Hornady sub-x 175gr load data...

So, I have a box of 100 of these little critters loafing here. Interested to try them out in .308W simply because I have them there...

I can find subsonic load data for the heavier 190gr version of this pill but nothing for the lighter, this seems a little strange to me as the pill is ID'd for sub work and I'm wondering if I'm missing something. Equivalent weight cast lead pill looks to run about 1.5-2gr less powder for the speeds listed in the supersonic data, which in my brain kind of makes sense for a fully jacketed pill. The swiss jew tightarse in me doesn't want to start loading up 20 pills to find out what's reliably subsonic, I'd rather use them for accuracy and grouping test so if they are going to play nice I have a good 70 or so to keep me going. So, has anyone been using these in .308, 1-10" twist and 20" barrel?

Have Red Dot and Trailboss on hand.

Cheers

10.7gr trailboss works well for the 190gr subs. Sorry no data for the 175gr ones.

My best bet would be to get a chrono (garmin) and just shoot a couple. start drom the top, lower in 1 or 0.5 gr increments to quickly get you into the ballpark. should only require 3 or 4 bullets. After that interpolating should get you close enough to the actual velocity.

For me the 190 shoot sub-moa at 50m but range is severely limited, so inwould not worry too greatly about accuracy

I guess you will be subsonic somewhere around 9gr (just a guestimate and might be completely off)

12.7 gr TB for 1061 fps

found at
https://hodgdonreloading.com/rldc/

although I note that at
https://hodgdonpowderco.com/wp-conte...ta-final-1.pdf

it is 10.5 gr TB for 1039fps with the 190gr sub-x


FWIW I use 10.0 gr TB with 165gr projectiles for subsonic .308, 18" barrel, 1/10 twist.

Quote:

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Originally Posted by longshot

12.7 gr TB for 1061 fps

found at
https://hodgdonreloading.com/rldc/

although I note that at
https://hodgdonpowderco.com/wp-conte...ta-final-1.pdf

it is 10.5 gr TB for 1039fps with the 190gr sub-x


FWIW I use 10.0 gr TB with 165gr projectiles for subsonic .308, 18" barrel, 1/10 twist.

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Yep seen that, hence why I'm cross checking.

Their data off the website doesn't appear to make sense...

190gr Sub-X - TrailBoss - 2.690 length - Max powder 10.5gr - Vel. 1039fps - Pressure 30100psi
175gr Sub-X - Trailboss - 2.495 length - Max powder 12.7gr - Vel. 1061fps - Pressure 27200psi

2.2 gr extra powder for the 175gr pill, I realise it's a little shorter than the 190gr but seated almost 5mm shorter for 22fps extra speed yet 2900psi lower pressure? I think I'm missing something or overthinking it, but 2.2gr extra powder for 2900psi less pressure indicates something I haven't experienced with Trailboss before. This is why I've asked on here if someone has actual real world results, as the info I have is basically the opposite of what I'd expect!

I use 6gn of ICI Nobel Shotgun Powder No 78 which is quite bulky and very close to both Red Dot and AS70N. I'm using the same load for both 204gn HP GC and 185gn FP GC cast bullets from Robert Walker. I can get 5 of either into a 2- 2.5in group at 50m..the 204 gn are doing 920fps, the 185gn are doing 960 fps on average. Both sound exactly like a suppressed subsonic 300BLK from a DOC Culler's expensive rig according to my mate who has had to listen to a stash of Fallow on the Nth Shore get decimated at 3am in the morning. Not his stash but he has been enjoying the venison. I nailed the old Stag at 36m with a shoulder shot with a 204gn. Bang Flop. Having run out of my 25ct sample pack of those I got from Robert a few years back I picked up some subX to try also. Havnt got there yet but will start with the same load. For subsonic thats where I would also start with powders like Red Dot or AS30N. For jacketed bullets check they leave the barrel each shot.

Interestingly the Walkers were cast at .313dia for 303B..I found by accident that my old Interarms Mark X just loves them in that dia. It won't shoot .309 cast worth a damn.

Anyway FWIW

That's not surprising, cast bullets in my experience work best when over groove diameter for some reason

They fill the grooves better is the explanation I have heard. A bit of squash longways as well as side to side, helps the pills to obturate into the grooves accurately and get a full seal of the bore I guess is the technical version...

Quote:

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Originally Posted by No.3

Yep seen that, hence why I'm cross checking.

Their data off the website doesn't appear to make sense...

190gr Sub-X - TrailBoss - 2.690 length - Max powder 10.5gr - Vel. 1039fps - Pressure 30100psi
175gr Sub-X - Trailboss - 2.495 length - Max powder 12.7gr - Vel. 1061fps - Pressure 27200psi

2.2 gr extra powder for the 175gr pill, I realise it's a little shorter than the 190gr but seated almost 5mm shorter for 22fps extra speed yet 2900psi lower pressure? I think I'm missing something or overthinking it, but 2.2gr extra powder for 2900psi less pressure indicates something I haven't experienced with Trailboss before. This is why I've asked on here if someone has actual real world results, as the info I have is basically the opposite of what I'd expect!

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In theory if 10.5gr can push a 190gr projectile out, it should push a 175gr projectile out.

Given that 10.0gr works for me with 165gr projectiles, I think if you try 10.5gr on the 175, it should be close to what you want.

it works out with quite a few smokeless powder cartridge combos ..... pretty darn close to ten grains of projectile weight added = minus 1-2 grn of powder....so its not at all out of the ordinary

Meh, in supersonic loads yes I'd agree but in this case we are setting the powder amount to control velocity. All other things being equal, it's not the weight of the projectile but the bearing length causing friction in the bore which gives the powder requirement in this case. So for a shorter projectile, less bearing length, less friction, less powder - the listed loads seem to be the opposite for the similar velocity in this case. I can't find any real-world loads to cross check that but it seems wrong to me... Starting at 12.5gr might end up with a wildly supersonic load so what I'm wondering is if Hornady has listed the 'max load-work down' but a subsonic velocity or something else is not kosher.

Info for the Speer round nose 180gr pill is generally noted at 10-10.5gr TB across the web from what I've seen for about 1040FPS depending on barrel, so where I'm getting a little confused/curious is why the maker of the 175gr Sub-X pill is stating 12.7 for 20FPS more than what would be considered normal a relatively similar pill, and then 2.2gr more than a heavier similar design pill from the same brand for only the same 20FPS more speed. It seems like an anamoly to me, and where my thinking is with this is trying 10gr as a start point, testing for stability and velocity and going from there - risk being a bore lodge. The 151gr cast 'Tokoroa special' load is about 8.5gr TB, so 2gr more for the 175gr Sub-X kind of fits the rule of thumb above.

This is where I started with TB which was in the same month as when I started reloading.

https://hodgdonpowderco.com/wp-conte...ads-2018-2.pdf

Note the instructions rather than the data, basically stating anywhere between full non compressed case capacity and 70% of same is where you want to be.
So by my logic, if you want to try a given powder weight that deviates from the single given weight (as opposed to min/max) then these instructions give you the min/max that you can play with.

While I am reluctant to table the following as a definitive, it is a possibility that the data given is the max data (generally with TB one works down rather than up) so is therefore the starting load. The greater case capacity being afforded by the shorter projectile. This may explain the apparent anomaly.

Just noticed the shorter projectile gives less OAL rather than greater powder capacity.

The other option is to email the tech department at Hornady, every time I email them looking for data on an unpublished powder, they come back with the information but also information about what powder they have found is best for the particular projectile for the particular cartridge.

Quote:

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Originally Posted by longshot

This is where I started with TB which was in the same month as when I started reloading.

https://hodgdonpowderco.com/wp-conte...ads-2018-2.pdf

Note the instructions rather than the data, basically stating anywhere between full non compressed case capacity and 70% of same is where you want to be.
So by my logic, if you want to try a given powder weight that deviates from the single given weight (as opposed to min/max) then these instructions give you the min/max that you can play with.

While I am reluctant to table the following as a definitive, it is a possibility that the data given is the max data (generally with TB one works down rather than up) so is therefore the starting load. The greater case capacity being afforded by the shorter projectile. This may explain the apparent anomaly.

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Yeah that's what I assumed as well (listed the max load and work down) but then I thought about the likelihood of ballsing it up when you assume with anything reloading and had the old ACC hmmm... That and looking at the listed velocities - something just ain't right. Less bearing surface = less friction = less powder to overcome the friction to get to the desired velocity, with the proviso that the barrel length is long enough to consume all of the powder (which mine should be at 20").

With supersonic loads, the equation works out a little differently as the time in the barrel is critical to getting enough powder burn for the expansion to drive the pill while it's still in the barrel and the gasses can push without dispersing (which is why we often run a slightly faster powder with a lighter bullet in any given case size). In the case of subsonics, from my (admittedly somewhat limited experience) two bullets similar profile but with one having a longer bearing length - if loaded with the same powder charge the shorter bullet will leave the muzzle faster. That's what has got me confused with the Hornady data, why are they getting virtually the same speed (22fps difference) when loading the lighter bullet with 2.2gr more TrailBoss?

Finally got up to the range to try these little critters out, loaded up 5 at 10.0gr Trailboss with Win .308 cases and CCI LR primers. Seated to the cannelure groove, crimped with a Lee Factory Crimp die.

One whoops on loading, see the pic on the "what have you reloaded today thread" which was all my fault - using the Hornady seating die with the long blunt bullets seated deep requires a bit more adjustment than you'd expect and the die just got to the cannelure with one little bit more to push in and the press cammed over. As I said, whoops... Bits recovered and reused so only cost was a case.

On to performance - 10.0gr was just supersonic but very reliable rounds with very consistent performance out of the 5 I loaded up to try. No sign of stability issues (1-10" twist), and speed close to 1100fps. Suitably quiet but not subsonic, just over. Grouping with the Magnetospeed fitted was low by 5" and 1" right, 3/4" group. With the suppressor fitted and the magnetospeed off, dead center and 7" low which correlates with the 400yd drop line on 6 power with my scope. Grouping was roughly 1/2" (would have been 3 shots touching but I shanked the last shot slightly).

All in all very acceptable performance, and I think my sweet spot will be in the 9.0gr of Trailboss area.

Interestingly the rifle performed well with supersonic ammo out to 200m, testing drop out at 300m created a hell of a lot of confusion finally locating the rounds down about 24" below aim point. If it wasn't for the performance with the trial batch of subs I'd be second guessing myself - I think the weather turning to crap between the initial shorter ranges and the later, longer range might have not helped, a stiff swirling head wind came to play.

Tried the 9.0gr Trailboss - rewarded with 995fps speed. Settled on 9.4gr - that will be the one I think. Should settle in at around 1040fps - should go close to the 7" drop at 50m and sufficient headroom under the 1080fps at sea level/0degC speed of sound. Normally we are slightly higher temp, and that gives a bit of a safety factor (20degC is something like 1110fps).

Remember to;
Drill out flash hole in case to 3mm
Use a magnum primer
Check that the last projectile has left the barrel before sending another down

Interesting you say that, I have had two people who use subs a LOT tell me that in no way should you ever drill a case's flash hole out and it's simply not required with subs set up like these. Magnum primers are definitely not needed I'm told as they can make your powder charge so light to get the velocity below the speed of sound that it could create other problems. So far with the subs I've used no cases have been drilled out and to the best of my knowledge all have been with standard large rifle primers.

I've only just started loading my own, as the guy who was doing them for me is no longer here (very inconvenient). I'm going off what I've been told with them, and it makes sense especially the primers. If a standard primer ignites the usual powders with the delay coating on the granules, the faster powders which are easier to ignite will be fine. There should be no issue with the 9.4gr of trailboss, it's roughly 1/3rd a .308 case full less the space with the Sub-X pill jammed back into the case (I suspect that this is partially the reason for the deep seating of this projectile into the .308 case - I might cut the side out of one after seating a proj just to see how much case volume they take up).

One other point I've been told is once you use cases for subs segregate them and don't use them for full house loads again. I don't know of any reason this would be an issue - possibly it may be due to the fact that the sub rounds don't tend to produce enough pressure to blow the shoulder back out if it was to get too short (repeated firing pin impacts shoving the case forwards maybe). I know that a few people say to fireform cases to your rifle before loading but against that factory sub loads aren't and they tend to work fine.

I'm finding this batch of subs with the Sub-X bullets to be a lot cleaner after firing (smoke/barrel residue) than the last lot which were cast lead bullets, I suspect that it may be due to the extra resistance in the bore over the cast lead and also I've crimped them (the cast lot weren't crimped). I tested the velocity of one today in the garden, through a block of pallet wood to check stability. Didn't have time to fish it out - might have a look tomorrow and see what the pill looks like.

Fully agree on the checking barrel clear, normally you hear the impact at the receiving end very clearly so this is usually not a problem in use.

Hopefully those two people you have talked to are right.
I'm just going off an article I read many years ago that highlights the safety requirements when reloading subs

Quote:

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Originally Posted by Gkp

Hopefully those two people you have talked to are right.
I'm just going off an article I read many years ago that highlights the safety requirements when reloading subs

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Yep, the numbers of sub rounds these two have used without issue (slaughtering type scenario for one, the other is pest controlling goats and the like and uses subs when disturbance is not an option) would tend to indicate that they are right. There's always the first time for a cock up I guess, which is why I double checked all my info prior to starting this little project off.

It's possible that the article you read might have been referencing gallery loads as well - this is one situation where flash holes were drilled out and magnum primers used although they did not use powder in these rounds.

I've always drilled the flash holes out and used magnum primers and also never had a problem.
My understanding of why it is done is because using such low volume of powder can be hazardous if you don't get a consistent ignition of the powder.

Have used approx 200x 151 cast bullets ex Robert, and about same number of Hornady 190 Sub-X. Mostly with Trailboss but also other powders. Also used other bullets at or near sub-sonic valocities. Never drilled a primer flash hole yet, don't intend to, and haven't had a problem yet. Also use standard LR primers no prob. Did use 100x Federal Magnum LR primers as was all I could get at the time, made sod-all difference to loads. All loads are tested at 50m before use on animals.Mostly use on goats but also the odd pig and deer, 70m the longest shot on deer. Still experiment a bit, just because I can, but see no need to go down the drilling flash hole route. Just my 2c.

As above. Not as many rounds fired but standard LR primers and Trail Boss. Never had any issues.

Been shooting subs in .308 for years never drilled flash hole or noticed any difference between magnum and standard primers.

Greetings,
I think the idea of drilling out flash holes and the magnum primers may have had some reason long ago when we did not have the easier to ignite powders we have now. I doubt there was ever any testing done as I have never seen it recommended in a manual. A lot of things in handloading have been repeated over and over again without ever being tested and this seems to be one of those. The danger of drilling out flash holes is that the cases could get mixed up and loaded with full power loads with uncertain results, best avoided.
Regards Grandpamac.

I have shot lots of .308 sub and a fair bit of 300blk sub, handloaded with TB. Never drilled out the flash holes.

As far as segregating out subsonic brass, I heard somewhere and it makes sense, that it is best to use fired brass and neck size when loading with TB, the theory behind this is that the lower pressures don't cause the brass to obturate as well as high pressure loads, subsequently reducing consistency. Not sure if this is exactly right, but I can say it isn't completely wrong.

I like to use brass of a different brand headstamp to that of the full power loads anyway, it just makes it easier to know what is subsonic and what isn't when out in the field.

Quote:

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Originally Posted by longshot

I have shot lots of .308 sub and a fair bit of 300blk sub, handloaded with TB. Never drilled out the flash holes.

As far as segregating out subsonic brass, I heard somewhere and it makes sense, that it is best to use fired brass and neck size when loading with TB, the theory behind this is that the lower pressures don't cause the brass to obturate as well as high pressure loads, subsequently reducing consistency. Not sure if this is exactly right, but I can say it isn't completely wrong.

I like to use brass of a different brand headstamp to that of the full power loads anyway, it just makes it easier to know what is subsonic and what isn't when out in the field.

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Greetings,
Repeated firing of low pressure loads can result in increased case headspace. A full power load will stretch the case to fit the chamber and eventually result in a head separation if not detected. You will often notice the primer sticking out on a low pressure load for this reason.
GPM.

I haven't noticed this so far with the subsonics - I generally FL resized and trim the first time as I generally find once fired struggles to fit into my rifle, then monitor and neck size only from there.

So far, I haven't seen any noticeable shoulder set back from the FL initial FL resized cases. Not getting any oddball primer behaviour - either primer protrusion/sticking out or extruding back around the firing pin (which can happen if the case isn't setting back against the bolt face and is held forward by the firing pin spring).

Back onto the original thread, it would seem I have a rather low friction barrel - sat down to have a discuss about the 175gr Sub-X with another that uses them. Load for load, I'm 1.1gr of Trailboss powder less than most loads for the same velocity which are around the 10.0gr range.

Would also explain why my supersonic loads are so far down on go out at 300m, diving off a cliff past about 240m basically. Theory on that is that the pill is sodding off before the pressure has peaked, not dwelling long enough in the tube. 24" barrel test velocity is listed as over 2800fps, my trajectory suggests less than 2600fps from a 20" tube with suppressor on.

Interesting how barrels can show distinct personalities.

Opps, that should have read 10.5gr of trailboss... whoops.