Rechamberd 21" s/s T/C Contender 375JDJ Experiences

[Camp Cook]

I hope its ok to post this info if not feel free to remove it... 

My 375 Win 21" factory s/s T/C Contender carbine barrel rechambered to 375JDJ on a s/s original Contender frame experiences.

I have been searching every source I can find for reload data for the 375JDJ and I find that it is extremely limited so I thought I would post this info for those that may have an interest in this rifle/caliber combo all loads use Win LR primers and all bullets except the 260gr Accubonds were seated to the base of the neck.

Due to the boattail design of the Accubonds I had to seat them slightly deeper to get the COL to fit the chamber and I will only post an average velocity for each load.

Hornady 220gr FP

48grs H322 = 2290fps
51grs IMR4064 = 2230fps

Sierra 250gr Gameking (unfortunately after talking with the Sierra Bulletsmiths this bullet will not expand/mushroom under 1900fps so would limit me to only 200 yard shots from this 300 yard rifle/cartidge combo)

48grs IMR4064 = 2150fps
49grs IMR4064 = 2200fps
50grs IMR4064 = 2240fps
51grs IMR4064 = 2290fps

Nosler 260gr Accubonds

50grs Varget = 2180fps
51grs Varget = 2220fps

51grs IMR4064 = 2230fps

I am still searching for a powder that will give me slightly lower pressures and slightly higher velocities my goal is 2300fps with the 260gr Accubonds but if all I can get is 2230fps with the 51gr IMR4064 load I will sight in 2" high at 100 yards which should give me -3" @ 200 yards and -17" @ 300 yards where the velocity should be around 1775fps still which should allow complete expansion/mushroom.

If anyone has any suggestions to a different powder I would appreciate it.

My thoughts this is a beast of a rifle to shoot... the jump from the recoil is crazy (and I'm used to shooting top loaded 300RUM/375RUM/45-70's) the reticle of the older Baush and Lomb Compact 2-7X scope I mounted on it is after only 50 shots already coming apart so I popped it off last night and mounted an almost new Leupold Compact 2-7X scope I am using a MGM 4 screw scope base and Leupold quick release rings.


Disclaimer: this is my data and so far is safe in my rifle reduce by 20% and work up your loads safely I accept no responsibilities for the use of this data.

[Grumulkin]

The Hornady reloading manual (7th edition) gives 375 JDJ loads with 3 different bullet weights.  Also, for a very reasonable fee, J. D. Jones of SSK Industries will mail you reloading data for his cartridge.

As for bullet expansion, in my opinion it's highly overrated.  Even without any expansion at all, a .375 inch hole in the heart or lungs is going to do something like kill the animal.

[Camp Cook]

Thanks for the thoughts, I have the data you mentioned as well as some from an ST article by Layne Simpson but I am using bullets that are not covered by JD or Hornady so had to sort of wing it a bit.

I will totally agree that a .375 bullet thru any heart/lung will kill, at issue and why I am trying to find a high BC bullet that will mushroom at the lower velocities is that (and maybe this is just me) I know that a mushroomed or wide flat meplat bullet produces a larger wound cavity/disruption then a round nose or spitzer style bullet.

I live in British Columbia, Canada and plan on hunting moose/elk/deer/grizzly/black bear with this little rifle/cartridge combo this year which is why I want the best performing, flattest tragectory 300 yard (which is the furthest I plan on hunting with this combo) capable bullet I can find.

I just found some 260gr Accubond with H322 reload data last night and will give that a try sometime this week.

thanks again for the thoughts.

[Camp Cook]

I tried 45grs & 46grs H322 with the 260gr Accubonds today which are the top recommended loads for this round.

45grs resulted in 1985fps and 46grs = 2010fps very disapointing results...