303 HPBT 174 Gr.

I know everyone agrees the flat base .303 are the most accurate but guys I am wondering why I am having such great results with 174GR. Sierra Match King HPBT projectiles.

I know how accurate many lots of surplus flat base will shoot as I shot countless rounds many years ago. I being a Lee Enfield fanatic made the decision to reload a couple of years ago and to be honest overall the Sierra Match Kings are to me amazingly accurate.

I was out with my son a couple of weeks ago and thought my Savage No4 was off a little and needed a scope adjustment. This gun is in the pictures I have posted in a different thread, it has a old 6X Leupold scope in a S&K no drill mount.

It has always been a pretty accurate gun and you have to understand I am OLD and can't shoot good groups as consistently as when I was 17 however it shot a 1" group at 300 yards. I was using a reactive target we had just repainted and had a hit, called low left by my son, took another and again a low left call. Said to him I was going to adjust the scope and he said, no try one more as I think you are getting a decent group. Well took the third and we drove to where we had hung the target and 1" and it was hard to believe. I am glad I had a tape measure in my vehicle and my son was with me as otherwise no one would believe me.

I shot a 1 1/2" group a few months ago and thought that was never going to be repeated but this one is the best I could even dream of shooting. The gun is one I bought from bearhunter a couple years ago and to be honest has always been a very accurate gun, the thing is I have always reloaded with Match King HPBT 174Gr .311DA.

I am using 40 or 41 Gr of Reloader 15 and weigh each load to a max tolerance of 1/10 of a grain. From what I have always read BT's just don't perform as well a FB projeciles. I am not saying I am a fantastic shot, as before I am now OLD so why should I get excited about reloading with FB projectiles?

I am sure hoping for comments of why I am having such great accuracy with the Match Kings, and believe me on any given day those loads are accurate to the point of being hard to believe.

Every person who has shot the gun with those reloads is amazed at how accurate it is. I can't understand why it is so accurate with what most say are not the right projectiles for that rifle.

Await comments.

The 174 MK normally shoots very well in barrels with reasonably tight interior dimensions and relatively little throat erosion. The flat-base bullets often help solve accuracy problems in worn throats or oversize bores simply because they are less liable to yaw when poorly supported.

https://www.milsurps.com/images/impo.../2unulu9-1.jpg

I tried to respond to this yesterday, but we were going through a heat wave, the computer crashed just when I hit send, let's see if I can do better today.
I've been pumping these pills for several years now, had a fair bit of success in prize meetings to.
The advantages of these projectiles is the long bearing surface, the soft jacket that allows adaquate bump for sealing and their consistant weight/diameter, all plus's when it comes to getting the best out of a barrel.

I have pushed them out of all my L.E's with good results, finding the solution to any slight innacuracy was either bedding or the need to push the pill slightly harder if the barrel was near totalled.

The only times I have had a yaw problem in any rifle was always due to low velocity or incorrect twist and only ever in sporting rifles.

I have only good things to say about this projectile, it overcomes all the problems that were supposedly there about boattail v flatbase.
Attachment 38648 300yds.Attachment 38650Attachment 38651 this is target rifle qualityAttachment 38654

I've had some really good results with the Sierra bullet in my No4T (see pic).
Using neck sized HXP brass containing 43 grains of R15 it gives me pretty much service velocity.

I also got very good results from the Hornaday flat based bullet but thats a soft point and over here in the UK you have to have special permission on your Firearms certificate to have those now.

Woops, massive stuffup, it's a wonder no one picked it, the target shown as a 300yd is actually 500yd and a sight in at that.
Here's the correction........Attachment 38675

.......and here's the right one.Attachment 38676 this possible at 300yds, 2 sighters and 10 to count.
This is the rifle, 1918 Enfield Sht. LE in target rifle configuration.
Attachment 38677 and groups at 100yds.Attachment 38678Attachment 38679

Same conclusion here - from a rather limited use of that bullet at 100 yards (Lee Enfield No.4 Mk II rifle with a like new barrel).

Remarkably precise bullet but I would not bet my bottom dollar that it would replicate the trajectory of the Mk VII bullet all the way up to 800 yards - using the Mk I backsight of my rifle. I want to be able to use my backsight as far as possible.

Hence, the search for a true "new manufacture" Mk VII bullet (see other thread) but I am not going to hold my breath meanwhile. The experimentation with the Sierra Match King 303 HPBT 174 gr. bullet will be carried on come next spring.

No one will replicate the trajectory of the original round, you are living in a dream world there.
Unless some manufacturer decides to stoke them with cordite.:beerchug:

My dear muffett.2008,

Come hell or high water, I will still try to replicate the trajectory of the original Mk VII round as long as I live - and with "non-cordite" powders. ;)

That's the kind of challenge that I cannot decline - and shooting is always fun, anyway ! Who knows ? Maybe I will be successful ?

Snowy Owl

Quote:

---

Originally Posted by muffett.2008

This is the rifle, 1918 Enfield Sht. LE in target rifle configuration.

---

Whats the sights ?

PH5A rearsight,modded to 1/4 adjustments, Kiwi modded nosecap with PH tunnel inserts, Motty barrel, bedded with armagrout and rubber nose mod.
Attachment 38698Attachment 38699Attachment 38700

Thanks Muffer, It certanly does the business, any more info on the Motty barrel ?

Just a heavy Motty barrel fitted, dated 1950, I picked this and one other Range Rifle up together from an old target shooter, the barrel looks pristine and was coppering up, so I told myself 'new barrel' and ran it in as per target rifle.
I love it, when I've got time, it gets a run along side my target rifle. I'ts happy at any range, although the new centre sizes are making it hard to get possibles.

Quote:

---

Originally Posted by muffett.2008

No one will replicate the trajectory of the original round, you are living in a dream world there.
Unless some manufacturer decides to stoke them with cordite.:beerchug:

---

Not all Mk.VII was cordite loaded, hence the Z suffix on those that were not.

You're right Beerhunter, but that's really where the similarities begin to seperate.
The cordite load for the standard Mk.VII was 36.5 sticks of cordite, +/- 1.5 sticks.
The loads for the 7Z and 8Z range from 40-41 grains of N.C or 36 grains of Neonite.
Lets put that into context, cordite at a known velocity of aprox. 2450-2550 fps, or 40-41 grains of N.C powder, the same load I am using today with modern powders at 2700 fps.
We will not get into the Neonite, other than to say it is a very fast and dangerous powder.

Now to the projectiles, The flat base we are all aware of, the boattail was introduced from
8Z on, it was so extreme, it even looks like a boat, compared to the very small boattail on modern projectiles, allowing for a long bearing surface, as opposed to the very small one of the military BT.

That brings us to the match cartridges of the day that were so sought after by Marksmen and Snipers alike, it's projectile also having a long bearing surface and small BT.
It's load was the standard load but tolerances were more controlled, an example of it's accuracy of load is a test fire of five rounds of Kynoch 303S.L.
1. 2496fps lo. 2496
2. 2512 " hi. 2512
3. 2507 av. 2502
4. 2499 ES 16.59
5. 2496 SD 07.14
Attachment 38714
These are magic figures for something made back in the 30's, that's the sort of consistancy we are chasing at a slightly higher velocity, the less air time the less wind variation.

Quote:

---

Originally Posted by muffett.2008

No one will replicate the trajectory of the original round, you are living in a dream world there.
Unless some manufacturer decides to stoke them with cordite.:beerchug:

---

IMR 3031 is (I'm told) usually used as a cordite replacement due to it's similar pressure and burn characteristics.

Quote:

---

Originally Posted by waco16

I've had some really good results with the Sierra bullet in my No4T (see pic).
Using neck sized HXP brass containing 43 grains of R15 it gives me pretty much service velocity.

I also got very good results from the Hornaday flat based bullet but thats a soft point and over here in the UK you have to have special permission on your Firearms certificate to have those now.

---

One question, using 43 grains of RX15 are you showing any signs of over-pressure? I ask as your load is a full 3 grains over the max in the Hornady book and 1 grain using the Lyman book.

I know the difference in Hornady is the fact they test with their own bullets so know exactly from what materials they use what they believe should be the Max. load. I also know most reloading manuals error on the side of caution as we live in a sue somebody to retire atmoshphere.

The aim when I started was to try and match service velocity (the Sierra bullet being the same weight as the MkVII).

I began with the starting load in the Sierra manual and went up in half grain increments using a Chronograph to check velocity.
All they way up to this load there were no over pressure signs.

Normal caveats apply - safe in my firearm etc etc........

Like I said before, you cannot duplicate the original cordite load...........in safety.

muffett.2008,

Well, maybe you are right and then, maybe not.

The mere fact that the odds are against me makes me think that it's worth trying. A good challenge here - for some years to come. ;)

Snowy Owl

I admit I am a Hornady fan and just had my son point out they are now making .303 British Vintage Match ammo in 174 grain BTHP. Ballistics are muzzle 2430 FPS, 0 at 200 yards give you +2.6 inches at 100 yards, -10.5 inches at 300 yards, -30.1 inches at 400 and -60.4 inches at 500 yards. At 500 yards it is still 1669 FPS.

muffet.2008 how does this compare to original cordite MKVII?

The problem is not bullet weight; any bullet maker worthy of the name can deliver that.

The burning issue is the FORM of the bullet and its relationship with the real world of Lee-Enfield rifling dimensions.

The original Mk7 bullet has an open base; the slinky hollow-point boat-tails do not.

That open base will "bump-up" a little as it gets booted up the backside by 40K plus psi. - solid-based boat-tails; not so much.

So, if your slinky HPBT does not even attempt to bulge a little to obturate the rather generous grooves of a Lee Enfield barrel, you will get high-pressure gas bleed around the bullet. This will cheerfully burn the throat and the beginnings of the rifling.

Another problem with "slinky" bullets is that they are long for their weight. To feed reliably, A Lee Enfield requires a bullet that is a fairly close fit to the internal length of the magazine. If your "magic" bullet is significantly longer that a Mk7, then you have to seat it down into the cartridge case. This, of course, reduces the space for propellant. A racy "VLD" boat-tail will add a bit to the stern as well.

Regarding fuel for these beasties, what was the powder used in Mk7Z? For that matter, what did FN use in their very nice post WW2 Mk7 ball ammo?

And all of the foregoing assumes a barrel in very good condition, especially at the throat The throat is somewhat important, as it it how the bullet is introduced into the rifling.

I occasionally drag my Swiss K-11 out to the range for fun. It shoots well with "proper" GP-11 ammo, but that stuff is like hen's teeth around here. So, I fiddled around with various recipes and endes up using a Hornady A-Max. Before settling on these A-Max loads, I ran up a batch of Sierra Match-Kings with good results. A fellow enthusiast asked if he could try some of these Sierra-bulletted loads in his K-31. Instant drama: The bolt would not close and the round would not extract. Dodgy load? Nope! The K-31 is throated EXCLUSIVELY for the GP-11 bullet, whereas my old K-11 is throated rather generously for the older round-nosed bullet; somewhat akin to the .303 Mk6.

Eventually we cleared the K-31 and did some more homework. The GP-11 bullet has a SECANT ogive whereas the Sierras hava a TANGENT ogive. The K-31 has a very short throat to make the most of the shape of the GP-11 bullet. The Swiss rifles also have VERY tight bore and groove specs, my K-11 groove diameter mikes out at .3075".

Quote:

---

Originally Posted by Bruce_in_Oz

Regarding fuel for these beasties, what was the powder used in Mk7Z? For that matter, what did FN use in their very nice post WW2 Mk7 ball ammo?

---

According to Temple, the charge for the Mk.7z was 41grains of N.C Powder or,36.5 grains of Neonite.
FN used IMR 16, Neonite or N.C (Z)3, which is probably identical to IMR 16..........B.A Temples words, not mine.

Woodleigh makes a 174 grain .312 softpoint with a flat base. Expensive. However, their intention was to duplicate the original Kynoch ammunition as closely as possible. I have to wonder if this is as close as possible to the original service bullet as well.

is that available over here or is it a UK thing?