Boolit vs. neck size......arrggghh!

[3006guns]

I have several rifles that share the same groove diameters, literally. My Enfield No.4, No. 1 MKIII*, 1909 Argentine carbine and an 1889 Belgian carbine all slug at .3145...almost identical. I have a couple of molds that drop 170 gr. boolits right at .315 and have been shooting them sized to .315 (ACWW) with gas checks, 10.7 gr. of TB. The sizing operation is simply to seat the checks and lube. Accuracy is ho-hum at best, even at 50yds. Although I occasionally get clover leaf groups of say, three shots, the fourth will be guaranteed to be a flyer.

Careful measuring of the fired case mouths (small hole gauge and mic) shows an i.d. of .315, so I'm right at the ragged edge in my opinion. Allowing for brass spring back of the neck, I just don't think there's room for a larger boolit.

So, would heat treating or water dropping of the boolit help? That is, trying to get the hardness up in hopes of gripping the rifling a little better....or am I just wasting time?

[BABore]

Look for another brand of brass with thinner wall, ream the neck ID, or turn the neck OD. Those would be the choices.

[onondaga]

A few suggestions to consider:

Hone your boolit mold to drop your boolits at .3165"

Don't size your brass at all. Use a universal de-prime die.

Just chamfer the neck inside. Use the Frankford Arsenal Mica Lube kit with inside neck mica brushing.

Prime, Charge, Seat Boolit.

Check chamber fit by loading a round to chamber.

Shoot.

Gary

[3006guns]

Thanks guys. I should have mentioned that this is a fresh lot of Privi brass I just got two days ago. Hate to turn/ream necks if I can avoid it although that would be the "normal" route! Just trying to find out if there was something I overlooked.

I might try the "non sizing" route and just keep the brass segregated. I realize that I'm pushing the neck a bit, but the powder charge is low enough that it shouldn't cause any real problems. I'll try beagling the mold, lube and seat. If the round chambers O.K. I'll shoot it and see what the results are.

[Mk42gunner]

First of all I don't have any rifles that slug quite that large, but I do have a suggestion. Buy a mold that drops a heavier boolit. Most of my .30-31 calibers shoot better with a heavier boolit.

Robert

[3006guns]

Thanks MK42gunner.......I believe I have a Lyman that drops a 200+ gr. that might be the same size, and a good candidate for lapping too.

[303Guy]

Buy a mold that drops a heavier boolit. Most of my .30-31 calibers shoot better with a heavier boolit. My sentiments axactly. My thinking is that the boolit shout fill the throat right into the bore, preferably without being a bore rider but that would be dictated by the throat itself. Harder? Not in my opinion but I'm a paper patcher. I only once had succes with plain cast and that was when I tried the filling the throat idea and going pretty heavy - 245gr (or was it 225?) in my 303 Brit. The group was as big as the shake caused by my heartbeat! Then I decided there were no buffalo in my parts.

[Char-Gar]

Don't borrow trouble worrying about formulas and numbers. Go shoot the rifles and see what you have. You will probably find out you are expending energy concerned about a non-issue.

If there is a real issue, then neck turn the brass to reduce it's thickness a few thou.

[turbo1889]

Another option would be to open up the neck of the chamber by 0.001"-0.002" using a simple machinists' straight reamer. I did that with an SKS I had that needed a 0.316" diameter boolit but the chamber neck wouldn't allow anything larger then about 0.313"-0.314" to chamber. Everything works Ay-Okay now.

That’s a permanent modification, however, so think about it for a while before doing it. I recommend buying several of the reamers (they are fairly cheap) and open it up in one step of 0.001” at a time since a simple straight reamer doesn’t have a pilot bushing like a chamber reamer and expanding the diameter only 0.001” at a time (T-handle with extension hand turned cutting with cutting fluid) will keep you on center especially if you cut the neck off of a fired case and then drill out the primer pocket to keep the tail end of the reamer drive shaft axially true with the chamber.

[Char-Gar]

To each their own, but I sure wouldn't take a reamer to a rifle, if I could neck turn the cases. One of the axioms of gunsmithing is to work on the least costly part in case you screw up.

[walltube]

3006guns,

Relax, you're dealing with mil-surp rifles. :)

Enfields can be an adventure not unlike suddenly finding your self in a parallel universe. What works well with one No.4 Mk.I, Mk. 1 No. III, etc. is almost a certainty to not work so well in another. Then, if you are thinking to apply Enfield "solutions" to a Mauser rifle? Padded rooms and straight jackets may be in store for you . :lol:

I would suggest not altering the No.4 brass or firearm. That you cannot undo. But you may achieve some initial success experimenting with long, heavy boolits of air cooled WW seated long till the boolit nose touches the rifleing. Champher case mouths with a VLD type tool, makes for easier, less damaging boolity entry. Fat boolits and 16 grains A2400 works for me as a get aquainted load at 50 yds.

Beagling works O.K. to a point. Making boolits (too) fatter can bring you to the edge of diminishing returns. For example: a lovely Lyman 311335 Beagled to fit a certain '03A3 has created such a large dia. gas check shank that defies fitting all but .338 cal. g'checks. Impractical! Corrective surgury is in its future.

Charger and onandaga have sound advice, in my humble Op. Take it easy and enjoy the hobby.

Support our vendors,
Harold

[leadman]

I would water drop some boolits and try that. Can't hurt. I do get better accuracy with harder alloy in the margin bores of some mil-surps.

Then I would try a little more powder if you have the room, if not try like 13grs of Unique or 19grs of 2400. I haven't used TB yet, but these loads I listed seem to work in all my full size mil-surp cartridges.

[3006guns]

It's been a couple of days since I asked about this, so here's an update......

First of all, my measurement of the fired case neck was incorrect. The very mouth evidently shrank back more than the neck itself and that's where I took my measurement. Measuring inside the neck itself revealed a fired diameter of close to .318. That's a little more like it. Not sure why the case mouth acted that way....new brass? After two more firings they seem to be nice and cylindrical now.

Neither of my Lyman 200+gr. molds would "beagle up" enough to produce a satisfactory boolit, but a three cavity Hensely and Gibbs produced a .317 170grn. projectile when I tried it. I loaded some of them unsized in 7.65 Mauser and fired them in the 1889 Belgian at 50yds. The results were not spectacular but encouraging, so my next task was to open up a spare .311 die to .3165 then shoved about twenty of them through, complete with gas check. Since I'm using powder charges that produce less than 1600fps, the check isn't really necessary but I wanted to keep the bases square. I also pulled a couple of the seated boolits before shooting and their dimensions had not changed...still .3165.

Yesterday's shooting was done at 100yds. and except for a couple of flyers, produced a group of about 4"......which may be the best the poor gun can do. The ten rounds loaded with 10.7gr. of Trail Boss gave the best group, while the ten loaded with 10gr. of Unique shot higher and were spread out more.

Last night I shifted gears and loaded another group, this time in 7.7mm Jap for my type 99, and will try it today barring thunderstorms in my area. This time I'll be using just Unique and see what I can do, for the simple reason that I have a lot of it. I didn't mention this rifle in my original post, but it slugged almost the same as the others. I swear I must have found a group of "arsenal over runs" that were out of spec or something, but hey.......just like oversize girls, oversize bores need love too!

At any rate I'm having a ball experimenting with the different rifles. It looks like the advice on using a 200gr boolit is wise, so I'll start saving for a custom mold in the future.

[turbo1889]

. . . First of all, my measurement of the fired case neck was incorrect. The very mouth evidently shrank back more than the neck itself and that's where I took my measurement. Measuring inside the neck itself revealed a fired diameter of close to .318. That's a little more like it. Not sure why the case mouth acted that way....new brass? After two more firings they seem to be nice and cylindrical now. . .

Trim length ??? Were the cases too long on the initial firing and the mouth of the cases was protruding into the beginning of the throat and thus being constricted upon firing ???

That was my first thought upon reading what you wrote there.

[3006guns]

No, the oal of the cases was below the maximum by a fair amount, in fact it was the first thing I checked as I trimmed all cases to the shortest of the lot. The "crimp"..for lack of a better word..was so small that it could only be measured with inside small hole guages, and that's where I made my initial mistake i.e. measuring only the mouth. Once they were fired a couple more times it disappeared. I can only guess that there was some tension in the brass from the original drawing operation and subsequent firings ironed it out...then I got a true reading. Strange, I know but all seems normal now!

[Mk42gunner]

It's been a couple of days since I asked about this, so here's an update......

First of all, my measurement of the fired case neck was incorrect. The very mouth evidently shrank back more than the neck itself and that's where I took my measurement. Measuring inside the neck itself revealed a fired diameter of close to .318. That's a little more like it. Not sure why the case mouth acted that way....new brass? After two more firings they seem to be nice and cylindrical now.

Neither of my Lyman 200+gr. molds would "beagle up" enough to produce a satisfactory boolit, but a three cavity Hensely and Gibbs produced a .317 170grn. projectile when I tried it. I loaded some of them unsized in 7.65 Mauser and fired them in the 1889 Belgian at 50yds. The results were not spectacular but encouraging, so my next task was to open up a spare .311 die to .3165 then shoved about twenty of them through, complete with gas check. Since I'm using powder charges that produce less than 1600fps, the check isn't really necessary but I wanted to keep the bases square. I also pulled a couple of the seated boolits before shooting and their dimensions had not changed...still .3165.

Yesterday's shooting was done at 100yds. and except for a couple of flyers, produced a group of about 4"......which may be the best the poor gun can do. The ten rounds loaded with 10.7gr. of Trail Boss gave the best group, while the ten loaded with 10gr. of Unique shot higher and were spread out more.

Last night I shifted gears and loaded another group, this time in 7.7mm Jap for my type 99, and will try it today barring thunderstorms in my area. This time I'll be using just Unique and see what I can do, for the simple reason that I have a lot of it. I didn't mention this rifle in my original post, but it slugged almost the same as the others. I swear I must have found a group of "arsenal over runs" that were out of spec or something, but hey.......just like oversize girls, oversize bores need love too!

At any rate I'm having a ball experimenting with the different rifles. It looks like the advice on using a 200gr boolit is wise, so I'll start saving for a custom mold in the future.

Might be easier (or cheaper) to find an 8mm mold, and run it through a .323" or so die to lube then run it through you .3165" die.

Sure it would be more work, but that is half the fun.

Robert

[3006guns]

You've just provided the answer I've been looking for! This is one of those "doh" moments.....

I have a 200gr. Lyman 8mm single cavity that I bored out to a plain base. The original Lyman machining on the nose was horrible, so I didn't lose anything by changing it at all, and it's proven to be a very accurate boolit in my Yugo. I'll try it tonight.

This is the reason that I value this forum so much. Sometimes when your brain is stuck in low gear another shooter gets you moving in a better direction.

Edit: Ah, well.......good try anyway. By the time I got it down to .3165 (two stages) the lube grooves moved from the boolit up to the top of the sizing die. I'll try the 170gr. H&G's instead......as soon as it stops raining.

[Mk42gunner]

Well it was worth a try. I have always heard that as long as the lube grooves were filled you could size a boolit down quite a bit, but if the grooves aren't filled, they just smooth out.

Robert

[mroliver77]

If it were me I would pick one gun with a nice barrel and work on making it shoot well. A hammered lead impression of the neck/throat area is a must (for me) with a troubled gun. I cut the neck short when doing this and get an exact measurement of the neck i.d. of the chamber plus the oal and the throat dimensions. Armed with these measurements I can pick(or modify) a suitable boolit or go looking for one. Once your set up then it is time to play with powders. This sounds like a lot of hassle but really is pretty quick and easy.
I also would consider going to a more powerful charge. Keep us updated.
Jay

[Gswain]

One thing I would check at very least, is are you pushing the bullet fast enough to stabilize it with the small charge you are using? I would at least look at maybe using a slower burning powder for some higher velocity, especially if you are having trouble with your groupings like that. Not enough twist can equal flyers.