Subsonic 303 British

[grumpy1]

I tried to load some 303 British with a lee C312-185-1R over 8gr of red dot and I was wondering if anyone had any info that would tell me what velocity I am getting. I do not have a crono and I want to keep it a bit slow because I didn't gas check them. Any info on changing charge or trying maybe some Unique powder. As of right now I only have those two. Any help would be appreciated. Thanks

[Outpost75]

8 grains of Red Dot won't be subsonic, but probably around 1400 fps and without gascheck is about at the threshold of leading. For a subsonic load reduce the charge to 6 grains and then see if the load "cracks" or "pops". If you still get the supersonic "crack" reduce 1/2 grain and try again. I use 6 grains with #314299 without the GC for 1080 fps in my No.4

[earlmck]

I asked old friend "QuickLoad" your question. QL says 8 grains Red Dot should be about 1260 fps and 19k psi, while you would need 10 grains to get to 1400 fps. And QL agrees almost exactly with Outpost on 6 grains giving 1080 fps with 13k psi.

Moving to Unique would give just slightly lower velocities and somewhat lower pressures; QL showing 8 grains of Unique giving 1240 fps at 14k psi.

For a subsonic load Outpost's 6 grains Red Dot looks hard to beat.

[GhostHawk]

Agree with Outpost. I think 8 will put you over, may or may not cause problems or leading at that speed.

My pet load for quiet is 4.6 grains of Red Dot and I shoot it in a lot of different calibers and under a wide range of boolit weights.

From .223 to .444marlin.

I like the Lee .312 185 and I think you will have to go below 6 to get subsonic. That being said 8 may give you decent accuracy and no problems. I would do a small ladder test starting at 4.5 up to 8. Note where you start hearing the "Crack"

[Jeffrey]

In what part of the world are you? You do not say on your profile. If you are in south Mississippi or in driving distance, I would be happy to get with you and put some over my screens. I might want to do the shooting myself, though. If anyone is going to shoot my chrono, it is going to be me. LOL

[leebuilder]

Good info. I need a chrony as well.
Can I ask a favor?
What do QL say for Noe 314125hp in 303 br.

Size .314, dropped weight 119gr,
5.5 gr titegroup
Tried it all, PCed with GC, PCed without and lubed the old fashion way.

It has the crack, excellent accuracy at 66m.
Heads don't mushroom out that much hitting wood and peat.
Thanks

[grumpy1]

I am in Ontario Canada, I just updated my profile. I think this was my first post but I have been lurking for quite a while. You guys on here make me wonder where have been all my life, there is so much knowledge on here it is unbelievable. Thanks all

[earlmck]

Good info. I need a chrony as well.
Can I ask a favor?
What do QL say for Noe 314125hp in 303 br.

Size .314, dropped weight 119gr,
5.5 gr titegroup
Tried it all, PCed with GC, PCed without and lubed the old fashion way.

It has the crack, excellent accuracy at 66m.
Heads don't mushroom out that much hitting wood and peat.
Thanks

QL thinks you are right around 1200 fps and 8600 psi with that one depending on where your seating depth comes in, leebuilder.

[leebuilder]

QL thinks you are right around 1200 fps and 8600 psi with that one depending on where your seating depth comes in, leebuilder.

Thanks thought it would be a bit higher.
I seat just till the rounds chamber with ease, no measurment taken.
Thank you earlmck!!!!!!

[Ballistics in Scotland]

Those loads might work, but I would feel more confident of accuracy with a lighter and round-nosed bullet. The .303 and its 10in. twist was designed for 215gr., which gave long-range accuracy when the velocity had declined to the figures mentioned. But a cartridge loaded down to those velocities isn't at all the same animal.

A bullet keeps speed of rotation a lot better than linear velocity. I interpret that, perhaps wrongly, because rotation just means rubbing against the air, but travelling a thousand yards requires it to elbow aside some four or five times its own weight in air. Be that as it may, it happens. An extreme example is a bullet fired vertically into the air. It therefore reaches a velocity of zero, and must spend nearly three seconds within sixteen feet of a particular point. Most bullets take around a minute from firing to return to earth, a time of which much less than half sufficed for it to lose all linear motion. In a vacuum it would regain exactly its muzzle velocity, but in air the terminal velocity acquired in its descent is so low that being hit on the head may do you very little damage. But these bullets are still spinning as they land, and are usually well enough stabilized to land base-first.

A bullet which has slowed from 2400 to 1200ft.sec. is therefore spinning nearly as fast as it ever did. If you could watch a point on its surface, it would be traveling in a much tighter helix. But a bullet which comes out of the muzzle at that velocity is spinning slowly, and is more liable to tumble or wobble.

[leebuilder]

Thanks for the insight BOS, i tend to agree with all your points. The proof is on the paper, i even tried some culls to induce a wider group, i only succeded in a 1/4 inch increase. I see no yaw on the paper every hole is a clean as target 22 ammos hole. I have only tried them faster out to a 100m once, 16gr 2400, fail and 13gr unique was ok i assume it wont work but i willl still try.
I like this round and its fun and quite thrifty to shoot. I have shot this round out of several rifles, from a 1 7/8 groove (wartime savage with one complete groove and the other groove ????? Have no idea and a new critron barrel, no4s and no1 ) all witb the same results best 1.5 inches to 2.25 inches worst with a minimun of ten rounds per group.
be well

[303Guy]

Don't forget that the higher the velocity, the higher the spin required to stabilize. Depending on bullet profile, the higher the muzzle velocity, the less stable it can become (to a point). Or more precisely, the less the factor of stability becomes, which is quite high in the old Brit with it's 10 inch twist. I've shot 245 grain boolits (torpedoes actually) that went nose first through paper at around 25 meters. One problematic area is transition velocity. Some bullet profiles can be very unstable at transition speeds, some not too bad.

MythBusters did an episode on bullets fired vertically and what Ballistics said. Those things came down base first (the one's they could find). Those MythBuster guys have way too much fun!

[fjruple]

I shoot what I consider a "light" load. I used a NOE 198gr lead gas checked bullet sized to .314 diameter backed with 13.0 grain of LongShot powder. I have to set my sights at 300 yards for 100 yards. On occasions I have used 700X in lieu of the LongShot. As far as accuracy it depends on the Lee Enfields that I own one with newer barrels are very good. In my P14s the loads shoots great, I have new criterion barrels on them and they very accurate with the PH5B Parker Hale Target rear sights.

[truckjohn]

For real low velocity work - your best bet is just to work up out at the range.
Take a teeny punch + hammer to knock out old primers and a hand primer unit with you.

Make sure you have a stout cleaning rod and a mallet handy to knock out squibs.
Check the bore after EVERY shot. You will absolutely stick a few while sorting out the load..

So for example - start around 2 grains of Uniqie/Red Dot and work up..... or alternatively start at 8-10 grains and work down till it's quiet and fun. I ended up using a cut down 22lr empty held with a bent paper clip as a dipper. I just clipped it off progressively shorter until I stuck one. Found a new 22 case and made that one maybe 1/8" longer than the one that stuck it and viola! I had it about right volume... knock the primer out. Insert new primer. Throw a wee little charge of Unique.. push the bullet in. Manually chamber and viola!!!! Fun fun fun.

Just make sure you have plenty of bullets - as it is so much fun. They literally "mouse fart" kinda like a little kid's pop-cork gun...

[Kegcaissy]

For these subsonic loads i use Lee TL314-90-SWC with 3.5gr of bullseye in 303. The mold may need to be enlarged with aluminium tape to get a full 0.314''. Great for indoors ranges.

[Tackleberry41]

Without a chrony, your guessing. I have messed with alot of subsonic loads, 223, 308, 7.62x54r, 7mm mauser, 8mm mauser, 45-70, 44 mag. I could fiddle with a load get it perfect at 1050fps, then go visit a friend at a lower elevation and they are no longer subsonic. Minor variations in seating depth changes things. Or I used existing 223 data, and nearly had stuck bullets. One might be 1050fps, the next 850fps. Took some experimenting with powders to find one that worked well, and consistently. Impossible without a chrony.

[truckjohn]

The rules are a bit different when shooting really low velocity with cast. For example - lightly oiled barrels are a necessity....

With a lightly oiled barrel and good lube on the bullets - I was able to shoot quite a few 30-30 bullets in the 500-600 FPS range (chrono'ed). Super fun... You could hit cans - but you had to hold several feet over at 100 yards. Same for big huge 1 oz slugs in my Martini rifle over a small charge of Trail Boss... You wouldn't believe how hard those Martini slugs hit a 300 yard gong running so slow out of the muzzle that you could see them fly...

I haven't shot low velocity cast in a 223 - but I have shot piles and piles of 750fps CCI quiets and Aquila SSS in my 22's without issue.... Those were considerably louder than those 30-30 rounds and especially the Martini rounds - it was like a kid's pop cork gun...

[rsrocket1]

Actually, you want a really heavy bullet and the fastest powder you can find. A heavier bullet will launch slower with the same amount of powder compared to a lighter bullet. It also allows for a good build up of pressure for a clean, even burn. Too light of a load behind a light bullet leads to low pressures and when the peak pressure gets significantly below 9,000 psi, it becomes uneven and inconsistent.

Different gun, but my subsonic load is 6.5g Red Dot under a Lee C309-200-R bare base bullet in a 24" Remington 788 in .308.
Quick load tells me I should get 1040 fps but my chrony at 10' told me the average was 1005 fps.



To get subsonic with my C309-113-F's I had to go down to 3.8g Red Dot and unless I tilted the barrel up each time before I shot, the velocities were all over the place and even when I did, the accuracy was not good.

[Tackleberry41]

Might try another powder and enlarging the flash holes. I could not get 223 to work, large swings in velocity, until I drilled out the flash holes. Now the small charges of solo 1000 work great. I do not have to tilt the barrel up w my 308 subsonic, enlarged flash holes. I use Solo 1000 as I have a bunch of it.

[Alferd Packer]

Thanks guys.
I enjoyed reading these thoughts on .303.
I have the LEE six cavity 90 gr tumble lube swc.
The darn thing has always thrown bullets .321.
Not supposed to, but I always have to size them down all but erasing the tumble lube lines making them smooth sided.
I just tumble them in LLA and load and shoot.
I resize them to .314 and .310 which really smooths the sides.
I never bothered to send the mould back to LEE for another and this was in the 1980's I believe.
Now. The thing would have always worked great for an 8mm which I never got around to acquiring and now they are out pricing them and the Moisin Nagants as well
I always found enough to keep me busy with the 30 calibers- .308 and the Brit .303.
Thanks again for the food for thought threads.