Thread: Hornady sub-x 175gr load data...

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

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

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.

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.

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.