.303 Brit, cast boolet mold recomendation

[scottyp99]

Hi guys,
I have a 1942 Savage No. 4 Mk.1 with a 2-groove barrel. I recently did a chamber cast with Cerrosafe, and the bore measures out to be.303", the grooves are .314", and the throat is .312". I'm looking at this mold:

https://www.midwayusa.com/product/1016831667?pid=700797

I'd like some advice on choosing a boolet mold that will give me the best chance of good accuracy with velocities in the 1300-1500 fps range. I'm a real newb at bullet casting, the only experience I have is casting Lee key drive 7/8the ounce slugs. I guess you could say I know how to cast, but I don't know much about the 303. I'm looking at the preceding mold simply because of the throat diameter.

Scotty

[Bloodman14]

You are going to get a few different responses on this one. Some say to size to throat diameter, others say .001-.002 over groove size (in your case, size to .316). At that velocity, air-cooled wheel weights will do just fine. Using that mold, with that speed range, I would start with 10 grs. of Unique, or 13 grs. of Red Dot, and see how she does. She may want a heavier boolit; I use the Accurate 316-215B at .316, or NOE 316299 at the same size. Both do well for me with either powder. Work your loads up or down with both powders and the Lee 160; the rifle will let you know.

[BUFFALOW RED]

The Lee your looking at is .312 to small diameter for the Brit I think

[Outpost75]

NOE's version of #315299 is hard to beat, but Accurate 31-215B is also a good choice.

[scottyp99]

One thing I'm curious about is that the throat is actually smaller than the rifling grooves. Is that normal in a 2-groove barrel, because the boolet is squeezed into only 2 grooves? Also, I don't understand what the point would be having the boolet any larger than the throat.

Scotty

[Bloodman14]

That's one of the theories about sizing, as I mentioned above. There is evidence that supports both schools of thought. The only way to determine which works for your rifle is to experiment.
Yes, your thinking is correct, to a point. The boolit is being squeezed into 2 grooves, which, in the Enfield, are narrower than the lands. This allows a boolit to be displaced into the grooves, thereby sealing the bore.
If your throat is smaller than your bore, there may be some issues. Hopefully, someone who knows more about throat sizing will be able to help (I size to bore with no issues).

[Outpost75]

One thing I'm curious about is that the throat is actually smaller than the rifling grooves. Is that normal in a 2-groove barrel, because the boolet is squeezed into only 2 grooves? Also, I don't understand what the point would be having the boolet any larger than the throat.

Scotty

Throat should not be smaller than groove diameter of rifling. If yours measures as such I believe you have an accumulation of metal fouling or other residue in the throat and origin of rifling. I would clean very well and repeat the measurement.

My Cdn. No.#4Mk1* Long Branch was made in 1943, has a 2 groove barrel and is typical of its type. My barrel is .304" on the lands and .316 in the grooves, with chamber neck diameter .346.”

Before ordering a mold you must know the actual chamber dimensions of your rifle. The easiest way to do a “pound cast” of a .303 chamber is to take a factory .38 Special soft lead, round-nosed bullet, drop it into the chamber, and then use the Brownell’s .38/9mm Squibb Rod to pound it into the chamber neck until the .35” diameter of the squib rod comes to a hard stop against the shoulder of the chamber. Tapping the slug back out you capture the neck diameter, case mouth transition, throat diameter and origin of rifling, which is all you need to know to order your mold from Accurate or NOE.

In my No.4 the width of grooves is .115." A full ¾ of bullet circumference is displaced by the lands and either distorted into the grooves, or extruded longitudinally towards the base as the bullet travels down the bore. This can result in ill-fitting plain bullet bases emerging out the muzzle out-of-square. GC type bullets used without the gas-check, or bevel-based bullets are actually more forgiving than a flat-base and are easier to seat straight and shoot well below 1300 fps.

If bullets are sized .314 in a common sizer with Hornady gas checks the bullets are too small to seal the throat of my No.4. My NOE clone of #315299 has a slightly larger GC heel so that bullets can be gaschecked and crimped at .316, leaving the bullets unsized at .315, which works well.

I use 30 grains of 4895, 4064, RL15 or Varget with a 1" square of 1/4" thick Dacron quilt batting tucked loosely into the case neck before seating the bullet as a "full-charge" load with a GC bullet, using the "300" setting on the Mk2 battlesight, or alternately 16 grains of IMR4227, 17 grains of IMR3031 or 20 grains of RL7 without the GC with the L-peep flipped to the "500" aperture for 100 yards.

Attachment 273660Attachment 273661Attachment 273662Attachment 273663Attachment 273664Attachment 273665Attachment 273666

[DonHowe]

My copy of the Lee 312-185 after Lee-menting casts .315.

[longbow]

I use the NOE 316299 and my .303's seem pretty happy with it. All mine are 5 groove though and the two groove barrel apparently aren't the easiest to get shooting cast boolits.

Here's an article by David Southall that may help:

http://www.303british.com/id37.html

Lots of other good info on that site too.

I have found that my .303's, all of which have "fat" barrels with groove diameters of 0.314" +/-, boolits of 0.316" checked and sized to 0.315" work well. If you can size to 0.316" like outpost75 that's probably even better. I have loaded some PB boolits of 0.318" and they chamber and shoot fine so I am of the opinion that big is good.

Something else I'll mention is that I started out with moderate loads and boolits cast from ACWW which worked fine but when I tried somewhat higher cast boolit velocities accuracy went South quick. Recovered boolits showed skidding in the rifling so I tried oven heat treating which solved it. I hadn't had any problem in the past with my .308 and ACWW but it has 1:12" twist where the Lee Enfields are 1:10" twist. Might not be a problem but something to keep in mind.

Strangely I never used to like Lee Enfields until I bought a No. 5 for my son... then I had to have one... now I have two No. 5's and two No. 4's.

Longbow

[Bad Ass Wallace]

I have been using the 190gn 0.314 from CBE for many years.

[scottyp99]

The chamber cast came out with nice, sharp rifling, so I'm fairly confident about the bore and groove diameter, but I'll give it a good scrubbing and do another chamber cast. I've been shooting plated in it, maybe some copper has built up in the throat. I'll start looking at the 314299, too.

Scotty

[MOC031]

The chamber cast came out with nice, sharp rifling, so I'm fairly confident about the bore and groove diameter, but I'll give it a good scrubbing and do another chamber cast.

You are well on the right track being concerned about getting the measurements right.

I am one that is not so concerned about groove diameters - perhaps because my 1950 Long Branch Lee Enfield has a five groove barrel and I don't have the tools and knowledge to measure it. I do know from using pin gauges that my bore is about .3045", and I do know my throat/ball seat measurement just at the beginning of the lands. I used that to pick two different designs in an Accurate mould, made to fit the measurements I had. I concentrated mostly on fitting the throat/ball seat because of the designs I was looking at.





They shoot very well in my Long Branch, but my Long Branch was the pick of the litter to begin with, and is extremely accurate with ball ammo and faux Mark VII ball using Sierra and Hornady 174 grainers. I did specify some dimensional changes - which were right on the money, as ordered.

I'd suggest you consider Accurate once you are satisfied with your measurements. They are not only excellent quality moulds, but you can fine tune the measurements within reason for your rifle. I'd also suggest you think about two different designs that look like they could be winners - you get to test two different designs in one set of blocks. One of the two I chose above was it looked like it would be a pretty respectable hunting bullet if I decided to do that. I ended up with two winners. If it would have been only one, I would have considered selling the mould and rebuying the design that worked in a multi cavity mould.

One other thing you should figure out ahead of time is whether or not you're going to go with powder coating your bullets versus conventional lubes. For a bore riding design, powder coating could make a big difference in fit.

[John Boy]

In my Steyr Martini 1883 Mark III, 303 British ... the bullets used are:
* Ideal 311299, 200gr GC
* Saeco 305, 180gr

[scottyp99]

I have been tumble lubing boolits with Lee Liquid Alox and Johnson's Paste Wax, and I really don't have any experience with any thing else, it works really well, and I will probably just do the same thing with the 303 boolits.

Scotty

[Jniedbalski]

Nice write up outpost 75. I have a I think a 52 or 53 4 MK2 rifle. It came black and grimy but cleaned up looks like new. I got it in the late 80’s for 79$ I also have a early 50’s polish molsen and a early 50’s Swiss rifle. A lot of people at that time where collecting the ww1 and ww2 year built guns. I learned the early to middle 50’s made rifles where cheeper And always better made and in better shape. They may not be worth as much but I would rather have the early 50’s made gun. Does any body know about the 4 Mk2 ? Will try tonight to look up the info on the rifle and year

[Jniedbalski]

I cleaned off all the grime off my stock and used Lemmon oil and maybe some orange oil on the stock. I hand rubbed it and now it’s slick as glass . It has a nice slick Matt finish

[Outpost75]

I used Fairtrimmer's military stock oil from Brownell's on my Long Branch

Attachment 273805Attachment 273807

[MOC031]

I used Fairtrimmer's military stock oil from Brownell's on my Long Branch

Attachment 273805Attachment 273807

I think I've seen that rifle somewhere before...

I was curious about the Fairtrimmer's stock oil, wondering how it differed from the ol' boiled linseed oil. A brief DuckDuckGo search indicated that it might not be available anymore. I didn't look too hard however. Many rifles like mine don't really need much in the way of stock maintenance - most of the time they're nice and snug in the gun safe; and they only come out for nice days on the range. A little different than being out in the elements 24/7 during a war, or even days of hunting in varying conditions.

Noticing the sight you have mounted on your Long Branch, you probably are aware, but for those who aren't, a period correct alternate sight for the Long Branch and other No. 4 Mk 1 rifles is the earlier Mk 1"Singer" variant of the ladder sight. The sight shown in your pictures superseded the Singer sight for expediency and simplicity of manufacturing during war. Both can be found on Fleabay and elsewhere, although prices are starting to really go up...

The advantage of the Singer is that it is thumbscrew click-adjustable for elevation, with 50 yard graduations on the ladder, 25 yards per click, i.e. four clicks from the 200 yard zero will take you to 300 yards, etc and so forth. To swap them out, you simple remove the stake securing the sight axis pin, lift out the current sight - making sure the tensioning catch pin and spring don't launch themselves into the surrounding environment by simply cupping your hand over the sight as you lift it - then put everything back with the different sight in place.

Soooooo... whatever handload either cast or jacketed makes your Lee Enfield sing at whatever distance, there's probably a click that will get you pretty darned close.

Crappy picture follows that I just grabbed with my old steam powered cellphone. And BTW, let me take a moment to thank you for all the knowledge and help you've shared over many, many years in many venues. For myself and many others, it has really made a difference.





The elevation table below is for half minute adjustable competition sights from A.J. Parker and Parker-Hale, but may be useful as it gives the differences in minutes between ranges with .303 British Mk VII ball ammunition. The Mk 1 Singer, click adjustable sight, obviously, is not in half minute of angle clicks.

The No 4 rifles may be fitted with one of the four following back sight assemblies, see Figure 2-9:
a. Mk 1 (1). The Mk I back sight is a folding leaf type sight with a screw type adjustment for ranges from 182.88 metres to 1188.72 metres (200 yards to 1300 yards) with click stops at 22.86 metres (25 yard) increments. The scale is marked in increments of 91.44 metres (100 yards);

b. Mk 2 (2). The Mk 2 back sight is a dual range flipsight with apertures set for 274.32 metres and 548.64 metres (300 yards and 600 yards);

c. Mk 3 (3). The Mk 3 back sight is a leaf type sight with a click type sliding range adjustment. The range setting is adjustable from 182.88 metres to 1188.72 metres (200 yards to 1300 yards) in increments of 91.44 metres (100 yards).

d. C Mk 4 (4). The C Mk 4 or Canadian Mk 4 back sight is also a folding leaf type sight. It is similar in nature to the Mk 3 sight, however, the slide catch has been redesigned to reduce the susceptibility of the catch to damage. It is adjustable from 182.88 metres to 1 188.72 metres (200 yards to 1 300 yards) in increments of 91.44 metres (100 yards).

Don't mind the S&K mount and scope in the background - it only goes on the Long Branch when doing load development because something new came along.

[Eddie1971]

My old 1916 SMLE loves the NOE 316-299 powder coated, gas checked, sized .316 over 36 grains of IMR 4350.

[scottyp99]

OK, I have given the chamber a good scrubbing, and observed it using a bore scope. The rifling grooves go right up to the end of the chamber! The grooves just get a little shallower as they aproach the chamber. So, my throat is definitely less than .314". I'll be doing another chamber cast this weekend, (Man, that Cerrocast is really neat stuff! It melts by blowing a heat gun on it for a few minutes.) Until then, let's just say the throat IS .312". How will a .312" throat and a .314" groove diameter affect my boolit choice? Would it be a good idea to use a .312" diameter boolit, hoping it obdurates into the .314" groove when the boolit squeezes down into the .303" bore? I would think that the wide lands squeezing the boolit by .009" would be more than enough to fill the two .314" grooves. That's only .002" more than the original boolit diameter, and the lands are much wider than the grooves.

Scotty