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aorelup
Guest
Anyone loaded any subsonic rounds for 243 using trailboss with 105 a-max? If so, can I have your data? Thanks in advance.
TomD
e publius unum
Something about the concept of a subsonic .243 load seems a contradiction, sorta like subsonic 220 Swift loads.
I've seen published low velocity loads under cast bullet loads. There will probably be .243 data data because I once needed .223 data to firelap a very rough factory barrel. If memory serves, the low velocity was done by using smallish charges of fast powder so I very much doubt you are going to make it happen with reduced charges of your normal stuff. Be careful with charges that fill a small percentage of the case, for some reason that combo sometime goes off all at once giving a huge pressure spike. The heavy (for caliber) bullet isn't going to make things easy.
Actually the long-high-BC bullet doubles the contradiction.
Edit: Just found an old manual with cast bullet charges. The slowest for .243 was 1850 fps. Very probably, if you want subsonic, you're going to need another type of round.
I've seen published low velocity loads under cast bullet loads. There will probably be .243 data data because I once needed .223 data to firelap a very rough factory barrel. If memory serves, the low velocity was done by using smallish charges of fast powder so I very much doubt you are going to make it happen with reduced charges of your normal stuff. Be careful with charges that fill a small percentage of the case, for some reason that combo sometime goes off all at once giving a huge pressure spike. The heavy (for caliber) bullet isn't going to make things easy.
Actually the long-high-BC bullet doubles the contradiction.
Edit: Just found an old manual with cast bullet charges. The slowest for .243 was 1850 fps. Very probably, if you want subsonic, you're going to need another type of round.
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aorelup
Guest
Hodgdon has a subsonic load published on it's site using trailboss with 100gr Speer HPBT.
HOWEVER, the charge does not follow the pattern of other calibers' minimum loads using this powder, which leads me to question if the published data is correct.
There is info on the Hodgdon site which states that trailboss can be used with any jacketed rifle round. Max charge is determined by making a mark on the brass where the base of a given bullet will be seated, filling the case to that mark with trailboss, then weighing that charge. Determining minimum charge is a simple matter of multiplying that charge by 0.7 (70% max charge).
What gives me pause is the published trailboss min load for 243 with 100gr SPHPBT falls outside that formula.
Minimum charge is 8.0 grains, max is 15.3. By Hodgdon's published formula, the min charge should be 10.7gr. The published min is ~52% max load.
HOWEVER, the charge does not follow the pattern of other calibers' minimum loads using this powder, which leads me to question if the published data is correct.
There is info on the Hodgdon site which states that trailboss can be used with any jacketed rifle round. Max charge is determined by making a mark on the brass where the base of a given bullet will be seated, filling the case to that mark with trailboss, then weighing that charge. Determining minimum charge is a simple matter of multiplying that charge by 0.7 (70% max charge).
What gives me pause is the published trailboss min load for 243 with 100gr SPHPBT falls outside that formula.
Minimum charge is 8.0 grains, max is 15.3. By Hodgdon's published formula, the min charge should be 10.7gr. The published min is ~52% max load.
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aorelup
Guest
I have to wait until Monday!
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Donald
Guest
The new Hodgdon magazine type reloading manual gives some information on using Trail Boss powder. They state that it is impossible to overload a cartridge with TB. It seems to shoot best at about 70% load density, so they say. I have a friend that shoots a supressed AR10 with 170 grain bullets at about 1100 fps. The load is 9 grains of TB. It of course will not cycle the action. The 9 grain load fills about 3/4 of the case. There is also a lot of information in this new mag/manual about IMR 8208 XBR powder. HTH
Donald
Donald
S
Stonewall
Guest
Some of the older Speer 6mm 100 gr bullets gave higher pressure and had it's own loading data.
Check the various manuals i.e. Speer #12.
Call Hodgon and post the response.
Glenn
Check the various manuals i.e. Speer #12.
Call Hodgon and post the response.
Glenn
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aorelup
Guest
I talked to a Hodgdon rep today. He stated the 70% max load was a 'guideline' and not a hard set rule. The posted data had been tested and was safe. I now feel safe about using the published data as a start point and will post what I come up with.
Difficult to overload as long as there is no COMPRESSION of Trail Boss.
tinman
New member
170 gr 243 bullet???
tinman
New member
Yes silencer