I'm having fun!)